valve train clearances and problems



valve train clearances and problems

Postby grumpyvette » October 15th, 2008, 2:54 pm

you might want to read thru these links and sub links it will help you avoid costly mistakes
viewtopic.php?f=52&t=1376&p=3033#p3033

http://www.lunatipower.com/Tech/Valvetr ... metry.aspx

viewtopic.php?f=52&t=181

viewtopic.php?f=52&t=9687&p=48105#p48105

http://www.youtube.com/watch?v=o5is9BsH5OU

viewtopic.php?f=52&t=788

viewtopic.php?f=52&t=697

viewtopic.php?f=52&t=196&hilit=adjusting+valves

http://www.racingsprings.com/

viewtopic.php?f=52&t=10696&p=46481#p46481

viewtopic.php?f=52&t=9815

http://www.compcams.com/Products/CC-%27 ... %27-0.aspx

viewtopic.php?f=44&t=772&p=1122&hilit=+cutting+tool+filter#p1122

preventing cam & lifter break-in failures

ValveSpringClearance01.jpg

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it should be rather obvious that there's options,you'll chose in both valve train components and lubricants, cam failures are usually the result of incorrect CLEARANCES or too much SPRING PRESSURE or LACK of ADEQUATE LUBRICATION,USE DECENT MOLY CAM LUBE, and decent quality oil, adding MAGNETS to trap metallic CRUD HELPS, if your not getting constant oil flow from each rocker /push rod at idle theres something wrong and that needs to be checked

if you change the rocker ratio the push rod alignment changes and you might need a LUIS TOOL to lengthen the cylinder head clearance slots in the cylinder heads.
be sure to check clearances carefully like coil bind,and push-rod to guide plate alignment and clearances ,verify the rocker slots don,t bind on the rocker studs as this is a common problem with stock stamped style 1.6:1 ratio rocker, verify the push rods don,t bind in the slots in the cylinder head, if they do even for an instant at one point in the rockers arc, they can bind the lifter rotation on the cam lobe and cause the cam to wipe, out the lobe and the lobe & lifter contact area resulting in a quickly failed cam,and/or restrict oil to the rockers
s
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READ

http://www.rehermorrison.com/blog/?p=21

http://www.rehermorrison.com/blog/?p=58

http://www.centuryperformance.com/check ... g-144.html

http://www.hotrod.com/techarticles/engi ... index.html
these adjustable push rod guide plates come in handy at times
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(1) get a decent ROLLER CAM, add a high volume oil pump, baffled 8 qt oil pan, with a windage screen and check your clearances and avoid the problem,USE DECENT MOLY CAM LUBE,and decent quality oil,adding MAGNETS to trap metallic CRUD HELPS


(2) use a SOLID lifter flat tappet cam with lifters with the lube feed holes,add a high volume oil pump, baffled 8 qt oil pan, with a windage screen and check your clearances and avoid the problem,USE DECENT MOLY CAM LUBE, and decent quality oil,adding MAGNETS to trap metallic CRUD HELPS


http://www.competitionproducts.com/prodinfo.asp?number=651080DL

(3) mod the lifter bores for more oil flow,add a high volume oil pump, baffled 8 qt oil pan, with a windage screen and check your clearances and avoid the problem,USE DECENT MOLY CAM LUBE,and decent quality oil,adding MAGNETS to trap metallic CRUD HELPS


http://www.compperformancegroupstores.c ... gory_Code=


(4)USE DECENT MOLY CAM LUBE

http://www.cranecams.com/index.php?show ... l=2&prt=15 ,
add a high voluum oil pump, baffled 8 qt oil pan, with a windage screen and check your clearances and avoid the problem,and decent quality oil,adding MAGNETS to trap metalic CRUD HELPS


(5) thinking things thru and verifying clearances and spring pressures, and having a well thought thru lube system will significantly lower your chances of having problems,USE DECENT MOLY CAM LUBE,and decent quality oil,adding MAGNETS to trap metallic CRUD HELPS
.......I have not seen a cam fail in years UNLESS the guy installing it failed to follow those tips
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many more modern oil formulations lack the correct additives for flat tappet lifters, so be very sure you check to see what oil your using and if its designed for flat tappet lifter applications

anyone see a PATTERN?

you might want to read thru this AGAIN
http://www.highperformancepontiac.com/t ... index.html

http://www.cranecams.com/?show=article&id=2]http://www.cranecams.com/?show=article&id=2

