youve installed 1.6:1 ratio rockers and the pushrods rub...

[grumpyvette]

youve installed 1.6:1 ratio rockers and the pushrods rub...in the guide slots in the cylinder heads,
this is a comon problem,easily solved...
YOU NEED A louis tool, YOU WANT ABOUT .060 CLEARANCE, IT MAKES THE JOB EASY

https://www.summitracing.com/parts/pro-66485

its used to hold a drill in the exact location to elongate the push rod slot, giving the clearance required
One of the most frequent questions I hear, is
" will adding 1.6:1 roller rockers really do much for my engine vs the standard 1.5:1 ratio roller rockers?"
changing just the rocker ratio but sticking to the cheaper stamped ball & socket stock rocker design tends to have a minimal power advantage, the fact that the aftermarket stamped rockers do tend to be a bit more consistent in effective ratio helps but gains of 5-8 hp are common, not the 10-12 hp commonly quoted from what IVE seen on dyno results.
keep in mind the flat side of the rockers axle or trunnion faces up to mate with the adjustment nut, and the rounder side faces the cylinder heads, 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.
swapping to 1.6:1 ROLLER ROCKERS from your old standard ball & socket stock rockers is usually worth 15-20hp, occasionally a bit more, the change in lift at the valve with the new higher ratio rocker is a minor factor compared to the reduced friction decent roller rockers provide, but together the two factors, higher valve lift and less friction are usually worth the time and effort, swapping from a 1.5:1 to a higher 1.6:1 ration can at times provide little if any benefits but on other combos the results are very noticeable (ON A DYNO) especially if your really UNDER CAMMED for the application
keep in mind that on an LT1/LT4 engine, in a corvette, that had about a 330-350 hp rating, the rockers having a gain of 12hp-17hp like I mentioned is about a 4%-5% boost, while its not going to pin you back in the seat during acceleration it might put you an extra 8-10 feet ahead in a 1/4 mile drag race as you go through the lights compared to the old combo
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 rockerss

check all valve train geometry and clearance on any engine you assemble or modify the valve train on.

http://store.summitracing.com/partdetail.asp?autofilter=1&part=PRO-66485&N=700+115&autoview=sku
https://www.summitracing.com/parts/pro-66485

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.

btw place a magnet like this under each pushrod slot to catch the drill chips from iron heads

http://www.kjmagnetics.com/proddetail.asp?prod=D82SH&cat=167

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

many, but not all, aluminum performance cylinder heads already were manufactured with the longer slots, now I generally use ALUMINUM ,BRODIX,TRICKFLOW,AFR, ocasionally DART, heads and I can,t remember a recent set that was needing to be clearanced there. but remember the rockers you sellect, pushrod length, spring height all effect the geometry and the clearances can easily be changed
a rocker stud girdle helps also, as it tends to stabilize the studs flex and minimize the changes in clearances as the springs load/un-load
keep in mind most performance heads your pushrod guide plates not the slots in the castings to align the pushrods
(BOTH the pushrod guide plates and rocker girdles are usually unique to that particular heads geometry, so make sure what you want fits the application when ordering parts)

http://www.airflowresearch.com/car-craft-nov-2014-pushrods.php

http://store.summitracing.com/partdetail.asp?part=TFS-30400700&autoview=sku

http://store.summitracing.com/partdetail.asp?part=TFS-30400701&autoview=sku

its very common to find you'll gain a couple horsepower with the addition of a rocker stud girdle employed,
as youll have both more precise valve train control and less deflection, Ive seen guys instantly gain an extra 150 rpm-200 rpm,
before they started feeling valve float or loss of valve train control and its certainly less stress on the cylinder head casting and rocker studs.
the one thing ID suggest is that before you buy any rocker stud girdle you ask questions, many cylinder head designs use non-standard rocker stud spacing.

