MACHINING VORTEC HEADS, and OTHER HEADS



MACHINING VORTEC HEADS, and OTHER HEADS

Postby grumpyvette » October 7th, 2008, 1:48 pm

LOOK THRU THE LINKED INFO ITS WORTH THE TIME AND EFFORT
keep in mind vortec heads without push rod guide plates or press-in rocker studs used with the push-rods MUST use self aligning rockers, standard rockers used without push rod guide plates will not maintain proper alignment and only screw in rocker studs can be used with push rod guide plates
I thought I post these flow numbers on ported vortec heads ive seen posted , just in case anyone has ever wondered or wanted to know the flow numbers a set of stock vortecs. I was also curious if any of you have any guesses on what gains I picked up on the port work.
INTAKE LIFT------- STOCK---- PORTED-- GAIN
.1---------- 59--------- 64--------- +5
.2---------- 117------- 132------- +15
.3---------- 170------- 187------- +17
.4---------- 214------- 236------- +22
.5---------- 226------- 255------- +29
.6---------- 219------- 259------- +40
EXHAUST
LIFT STOCK PORTED GAIN
.1---------- 42----------46--------- +4
.2---------- 83----------90--------- +7
.3---------- 123--------139--------+16
.4---------- 136--------161--------+25
.5---------- 143--------174--------+31
.6-----------147------- 178--------+31
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YOU MIGHT NEED A DRILL PRESS TO RE-DRILL SOME INTAKES TO GET THE CORRECT BOLT ANGLES
viewtopic.php?f=27&t=970&p=1691#p1691

VORTEC HEADS HAVE A DIFFERENT INTAKE BOLT ANGLE ON SOME BOLT LOCATIONS
VORTEC HEADS YOULL FIND IN SALVAGE YARDS HAVE THESE HEAD MARKINGS
The L31 Vortec comes in two different casting numbers, 10239906 (#906) or 12558062 (#062). Originally, the stock #906 casting head was available in two versions. One version had an Inconel exhaust seat with single angle valve grind and was available on 1 ton trucks. The other version was the traditional three angle valve grind. Other than that, the #906 is the same as the #062 head.
GM Performance Parts Bowtie Vortecs are offered in “small port” (#25534351), which has 185cc intake ports/65cc exhaust ports, or the “large port” (#25534445), which features 225cc intake ports/77cc exhaust ports. Both GM factory and GM Performance Parts Vortecs come with 1.94 intake/1.50 exhaust valves. According to the engineers at GM, “Stepping them up to 2.02 valves doesn’t help them any, so it’s not recommended. The port was designed to match the 1.94 valves. With the Vortec flow velocity,

things that can cause the guides to go bad are

1) Improper valve train component geometry in the rocker arm sweep on the tip of the valve stem.

viewtopic.php?f=44&t=2839&p=12739#p12739

2) Lack of oil flow to the valve stems and lack of assembly lube on the valve stem before firing the engine.


3) cheap parts that are not clearanced correctly

4) improperly installed valve seals or the wrong valve seals


youll miss a TON OF INFO IF YOU DON,T READ THE SUB LINKS

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

viewtopic.php?f=52&t=266&p=322&hilit=215cc+vortec#p322

http://www.onedirt.com/tech-stories/eng ... evy-heads/

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

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

http://www.sallee-chevrolet.com/Cylinde ... Vortec.cfm

http://www.strokerengine.com/SBCHeadsFlow.html

http://www.jegs.com/i/Patriot+Performan ... 1/10002/-1

viewtopic.php?f=44&t=6181&p=19320&hilit=vortec+port#p19320

viewtopic.php?f=52&t=322&p=9895&hilit=flow+numbers#p9895

viewtopic.php?f=52&t=5537

http://racingfeed.com/downloads/chevy_flow_data.pdf

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

http://www.customclassictrucks.com/tech ... index.html

http://carcraft.automotive.com/9794/vor ... index.html

http://www.crustyquinns.com/tech/easyout.html

viewtopic.php?f=52&t=1053&p=1989#p1989

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

http://www.customclassictrucks.com/tech ... to_04.html

http://www.goodson.com/

http://www.goodson.com/technical_support/

theres alot of good info in the links guys

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

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

http://www.popularhotrodding.com/engine ... index.html

viewtopic.php?f=52&t=181

viewtopic.php?f=52&t=528

http://www.chevymania.com/tech/vortec.htm

viewtopic.php?f=52&t=2077&p=44546&hilit=ccing+heads#p44546

viewtopic.php?f=52&t=2630&p=6788&hilit=+shrouding#p6788

viewtopic.php?f=52&t=181

viewtopic.php?f=52&t=528

viewtopic.php?f=52&t=401

Got questions? We've got the answers. Call 1-800-533-8010 from 8:00 am to 5:00 pm (central time), Monday through Friday