FROM MORTEC
If you are building a SMALL or BIG block Chevy with a flat tappet cam, (solid or hydraulic lifters) be careful during the initial engine break in. It is very easy to lose a cam lobe and lifter during initial break in. This is especially true with a higher than stock lift cam and higher pressure valve springs. The increased push rod angles found on the BBC and poor preparation can make cam lobe failure after initial fire up a distinct possibility. You can help prevent this cam lobe failure by making sure the engine is pre-lubed prior to initial fire up. Use a good high pressure lube on the cam lobes and lifter bottoms during assembly. If possible use a lighter pressure stock valve spring (or if using a valve spring with multiple springs, take out some of the inner springs) to initially run the engine. Then switch to the heavier pressure springs after break in. When the engine is first fired up, keep the engine rpms at 2,500 or above, don't let the engine idle for 20 minutes or longer. This keeps lots of oil splashing up on the cam lobes. Make sure the engine can be run for this time period by having enough fuel available, ignition timing set correctly, coolant available for the motor, valve lash set correctly, etc. The idea is not to crank the motor over excessively before it starts up for the first time. If your BBC flat tappet cam survives this initial break in period, it will be good to go for many miles. After the initial engine break in, drain the oil and change the oil filter. Roller cams generally do not suffer these types of cam lobe failures during initial engine fire up.
if you've adjusted the valves correctly the lifter spins at all rpm levels,but that does NOT mean it wears EVENLY at all rpm levels due to several factors if you [color="orange"] look closely AT FLAT TAPPET CAMS [/color]you'll see that the center of the cam lobe is NOT centered under the lifter and that the lifter surface is slightly angled , BOTH these factors force the lifter to spin in its bore as the lobe passes under the lifter slightly off center.
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SOME of the reasons the higher rpm durring the break in phase is important is that

(1) the faster RPMs the better chances the lobe passes under the lifter floated on an oil film and the less time the oil film has to squeeze out between them

(2) the higher the RPM the greater the oil volume and pressure the engine pumps and the more oil flow is available at the lobes

(3)the higher the rpm level the more oil is thrown from the rods onto the cam lobes

(4)the higher the rpm the greater the lifters weight and inertia tends to compensate for the springs pressure and lower the net pressure as the lifter passes over the cam lobes nose

(5) at higher rpm speed the better chance a small wedge of oil is trapped between the lifter base and lobe from the oil thrown from the lobes surface by centrifugal force

(6) two different metal surfaces scraping past each other at low speeds may tend to wear and GALL as the oil is squeezed out but two different hardness steel surfaces that impact each other at higher speeds covered with oil tend to work harden as they mate and will tend to be separated by that oil

(7)as the lifter spins in its bore the contact point between the lobe and lifter base constantly changes and rotates with the lobe contact point not resisting its passage and the higher the rpms the faster the lifter rotates and the less time the lobe spends at any one point

BTW ADD E.O.S. to the oil and MOLY break-in lube to the cam
before starting the engine and pre-fill the filter and pre-prime the oil system before starting the engine.
I normally pour it in just before starting the engines cam break in,procedure. because I want to make sure that nothing in the oil/E.O.S. mix can settle out from sitting over a long period of time. now if your running a flat tappet cam you should have also used a moly cam lube on the lobes and be useing a mineral base oil for the break-in procedure, and youll need to do an oil and filter change after about the first 3-4 hours running time to remove that moly cam lube from the engine after its served its purpose of protecting the cams lobes and lifters at start up, aND AS THE LOBES/LIFTERS LAPPED IN. MOSTLY to prevent that moly grease and E.O.S from potentially partially clogging the filter after that mix cools down,but also because both those lubes might leave deposits in the combustion chamber ,over time that might aggravate detonation.
even G.M. suggests that E.O.S. is not a great long term oil supplement, and that its main function is to add extra oil film strength durring new engine break in.
Isky claims that the Comp XE cams violate the 47.5% rule. The 47.5% rule applies to flat tappet cams for SBCs with 1.5 rockers but the concept is still the same for other configurations where the designs are "on the edge" or "over the edge" for lobe intensity. For 1.5 ratio SBCs, the duration at .050 must exceed 47.5% of the total valve lift or your asking valve train problems. For example, take a Comp Cams Magnum 280H, with 230 duration and, 480 lift...230/.480 = 47.9% which exceeds 47.5% therefore would not pose a threat to components. We do not regularly hear about the older, safer HE and Magnum designs rounding off lobes anywhere near as often as the XE cam designs. Unfortunately, some of the Comp Cams XE dual pattern lobes break this 47.5% rule on the intake side so they are likely to be problematic. The design has "steeper" ramps that are too quick for durability and reliability according to other cam manufacturers. They will wipe lobes in a heart beat especially if you have not followed the proper break-in procedure. Other designs are more forgiving during break-in and less likely to fail.
http://www.gmpartsdirect.com/results.cf ... number=EOS
STOCK dog bone design hydraulic enclosed wheel roller lifters are generally designed for less than .550 lift and less than 6000rpm
the stock Chevy hydraulic roller lifters , dog bone and spider springs don,t always work reliably, ALL THE TIME with engines having over .500 lift or when spun over 6000rpm, its not all that rare for the lifter ,retainer to bend the retainer spring allowing the lifter to spin sideways, in the lifter bore, resulting in a destroyed cam, thats why Ive suggested BRAND NAME ,AFTERMARKET RETRO FIT CAM COMPONENTS BE USED
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don,t forget a few magnets in the oil pan goes a long way towards trapping unwanted metallic dust formed from the cam and rings lapping in durring break-in that might otherwise get embedded in your bearings or cause other problems
here is the magnets I use in every engine
add a few magnets to the oil pan and drain back area in your engine, the trap and hold metallic dust that comes from wear and increase engine life span by preventing that crap embedding in the bearings

