sellecting valve springs, and setting up the valve train



Re: sellecting valve springs, and setting up the valve train

Postby grumpyvette » February 9th, 2010, 9:34 am

IF FOR SOME REASON,YOUR THINKING OF STICKING ROLLER LIFTERS ON A FLAT TAPPET CAM CORE OR FLAT TAPPET LIFTER'S ON A ROLLER CAM CORE DON,T! YOU CAN NOT DO EITHER, WITHOUT QUICKLY DESTROYING THE CAM AND LIFTERS
there are quite useful ,cam selection soft ware programs that get you in the ball park, but the final selection is based on far more factors than most of those software programs address
http://www.camquest.com/
Impala65SS wrote:...

Assuming the pushrods been installed with guide plates, there will be slight wear only visible, not tactile, from rubbing against the guide plates, that is quite normal.

Invest in an adjustable pushrod, and a push rod length checking tool before you decide to buy any pushrods! Your head has been "done over", so the factory valve train geometry HAS been ever so slightly changed.
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The right length pushrod will yeild the right valve stem wear pattern - in the middle of the valve stem. This is particularly important if you ever want to try longer ratio rockers, as the wear pattern on the stem will be wider, i.e. closer to the valve stem edges.
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You can get lash caps to get more wiggle room, less wear on the valve stem too.
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flat tappet cams are designed for low spring pressures and have cam lobes that are cut at an angle to allow the lifter to spin, roller cams are flat, mixing lifter types either way on cam cores results in a ruined cam and lifters
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viewtopic.php?f=52&t=181


viewtopic.php?f=52&t=3802


http://www.kennedysdynotune.com/Valve%2 ... 20Tech.htm

QUOTE

As is widely known, the most important aspect of selecting a valve spring is to get a spring with the correct seat pressure, open pressure, and spring rate for the cam in the engine and with the rev limit that will be used kept in mind. Too little seat pressure robs power and impairs idle quality and vacuum. Too little open pressure can lead to valve float with resultant power loss and even damage to the valve train. So why not simply use the baddest, stiffest spring you can find?



It comes down to cost, wear on components, and maintenance. A very stiff spring needs a very stiff pushrod, heavy duty rockers with high quality studs or even shaft mount rockers, better than OEM lifters, retainers, and keepers. And even when the high quality, more expensive components are used spring life for stiff, high lift springs is diminished and more heat is generated during operation. So, you want enough spring, but not too much.



Flat Tappet Cams

How do you determine the right spring then? First, you need to decide what type of lifter you will be using. For flat tappet cams a seat pressure of 105-125lbs for small blocks and 115-135lbs for big blocks is appropriate. Open pressures should be in the 220-250lb range for low rpm street use and 250-350lbs for hi-performance or racing use. Go on the high side for a big block motor, though since these are not usually revved as high as a small block the need for added spring pressure is not necessarily large. In each case, the lighter the valves, the less spring is needed. Avoid the use of press fit rocker studs as open pressures approach 300lbs. For full-out race use, stiffer springs are often needed. However, unless the highest quality parts are used with careful assembly and break in the life of the cam and lifters may be short.



Hydraulic Roller Cams

Hydraulic roller (HR) cams require higher pressures to control the inertia of the heavier roller lifters and the faster acceleration of valve train components allowed by the use of the roller follower. Pure street small blocks should have 260-300lbs open pressure. For performance use, aim for 300-350lbs open. Racing small blocks that regularly see 6,000+rpm need over 400lbs open pressure. At these pressures, premium valve train components including a "billet" type cam are required. Even with these components, there will be reduced service life and the consequent need for more frequent parts inspection and replacement. Big blocks need closer to 300lbs open pressure for street driving and 350-375lbs is preferred for performance use. A racing big block needs 450lbs. As with small blocks, premium components including lifters are needed at higher pressures and rpm. As with solid lifter cams, seat pressures should be in the range of 105-125lbs for small blocks and 115-130lbs for big blocks for performance street cars. Blower cars and race cars will need higher seat pressures.



Solid Roller Cams

Solid roller (SR) cams were once considered very exotic. They are coming into more and more common use, first on race cars, and most recently on street-strip cars. These cams are typically designed with very steep lobes which produce very high rates of valve acceleration. To prevent the valves from bouncing on the seat, elevated seat pressures are required. Street-strip cars should aim for ~175-200lbs seat pressure. Mild race applications need 225-250lbs on the seat. Professional level racing require ~350lbs seat pressure or more. Obviously, for these last categories only the finest components should be used and they will need frequent replacement. In blown fuel cars, springs may last just one 1/4 mile run. It is difficult to give guidelines for open pressures, since application vary so much. But assuming that most of our readers are interested in street-strip use, we recommend a minimum open pressure of at least 400lbs. High rpm race engines will need a lot more. Professional race engines may require open pressures exceeding 750lbs.



Valve Lift and Spring Length Selection

Once you have determined the pressures you need, you can select a valve spring with the appropriate length by taking into account the amount of valve lift in you setup. Start with the installed height needed to get the required seat pressure. Subtract the maximum valve lift plus at least 0.050-60" for coil clearance. If the installed height minus the sum of the valve lift plus 0.050" is more than the coil bind height, the spring has enough lift. Of course, you will still need to check for interference between the retainer and the valve guide, the rocker and the retainer, etc. If the numbers indicate the spring is too short, you will need to pick one with a similar rate but a higher installed height. Special valve retainers or longer stemmed valve may be needed to accommodate higher lift. Some engine builders prefer to keep coil clearance at a minimum. This tends to have a dampening effect on the coils, potentially preventing harmful harmonic vibration. If this approach is chosen, each spring must be carefully checked for adequate clearance.



Example


Let's say you are putting together a small block with an aggressive HR cam for street-strip use. The maximum lift is .575". You know you will need seat pressure in the 125lb range and want ~350lbs open. Go to a spring catalog and look at the springs in a diameter to fit your heads. Find the springs that have at least the desired maximum lift and simply pick one with a rate that closest to your requirements. It's possible that to get the right rate you will need to shim a longer spring or to install at a higher than normal installed (closed) height using special retainers and/or a taller valve.



Spring Brands and Purchasing Springs

There are many good brands of valve springs available. However, we like to recommend and sell to our customers what we use. The brands we recommend are Comp Cams, Lunati, and Manley. Many of these springs are made by PAC in the United States and branded by the listed manufacturers. However, some of the brand name springs are actually lower quality imports, so be careful about what you are buying. You can consult their on-line catalogs (click on the name to go there) for a part number and call or email for our low price. Or. if you need help selecting springs, give our tech-line a call at 716-693-5354. We can provide all of the other valve train parts you need. Parts we handle include pushrods, valve locks and retainers, seals, shims, seats, etc. Either consult the manufacturers' on-line catalogs, or contact us. If you are thinking about springs, you may also want to consider one of our custom cams.
IF YOU CAN,T SMOKE THE TIRES AT WILL,FROM A 60 MPH ROLLING START YOUR ENGINE NEEDS MORE WORK!!"!
IF YOU CAN , YOU NEED BETTER TIRES AND YOUR SUSPENSION NEEDS MORE WORK!!
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Re: sellecting valve springs, and setting up the valve train

Postby grumpyvette » February 18th, 2010, 7:58 am

FROM CRANES WEB SITE
What is Valve Spring Installed Height?

Installed height (also called assembled height) is the dimension measured from the bottom of the outer edge of the valve spring retainer where the outer valve spring locates, to the spring pocket in the cylinder head, when the valve is closed.



How does installed Height affect spring tension?