YOULL NEED TO KNOW YOUR SPRING DIAM. SPRING BIND HEIGHT,, MAX CAM LIFT, CURRENT RETAINER TO VALVE GUIDE CLEARANCE, THE TYPE AND DIAM. OF THE VALVE SEALS YOU WANT TO USE, IN MOST CASES ALL THAT INFO CAN BE OBTAINED FROM THE CAM MANUFACTURERS AND THE PARTS THEY SUGGEST TO USE WITH THEIR CAMS, THE VORTEC HEADS DON,T FLOW EXTREMELY WELL OVER .550 LIFT SO THERE'S LITTLE SENSE IN EXCEEDING THAT AND THE PORTS WON,T FLOW WELL ON A 350-383 AT OVER 6000RPM EVEN PORTED SO THAT'S GOING TO LIMIT THE CAM SELECTION ALSO

in theory brass/bronze valve guides are minimally softer and wear faster,than iron valve guides, but in reality if your using the proper valve seals, and have your oil flow to the upper valve train functioning correctly with reasonably clean oil, theres a thin coat of oil between the valve stems and the surface of the inner valve guides, that prevents any wear if your valve train geometry has the main loads centered on the valves centerline. keep in mind having proper valve train geometry, and having constant clean oil flowing over and cooling the valve springs, and rockers, plays a huge part in valve wear issues.remember the surface Finnish, clearances, valve seals and oil viscosity along with proper valve train geometry and material used in the valves also effects valve wear
btw coating the valve stems with a mixed slurry of marvel mystery oil and crane cams MOLY assembly lube during the cylinder head assembly process, tends to prevent dry start issues with the guides seizing valve stems

CRANE CAMS SELLS TEFLON VALVE SEALS,they are commonly packaged on blister packs
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crane Tech Line - 386-258-6174

CROWER http://www.crower.com/index.php/contacts/

ERSON CAMS http://pbmperformance.com/store.php?catId=327

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the two striped things are plastic valve seal alignment guides that are temporarily placed over the top of the valve stem, then oiled lightly, they are placed over the valve keeper lock grooves to prevent the seals being damaged during the valve seal installation process.

both tools and info here(ABOVE)ANY TIME YOU NEED TOOLS OR ENGINE MACHINING ADVICE ASK THESE GUYS, THEY USUALLY KNOW EXACTLY THE RIGHT INFO.

this info below might help

http://www.customclassictrucks.com/tech ... index.html

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

http://www.chevyhiperformance.com/howto/97458/index.html

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

http://www.competitionproducts.com/prodinfo.asp?number=4716

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

http://www.chevymania.com/tech/vortec.htm

http://www.nastyz28.com/forum/showthread.php?t=56505

http://store.summitracing.com/partdetail.asp?part=CCA%2D5306&autoview=sku




The best way to get the right installed spring height is to get a spring height micrometer. Both Crane and Comp sell tools for machining the guides in various diameters. I ordered mine from Summit. Here are the p/n's"

Comp Spring Seat Cutter 1.440" OD
CCA4718

Comp Valve Guide Cutting Tool 0.530" OD
CCA4726

Comp Arbor for Cutting Tools 11/32" ID
CCA4732

If you want a spring seat locator with your springs (keeps the spring from moving around on the seat and protects the seat surface of the head)
then you can order Comp p/n CCA478316 seat locators and use CCA4719 (1.550" seat cutter) instead of the one listed above. The tools are used with a low-speed drill press using the arbor in the valve guide to keep it lined up (make sure your guides are good first). You slowly remove material and check the height constantly durring the process with the spring height micrometer until you get it right distance between the spring seat and the under side of the retainer (spring height can be adjusted with shims if you go a bit too deep but try to avoid that as youll cut into the heads and cause problems ). After the seat is at the correct height, you machine the guide to fit the valve seals and for the correct clearance.

READ THESE

viewtopic.php?f=52&t=1053

viewtopic.php?f=52&t=528

viewtopic.php?f=52&t=731

viewtopic.php?f=52&t=697

viewtopic.php?f=52&t=731
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: MACHINING VORTEC HEADS

Postby grumpyvette » October 19th, 2008, 8:58 am

you could easily use the same pushrods BUT youll need to VERIFY the geometry and clearances and theres an excellent chance that the push rod slots in the heads will need clearance work
this is a comon problem,easily solved...
YOU NEED A louis tool, YOU WANT ABOUT .060 CLEARANCE, IT MAKES THE JOB EASY

http://store.summitracing.com/partdetai ... toview=sku
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using a louis tool
http://www.summitracing.com/parts/tfs-3 ... /overview/

http://www.summitracing.com/parts/tfs-3 ... structions

you are aware theres reasonably priced aluminum heads designed for a small bore sbc that out flow standard vortec heads

These Proform pushrod slotting tools are designed to elongate the pushrod slot in the cylinder head. They will make room for higher ratio rocker arms. Use these tools with a drill and a 5/16 in. drill bit to elongate the pushrod slot.
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btw place a magnet like this under each pushrod slot to catch the drill chips from iron heads

http://www.kjmagnetics.com/proddetail.a ... SH&cat=167

vortec heads standard intake port alignment

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Youll need to do a test fit to verify, your intake can be used, some will work, some won,t both VORTEC and LT1/LT4 heads have slightly higher port locations than the standard first gen intakes , the vortec heads are a closer match to the LT1 than the first gen heads, youll need to measure carefully, I needed to weld my intake runners to add aluminum before I could port them to match my heads ports