http://www.kjmagnetics.com/proddetail.asp?prod=D66SH

http://www.kjmagnetics.com/proddetail.asp?prod=D66SH

http://www.kjmagnetics.com/proddetail.asp?prod=D82SH

these are even more tolerant of temp swings and retain strength at even higher engine oil temps plus they are smaller and easier to use

http://www.cranecams.com/?show=reasonsForFailure

https://www.holley.com/data/Products/Te ... NST150.pdf

http://www.circletrack.com/techarticles ... index.html

http://www.cranecams.com/?show=camQuestions

stuff like this is easily avoided or fixed if you have the correct tools and experiance, BBC engines tend to require extra care during the break-in due to high lifts and strong valve springs, I tend to smear MOLY cam lube over all the valve train surfaces, break the cams in at 2000-3000 rpm and use crane break in lube also, and run a decent high zinc content oil during the first few hours

yeah, check it out, the longer you run it if the lobes are wearing the more crud your pumping thru the engine,if you did lose a lobe its USUALLY a clearance issue like spring bind, rocker to rocker stud, or retainer to valve guide , improper lash/pre load or installation issue like the wrong spring loads or improper lubrication.
stock springs and rocker to valve stem clearance on some BBC heads won,t clear more than about .530 lift, many clear .560, but above that you almost always need to check carefully, or use aftermarket valve train components and custom machine work

the old familiar stuffs Part #1052367 is getting hard to find
E.O.S. was discontinued but.....
http://www.sdparts.com/product/1052367/GMEngineOilSupplimentEOS16ozBottle.aspx
the new stuff...
http://www.acdelco.com/html/pi_vehcare_lub.htm
(use the drop down menu)
Part 10-106
12371532
E.O.S. Assembly Lubricant (1 pint)

its still available if you know where to look, most but not all parts counter guys will know this but youll run into a few who just insist its not available

http://www.cranecams.com/?show=promo&id=48


btw MOLY base lubes are your first and best break-in lube during the first few minutes

http://www.cranecams.com/index.php?show=browseParts&lvl=2&prt=15

http://www.cranecams.com/pdf/548e.pdf


http://www.carcraft.com/techarticles/11 ... index.html

CRANES Super Lube Break-In Concentrate is an anti-wear additive formulated with a high concentration of special zinc dithiophosphate to provide sustained protection against cam lobe and lifter scuffing and wear. This oil supplement is to be added to the engine oil for the initial break-in period after the installation of a new camshaft and lifters.

Part No. 99003-1 -- 8-ounce container

http://www.digitalcorvettes.com/forums/showthread.php?t=84348

BTW before the next time you do a running valve adjustment you should find and use a set of cheap used tall valve covers which youve modified by cutting a wide slot along the center top surface, this retains a good deal more oil in the engine vs on the headers,but before assuming anything verify the old cam is having problems and your clearances/geometry on the valve train are correct

IVE always preferred STEEL roller rockers over ALUMINUM for two reasons
first STEEL has a MUCH GREATER fatigue life under repeat stress than aluminum, and steel generally has far fewer clearance insures with other components, plus some STEEL roller rockers are REBUILD ABLE

http://store.summitracing.com/partdetail.asp?part=CCA%2D1302%2D16&autoview=sku


http://store.summitracing.com/partdetail.asp?part=CRN%2D11600%2D1&autoview=sku

in MOST cases you can install 1.6:1 roller rockers with MINOR machine work, (I have seen on rare occasions no machine work necessary)
but in any case its easily done,

the tool comes with instructions

http://store.summitracing.com/partdetail.asp?autofilter=1&part=PRO%2D66485&N=700+115&autoview=sku

and before a dozen guys start telling you they installed them with zero problems on stock heads, keep in mind most guys don,t take the time to check ALL the clearances thru THE FULL rotation of the rockers arc. and it they don,t break or bind parts ,THEY assume its fine
but the truth is the push rod should NEVER touch either end of the slot even lightly anywhere in the arc.