Installed height is the determining factor of what the valve spring "closed tension" or "seat pressure" will be. The camshaft specification card, and the spring section of the catalog both show what the approximate tension a particular valve spring will exert if installed at a specific height.

For example, spring part number 99848 shows 114 lbs. @ 1.700". This means that if this spring is installed at a height of 1.700" it should exert 114 lbs. of tension with the valve closed. (Note: Spring tensions often vary measurably within the same production runs; therefore, it is recommended that each spring be tested on an accurate spring tester and the spring installed at the recommended seat pressure.)

How do you change installed height and what effect does it have?

The easiest way to shorten installed height is to insert a shim in the spring pocket below the valve spring. Another is to use a different design valve spring retainer. Retainers with a deeper dish will have more installed height, with a shallower dish, less installed height. You can also use a valve lock designed to change the location where the retainer is positioned on the valve stem. We sell heavy-duty, machined valve locks in std. height and also +.050 and -.050 heights to fine tune your installation. Longer length valves can be used to increase installed height.





The shorter the installed height (the more the spring is compressed), the higher the valve spring seat pressure will be, and the less distance the spring can travel before the spring reaches coil bind.

The taller the installed height, the lower the valve spring seat pressure will be, and the further the spring can travel before coil bind occurs.

(Note: Eliminating coil bind by installing the spring at a taller installed height is not a desirable option. The resulting reduced seat pressure will lead to a significant loss in performance and could also result in engine damage caused by the valve bouncing on the valve seat due to the reduced seat pressure. The best procedure is to select a spring that provides the desired seat pressure at the installed height on the head.)

What is the importance of valve spring seat pressure?

Adequate seat pressure is necessary to:

1) Insure tight contact between the valve face and the valve seat to seal the combustion chamber and provide proper heat transfer from the valve to the cylinder head.

2) Keep the valve from bouncing on its return to the seat. If the valve bounces, cylinder pressure (power) is lost. Repeated bouncing of the valve is like a hammering action that can result in the head of the valve deforming ("tuliping") or actually breaking from the valve stem resulting in catastrophic engine failure.

3) With a hydraulic cam the valve spring must exert enough pressure against the valve lifter (or lash adjuster) plunger to keep it centered in its travel to prevent "lifter pump-up". When pump-up occurs the valve is held slightly off its seat resulting in a significant loss of power and possibly a misfire. It is this loss of power and misfire that is often misdiagnosed as a fuel system or ignition system problem.

High oil pressures and high viscosity oils aggravate "lifter pump-up" in hydraulic lifters. When either oil pressure or oil viscosity is going to be increased beyond the manufacturer's recommendation, a corresponding increase in spring seat pressure is necessary to prevent "pump-up" (even with an "anti-pump-up" lifter). Since oil viscosity in no way relates to the oil's film strength, and the scuffing protection provided by the film strength, Crane Cams recommends following the OE manufacturer's recommendation with respect to engine oil.

Common Misconception:

Many people mistakenly think that using higher seat pressures causes a reduction in the horsepower delivered to the flywheel because higher seat pressures (and also higher spring rates required for high performance) require horsepower to compress the springs. This thinking is simply incomplete! For every valve that is opening and its valve spring being compressed, another valve is closing and its valve spring is expanding. This expansion returns the energy to the valve train and the engine. This results in a net power loss of "0" hp. Many engineering texts refer to this as the "regenerative characteristic" of the valve train. Recent tests at Crane have shown no horsepower loss on a hydraulic roller equipped engine when changing the seat pressure from 135# to 165#. Power actually improved significantly at top end, probably due to better control of the relatively heavy valves in the engine.

In Summary:

Always run enough seat pressure to control the valve action as it returns to the seat. Heavier valves require more seat pressure. Strong, lightweight valves require less seat pressure. When in doubt, run slightly more seat pressure . . . not less.

What is Valve Spring Open Pressure and Why is it Important?

Open pressure is the pressure against the retainer when the valve is at its maximum open point. Adequate open pressure is necessary to control the valve lifter as it first accelerates up the opening flank of the cam lobe and then quickly decelerates to pass over the nose of the cam which causes the valve to change direction. Inadequate open pressure will allow the lifter to "loft" or "jump" over the nose of the cam (referred to as "valve train separation", or "valve float"). When the lifter strikes the closing flank with a severe impact, camshaft life is drastically shortened.

Open pressure is a function of seat pressure, net valve lift, and spring rate. It must be sufficient to control the valve action at the highest expected engine speed without being excessive. Excessive open pressure aggravates pushrod flexing which in itself aggravates "lofting" of the valve and valve train separation. Selecting a spring to give the proper open pressure, while minimizing pushrod flexing, provides many opportunities for developing a unique, horsepower-enhancing combination. Obviously, lightweight valves require lower open pressures and tend to reduce pushrod flexing and valve train separation.

One final point: Excessive valve spring open pressure will result in reduced camshaft and lifter life.

What is a Valve Spring Coil Bind and how does it relate to spring travel and valve lift?

When the valve spring is compressed until its coils touch one another and can travel no further, it is said to be in coil bind. The catalog shows the approximate coil bind height for the various Crane Cams valve springs. To measure this you must install the retainer in the valve spring, then compress the spring until it coil binds. Now measure from the bottom side of the retainer to the bottom of the spring. This measurement is the coil bind height. This can be done on the cylinder head with a spring compression tool (part number 99417-1), in a bench vise, or in a professional valve spring tester.





Using the above figure, subtract the coil bind height "B" from the valve spring installed height "A". The difference "C" is the maximum spring travel. The spring travel must always be at least .060" greater than the full lift of the valve. This safety margin of .060" (or more) is necessary to avoid the dangers of coil bind and over-stressing the spring.

If coil bind occurs, the resulting mechanical interference will severely damage the camshaft and valve train components.

How do you increase spring travel?

The valve spring must have sufficient travel (plus .060" safety margin) to accommodate the amount of valve lift created by the camshaft and/or an increase in rocker arm ratio. To increase spring travel you can either raise the installed height (but this will lessen the spring tension), or change to a spring with additional travel. If there is not a standard diameter spring available with enough travel, the cylinder heads will have to be machined and a larger outside diameter (O.D.) spring installed.

Crane Cams offers some special valve springs in standard diameters which eliminates having to machine the cylinder heads. For example, a small block Chevrolet engine can use spring kit part number 11309-1 to handle .550" to .600" valve lift. The 85-00 302 Ford hydraulic roller engines can use spring kit part number 44308-1 to handle .550" lift.

*continued from Crane website*

Besides coil bind, what other types of mechanical interference should you look for?

When you increase the valve lift with a bigger cam or increased rocker arm ratio, you must be sure there is no interference between any of the moving parts. Some of the components that must be inspected for clearance are:

1) The distance from the bottom of the valve spring retainer and the top of the valve stem guide, or the top of the valve stem seal, must be equal to the net valve lift of the valve, plus at least .060" more for clearance.





2) When using rocker arms mounted on a stud, the length of the slot in the rocker arm body must be inspected to be sure it is long enough to avoid binding on the stud. The ends of the slot must be at least .060" away from the stud when the rocker is at full valve lift and when the valve is closed. Be especially careful when using stock Chevy stamped steel rockers and any high performance stock or aftermarket cam. These rockers will typically not provide enough clearance at full-lift, and will bind on the rocker stud.

Crane Cams offers long slot and extra long slot steel rocker arms to relieve this interference problem. Aluminum roller rocker arms may be required to provide sufficient travel on larger lift camshafts or when using longer ratio rockers.