its not horsepower, its the stress on the valve train, that makes a rocker stud girdle and its increased rigidity useful,
and thats more closely related to average stress levels, RPM and VALVE SPRING LOAD RATES
any time your occasionally exceeding 6000rpm or getting close too 330 lbs of open valve load rate Id strongly suggest screw in rocker studs
any time your intentionally exceeding 6000rpm and exceeding 350 lbs of open valve spring rate a rocker stud girdle might be a good idea.
and if your regularly exceeding 6500rpm and 400 lbs of open valve spring load rate its use is going to become almost mandatory
http://www.summitracing.com/parts/pro-66950

http://www.summitracing.com/parts/sum-141010
If your ordering any cam, be very sure you explain what year block and what cylinder heads will be used as there are differences in the cams. between early and later SBC, block s and the cams they require,and on big blocks theres similar issues, a mark VI cam is different from a MARK IV cam
READ THRU THESE LINKs ALSO
viewtopic.php?f=52&t=1719&p=4265&hilit=aligning#p4265

viewtopic.php?f=52&t=181

 

[grumpyvette]

if you can,t afford full roller rockers
the aftermarket roller tip rockers are worth the expence simply because they have LONGER slot clearance for the rocker studs and more precise ratios than stock rockers, most are forgings or cast rather than stamped liker stock,and youve stated your stock rockers bind on the studs at near full lift,the roller tips don,t do much, so don,t think thats a big deal.

BUT if I was going to swap rockers, a FULL ROLLER ROCKER DESIGN like I posted is well worth the extra expence as it will free up 7-10 hp MINIMUM due to lower friction alone, remember the vast amount of friction in a rocker is in the rocker fulcrum not the tip. a true roller rocker has roller bearings and an axle so the slot is replaced with a hole for the stud

http://www.vetteweb.com/tech/0204vet_sm ... index.html

pre-spraying all bearing and valve train components with a moly based spray, helps embed micro moly lubricants in the metallic surface micro fissures , a good paste lube like cranes assembly lube over the spray surface helps insure a good lubricant surface coating, that is far stronger than just the ZINC and PHOSPHATES in oil

its the attention to details and checking clearance etc. and time and care taken,
that makes the difference between a barely or average functional ,
and a rather exceptional engine build, yes the urge to get it running is strong,
but getting it done correctly is the goal

 

[grumpyvette]

getting custom pushrods and the correct valve train geometry

KEEP in mind the main idea here is to keep BOTH the rocker arm pushing strait down the center line of the valve to minimize friction and valve guide wear,and to keep the push rod length at the correct dimension to minimize friction and match the intended angle of operation designed into the valve train, and to do that the basic geometry and clearances in that valve train must be correct...Proper push rod length is absolutely critical for peak performance—minimizing bent or broken valve stems, guide wear, and energy-wasting valve side-loading friction.
With the lifter located on the round base circle, position the Push Rod length Checker (make sure you have the Checker with the proper diameter hole) over the stud. Ideally the Checker should contact the top of the push rod and the valve tip evenly at the same moment, should the Checker contact the push rod first, measure the gap between the front of the checker and the valve tip, and purchase a shorter push rod of the correct length. Should the Checker contact the valve tip first, measure the gap between the back of the Checker and the top of the push rod, and purchase a longer push rod.
the process of finding the correct length push rods not that difficult, you install the correct push rod checker for your application,on a rocker stud, install the adjustable push rod, in place of the stock push rod after roughly adjusting the adjustable push rod to the stock length once the cam is rotated so the lifter, your using to verify the correct length is resting on the cams base circle, and then you extend or shorten the adjustable push rod so the plastic push rod checker just rests on both the tip of the valve stem and the push rod checker as in the picture above, this gets you very close to the correct length, you then use the machinists blue or a magic marker and the rockers you will be using to determine the exact correct length by centering if possible but finding the minimum sweep mark width so the wear mark on the valve tip as close to the valve stem center line as you can get it and the minimum side loading on the valve stem is found. centering the mark is less important than minimizing the rocker tip wipe mark width