WATCH THE VIDEOS, READ THE LINKS
http://www.youtube.com/watch?v=qw5PWiOwXhI

http://www.youtube.com/watch?v=Cqx8Cs6O ... re=related

http://www.youtube.com/watch?v=5GBNLlsi ... re=related
http://www.digitalcorvettes.com/forums/showthread.php?t=82474

http://www.centuryperformance.com/valveadjustment.asp

http://www.2quicknovas.com/happycams.html

http://www.iskycams.com/camshaft.php

http://www.reedcams.com/degreeing.htm
http://www.centuryperformance.com/check ... g-144.html

keep in mind shims under the valve springs can be used to raise the spring or shorten the valves installed height, valve locks and retainers can be purchased with non-O.E.M dimensions to adjust the valves installed height or spring load rates
you use either or both depending on the application
a .050 PLUS valve lock moves the retainer .050 higher on the valve stem with no other changes, a plus .050 retainer would move the retainer .050 higher with stock valve locks or an additional .050 if matched to .050 plus locks
if you used a plus .o50 retainer with a set of minus .o50 valve locks the retainer would remain at the stock height on the valve stem
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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!!
grumpyvette

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Re: valve train clearances and problems

Postby grumpyvette » October 15th, 2008, 3:02 pm

MARVEL MYSTER OIL is a good high detergent oil designed to aid valve train and rings ETC. cleaning, I almost always add about 10% marvel mstery oil to my engines, but if your running flat tappet lifters Id point out that many current oils are designed for roller lifter engines so Id sellect an oil thats designed for the older design with the higher zinc content, and adding a can of E.O.S. to the oil and moly assembly lube on the lifters and cam, sure won,t hurt on that first break in, if your breaking in the engine in your driveway, have a running hose and a fan handy, water running thru the radiators cooling fins and a fan blowing air helps prevent over heating, have a timing light and USE IT, check your fluid levels and watch your gauges

GM's RECOMMENDED CRATE ENGINE START-UP PROCEDURE
Print this page out and check off boxes below (in the printed copy) when each step is completed.
Step Box
1) Safety first! If the car is on the ground, be sure the emergency brake is set, the wheels are chocked, and the transmission cannot fall into gear. Next verify that all hoses are tight and that both the radiator and radiator over flow jar/tank are full and have been filled with the proper anti-freeze and water mix.
2) Before starting your engine for the first time, add one pint of engine oil supplement ( EOS¹) to the crankcase oil and then check the oil level. Once this has been done, prime the oil system with an oil pump primer tool. Make sure number 1 cylinder is on TDC compression stroke, and install the distributor.
3) Adjust the distributor timing roughly by hand for a quick start up and smoothest idle possible.
4) When the engine first starts, verify that the engine rpm is at a safe level and that the timing is set near or at 30° before top dead center (BTDC). Run the engine speed between 1,500 and 2,500 RPM’s, varying the engine speed up and down with-in this range, to prevent overheating of the exhaust valves and the exhaust system. This should be done with no-load on the engine and for the first 30 minutes of operation.
5) After the first 30 minutes of the engine running, set the ignition timing according to the timing specifications. Now would be a good time to check thoroughly for leaks.
6) Adjust the carburetor settings, if necessary.
7) Drive the vehicle with varying speeds and loads on the engine for the first 30 miles. Be sure not to use a lot of throttle or high RPM.
8) Run five or six medium-throttle accelerations to about 3,800 RPM (55 to 60 MPH), then letting off in gear and coasting back down to 20 MPH.
9) Run a couple hard-throttle accelerations up to about 3,800 RPM (55 to 60 MPH), then letting off in gear and coasting back down to 20 MPH.
10) Change the oil and filter with recommended oil (10w30SG in most cases) and filter.
11) Drive the next 500 miles normally, without high RPM’s (below 3,800 RPM), hard use, or extended periods of high loading.
12) Change oil and filter again.
13) Your engine is now ready for many happy cruising miles!
Note¹: EOS P/N 1052367 can be used any time during the life of the engine.
Technical Note: This procedure has been corrected and improved from the original GMPP procedure by GILBERT CHEVROLET.

you'll be best served following the manufacturers suggested clearances or (LASH). if your running a solid lifter cam, if they suggest .016 than set them at that, its not critical that they are EXACTLY .016-018,should be fine, but get it as close as you reasonably can.
generally set them on a warm engine , but be 100% sure the valve train geometry and clearances are correct and oil flows from each individual pushrod to each rocker,
here's a few useful links

http://www.wallaceracing.com/valvelash.htm

http://www.cranecams.com/?show=faq&id=4

http://www.chevyhiperformance.com/techa ... index.html

http://www.centuryperformance.com/adjus ... g-149.html

http://www.small-block-chevy.com/cb_5.htm

http://www.fordmuscle.com/forums/engine ... tools.html
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: valve train clearances and problems