3) The underside of the rocker arm body cannot touch the valve spring retainer. You will need at least .040" clearance to the retainer throughout the full movement of the rocker arm. If necessary, a different shape retainer or rocker arm design will be required. In some cases, installing a lash cap on the tip of the valve stem can provide the clearance required.

4) Valve to piston clearance must be checked to be sure there is sufficient clearance. The intake valve must have at least .100" clearance to the piston and at least .120" clearance on the exhaust valve.

What is the critical point of crank rotation for checking valve to piston clearance?

The critical point for both valves is the "Overlap Period" as the exhaust cycle is ending and the intake cycle is beginning. You must start checking the clearance before and continue after T.D.C. on both the intake and exhaust valves to be sure you have the correct readings through the overlap period.
IF YOU CAN,T SMOKE THE TIRES AT WILL,FROM A 60 MPH ROLLING START YOUR ENGINE NEEDS MORE WORK!!"!
IF YOU CAN , YOU NEED BETTER TIRES AND YOUR SUSPENSION NEEDS MORE WORK!!
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Re: sellecting valve springs, and setting up the valve train

Postby grumpyvette » February 27th, 2010, 10:15 am

Tools to aid in the installation of your aluminum rocker arms:
Lock Nut Adjusting Tool: 778-66781
Feeler Gauge: 555-80500
Offset Feeler Gauge: 555-80501
Feeler Gauge and Handle Kit: 555-80502
Pushrod Length Checker Small Block Chevrolet 3/8" Stud: 778-66789
Pushrod Length Checker Small Block Chevrolet 7/16" Stud: 778-66790
Pushrod Length Checker Big Block Chevrolet 7/16" Stud: 660-42133
Adjustable Checking Pushrod Small Block Chevrolet 5/16": 270-99726-2
Adjustable Checking Pushrod Big Block Chevrolet 5/16": 270-99730-2
Adjustable Checking Pushrod Small Block Ford 5/16": 270-99725-2

1-800-345-4545 jegs.com
IF YOU CAN,T SMOKE THE TIRES AT WILL,FROM A 60 MPH ROLLING START YOUR ENGINE NEEDS MORE WORK!!"!
IF YOU CAN , YOU NEED BETTER TIRES AND YOUR SUSPENSION NEEDS MORE WORK!!
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Re: sellecting valve springs, and setting up the valve train

Postby Dustytrix » March 5th, 2010, 10:49 pm

Grumpy, I have been thinking again , about pulling out my pressed in rocker studs and putting in threaded ones , is this something that I can do myself? The heads are 906 vortec bosses already cut for high lift cam. I plan on not going over 6000 rpm and rarely that much. The cam I chose has 5.25 lift with full 1.6 roller rockers. So would I even need the screw in studs if I dont dog the motor all the time? :?:
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Re: sellecting valve springs, and setting up the valve train

Postby grumpyvette » March 6th, 2010, 9:32 am

read thru these links and their sub links

viewtopic.php?f=52&t=2746&p=7513&hilit=rocker+studs#p7513

viewtopic.php?f=52&t=401&p=6078&hilit=vortec+machining#p6078

viewtopic.php?f=52&t=4680&p=12650#p12650

viewtopic.php?f=44&t=6175&p=19304#p19304

viewtopic.php?f=54&t=10028&p=38941#p38941

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pictured above you see the last rocked badly out of alignment with the valve center line,
a good example why you need adjustable guide plates, this rocker if left too run off center like this, on the valve stem tip , will quickly destroy the valve guide and rocker

theres a good deal of useful info in this article

http://www.customclassictrucks.com/tech ... index.html
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Aluminum does have advantages, like light weight, and easy of machining compared to cast iron, example,cracks in valve seats on iron heads ",usually the result of overheating,"tend to result in coolant leaks that are not easily repaired, so you need a new cylinder head even if you had hundreds of dollars in port work done previously.
but on aluminum heads a bit of tig welding and machining for new valve seats repairs the heads rather easily

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ValveSpringClearance01.jpg

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heads might need to be milled to make then strait
it should be noted that if the rocker stud protrudes into the port it should be trimmed to the port roof as any threads sticking down into the runner disrupt flow and don,t supply extra support to the rocker stud,and stud threads should use loc-tite tread sealant.


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The valveguides for the Vortec heads are the same as all other small-block cylinder heads, but the Vortec heads come equipped with large valveguide seals.
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The valveguide seals keep oil from running down both the valve stem and valveguide, and entering the combustion chamber through the intake port at high-engine vacuum and the exhaust port when the engine is not running. This cuts down on engine smoke and exhaust emissions.
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This is the valvespring retainer installed without the valvespring. The maximum amount of valve lift that the Vortec head will tolerate is the distance between the bottom of the retainer and the top of the valveguide seal.
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BE aware you need to verify rocker adjustment lock nut to rocker slot clearance and yes it varies even with the same manufacturers different rocker designs
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The maximum amount of valve lift before the spring retainer hits the valveguide seal is 0.530 inches. It is generally accepted that 0.060 inches clearance needs to be maintained between the retainer and seal (0.530 - 0.060 = 0.470 maximum valve lift). The Vortec heads, as they come with the large valveguide seals, are only capable of accepting a camshaft with a maximum valve lift of 0.470 inches.
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All small-block cylinder heads built before the '96 Vortec heads had two grooves on the valve stems.
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The second groove accepts a quad ring. It sits just below the split lock retainers. The O-ring keeps the oil, which lubricates the rocker arm/valve stem tip, from running down the valve stem and into the valveguide.
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Small Block Vortec Cylinder Heads Specifications - Heads Up!
The O-ring must be accompanied by a tin shield over the outside of the valvespring (left). The tin shield keeps excess oil from splashing on the valve stem and valveguide. The tin shield and O-ring must be used together to be effective. Installing the earlier double-groove valves, an O-ring, and a tin shield will allow the Vortec heads to use camshafts with 0.500 inches of valve lift, without machining the valveguides lower for clearance. View Related Article
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IF YOU CAN,T SMOKE THE TIRES AT WILL,FROM A 60 MPH ROLLING START YOUR ENGINE NEEDS MORE WORK!!"!
IF YOU CAN , YOU NEED BETTER TIRES AND YOUR SUSPENSION NEEDS MORE WORK!!
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Re: sellecting valve springs, and setting up the valve train

Postby Dustytrix » March 13th, 2010, 8:14 pm

Its me again, I am trying to set up my valve assembly the push rod checker I got is like the plastic one you show from summit. Its says to put it on the stud and that both ends should touch valve and pushrod at the same time. OK it touches the pushrod first but if I press the pushrod down about an 1/8 inch then its touching both. Wouldn,t that be the same measurement that I would get when I adjust the zero lash and turn the set screw 1/2 turn? Thanks for your daily help :!:
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Re: sellecting valve springs, and setting up the valve train