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many standard intakes don,t fit some vortec heads because the vortec head ports extend higher, so a VORTEC STEALTH RAM should be a closer match than a first gen stealth ram intake
IF YOU WERE TO USE A standard intake on vortec heads, theres a good chance the upper port seal area will leak, if you use a vortec intake on standard heads theres a lip protruding into the runner port roof that can disrupt fuel/air distribution patterns, while either intake design can at times be made to function on a miss matched combo its almost always a compromise


youll usually find that vortec heads require minor machine work to use over about a .470 lift cam, changing springs helps with the clearance but your not going to be able to install a significantly higher lift like a .525 lift cam in most cases without machine work .
keep in mind changing springs may reduce the coil bind height but it won,t change the installed height or retainer to valve seal distance, or valve train geometry, and your supposed to have a minimum of .060 between max lift and coil bind. and changing springs alone won,t change much in clearances except perhaps coil bind height.
yes you can get springs and a set of off set valve retainers or valve keepers that change the installed height but that generally changes the rocker geometry and also requires different push rods etc.
your better off having a decent machine shop add better springs, after machining the valve seats and valve guides AND SHORTEN THE VALVE GUIDES adding new valve seals

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READ these links


viewtopic.php?f=52&t=181

viewtopic.php?f=52&t=1751

viewtopic.php?f=52&t=2746

viewtopic.php?f=52&t=1716

viewtopic.php?f=52&t=3141

viewtopic.php?f=52&t=1376

viewtopic.php?f=52&t=528

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in this picture the self aligning rocker is the center one with the raise ridges that keep in centered on the valve tip , the two end rocker require guide plates
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self aligning stamped rocker

viewtopic.php?f=52&t=181

viewtopic.php?f=52&t=2746


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http://www.summitracing.com/parts/edl-3817
the new TPI vortec, head compatible base costs about $500
having the current first gen L98 TPI intake and base welded and drilled , and ported to fit the vortec heads should cost under $200-$300, if you do the port matching, I had mine done, (by me doing the welding and drilling and port match work, ) and ported to matching on a friends intake , for well under $120 in tools and materials we used
(tig weld shield gas refill, a few aluminum tig rods and a carbide burr)
so yes I did the work my self on several TPI intakes for friends and the results worked just fine, but ID also point out that if you want a better intake that fits vortec heads BOTH Holley,s STEALTH RAM and FIRSTS IMPROVED TPI have VORTEC base options



READ THE LINKED INFO

viewtopic.php?f=55&t=5378&p=32456&hilit=port+matching#p32456

http://www.firstfuelinjection.com/

http://www.holley.com/7542P.asp

guide plates and screw in studs or

self aligning rockers have ridges to prevent the rocker from moving off 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: MACHINING VORTEC HEADS

Postby grumpyvette » October 19th, 2008, 9:02 am

http://chevyhiperformance.com/howto/97458/

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


http://www.babcox.com/editorial/us/us110128.htm

http://www.youtube.com/watch?v=8rl-_q09 ... =g-all-lgv

http://www.babcox.com/editorial/ar/eb120121.htm

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

http://64.90.9.168/cranecams/pdf/512e.pdf

http://www.summitracing.com/
CCA-982-KIT Chevrolet: 262-400, conical valve spring kit

http://www.streetrodstuff.com/Products/115/

http://www.carcraft.com/techarticles/116_0306_vort/index1.html

http://www.kendrick-auto.com/vortec_cs_gm_head.htm


(1) open throat to 85%-90% of valve size
(2)cut a 4 angle seat with 45 degree angle .065-.075 wide where the valve seats and about .100 at 60 degrees below and a .030 wide 30 degree cut above and a 20 degree cut above that rolled and blended into the combustion chamber
(3)blend the spark plug boss slightly and lay back the combustion chamber walls near the valves
(4)narrow but dont shorten the valve guide
(5) open and straiten and blend the upper two port corner edges along the port roof
(6) gasket match to/with intake and raise the port roof slightly
(7) back cut valves at 30 degrees
(8) polish valve face and round outer edges slightly
(9)polish combustion chamber surface and blend edges slightly
(10) remove and smooth away all casting flash , keep the floor of the port slightly rough but the roof and walls smoothed but not polished.
(11) use a head gasket to see the max you can open the combustion chamber walls
(12) blend but don,t grind away the short side radias

(13) have a local machine shop clearance the retainer to valve guide distance and add aftermarket springs and valve seals
(14) there are valve keepers available that add .050 extra clearance(USE THEM) but make sure the valve springs you use and the rocker/valve train geometry are set up correctly to work with the larger valve spring height and clearance!
(15) use the CORRECT matching rockers
(16) adding, machining for, screw in rocker studs is a good idea!
(17) your wasteing time and money runing a vortec head engine with an extreme high rpm cam,and intake, especially on a larger 383-427 displacement engine, the heads are designed to make massive torque in the 2000rpm-5500rpm range on a 350 displacement engine, they will not efficiently feed a 7000rpm combo on a larger engine so build your engine with that in mind

(18)if you intend to build a killer 383-427 sbc with vortec (STYLE) heads ID STRONGLY SUGGEST UPGRADING TO

E-Tec 200
Edelbrock E-Tec 200 heads have 200cc rectangular intake ports and 78cc exhaust ports. They outflow the “fast burn” aluminum heads by 10% on the intake and 17% on the exhaust, making power up to 6500 rpm. 64cc combustion chambers produce approximately 10.2:1 compression when used with flat-top pistons in 350-inch engines. E-Tec 200 heads come with 2.02" intake and 1.60" exhaust valves.
E-Tec 200
Chamber Size Bare (single) Complete (single)
64cc #60969* #60989*
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: MACHINING VORTEC HEADS

Postby grumpyvette » January 9th, 2009, 10:52 am

BTW when selecting a cam for use with vortec heads...