Postby grumpyvette » October 15th, 2008, 5:18 pm

http://www.american-automobile.com/Erso ... etrain.pdf
yes the cam lobes can very easily contact the connecting rods when the cam index is out of its proper timing, on almost any chevy engine the cam lobe center lines will be spaced at between 103 and 116 degrees, with the piston at TDC theres SUPPOSED to be about .060 MINIMUM clearance between the connecting rod bolts and cam lobes, this is a mandatory clearance check point and a plastic cable tie can be used to gauge clearance, its best done on each individual connecting rod to cam lobe clearance point AFTER the cams been degreed into the block as each connecting rods being installed but Ive generally done it during the several trial assembly points where I check other clearances like block to connecting rod clearance.
if you think about it the cam lobes will pointing basically up in the 180 degrees of rotation and be lifting the valves when the pistons are on the way up the cylinders, and point down toward the crank mostly when the crank throws pulling the rods downward,away from the top of the engine
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LOOK AT THE TWO REAR CYLINDERS
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thats why on some stroker crank engines a SMALL BASE CIRCLE cam is used to MAXIMIZE CLEARANCE,between the two moving parts.
a cams lobe lift is the difference the lifter moves off the cams base circle between its base circle and its max lobe lift, thus a cam with a 1.1" diam base circle and a .400 lobe lift would have a , .400 lobe lift and if you had 1.5:1 ratio rockers a .600 valve lift, but if you wanted more clearance you could use a smaller base circle at .900, and a 400 lobe lift this would allow the connecting rod, to sweep by with an additional amount of cam lobe to connecting rod bolt clearance, the change in diameter generally requires a swap to a stronger cam billet core . vs cheaper cast core,to maintain cam strength

removing the rod caps during clearance checks while building your 383 ,does seem to allow you to see the clearance issues a bit easier

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the cam rotates while indexed by the timing chain at 1/2 crank shaft speed , there are connecting rods designed to provide additional clearance.
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ERSON MAKES SOME DECENT PARTS

roller rockers have at least potentially the ability to reduce friction in the valve train and free up a few hp, your port flow and cam duration will have a great deal to do with the results you can expect. higher ratio rockers like the 1.6:1 roller rockers most guys buy can effectively add a slight amount of working duration to the valve timing and some additional lift. the problems are usually limited to clearance problems that the higher lift and different rocker geometry can cause
should you use 1.6 ratio roller rockers?

well swapping to roller rockers is always good for a few hp due to reduced friction but it depends on the cams ramp rates and total duration and lift, it can be as much as 7-8 degrees of effective duration or as little as 3-5 degrees, from what Ive seen, keep in mind that 1.6 ratio rockers tend to work much better on mild cams and lower lifts because the total flow change is greater and the stress levels on the valve train is relatively low. once you get over about .550 lift and about 235 at .050 lift and 5000rpm the resulting improvement in flow tends to be less than the resulting stress on the valve train compared to just getting the correct cam with a slight duration and lift increase that is better designed to run above 5000rpm due to the more controlled rate of lifter acceleration which can in a cam originally designed to run 1.5 ratio rockers get to valve float rpm.
look what your trying to do,... what 1.6 rockers are is a nice tuning aid that allows tweaking the cam timing, they are in no way a valid replacement for the correctly matched cam and 1.5 ratio rockers but they ARE an easy way to get a few cfm of extra airflow in the ports IF the ports potentially flow better than the cam your using allows. where I see the best results is in nearly stuck engines where the cam severely restricts airflow at the higher rpms, Ive even seen LOSSES in hp in engine with fairly hot roller cams when 1.6 ratio rockers are added. also sometimes only adding the 1.6 ratio rockers to the intake or exhaust can sometimes gain more than adding the rockers to both
when I was running a crane #114142 cam they helped , when I swapped to a 119661 roller cam they added zero hp over 1.5 ratio rockers in my 383.
http://www.lmengines.com/rocker_arm_changes.htm


http://www.vetteweb.com/tech/0204vet_rockers/


ValveSpringClearance01.jpg




MikeB wrote:.....