Postby grumpyvette » March 14th, 2010, 10:19 am

it sure sounds like your push rods a bit longer than ideal,usually the distance is more like 0.010-0.050", than 0.125" you describe,(with .010 - 0.0 being preferred) remember the lifter seat is supported by oil pressure, when the cars running and when parts get hot they expand, ID suggest the dye on the valve tip and looking for the rub marks as a further check
Proper push rod length is absolutely critical for peak performance—minimizing bent or broken valve stems, guide wear, and energy-wasting valve side-loading friction.
With the lifter located on the round base circle, position the Push Rod length Checker (make sure you have the Checker with the proper diameter hole) over the stud. Ideally the Checker should contact the top of the push rod and the valve tip evenly at the same moment, should the Checker contact the push rod first, measure the gap between the front of the checker and the valve tip, and purchase a shorter push rod of the correct length. Should the Checker contact the valve tip first, measure the gap between the back of the Checker and the top of the push rod, and purchase a longer push rod.
the process of finding the correct length push rods not that difficult, you install the correct push rod checker for your application,on a rocker stud, install the adjustable push rod, in place of the stock push rod after roughly adjusting the adjustable push rod to the stock length once the cam is rotated so the lifter, your using to verify the correct length is resting on the cams base circle, and then you extend or shorten the adjustable push rod so the plastic push rod checker just rests on both the tip of the valve stem and the push rod checker as in the picture above, this gets you very close to the correct length, you then use the machinists blue or a magic marker and the rockers you will be using to determine the exact correct length by centering if possible but finding the minimum sweep mark width so the wear mark on the valve tip as close to the valve stem center line as you can get it and the minimum side loading on the valve stem is found. centering the mark is less important than minimizing the rocker tip wipe mark width

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http://www.cranecams.com/pdf-tech-tips/mech-lift.pdf
IF YOU CAN,T SMOKE THE TIRES AT WILL,FROM A 60 MPH ROLLING START YOUR ENGINE NEEDS MORE WORK!!"!
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Re: sellecting valve springs, and setting up the valve train

Postby grumpyvette » September 21st, 2010, 11:46 am

CRANE CAMS,
How to Select A Valve Spring

one factor I will mention is that each manufacturer tends to look at durability, ramp speeds and max lifter acceleration very differently, one reason I tend to prefer CRANE & CROWER is that they both company's in general realize the engine must finish the race to win and a busted valve train is a HUGE problem,they both realize, and design valve train components and cam lobes with DURABILITY and reliable valve control as top priority,s that are far more important than squeezing every possible potential HP from a cam lobe design at the expense of long term durability

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notice the more aggressive cam lobe acceleration rate on the roller cam lobes
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notice the stepped cam nose to fit retainer plate


With the many choices of aftermarket cylinder heads, most with "longer-than-stock" length valves, the recommendation of a specific spring for a specific cam is almost impossible. It is now necessary to select the spring that will best fit the cylinder head configuration. We offer the following as guide lines only:

1) "FLAT-TAPPET" cam/lifter applications (Street & Street/Strip) seat pressures

a. Small Block 105-125# Seat Pressure

b. Big Block 115-130# Seat Pressure (Note: Big Block applications need higher seat pressures due to their larger, heavier valves.)

2) "FLAT-TAPPET" Open pressures should not exceed 330# open pressure (sustained after spring break-in) for acceptable cam and lifter life.

a. Open pressures should be a minimum of 220# for applications up to 4000 RPM.

b. For good performance above 4000, open pressures should be at least 260# with stock weight valves. (Light weight valves require less spring open pressure.)

c. Spring open pressures over 280# can cause "pressed-in" studs to come loose; therefore, we recommend screw-in studs for open pressures above 280#.

3) HYDRAULIC ROLLER CAMS require higher spring seat pressures to control the heavier roller tappets and the more aggressive opening and closing rates available to roller cam profiles.

a. Small Block applications: 120-145# seat pressure

b. Big Block applications: 130-165# seat pressure

4) HYDRAULIC ROLLER CAMS use higher open pressures to control the high vertical opening inertia of the heavier roller followers.

a. Small Block applications need at least 260# for general driving applications up to 4000 RPM.

b. Moderate performance small block applications like 300-360# open.

c. Serious small block applications can tolerate 400-425#* open pressures and still expect
"reasonable" valve train life when top quality springs, pushrods, and lubricants are used.

d. Big Block applications need at least 280# for general driving applications up to 4000 RPM.

e. Moderate performance big block applications like 325-375# open pressure.

f. Serious big block performance applications can tolerate 450#* open pressure and still expect "reasonable" valve train life when top quality springs, pushrods, and lubricants are used.

*Note: Open pressures in excess of 360# require the use of roller tappet bodies made of billet steel. Crane hydraulic roller and solid roller tappets are made from 8620 bearing grade steel to withstand the stresses of high-performance use. Most stock hydraulic roller tappet bodies are made of cast iron and cannot tolerate high spring loads.

5) SOLID LIFTER ROLLER CAM/LIFTER
Applications are generally used for serious street/strip use and full competition. Most are not used in "daily-drivers" where day-to-day reliability is stressed. Instead, most of these cams are intended for "winning performance." These cams are designed with "very aggressive" opening and closing rates. High seat pressures are necessary to keep the valves from bouncing when they come back to the seat. In all cases, the valve action and spring pressures required mandate the use of high-strength, one-piece valves.

a. Seat Pressures are determined by valve/retainer weight, engine RPM and life expectancy of components before replacement is required. Milder roller cams require 165# on the seat as an absolute minimum. 180-200# is common for most modest performance applications. 220-250# is common for most serious sport categories and some circle track professional categories. Pro-stock and Blown Alcohol/Fuel drag applications use as much as 340-370# on the seat. (The racers sometimes change springs as often as every 1/4 mile run!)

b. Open Pressures need to be high enough to control the valve train as the lifter goes over the nose of the cam. Ideally, the minimum amount of open pressure to eliminate or minimize
valve train separation is desired. Any excess open pressure only contributes to pushrod flex,
which can aggravate valve train separation. For serious racing applications this can be deter-
mined only by experimentation and track testing. For general guidelines we offer the following:

i. Street/Strip performance with long cam/lifter life desirable, 350-450# open.
ii. Circle track and moderate bracket racing 450-600@ open.
iii. Serious drag racing and limited distance circle track racing 600# and more.


high spring loads don,t play well with cast core roller cams over long term use, and flat tappet cams are also subject to high wear with higher spring load rates, heres a very clear example of why you should only use Billet cam cores with roller cams having over about 320 lbs of spring pressure and why you MUST verify valve train geometry and clearances.


cast cam cores tend to wear and fail faster than hardened billet cores, under high stress
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you might also want to remember that metal worn from the cam lobes did NOT vaporize, its more than likely that some of its embedded in the bearings,valve train and cylinder walls, because the oil filter won,t catch all of it, instantly before it circulates thru the engine
IF YOU CAN,T SMOKE THE TIRES AT WILL,FROM A 60 MPH ROLLING START YOUR ENGINE NEEDS MORE WORK!!"!
IF YOU CAN , YOU NEED BETTER TIRES AND YOUR SUSPENSION NEEDS MORE WORK!!
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Re: sellecting valve springs, and setting up the valve train

Postby grumpyvette » November 6th, 2010, 1:48 pm

don,t forget as many guys do, that swapping to a higher ratio rocker changes the push-rod rocker geometry,and clearances, the heads and rockers used obviously effect the required clearance, but you'll usually want at least 60 thousands clearance on the push rods to slot measurements and you'll want to rotate the engine thru two complete revolutions while verifying that clearance, while watching the push-rod geometry as it changes as the rockers move thru their arcsand may require a different length push-rods.

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ok after doing dozens of cylinder head valve spring upgrades I have some basic familiarity here. I usually buy valve springs from these guys

http://www.racingsprings.com/Valve%20Springs/Store/13

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it helps if you know what your dealing with before making changes
http://www.racingsprings.com/Store/ProductView.asp?ProductID=228

youll want a spring with about a 130lb seat load and about a 330-350lb open load on most street hydraulic roller cams

the seat can be shimmed to get the installed height loads right and the valve keepers and valve spring retainers BOTH are available in plus .050 type designs so while it might require valve lash caps and longer push rods it is possible to get more retainer to valve seal clearance without major machine work.
I'm reasonably sure you failed to read thru the links

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you get real close by using a push rod checker that matches your engine, rocker stud diam, etc.
(btw its upside down in this picture)


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the process of finding the correct length push rods not that difficult, you install the correct push rod checker for your application,on a rocker stud, install the adjustable push rod, in place of the stock push rod after roughly adjusting the adjustable push rod to the stock length once the cam is rotated so the lifter, your using to verify the correct length is resting on the cams base circle, and then you extend or shorten the adjustable push rod so the plastic push rod checker just rests on both the tip of the valve stem and the push rod checker as in the picture above, this gets you very close to the correct length, you then use the machinists blue or a magic marker and the rockers you will be using to determine the exact correct length by centering the wear mark on the valve tip as close to the valve stem center line as you can get it.