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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heads might need to be milled to make then strait

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

http://sallee-chevrolet.com/Cylinder_Heads/Vortec.cfm
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casting numbers
10239906 and 12558062..96-up...350.........."Vortec 5700", "L31", 64cc chamber,
170cc intake port, 1.94"/1.5" valves


http://www.jegs.com/i/GM+Performance/80 ... 6/10002/-1

GM Performance 25534446
[b]THERES ALSO A LARGE PORT VERSION THATS FAR SUPERIOR FOR MAKING PEAK HP, the 170cc versions designed to produce max torque at about 4000rpm on a 350 displacement and youll have a hard time exceeding 450 hp, with those heads, the large ports can support 600hp with minor port work


this INFO PROVIDED IN THE LINKS, and SUB-LINKS BELOW might help

viewtopic.php?f=52&t=181

viewtopic.php?f=52&t=904

viewtopic.php?f=52&t=965

viewtopic.php?f=69&t=1040&hilit=vortec

http://www.competitionproducts.com/prod ... CH353-ES-1

BUT keep in mind those SMALL PORT vortec heads will become restrictive even when matched to a good high flow rate intake like a HSR (HOLLEY STEALTH RAM) by about 6000rpm,and if your using an automatic transmission,your transmission generally shifts before you hit 6000rpm, so there's no sense in selecting a cam that makes most of its power well above that rpm point.
most stock vortec heads are restricted to either a .480 lift or with the optional better springs installed that some places supply at extra cost, on some heads to a .520 -.550 lift, so verify your clearance issues before installing a larger cam, STOCK rods and rod bolts generally cause clearance problems unless you use a small base circle cam once both the duration exceeds about 225 deg. and the lift exceeds .520 in a stock short block


HERES INFO ON THE LARGER VORTEC HEAD VERSIONS

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

read thru this, its basically an engine build where they use all the tricks to get a fairly stock set of mildly reworked large port vortec heads , with a much improved valve train to produce thier max power

now those heads, intake and a milder roller cam, would be more useful to most of us ,on a slightly less exotic 406 or 383 SBC combo

Vortec Bow-Tie Brief
There are two versions of the new GM Performance Parts Vortec Bow-Tie cylinder heads: This one, PN 25534371 (bare) and PN 25534431 (complete), with the larger ports, and another with smaller ports, PN 25534351 (bare) and PN 25534421 (complete) with 185 and 65cc volume, otherwise, the architecture and improvements over the L31 design are the same. We will test the smaller version very soon in a dynamometer exercise. We were able to get an exclusive look at the big-port heads just as they were used in a NASCAR-type application.

Out of the box, they feature revised intake and exhaust ports and are machined for a 2-inch intake and 1.55-inch exhaust valves. The deck surface is 0.045-inch thicker than the L31s, and it has 65cc combustion chambers, a 206cc intake, and 77cc exhaust ports (see Flow Chart). The head is also machined for 3/8-inch screw-in rocker studs and a large valve spring pocket, and it will accept up to a 0.530-inch lift camshaft without modification. These castings are identified by the Bow-Tie logo below the exhaust port and the Vortec logo on top of the intake port area. The GM logo is also cast into the bottom of the intake port runners.

All concerned will be delighted to hear that the head includes intake manifold mounting holes for both early-model six-bolt and late-model four-bolt Vortec design. Mandated GM intake manifolds include a raised runner-type PN 10051103 (six-bolt type) or Vortec design PNs 12366573, 12496820, 12496821, 12496822, and 12499371 (four-bolt type). Though production cylinder head and intake manifold gaskets are acceptable, the hot squeal is Fel-Pro (PN 1142 for the MLS and PN 1289 for the intake). As per Scoggin-Dickey, pricing is: small port 4421 complete, $499.95; small port 4351 bare, $269.25; large port 25534431 complete, $539.95; and large port 25534371 bare, $293.25.

http://www.superchevyperformance.com/Vo ... 534431.htm

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

http://paceperformance.com/index.asp?Pa ... dID=104477

replacing worn valve guides

http://www.enginebuildermag.com/2003/12 ... ditioning/

http://www.calgaryfieros.com/OSGdocs/va ... seals.html

https://www.youtube.com/watch?v=PR8cDaum7ss

http://www.hthoward.co.uk/engine-machin ... -sleeving/

http://www.hotrodlane.cc/New%20LS%20Lin ... inding.htm
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[size=150]related threads, with info you might need

Available Vortec Heads

GM
12558060
10239906
12558062 - Assembled Iron
12529093 - Bare Iron
25534351 - Bowtie Sm Port Bare
25534421- Bowtie Sm Assembled
25534445 - Bowtie Lg Port
25534446 - Bowtie Lg Port Assembled
12497186 - Aluminum Bare
12464298 - Aluminum Assembled