ValveSpringClearance01.jpg


viewtopic.php?f=52&t=181
Grumpy -- man, those are some big clearance numbers!


maybe so but its what most of the cam and valve train component manufacturers suggest using, and since they spend hundreds of thousand$ on research, and have done YEARS OF RESEARCH AND TESTING, I tend to go with their experience.
now Ive only built a few hundred engines in the last 45 years but so far it seems to be good advice


youll also want to verify piston to valve clearances and correct quench

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keep in mind that the intake valve usually starts to open well before the piston reaches TDC on its exhaust stroke, and continues to extend out towards the piston after it passes TDC and follows it down into the bore as it descends on the intake stroke, generally closest contact points are in the 20 degrees btdc too 20 degrees atdc, obviously exact potential clearances are dependent on both cam timing and cam indexing
http://www.sallee-chevrolet.com/Proform/rocker_arm_pics.html

http://www.cranecams.com/master/goldrace.htm

http://www.compcams.com/information/Products/RockerArms/ProMagnum.asp

http://www.trickflow.com/product/camsandvalvetrain/pr_rollerrockers.htm

http://www.fl-thirdgen.org/rockerswap.html

heres a simple way to get close to the correct length
BUY ONE OF THESE
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http://www.jegs.com/cgi-bin/ncommerce3/ProductDisplay?prrfnbr=3567&prmenbr=361

after making sure the valve springs are correctly installed you drop the checker in place on the rocker stud and install your adjustable push rod
adjust the length to fit and measure the resulting length if its within twenty thousands of the stock length its fine for most applications, if its more than 30 thousands long or short get the closest length set available

btw, if your one of the people that still does not own an adjustable push rod! you can easily make your own by cutting a stock push rod in 1/2 (2 pieces), removing 1 inch from the total length an then with about 2 " of a 4 inch section of 3/16 or 1/4" thread rod installed and (in one section epoxy it in place leaving about 2" sticking out thread two nuts onto the thread rod and slip on the other end of the cut push rod,(no epoxy) use the two nuts to adjust to stock length and let the epoxy hardened in the one section[/color] now you can easily measure and order custom push rods using the push rod checker and adjustable push rod as tools
AND YEAH IT ONLY WORKS WITH THE CYLINDER HEADS ON AND THE INTAKE REMOVED BECAUSE THE HOLE IN THE CYLINDER HEAD that Guides THE PUSH ROD WON,T ALLOW THE NUTS ON THE ADJUSTABLE PUSH ROD TO PASS THRU, UNLESS YOU PLACE THE CUT ABOUT 1" from the UPPER END OF THE ADJUSTABLE TEST PUSH ROD [b]BUT I prefer to place the adjusting nuts centered as I like to watch for all clearances with the intake manifold removed while manually checking as I turn the engine over by hand durring assembly, and at that point, while checking all the clearances, I use test springs which apply very little load on the push rod

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http://www.jegs.com/cgi-bin/ncommerce3/ProductDisplay?prrfnbr=3272&prmenbr=361

HERES OTHER TOOLS YOU MIGHT NEED
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SOMETHING TO READ
http://www.compcams.com/information/Products/Pushrods/

CCA-7705 5.800 in. to 9.800 in. adjustment range, Master pushrod length checker 4 piece kit ... $78.69

here

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self aligning rockers have ridges to prevent the rocker from moving off the valve stem
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notice the approximate location and relationship between the cam pin and crank key

http://www.superchevy.com/technical/eng ... index.html
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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!!
grumpyvette

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Re: valve train clearances and problems

Postby grumpyvette » October 15th, 2008, 8:26 pm

once you've installed a new cam in your engine its necessary to determine the correct valve train geometry, this is MANDATORY if you want the cam to function correctly.
yes the stock length may work just fine! but you must check!
http://www.racingsprings.com/PDF/Design ... v%2001.pdf
if you don,t think use of the correct valve springs and rockers matters heres the dyno results on a 496 BBC chevy engine with a new set of valve springs and roller rockers, obviously if correctly selected,they can make a difference
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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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read this thread also

viewtopic.php?f=32&t=1000

heres a quick way described below
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correct length..................too short............................too long

" to QUOTE MOTORMAN.....
you just put the lifter on the cam base circle,slip the checker over the stud,if the checker hits the valve first use a feeler gauge between the checker and the push rod tip to see how much longer push rod you need. if the checker hits the pushover first use a feeler gauge to check the gap at the valve stem tip and that is the amount you need to shorten the push rod"

its not that difficult to figure out, read these links also

http://www.compcams.com/information/Products/Pushrods/

http://www.powerandperformancenews.com/s...=LENGTHCHECKERS

yes you need to check.
heres a simple way to get close to the correct length
BUY ONE OF THESE
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http://www.jegs.com/cgi-bin/ncommerce3/ProductDisplay?prrfnbr=3567&prmenbr=361

after making sure the valve springs are correctly installed (correct height, and you've checked for spring bind,retainer to valve guide, retainer to rocker,rocker to rocker stud,and push rod to cylinder head slot clearance ETC, you drop the correct style push rod checker in place on the rocker stud and install your adjustable push rod
adjust the length to fit and measure the resulting length if its within twenty thousands of the stock length its fine for most applications, if its more than 30 thousands long or short get the closest length set available
be aware the push rod checkers come in 3/8" and 7/16" stud models, and bbc and sbc models

http://www.compcams.com/Products/CC-%27 ... %27-0.aspx

btw
http://www.powerandperformancenews.com/s...;Category_Code=

BEEHIVE DESIGN springs , with the upper side being smaller in diam. and using a smaller retainer,
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available from several manufactures similar too these give much greater clearance to the rocker/retainer area and tend to control valve float harmonics if you find that your current springs won,t work