ACTUALLY READING links WILL help

http://forum.grumpysperformance.com/viewtopic.php?f=52&t=181

http://forum.grumpysperformance.com/viewtopic.php?f=52&t=1376



http://forum.grumpysperformance.com/viewtopic.php?f=52&t=697

links may help



http://forum.grumpysperformance.com/viewtopic.php?f=52&t=1376

http://forum.grumpysperformance.com/viewtopic.php?f=52&t=528


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http://forum.grumpysperformance.com/viewtopic.php?f=52&t=1005&p=15534&hilit=spring+shims#p15534

http://forum.grumpysperformance.com/viewtopic.php?f=52&t=282

http://forum.grumpysperformance.com/viewtopic.php?f=44&t=2839&p=7344&hilit=adjustable+guide#p7344

http://forum.grumpysperformance.com/viewtopic.php?f=52&t=126&hilit=louis+rocker
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and you may need too use the correct adjustable guide plates when you find the push-rod alignment is in need of minor tweaking to get the clearance and geometry correct

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using a louis tool, this tool is a GUIDE /tool for use with a high quality DRILL,its made of HARDENED STEEL that FORCES the DRILL BIT to drill thru the head to correctly lengthen the push-rod slot for increased clearance, they usually come WITH INSTRUCTIONS AND THE NECESSARY DRILL

Ive used either one of these two products, applied on clean dry threads by dipping the stud threads just prior to assembly on those threads, waiting a minute for the stuff to start to get tacky,then screwing them in for decades

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Ive never had a leak or loose stud, never had any issues removing them if required ,with the proper socket and breaker bar later either,
BTW, remember to visually verify the stud length and cut them a bit shorter if required you don,t want the lower end protruding into the intake port and any threads doing that do NOTHING to increase the stud rigidity but they sure can reduce port flow rates if left sticking down into the air flow path
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IF YOU CAN,T SMOKE THE TIRES AT WILL,FROM A 60 MPH ROLLING START YOUR ENGINE NEEDS MORE WORK!!"!
IF YOU CAN , YOU NEED BETTER TIRES AND YOUR SUSPENSION NEEDS MORE WORK!!
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Re: sellecting valve springs, and setting up the valve train

Postby grumpyvette » October 26th, 2011, 11:24 am

lash caps, can be used to lengthen the valve slightly and protect the tip of the valve from excessive wear
It is some what likely that you can run the same length push-rod with the lash caps installed as you can run without them, but you obviously need to verify clearances and valve train geometry. The caps work great for guys who have high spring pressures ,they can give you some extra clearance from underneath the rocker arm to the valve spring retainer.
you might find that lash caps IMPROVE the geometry or you might find they throw it so far out new push rods are required, you need to verify not guess,THERE'S MORE THAN THREE TYPES. AND THE MOST COMMON JUST SNAP OVER THE VALVE TIP WITH A SLIGHT FRICTION FIT, the tip of the rocker prevents them from riding up on the valve stem, and coming loose
most sit on the tip like this picture
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you are aware you need the lash caps to be the same diameter as the valve stem diameter??

THEY COME IN different heights and diameters
http://www.summitracing.com/search/part ... ash%20caps
http://www.enginebuildermag.com/Article ... signs.aspx

viewtopic.php?f=52&t=9687&p=36006#p36006
THERE ARE COMBO LASH CAPS/KEEPERS, and locking lash caps
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http://www.competitionproducts.com/Mant ... 603751-16/

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rocker body rubbing retainer BEFORE lash cap installed
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rocker body clearance preventing its rubbing retainer AFTER lash cap installed
the advice earlier in the thread on checking push rod length should be re-read if in doubt



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Because today's racing engines run at higher and higher rpm levels and the cam profiles are extremely harsh, the tip of the valve stem is subjected to a tremendous amount of pounding. These engines always run just on the brink of valve float-one of the most severe conditions that can exist. The best solution to this problem is the use of quality Lash Caps. These lash caps are precision machined and ground perfectly flat to maintain accuracy of valve train adjustment.They fit the valve stems well and can be removed with relative ease because of a tiny hole to relieve the suction created when removing the lash cap. The Chrysler "Hemi" engine has benefitted greatly from this design. A special version is available to accommodate the very short tip on these valves. For the ultimate in strength and reliability, you will not find a better part than the COMP Cams® Lash Cap. A must for titanium valves.

http://www.jegs.com/p/Comp-Cams/Comp-Ca ... 5/10002/-1

http://www.jegs.com/i/Crane-Cams/271/99 ... Id=1354633

http://www.pauter.com/RockerInst.htm

obviously valve float and improper lash clearance can cause problems but in some cases, lash caps can reduce wear

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in most cases when you see valve tip damage like this its the result of valve float or a weak valve spring or improperly adjusted valves alowing the rocker to bounce on the valve tip., in many cases youll need to swap to a higher spring load rate and new springs to prevent or reduce this damage
IF YOU CAN,T SMOKE THE TIRES AT WILL,FROM A 60 MPH ROLLING START YOUR ENGINE NEEDS MORE WORK!!"!
IF YOU CAN , YOU NEED BETTER TIRES AND YOUR SUSPENSION NEEDS MORE WORK!!
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Re: sellecting valve springs, and setting up the valve train

Postby grumpyvette » January 29th, 2012, 6:19 pm

High Performance Rocker Arms, Valve Springs, Retainers and Locks

By Larry Carley


Upper valvetrain components have more of an effect on power and reliability than you might realize. Most engine builders know that changing the rocker arm ratio increases valve lift for more power. But did you know that changing the rocker arm pivot point can also reduce friction and the rate at which the valves open and close?

On a small block Chevy, altering the rocker arm geometry without changing the rocker arm lift ratio can add 15 to 20 horsepower at the rear wheels.

The stock lift ratio for a small block (SB) Chevy V8 rocker arm is 1.5:1, and for a big block (BB) Chevy V8, the ratio is 1.7:1. Bolt-on aftermarket high lift rocker arms with higher ratios are often used to get more net lift out of an existing cam profile. The most common high lift ratio upgrade for a SB Chevy engine is 1.6:1 rocker arms, and 1.8:1 rockers for BB Chevys. But some performance rockers now offer ratios as high as 2.0:1 or even higher!

Increasing the lift ratio adds horsepower with little or no loss in low rpm torque, idle quality or vacuum. By opening and closing the valves at a faster rate, the engine flows more air for the same number of degrees of valve duration. High lift rocker arms also reduce the amount of lifter travel needed to open the valves, which reduces friction and the inertia of the lifters and pushrods that must be overcome by the valve springs to close the valves. On the other hand, increasing the rocker ratio also increases the effort required to open the valves because of the leverage effect. The higher the rocker arm ratio, the greater the force the camshaft, lifters and pushrods have to exert to push the valves open. But when the valves close, the increased leverage of the rocker arms works the other way making it easier for the springs to shut the valves and push the rocker arms, pushrods and lifters back to their rest positions.