EQ Lightning
CH350H - VORTEC HYBRID W/HEAT RISER 69-86 INATKE BOLT PATTERN AND PERIMETER VALVE COVER Iron
CH350G - 87-95 VORTEC HYBRID W/HEAT RISER MARINE/AUTO USE Iron
CH305B - 305 CHEVY 96 UP VORTEC 1.840" VALVE Iron

Patriot
2150 - Bare Iron
2151 - Assembled Iron

Summit
151124 - Iron

AFR
912 - Aluminum

RHS
12410-01 - Iron
12410-02 - Iron

Scoggin Dickey Parts Center
SD8060RA2 - stock iron casting modified for 600 lift

Dart
10024370 - Bare Iron
10024370A - Assembled Iron

Edelbrock
60959 - 170cc Bare Aluminum
60969 - 200cc Bare Aluminum
60979 - 170cc Assembled Aluminum
60989 - 200cc Assembled Aluminum
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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Posts: 14105
Joined: September 14th, 2008, 1:40 pm
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Re: MACHINING VORTEC HEADS

Postby grumpyvette » October 16th, 2009, 6:51 pm

What is a "Vortec head"?
Image
VORTEC HEADS YOULL FIND IN SALVAGE YARDS HAVE THESE HEAD MARKINGS
The L31 Vortec comes in two different casting numbers, 10239906 (#906) or 12558062 (#062). Originally, the stock #906 casting head was available in two versions. One version had an Inconel exhaust seat with single angle valve grind and was available on 1 ton trucks. The other version was the traditional three angle valve grind. Other than that, the #906 is the same as the #062 head.
GM Performance Parts Bowtie Vortecs are offered in “small port” (#25534351), which has 185cc intake ports/65cc exhaust ports, or the “large port” (#25534445), which features 225cc intake ports/77cc exhaust ports. Both GM factory and GM Performance Parts Vortecs come with 1.94 intake/1.50 exhaust valves. According to the engineers at GM, “Stepping them up to 2.02 valves doesn’t help them any, so it’s not recommended. The port was designed to match the 1.94 valves. With the Vortec flow velocity,

ok basically its a thin wall cast iron cylinder head designed to maximize the engines volumetric efficiency in the mid rpm range to maximize the torque on chevys 350 truck engines

viewtopic.php?f=52&t=8596&p=30222#p30222

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

http://www.alexsparts.com/valve-spring- ... yd-roller/

Beginning in 1996 to '00, L-31 Vortec heads were installed from the factory on GM truck and van 350 sbc engines.
there are two casting numbers, for the L-31 Vortecs #906) and the #062 , both castings are similar

What makes Vortec heads any better than the old camel hump or fuelie heads ?
well first most of the older fuelie heads had 155cc ports vs the vortecs 170 cc ports, and the vortec head have a raised port roof that gives a straighter shot from the carb base to the back of the intake valve if the correct intake is used.
the cross sectional area thru the port near the push rods is significantly wider than most of the older fuelie heads and the intake valve seat has a 3-angle grind from the factory, something that was not a factory procedure on the stock fuelie heads The intake valve is also back-cut as is the exhaust. The exhaust port,tends to need some work with a die grinder to increase flow and having a bit more duration and lift on the cam won,t hurt with most vortec heads.
vortecs are DUAL QUENCH AREA heads designed to reduce the ignition advance necessary with the older fuelie heads, it was not uncommon, for engines running the older heads to use a 36-38 degree total ignition advance , the vortecs usually run better at 32-33 degrees total advance
the vortec head is basically an LT1 head with the water ports having been restored to the earlier gen I configuration, that routes coolant thru the intake manifold, so a standard water pump can be used
keep in mind the intake manifold bolt angles and port shapes and locations are very slightly changed and are different on vortec heads
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standard small port intake on vortec heads

there are several sources for ('Vortec' heads)


GM L-31 Vortec stock
http://paceperformance.com/index.asp?Pa ... odID=22816
GMPP 'large port' Vortec Bow Tie
PN 25534431

http://paceperformance.com/index.asp?Pa ... dID=104477

viewtopic.php?f=69&t=1040&p=1943&hilit=206cc#p1943

theres an aluminum clone
'Fast Burn'
12464298
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viewtopic.php?f=52&t=181

* Retainer to guide clearance is the main problem in performance applications as the heads were designed for low lift truck cams and mid rpm torque, Vortec. For valve lifts above .460" they need to be checked for valve guide to retainer clearance and spring bind issues clearance. This varies between casting, and manufacture dates. but youll need to check with any cam having a .470 or greater lift.

Scoggin-Dickey, summit racing and several sources sell Vortec heads with the better valve springs and clearance already modified for higher lift cams

Sallee Chevrolet has an interesting solution to this problem (from their website):
Crane Cam’s 10309-1 drop-in valve spring and retainer kit which is good for .550” lift with no machining. The installed height for this Crane Cams kit is taller and the lower part of the retainer is shorter. The “AVERAGE” clearance between the retainer and seal is .575” for this kit."