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the push rod length checker is used after the stock rockers removed like in this picture, simply rotate the engine to TDC on the rotation where BOTH valves are SHUT, remember there's a 720 degree repetitive cycle, #1 fires on one rotation at TDC and #6 fires on the next rotation, you measure when both valves are closed at TDC and read the links again,
BTW they make check gauges for 7/16" and 3/8" studs get the one matching your engine size
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Specialty Auto Parts U.S.A.,
Proper push rod length is absolutely critical
for peak performance—minimizing bent or
broken valve stems, guide wear, and ener
gy-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 prope
r 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 ro
d first, measure the gap between the front
of the checker and the valve tip, and purchas
e 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 r
od, and purchase a longer push rod.
Specialty Auto Parts U.S.A Inc

http://www.summitracing.com/parts/pro-66789/overview/
KEEP IN MIND THE PICTURE at SUMMIT IS UPSIDE DOWN

http://www.summitracing.com/parts/cca-7901-1/overview/

http://www.summitracing.com/parts/cca-7901-1/overview/
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youll need these also
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BTW DON,T assume that the intake and exhaust push rods are the same length, yeah they usually are on a SBC engine but there are exceptions....CAREFULLY CHECK SEVERAL or ALL CYLINDERS
especially if your using aftermarket heads and roller rockers
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: valve train clearances and problems

Postby grumpyvette » January 14th, 2009, 10:05 am

get the ignition timing as close as you can, but use a timing light as soon as you can to verify the ignition timing, if its off significantly the engine can run into detonation or the headers can get extremely hot.
letting it idle is not always necessary , you can just set the timing at 34-36 degees at 3100 rpm and wait untill its got the cam lapped in, but if youve got the correct molly cam lube, E.O.S. in the oil, plenty of oil pressure and all your clearances are correct, and plenty of oil in the engine,a brief time at idles not likely to cause problems in my experiance, its been over 28 years since IVE seen a cam lobe problem at break-in, and then it was a clearance issue not procedure.
ID bet the vast majority of cam problems can be traced too clearance or geometry issues or lack of moly assembly lube and E.O.S. and failure to provide lots of oil flow, not failing to keep the rpms over 2500rpm for the first 1/2 hour
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: valve train clearances and problems

Postby grumpyvette » July 28th, 2014, 11:58 am

occasionally you'll have an application where you'll want to use roller rockers and short valve covers and find theres a clearance issue,its usually NOT the rockers as much as the taller JAM NUTS, or drip tabs inside the rocker covers causing the clearance issues , roller rockers don,t require the same volume of oil so drip tabs can be cut out with no durability issues if you use roller rockers, but the interior slot length and width of the roller rocker slot the jam nuts fit into in many cases are so small and restrictive that you can,t use any thing but a jam nut with the hex located well above the rocker to lock the rocker in place
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there are some jam nuts that are slightly shorter in length
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viewtopic.php?f=52&t=6186&p=19333&hilit=rocker+roller+flat#p19333
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: valve train clearances and problems

Postby grumpyvette » September 8th, 2014, 10:43 am

ALLEN wrote: grumpy, Ive bent another push rod and I carefully verified I don,t have any piston to valve interference (its .120 on the intakes and .140 on the exhaust)or coil bind issues , any ideas?


the most common fault I see is guys who fail to verify the clearances in the valve train that may not be obvious like the rocker slot to rocker stud clearance, or retainer to valve guide, clearance, or the edge of the valve to the valve pocket in the piston. most guys check for coil bind and push rod length, and use some clay to verify the valve face to piston clearance but few guys that I see come to my shop seem to have verified all the potential issues like push rod to push rod guide plate clearance over the full sweep of the rocker travel.

preventing cam & lifter break-in failures


it should be rather obvious that there's options,you'll chose in both valve train components and lubricants, cam failures are usually the result of incorrect CLEARANCES or too much SPRING PRESSURE or LACK of ADEQUATE LUBRICATION,USE DECENT MOLY CAM LUBE, and decent quality oil, adding MAGNETS to trap metallic CRUD HELPS, if your not getting constant oil flow from each rocker /push rod at idle theres something wrong and that needs to be checked