On SB Chevy engines, the stock stud-mounted rocker arms are supposed to be self-centering and self-aligning. The ball pivot inside the stamped steel rocker arm allows the tip of the rocker arm to follow the top of the valve as the valve is pushed open. This creates some back and forth scrubbing friction between the tip of the rocker arm and the top of the valve. And the higher the valve lift and the stiffer the springs, the greater the friction. Over time, this can cause side wear in the valve guides, tip wear on the end of the valve stems, and worn rocker arms.

Aftermarket performance rocker arms, whether they are stamped steel, stainless steel, or diecast, extruded or machined aluminum, usually have a roller tip to reduce friction between the rocker arm and valve. The roller, in theory, rolls back and forth on the top of the valve stem to reduce friction, wear and side forces exerted against the valve. Most stud-mounted aluminum rocker arms also have a needle bearing fulcrum to further reduce friction at the pivot point, and a hardened steel insert in the short end of the arm to accommodate the pushrod. Power gains of 15 to 30 horsepower are often claimed for aftermarket rocker arms even with stock ratios because of reduced friction. Aftermarket performance rocker arms are also stronger than stock stamped steel rocker arms, and provide improved reliability and longevity. But stud-mounted rockers have certain limitations.

One is that they often require pushrod guide plates to help keep everything in proper alignment, especially at high rpms and spring loads. Another limitation is that they can't handle valvetrain misalignment very well. If the rocker arm twists, it may bend the pushrod and/or allow the tip of the rocker arm to walk off the side the valve tip. If that happens, the rocker may push down on the retainer instead of the valve, causing the locks to pop out and the valve to disappear down the guide, destroying the engine.

SHAFT MOUNTED ROCKERS
The hot setup today is shaft-mounted rocker arms. Shaft mounted rockers would seem to be a throwback to the days before the first stud-mounted stamped steel rocker arms appeared on small block Chevy V8s in 1955. One of the features that made the SB Chevy such a performer was its lightweight, high revving valvetrain. But keep in mind, that was a time when maximum engine speeds were in the 6,500 to 7,000 rpm range, not 8,500 to 9,000 rpm or higher, and most engines were running single springs, not double or even triple springs.

Shaft mounted rockers have a number of advantages. One is better alignment. The shaft is rigid so the rockers are held in perfect alignment. This eliminates the need for separate pushrod guide plates while also limiting valve train deflection. At high rpm, pushrods and rocker arm studs can flex quite a bit, and the more they deflect the more it hurts valve lift, duration and valve control. This costs horsepower and can be seen on a dyno. So the more rigid the valvetrain, the less the valve flutter at high rpm. Shaft mounted rocker arms also provide extra strength and support, eliminating the need for a separate stud girdle. Aluminum stud girdles are often necessary to reinforce the valvetrain when a high lift cam (or rockers) and stiff springs are used. The girdle clamps around the studs and ties them together to reduce stud flex and the risk of breakage. But the girdle also makes it harder to adjust the valves. Shaft mounted rocker arms don't have that issue because the adjusters are on the arms, not the studs, and are easily accessible.

Mounting the rocker arms on a rigid shaft also eliminates the "jack hammer" effect that occurs with stud-mounted rockers. Every time the valve opens and closes, the change in valve lash that occurs with a solid lifter cam causes a stud-mounted rocker arm to slide up and down on its stud. This hammering effect can pull a pressed-in stud out of the cylinder head, and may cause fatigue failure in a screw-in stud or the rocker arm.

Another advantage of shaft-mounted rockers is better geometry. By lowering the pivot point of the rockers slightly with respect to the valves and pushrods, the arc that the tip of the arm follows is moved further down the curve. This reduces the back and forth scrubbing on the top of the valve, which reduces friction even more. One supplier of shaft-mounted rockers says this change alone reduces the torque it takes to turn a SB Chevy over by 80 ft. lbs, and is good for 15 to 20 horsepower.

Lubrication can also be an advantage with shaft-mounted rockers. Some have internal oil passages that route pressurized oil directly to the rocker arms and/or valve springs instead of relying on splash lubrication from oil squirting up through the pushrods. Shaft mounted rockers are available from a number of aftermarket suppliers, and fit not only stock SB Chevy and Ford heads but also most of the popular aftermarket heads made by Brodix, World, Edelbrock and others. The shaft-mounted rockers typically sell in the $700 to $900 range and are an excellent upgrade for any performance engine.

Another supplier of aftermarket rocker arms has taken a similar approach by redesigning some of their stud-mounted rocker arms for the LS1 Chevy. The rocker arms require milling the stud pads on the cylinder heads .170" to accommodate the lowered rockers, but the net result is better geometry, less side wear on the valves and faster initial opening that produces more horsepower.

What you may not know is that the actual ratio at which a rocker arm opens a valve is not constant, but varies as the valve opens and closes depending on the arc the arm travels and the position of the rocker pivot point with respect to the top of the valve and the pushrod. The stock LS1 rockers are mounted rather high and initially open the valve at a rate equivalent to about 1.54 to 1 before eventually reaching 1.7:1. The quick lifting aftermarket rocker arms, by comparison, lift the valve off the seat at a ratio that is closer to 1.8 to 1 and then goes to 1.7 to 1 at .200" valve lift. This has the same effect as increasing valve duration about six degrees, and produces 15 to 18 more horsepower.

INTERFERENCE ISSUES
As the ratio of the rocker arms goes up, the net lift of the valves increase and the valve springs are compressed much closer together. Clearances must be checked to avoid coil bind and contact between the bottom of the valve retainer and top of the valve guide. Springs should have a safety margin of .060" of remaining travel at maximum valve lift to avoid coil bind. The minimum clearance between the retainer and valve guide at maximum valve lift should also be .060". If the minimum clearances are not maintained and the valve spring or retainer bottoms out, the valvetrain will usually bend or break a pushrod. Clearance between the rocker arm and spring retainer must also be checked at maximum lift to make sure they don't touch. The stock rockers on a SB Chevy V8 can handle about .470" of valve lift. More lift requires switching to "long slot" rockers or aftermarket rockers with extra clearance.

High lift aftermarket rocker arms or a high lift cam may require using different springs that allow increased spring travel. Some springs cannot handle a maximum valve lift of more than .550". For higher lifts, different springs are required. Follow the spring supplier's recommendations when matching valve springs to maximum valve lift. Another way to avoid spring bind is to raise the installed height of the valve or to lower the spring seat. But both of these will reduce spring tension, which is not the way to go with a high revving engine.

For small block street performance engines with a flat tappet cam and no more than .450" of lift, single springs with 80 to 90 lbs. of seat pressure with the valves closed are usually adequate. For street/strip performance engines, springs with 100 to 120 lbs. of seat pressure are usually recommended. For street hydraulic roller cams, seat pressure should typically be 105 to 140 lbs., and should not exceed a maximum of 150 lbs. with a mechanical roller cam.

Double or even triple springs are usually required to achieve higher spring pressures. Seat pressures for double springs typically range from 130 to 150 lbs. or higher, and 300 or more lbs. for triple springs. Most NASCAR teams run dual springs with seat pressures of 190 to 200 lbs. and open pressures of 500 to 600 lbs. at .750" lift. Pro Stock drag racers, by comparison, typically run triple springs with seat pressures of 375 to 475 lbs. with the valves closed, and up to 1,000 lbs. open!

Increasing spring pressure increases the rpm and horsepower potential of the engine. Every additional 100 rpm may be worth an extra 20 or more horsepower on a highly modified performance motor. The current limit for steel valve springs is about 83 to 85 cycles per second, or about 10,000 rpm. NASCAR teams run a 200 to 400 mile race at 8,500 to 9,000 rpm. But drag racers only run a quarter of a mile.