IVE BUILT almost a dozen vortec head equipped sbc engines and if your looking for a fairly cheap option on a street cruiser with a 350-383 and your hp goal is under 440hp these might be a reasonable option, in out of the box condition,but there are far better heads available IF your goals are over 460hp, as the stock small port vortecs, can easily become a serious restriction to your power potential, if not modified fairly extensively.ID suggest you try not to exceed .475 as a MAXIMUM, on completely stock vortec heads (and many other SBC heads,)but keep in mind you can gain clearance with new springs and off set retainers and valve locks if you want to CHEAT just a bit, the distance between the valve spring seat and the lower edge of the retainer can be changed, by .050
fairly cheaply and easily, without machine work thru the use of new valve springs and off set valve locks, the off set valve locks have the groove notch placed so the retainer sits .050 higher on the valve stem, this reduces the stock springs load rate,slightly, but there are springs that will easily work in most applications, that have similar load rates that work great at the slightly longer installed height, or in some cases a shim can be used under the spring to retain the same load rate if its not coil bind but retainer to valve seal thats the clearance your trying to increase


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above is a very typical machine shop invoice for reconditioning a set of used vortec heads, notice theres $982 plus in charges and theres a great deal more that could easily be required to recondition used heads, now add the rather typical purchase price of at least $200-$400 for a set of clean used vortec heads and you quickly find you could buy better heads for the cost involved
so be aware that just the cost of used or bare heads is not the total cost youll see.
and THATS NOT EVEN PORTED HEAD OR A 5 ANGLE VALVE JOB OR LARGER RACE VALVES

RELATED INFO
viewtopic.php?f=52&t=8460


http://www.cranecams.com/index.php?show ... 3&prt=2128

http://www.cranecams.com/?show=browsePa ... er=99099-1


viewtopic.php?f=52&t=181

viewtopic.php?f=52&t=1716&p=4250&hilit=+beehive#p4250

http://www.nastyz28.com/forum/showthread.php?t=56505



actually measuring clearances helps a great deal

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viewtopic.php?f=52&t=1751&p=4387#p4387
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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: MACHINING VORTEC HEADS

Postby grumpyvette » January 10th, 2010, 8:23 pm

http://www.cylinderheadsupply.com/valve ... nAodymUULA

http://www.youtube.com/watch?v=PR8cDaum7ss

http://www.cylinderheadsupply.com/valve ... izing.html

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

http://www.articleclick.com/Article/Usi ... ool/952814

http://www.streetperformance.com/m/cats ... -tool.html

http://www.phatperformanceparts.com/Pro ... lick=37735

https://www.goodson.com/technical_suppo ... Guides.pdf

http://www.summitracing.com/search/Part ... ing-Tools/
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Comp Cams Valve Guide Cutting Tool
Upgrading your camshafts to get more horsepower is a good idea. But here's the catch- if you're going to upgrade your camshafts, you have to do so as well for the rest of your valve train, especially the valve guides. The thing is, you're going to need bigger springs to be able to handle your aggressive camshafts. You'll need to modify your valve guides. What you need is the Comp Cams Valve Guide Cutting Tool. What you really want is to shorten your valve guides. This is to accommodate the high valve lift brought by your new camshafts. The shorter the valve guide, the more valve lift and the less stressed your valve springs will be. Professional, or even seasoned street drivers, know all too well the problems associated with improper valve train setup. The more strain you put on your springs, the more likely that they'll bottom out, or worse, even break under high engine speeds. You'll also likely experience 'valve float' wherein your valve springs can't pull back your valves at high rpm's (revolutions per minute), so you lose power. So make sure you set things up correctly with the Comp Cams Valve Guide Cutting Tool. This ultra tough tool works with three different-sized arbors. No matter how many valve guides you go through, this tool will cut them clean as a whistle. No more second guessing with your valve train setup. Do things right the first time around with the Comp Cams Valve Guide Cutting Tool.

http://www.rpmmachine.com/pioneer-valve ... ools.shtml

http://www.jegs.com/i/Comp+Cams/249/4720/10002/-1#

http://www.vtwinmfg.com/catalogs/cyr/pdf/1249.pdf

viewtopic.php?f=52&t=1159&p=2362#p2362

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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: MACHINING VORTEC HEADS

Postby grumpyvette » March 20th, 2010, 5:16 pm

theres some good info in the links below, keep in mind you can increase your compression ratio by milling the cylinder heads to reduce combustion chamber volume and angle milling the heads will generally remove a larger volume, than a flat mill, but it requires a good deal more machine work and while it tends to also increase the port flow rates it also tends to change the valve train geometry.