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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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GRAPH SHOWING VALVE AND PISTON LOCATION, ,USUALLY AT ITS CLOSEST BETWEEN 10-20 DEGREES BFTDC and USUALLY AT ITS CLOSEST BETWEEN 10-20 DEGREES AFTDC
YES TAKING THE TIME TO READ SUB LINKS IS WELL WORTH THE EFFORT
http://www.enginebuildermag.com/2011/01 ... cker-arms/

http://www.hi-flow.com/HP012dVT.html

viewtopic.php?f=54&t=120&p=28636#p28636

http://static.summitracing.com/global/i ... 411-16.pdf

viewtopic.php?f=52&t=6641&p=21035#p21035

viewtopic.php?f=52&t=399

http://static.summitracing.com/global/i ... 82%291.pdf

viewtopic.php?f=44&t=2839&p=12739&hilit=guide+plate+adjustable#p12739

viewtopic.php?f=52&t=126&p=37621&hilit=spring+bind#p37621

viewtopic.php?f=52&t=7716&p=38047&hilit=spring+bind#p38047

viewtopic.php?f=52&t=9687&p=36006&hilit=spring+bind#p36006
CRANE CAMS wrote: Besides Coil Bind, What Other Types of Mechanical Interference Should You Look Out For?
When you increase the valve lift with a bigger cam or increased rocker arm ratio you must be sure that 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. ? Crane Cams offers steel long slot and extra long slot rocker arms to relieve this interference problem. Aluminum roller rocker arms may be required to provide sufficient travel on larger lift camshafts.

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.
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: valve train clearances and problems

Postby grumpyvette » November 4th, 2014, 9:22 am

tthorp32 wrote:I have a 383 stroker that has 10.5:1 compression with trick flow twisted wedge g1 heads. The max lift I can use from a cam before the valves hit a piston is .520 if I use different springs. "So long as you stay at or below 236* @ .050" Duration, No less than a 108* LSA, you can go up to about .520" lift before piston to valve clearance becomes an issue." I need help on cam selection. I want a hydraulic roller cam. It's a non roller block. I'm trying to make around 500 horsepower. It's a street strip setup with a t56 transmission. Also 1.52:1 rocker arms. Thanks in advance!



What valve springs would go good with this? Will any beehive springs fit those heads?

first ID point out that those are the guide lines that came with those heads and
THEY DON,T ALWAYS APPLY, you NEED TO ACTUALLY MEASURE YOUR PISTON TO VALVE CLEARANCE AND VALVE TRAIN CLEARANCES
you will be taking a HUGE gamble if you don,t VERIFY your TRUE clearances, and ID also point out that the valve springs can be and should be UPGRADED for use with a roller cam as the load rates are different, plus the fact that your valve springs and seals are at least 15 years old now, because they stopped selling those heads at least that long ago.
they are decent heads if in good condition but need better springs for a hydraulic roller cam.
It would help to know more about the car weight, rear gear, headers etc, and if you need to pass emission testing.
check the valve seals and valve guides for wear, as the G1 heads have a reputation for wearing originally installed valve guides


this is what is SUGGESTED BY most cam manufacturers

ValveSpringClearance01.jpg


viewtopic.php?f=52&t=3293&p=8709&hilit=twisted+wedge#p8709

viewtopic.php?f=52&t=181

viewtopic.php?f=52&t=399
viewtopic.php?f=52&t=399&p=488#p488

I don,t know many or in fact any engine builder that doesn,t have some good model clay in his tool box for checking clearances
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or a can of wd 40 to spray on the valves and clay too prevent clay sticking to parts measured, use good quality modeling clay, some crap like kids PLAY DOUGH, is SPRINGY and won,t give exact and consistent measurements, I pick mine up at a local arts & craft supply

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Image


when you select a hydraulic roller cam from any major manufacturer like crane or crower they will suggest a matching valve spring kit.generally hydraulic roller cams require a bit heavier load rates as the lifters are heavier and impart more inertial loads on the valve train, mandating the stronger springs use to maintain the lifter to cam lobe contact as rpms increase, this usually but not always involves minor machine work or at least a change on the valve shims and retainers, but frequently youll need to swap to different valve seals. so check with the manufacturer and be sure to ask lots of questions so you don,t assume you can just stuff a new cam in and have it work, because in most cases not following the guidelines voids the warranty and prevents the cam from functioning as nits designed too.
Hydraulic Roller Camshaft:generally use, 130-140 lbs Seat Pressure/300- 355 lbs open pressure

related info
viewtopic.php?f=52&t=181

viewtopic.php?f=52&t=3802

viewtopic.php?f=52&t=1376

viewtopic.php?f=52&t=2746

viewtopic.php?f=52&t=5522

viewtopic.php?f=52&t=9392
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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!!
grumpyvette

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