High pressure valve springs can deliver the rpms, but there's a price to be paid because the springs don't last. Running at such high rpm wears out the springs. Consequently, the springs have to be replaced fairly often (every race with NASCAR engines, and after so many runs with drag racers).

Higher spring pressures also puts more load on the rocker arms, pushrods, lifters and cam lobes, which increases the risk of something breaking.

According to one major camshaft supplier, standard camshafts can usually handle open valve spring pressures of up to 550 lbs. But for higher spring pressures, a carburized 8620 or 9310 steel camshaft is required.

Installing double springs may require the following modifications:
•
Flycutting the spring seats in the heads to accept the springs.
•
Changing the spring retainers to ones that are designed for double or triple springs.
•
Changing the valve seals and/or machining the guides for extra clearance.
•
Replacing pressed-in rocker arm studs with screw-in studs and a stud girdle, or installing shaft-mounted rocker arms.
•
Replacing the stock pushrods with stronger and stiffer 4130 chrome moly pushrods (to prevent pushrod flexing and breakage).
•
If the springs provide more than 350 lbs. of pressure when the valves are open, the stock stamped steel rockers will have to be replaced with stronger aftermarket steel or aluminum rockers.


BEEHIVE SPRINGS
Beehive springs that taper towards the top are a hot commodity in the aftermarket, but date back to the earliest days of the automobile. Like shaft-mounted rockers, though, they are finding new applications in todays high performance engines. Chevy LS1/LS7 series engines use a factory beehive spring, as do Ford modular 4.6L V8s. Similar spring designs have been developed for SB Chevy and Ford engines by aftermarket suppliers. Unlike a conventional valve spring that has a constant diameter, a beehive spring tapers in toward the top sort of like a real beehive (thus the name). A smaller top means a smaller and lighter valve spring retainer can be used to reduce weight. Also, the change in the diameter of the spring as it tapers toward the top creates a progressive spring rate that helps the spring resist harmonics that occur in conventional constant rate springs. The bottom line is that beehive springs perform better than conventional single springs on many (but not all) engine applications.

One spring supplier said their beehive springs can increase the rpm potential of an engine 100 to 1,200 rpm depending on the cam, valvetrain and other engine modifications. The maximum amount of valve lift a beehive spring can handle is about .650", so if the engine needs more lift it will require dual or triple springs.

Beehive springs have been popular on the street, but some racers are cautious about using them because there's no safety margin if a spring breaks. With a double or triple spring, the engine won't eat a valve if a spring breaks. The extra springs serve as a backup to pull the valve shut.

SPRING COATINGS
Heat is the main enemy of the springs, with dual and triple springs typically generating more heat than single springs because they rub against each other. Managing heat, therefore, is critical for spring longevity.

The durability of a spring depends on the quality and purity of the alloy that is used to manufacture the spring, the heat treatment the spring receives, and any additional surface treatments the spring is given. Some springs are nitrited while others are coated with proprietary chemicals that help the spring run cooler. Another trick that can extend spring life is to have the springs cryogenically treated. Freezing the springs to 300 degrees below zero can increase spring life up to five-fold, according to those who do it.

SPRING INSTALLATION
There are a couple of things to watch when installing valve springs. One is height. This ensures the springs have the required pressure to keep the valves shut. Height is checked by measuring the distance between the spring seat in the head and the retainer on the valve stem. Most performance valve springs are closely matched, but if adjustments are needed it can be done by shimming the valves to equalize pressures. The thicker the shim, the more it increases spring pressure. Don't overshim, though, because doing so may lead to coil bind with a high lift cam or rocker arms.

Shims are made of hardened steel, come in various thicknesses and are usually serrated on one side to prevent rotation (the serrated side faces the head). Some shims are also designed to help insulate the springs from heat generated by the cylinder head. Springs should also be lubricated when they are installed in a new engine, especially double and triple springs, to reduce friction. Soaking the springs in oil or coating them with assembly lube should provide adequate protection during the critical first start-up.

VALVE SPRING RETAINERS & LOCKS
Reducing weight on the valve side of the rocker arm has more of an impact than reducing weight on the pushrod side because of the leverage effect. Lightweight valve retainers made of titanium have long been the preferred upgrade here. But in the past year, the price of titanium has skyrocketed. Most of the world's titanium supply comes from Russia and is being consumed by China. Some aftermarket suppliers have responded to the changing market conditions by introducing new lightweight steel retainers.

For street applications, steel retainers with stock 7 degree locks are usually recommended. But for racing or high rpm roller cams, titanium retainers with 7 or 10 degree locks can reduce weight. Some locks have an extra step inside that reinforces the bottom of the retainer and reduces the risk of the valve pulling through at high rpm. When the valve locks are installed around the valve stem, their edges must not touch each other. They should clamp against the valve stem and hold it securely. Keep in mind that the design of the retainer affects the installed valve height and spring tension.
IF YOU CAN,T SMOKE THE TIRES AT WILL,FROM A 60 MPH ROLLING START YOUR ENGINE NEEDS MORE WORK!!"!
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Re: sellecting valve springs, and setting up the valve train

Postby grumpyvette » January 29th, 2012, 6:20 pm

The Truth About Valve Springs (from comp cams)
Valve springs are one of the most critical and most overlooked components in your engine. Proper selection of the valve spring begins with identifying the application and selecting all of the valve train components to achieve the engine builders’ goals.

The spring is selected to complement the system and must be matched with the entire valve train in order for the engine to reach its full potential. It does absolutely no good to install a cam that will rpm to 8000 if you do not have the correct springs. Improper selection of the wrong valve spring is one of the most common causes of engine failure. Other common causes are the incorrect installation and improper handling of the valve springs.

Selecting a Spring
1. Use only the valve springs that will give the correct spring pressure with the valve both on the seat and at maximum lift.

2. The outside diameter of the recommended valve spring may require that the spring pocket of the head be machined to a bigger size.

3. One of the easiest and sometimes most costly mistakes made in racing engines is not positively locating the spring. A valve spring that “dances” around on the cylinder head or retainer causes harmful harmonics and excessive wear. A spring that is forced onto a retainer is likely to fail at that coil. That is why we have such a large selection of steel and titanium retainers, hardened steel spring seat cups and I.D. locators to better match our springs. A spring that is contained properly at the retainer and the cylinder head will offer the longest possible service life.
Proper Spring Handling
1. Handle springs with care. Never place in a vise, grab with pliers or hit them with a hammer. This will damage the surface of the spring, which will cause a spring to fail.

2. When separating double or triple springs, use only a durable plastic object that cannot harm the shot-peened surface of the spring. Never use a tool or hard metal object like a screwdriver.


3. Valve springs are shipped with a rust preventative coating that should remain on the spring throughout engine assembly. Do not clean springs with acidic or evaporative cleaners. This causes rapid drying and promotes the formation of rust on the surface, which can cause catastrophic failures. Even a slight amount of corrosion can grow to be a problem.

4. When installing springs, use COMP Cams® Valve Train Assembly Spray (Part #106) to ease assembly and improve the life of the spring.
Checking Loads
1. COMP Cams® has matched each set of springs for load consistency. A variance of + or -10% is acceptable for new springs.

2. When checking the spring loads on a load tester (Part #5313) measure and note the thickness of the retainer where the outer spring sits. Assemble the retainer on the spring and place on the base of the spring checker.