you can normally get away with a .025-.030 thousands flat mill on the cylinder head , without doing much more that pinching the rubber intake end gaskets in the trash and using a bead of high temp silicone as a replacement end gasket on the block rails,
that will increase compression, by reducing the combustion chamber volume by several CCs,(depends on the heads naturally, but you can figure some where in the .004-.007 thousands milled for a reduction of each cc of combustion chamber volume, your local machine shop should be able to give far more exact info when they know which head casting is to be machined, and if your flat milling or angle milling the heads.)
one of the reasons the newer engines use a shallower valve angle it the tendency to increased flow
READ THE LINKED INFO, in the links below as they contain a great deal of useful information



viewtopic.php?f=55&t=2773&p=7200&hilit=gasket+porting+intake#p7200

viewtopic.php?f=52&t=462&p=7593&hilit=gasket+porting+intake#p7593

viewtopic.php?f=52&t=731

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

http://www.aa1car.com/library/ar996.htm

http://www.enginebuildermag.com/Article ... acing.aspx

http://victorylibrary.com/mopar/intake-mill-c.htm

viewtopic.php?f=52&t=2077&p=5565&hilit=burret#p5565

http://www.popularhotrodding.com/engine ... index.html

http://www.chevyhiperformance.com/techa ... to_04.html

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

viewtopic.php?f=44&t=464&p=570&hilit=intake+gasket+dimple#p570

viewtopic.php?f=44&t=700

http://circletrack.automotive.com/79173 ... index.html

http://www.samracing.com/CHP-July-06_page3.html


http://www.goodson.com/technical_suppor ... illing.php

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http://www.circletrack.com/enginetech/c ... 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!!
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Re: MACHINING VORTEC HEADS, and OTHER HEADS

Postby grumpyvette » May 31st, 2010, 9:03 am

grumpyvette?
I'm saving money to complete my vortec head swap for an 1988 350 in my 280z, i bought an COMP Cams CL12-238-2 cam and i'm now looking for some cheap vortec heads(1996+) at local junkyards but was reading online that stock vortec heads are only good for up to .450 lift.. would the cam i bought work with no other mods?


http://www.summitracing.com/parts/NAL-12558060/

http://www.onedirt.com/tech-stories/eng ... evy-heads/

youll be pushing or at, the clearance limits of the stock valve springs, with that cam lift on most stock vortec heads.
their are retainers and springs you can swap to that allow a .500 lift rather easily or you can buy heads already modified with the springs installed from several sources, and Im sure youll find people on the net who say they are running that cam with the stock heads that report having no problems, simply because many guys figure that if the engine spins with a breaker bar, after a cam install without binding your free/clear, but that's not really a reliable test route.
BTW remember the stock first sbc gen I intakes and rockers and valve covers won,t work, be sure to get the vortec parts at the salvage yard,

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

viewtopic.php?f=52&t=181

why is it that so many of you gentlemen are so reluctant to actually take the time to measure valve train clearance, spring load rates and valve train geometry and make every effort to avoid doing things correctly?
yes it takes some knowledge, some tools and some time, but in the long run its gives you some piece of mind knowing its been done correctly, and your far less likely to have catastrophic engine failures as a result.

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this chart showing the new WIEAND AIRSTRIKE intake flows better than the comparable edelbrock vortec intake might prove to interest some guys
viewtopic.php?f=52&t=2746

viewtopic.php?f=52&t=2661
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: MACHINING VORTEC HEADS, and OTHER HEADS

Postby grumpyvette » November 17th, 2010, 8:59 am

theres a good deal of useful info in this article

http://www.customclassictrucks.com/tech ... index.html
CRANE CAMS SELLS TEFLON VALVE SEALS,they are commonly packaged on blister packs
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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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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.

polishing the combustion chambers and smoothing contours tends to reduce detonation and improve power
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Post by David Redszus »
A highly polished surface has less surface area than does a rough surface. Consequently, the heat transfer to the polished surface is reduced. If you want the chamber to remain hotter, polish the surfaces of piston crown and combustion chamber. You would have to measure the surface roughness before and after polishing in order to estimate the thermal benefit.
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: MACHINING VORTEC HEADS, and OTHER HEADS

Postby grumpyvette » October 21st, 2011, 4:10 pm

Vortec Heads info from (http://www.chevymania.com/tech/vortec.htm)
Many people are talking about Vortec heads these days. While the Vortec head is a very powerful and inexpensive production head there is some confusion as to exactly what makes a head the Vortec head. This article will explain the Vortec head and give you picture comparisons so the next swap meet you will know for sure your buying a set of 'Vortec' heads!


A Little History
The Vortec name first appeared on 4.3L V-6 engines in 1986.These engines were the first to use a new "Vortex technology" designed to create a vortex (powerful swirl like a tornado) inside the combustion chamber. The Idea behind this is to create a more even and well mixed air/fuel charge that both generates more power and is more efficient. Over the years this Vortex technology has changed and improved to develop many new changes in the GM power train division. In today's world 'Vortec' Means power and here is where the confusion starts. There are literally thousands of cylinder heads that have been made with the vortex technology since 86 and many people refer to 87 and later small block heads as 'Vortec' heads. While this is a half truth the heads that GM sells under the Vortec name and the ones everybody is buzzing about did not exist until 1996.
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As you can see by the picture on the left the intake bolt angle for the vortec is different, 72 degrees vs. 90 degrees of earlier heads. It is also located in the upper 1/3 of the head and uses a 5/16 coarse thread instead of the usual 3/8 coarse thread of earlier heads. When the vortec heads are bolted on an engine all 8 attachment bolts are almost strait up.