3. Compress the spring to the desired installed height. This is the measurement between the top of the spring (on the bottom side of the retainer where the outer spring sits) and the bottom of the spring on the base.
* NOTE *
Since the retainer is installed in the spring when checking the spring loads, make certain that the thickness of the retainer is not included when calculating the installed height and is accounted for when compressing the spring. The spring load checker will show to be higher with the spring installed at the correct height.


Installation
1. Before installing the spring on the cylinder heads, check the installed spring height (Diagram A). This is the distance from the bottom of the retainer to the surface where the spring rests on the head. The valves, retainers and valve locks will be used in this step. First, install the valve in the guide, then install the retainer and valve locks. Pull the retainer tightly against the valve locks while holding the valve assembly steady.
Measure the distance between the spring seat and the outside step of the retainer using your height micrometer (Part #4928 or #4929) or a snap gauge and a pair of calipers. Repeat this procedure for all the valves and record your Information. After you have measured all the valves, find the shortest height. This will become the spring’s installed height on your heads. If your combination includes a dual or triple spring assembly, it will be necessary to allow for the inner steps of the retainer.

2. Once you have determined the shortest installed height, it will be necessary to use shims to obtain this height (±.020” is acceptable) on the remaining valves. These are available through our catalog or at any of
your local COMP Cams® dealers.

3. Before removing the retainers, measure the distance from the bottom of the retainer to the top of the valve seal (Diagram A). This distance must be greater than the lift of the valve. If not, the guide must be machined. This is a very common cause of early camshaft failure.

4. Once the valve springs have been installed, it is important to check for coil bind. This means that when the valve is fully open, there must be a minimum of .060” clearance between the coils of both the inner and outer springs. If this clearance does not exist, you must change either the retainer or the valve to gain more installed height, or change to a spring that will handle more lift or machine the spring seat for extra depth.

5. Always check for clearance between the retainer and the inside face of the rocker arm. This will be most evident while the valve is on the seat. Rocker arms are designed to clear specific spring diameters, so you should check to see that you have the proper rocker arm/retainer combination. This situation can also be the result of improper rocker geometry and may be corrected with different length pushrods or a different length valve.

6. To aid in the engine breaking process, spray the springs, rocker arms and pushrods with COMP Cams® Valve Train Assembly Spray (Part #106).


Breaking In a Spring

1. It is important for new springs to take a heat-set. Never abuse or run the engine at high rpm when the springs are new. Upon initial start-up, limit rpm to 1500 to 2000 until the temperature has reached operating levels. Shut off the engine and allow the springs to cool to room temperature. This usually will eliminate early breakage and prolong spring life. After the spring has been “broken-in”, it is common for it to lose a slight amount of pressure. Once this initial pressure loss occurs, the spring pressure should remain constant unless the engine is abused and the spring becomes overstressed. Then the springs must either be replaced or shimmed to the correct pressure.
IF YOU CAN,T SMOKE THE TIRES AT WILL,FROM A 60 MPH ROLLING START YOUR ENGINE NEEDS MORE WORK!!"!
IF YOU CAN , YOU NEED BETTER TIRES AND YOUR SUSPENSION NEEDS MORE WORK!!
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Re: sellecting valve springs, and setting up the valve train

Postby grumpyvette » January 6th, 2014, 11:34 am

69-CHVL wrote:Pretty interesting...let's see how these do.


Image


Progressive frequency increases RPM limit & creates ability to run more aggressive camshafts
Constantly decreasing diameter from bottom to top reduces active mass & decreases applied forces – result is longer valve train component life & less parasitic horsepower loss
Reduced mass improves RPM stability
Conical design is the best natural frequency damping setup – dampens without wear, heat/friction or risk from interference contact
Superfinish surface processing increases both lift capability & spring longevity

Expected to become the new standard in high performance valve spring design, COMP Cams® Conical Valve Springs utilize round wire and feature a diameter and progressive pitch driven natural frequency. This design increases the valve train RPM limit while reducing resonance concerns and decreasing dynamic spring oscillations. The result is longer spring life and the ability to run more aggressive camshafts. A breakthrough in valve spring development, COMP Cams® is the very first to introduce this advanced conical design.

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136 @ 1.800 412 @ 1.170

145 @ 1.900 495 @ 1.225

160 @ 1.900 495 @ 1.210


now not having seen several dyno tests , showing any consistent advantage in their use, yet I,m inclined to wait before jumping on the band wagon..
mostly because I know that properly set up dual valve springs. on a properly selected cam, can easily control valves at well over 7500rpm and I rarely build engines designed to operate over that rpm range.
yes Im well aware that some of the European built engines have used these type springs for several years , but the much larger and heavier valves in the larger American V8 engines MIGHT pose a different set of inertial values, the springs may not handle as well.
So Ill wait to see some consistent results using some more adventurous and well funded guys experimentations
IF YOU CAN,T SMOKE THE TIRES AT WILL,FROM A 60 MPH ROLLING START YOUR ENGINE NEEDS MORE WORK!!"!
IF YOU CAN , YOU NEED BETTER TIRES AND YOUR SUSPENSION NEEDS MORE WORK!!
grumpyvette

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Re: sellecting valve springs, and setting up the valve train

Postby 87vette81big » January 6th, 2014, 7:10 pm

I have had sucess using Iskenderian & Crower Valvesprings.
After run in 5# seat pressure lost at most.
Its impossible to analyze new valvesprings without a Spintron , dyno, & real world race testing.
Isky Tool Room Gold & PSI valvesprings excellent if you can afford. $400 a set to start.
Titanium valvesprings have been made.
Pretty exotic. $1k to start for a set.
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Re: sellecting valve springs, and setting up the valve train

Postby grumpyvette » June 29th, 2014, 3:17 pm

I'm frequently amazed , that people in general don,t think to ask about options that are readily available when building or modifying custom performance engines, component parts don,t generally need to follow exact production engine specs and in fact its usually a dis-advantage to be limited to the use of some components physical dimensions.
most cylinder heads have rather limited casting thickness in the valve spring seat area thus if you need a lot more room to install a taller valve spring your limited on how deep and wide the valve spring seats can be cut, yet few guys realize that installing a longer valve also allows a taller installed height on the valve spring without cutting the heads seat area.

http://www.summitracing.com/parts/mil-45635-1/overview/

http://www.coasthigh.com/chevy-big-bloc ... /18111.htm

valve guide cutters come in a wide variety of sizes as do valve springs
http://www.jegs.com/i/Comp+Cams/249/471 ... 7AodHUQApw
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https://www.google.com/search?q=cutting ... 6981467968
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valves up to .350 longer are easily available or found and purchased
http://www.summitracing.com/parts/mil-45620-8/all
http://www.summitracing.com/parts/man-1 ... 7Aod7QcAxw
http://www.ferrea.com/Big-Block-Engine-Valves/p34231
http://www.theengineshop.com/products/b ... alves.html
http://www.scorpioncheckout.com/category_s/150.htm
http://www.racingheadservice.com/rhs/bi ... ollerhtml/
http://www.dartheads.com/products/big-b ... kit-9.html

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read related info
http://www.cranecams.com/uploads/instructions/12e_.pdf

https://www.lunatipower.com/Tech/Valvet ... gTech.aspx
http://www.carcraft.com/techarticles/vo ... g_upgrade/
http://www.compcams.com/Pages/415/truth ... rings.aspx
IF YOU CAN,T SMOKE THE TIRES AT WILL,FROM A 60 MPH ROLLING START YOUR ENGINE NEEDS MORE WORK!!"!
IF YOU CAN , YOU NEED BETTER TIRES AND YOUR SUSPENSION NEEDS MORE WORK!!
grumpyvette

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