You can also see by the picture on the right that the vortec head has only the outer bolts and the center bolts are no longer used. If you look at the bottom right of that pic you will also notice that there is no heat riser passage either but there is a indent where it would have been. Since the heat riser has been deleted form the vortec head if you choose to run these heads and have to retain the EGR valve for emissions you will have to change the exhast mainfolds, usually the drivers side at least, and obtain the EGR tube. This pipe feeds exhaust gasses from a port on the exhaust manifold to a port on the intake manifold that feeds the EGR valve.

With this new bolt pattern you will have to have a vortec style intake manifold, or you can drill and tap the cylinder head for the early style intake pattern. I have personally done this a few times but it takes very careful preperation and if not done correctly you can make the heads unusable. If you choose to try this you need to be aware of a few things, The old style intake and gasket may not cover the smaller bolt hole up top, The new bolt hole will intersect the smaller old one, drilling to deep on the outer bolt holes can punch through into the water passage, and the metal is kinda thin in the center where there are no existing bolt holes. I reccomend installing small 5/16 allen plugs in the old bolt holes with red locktite before you drill the new holes. Once drilled and tapped, clean with brake parts cleaner then cover the original holes and allen plugs with JB weld and smooth it down. This will prevent any leaks from sprouting from the old smaller bolt holes. When installing the bolts don't over torque the center 4 bolts or they will strip!!!! No more than 25 ft/lb on the center 4!


These are part numbers for new aftermarket intake manifolds that will directly bolt to the vortec heads. There are now several different varriations of the vortec intake and many brands, I only list the GM and Edelbrock brand vortec intakes because I have used them, I know these work!
GM Vortec intakes
Part # 12496820 is a low rise dual plane with EGR provision and dual carb bolt pattern.
Part # 12366573 is a high rise dual plane manifold with a holley carb flange.
Part # 12496822 is a high rise single plane manifold with a holley carb flange.
Part # 12496821 is a Throttle Body Injection manifold with EGR.
Part # 12498060 is the SDPC TPI vortec base manifold.


Edelbrock Vortec intakes
Part # 2116 Performer manifold non-EGR
Part # 7116 Performer RPM manifold
Part # 7516 Performer RPM Air Gap manifold
Part # 2912 Victor Reports 2-Barrel manifold
Part # 2913 Super Victor 4-barrel 4150 flange


A Word on Power
Valve Lift Intake Exhaust
.100 70 48
.200 139 101
.300 190 121
.400 227 140
.500 239 147
.600 229 151

As you can see in the table above, Vortec heads have excellent flow characteristics! In fact GM states that production vortec heads flow better than Bowtie Phase 2 Cast iron heads!!! Vortec heads have been used in many performance applications and by many performance magazines over the years and on average these heads, with standard off the shelf intake, exhaust and conservitive camshafts, make 400 + HP.

When GM designed the vortec head they basically took the intake and exhaust ports from the now infamous LT1 cast iron heads (the ones installed on SS Impalas) and packaged them in a standard water flow cast iron head with a new bolt pattern. GM uses a new 'Cast Port' head process that make for a very good port shape that is consistent from runner to runner and cylinder head to cylinder head. The only drawback to the vortec head is that the stock valve springs can only attain around .425" valve lift, mostly due to the oversized valve guide bosses and tall seal height. Machining the valve spring pockets for larger valve springs and reducing the seal height will allow for lifts into the .550 range. Adding screw in studs and guide plates makes these heads quite good performance pieces but it can set you back about $200 for machine work. Please note that Vortec, and all center bolt valve cover style heads, use a self aligning rocker arms! If you have the screw in studs and guide plates done, you will have to get new non self -aligning rockers!
Since vortec heads have been in production since 1996 you can find more than a few sets at swap meets and even salvage yards. GM sells them at the parts counter in 2 versions, a bare casting Part # 12529093 and fully assembled part # 12558060. The assembled version comes with 1.94/1.50 valves and stock valve springs. Both heads have 64 cc chambers, 170 cc Intake runners and 3/8" press in rocker studs.
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: MACHINING VORTEC HEADS, and OTHER HEADS

Postby grumpyvette » August 2nd, 2013, 12:43 pm

casting numbers on the stock production 170cc port vortec heads
10239906 and 12558062..96-up...350.........."Vortec 5700", "L31", 64cc chamber,
170cc intake port, 1.94"/1.5" valves
BTW theres two common vortec intake manifold gaskets, these vortec heads have taller ports than the standard 23 degree first gen SBC heads
The Fel Pro 1255 is .120 thick
The GM 89017465 is .060 thick

https://www.youtube.com/watch?v=8rl-_q09Jsg

http://www.jegs.com/i/GM+Performance/80 ... 6/10002/-1

GM Performance 25534446
THERES ALSO A LARGE PORT VERSION THATS FAR SUPERIOR FOR MAKING PEAK HP, the 170cc versions designed to produce max torque at about 4000rpm on a 350 displacement and youll have a hard time exceeding 450 hp, with those heads, the large ports can support 600hp with minor port work

READ THESE LINKS AND SUB LINKS

viewtopic.php?f=44&t=4462&p=12023&hilit=vortec+block+restrictive#p12023

viewtopic.php?f=52&t=266&p=322&hilit=215cc+vortec#p322

http://www.summitracing.com/parts/nal-25534446

viewtopic.php?f=69&t=1040&p=1943&hilit=215cc+vortec#p1943
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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