If your going to swap to roller rockers on a 1992-96 lt1 corvette, youll need the narrow body self alighning rockers and ID strongly suggest the 1.6:1 ratio, but yes having done that on both my sons 1992 corvette and my 1996 corvette I can assure you youll feel a minor improvement . (12-17 flywheel HP is common)
just be aware that you may need to remove the inner valve cover drippers (a couple seconds work with a die grinder) and you must check clearances like spring bind and retainer to valve seal clearances, push rod to cylinder head slot and similar issues DON,T ASSUME ANYTHING

http://garage.grumpysperformance.com/index.php?threads/valve-train-clearances-and-problems.528/

http://garage.grumpysperformance.co...e-springs-and-setting-up-the-valve-train.181/

http://garage.grumpysperformance.com/index.php?threads/rocker-push-rod-wear-issues.9815/#post-56576

http://garage.grumpysperformance.co...rocker-ratios-and-the-effects.126/#post-35548


https://www.summitracing.com/parts/scc-scp1035/overview/

https://www.summitracing.com/parts/crn-10758-16/overview/make/chevrolet

heres useful links and info below
yeah! I know your first inclination is to skip reading the links.....DON,T its all valuable info you need to look thru
http://www.compcams.com/information/Products/Pushrods/

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

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

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

http://www.thedirtforum.com/pushrodlengths.htm

viewtopic.php?f=52&t=5931

viewtopic.php?f=52&t=9687&p=36006#p36006

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

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

http://www.racingsprings.com/beehivesprings.htm

http://www.trendperform.com/

viewtopic.php?f=52&t=9815

http://www.popularhotrodding.com/tech/0 ... to_32.html

http://www.highperformancepontiac.com/t ... index.html

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

http://www.mantonpushrods.com/

http://www.aa1car.com/library/2004/eb30431.htm

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

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

http://trendperform.com/measuring/

http://www.compcams.com/Technical/FAQ/V ... ometry.asp

http://www.grapeaperacing.com/GrapeApeR ... etrain.pdf

clearances, and geometry in that valve train must be correct...
http://garage.grumpysperformance.com/index.php?threads/rocker-push-rod-wear-issues.9815/#post-54232

some roller rocker too retainer combo clearance issues cause problems easily solved with beehive springs and smaller retainer diameters

look through this thread
http://garage.grumpysperformance.com/index.php?threads/two-loose-valve-locks.9687/#post-47884

http://garage.grumpysperformance.co...e-springs-and-setting-up-the-valve-train.181/
http://www.use-enco.com/CGI/INSRIT?PMAK ... TPG=INSRHI

Pushrod Too Long: Notice how the pattern is wide, and shifted to the exhaust side of the valve tip.

Pushrod Too Short: Notice how the pattern is wide, and shifted to the intake side of the valve tip.

Pushrod Length Correct: Notice how the pattern is narrow and is centered on the valve tip.

if your rocker geometry, does not appear to be correct ,start at the basics
http://www.summitracing.com/parts/PRO-66789/

http://www.summitracing.com/search/...d-length-checkers?autoview=SKU&ibanner=SREPD5
Proform Pushrod Length Checkers 66789 SBC 3/8" rocker studs

Proform Pushrod Length Checkers 66790 SBC 7/16" rocker studs

Proform Pushrod Length Checkers 66806 BBC 7/16" rocker studs

http://www.summitracing.com/parts/TFS-9001/

verify your correct geometry first

http://www.thedirtforum.com/pushrodlengths.htm

http://www.compcams.com/catalog/278.html

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

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


YOU'LL NEED TO CAREFULLY CHECK YOUR PARTICULAR ENGINE!
heres a simple way to get close to the correct length
BUY ONE OF THESE

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 pushrod
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

<b>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 harden 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 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 during assembly, and at that point, while checking all the clearances, I use test springs which apply very little load on the push rod</b>

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

HERES OTHER TOOLS YOU MIGHT NEED

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
http://store.summitracing.com/egnsearch ... &x=36&y=11

http://www.summitracing.com/parts/sum-900013/overview/

http://www.summitracing.com/parts/sum-900012/overview/

The following Mechanical operating clearances must always be verified to ensure proper operation of the camshaft:
Spring coil bind clearance
Retainer to seal/valve guide boss clearance
Piston to valve clearance
Rocker arm slot to stud clearance
Camshaft end play
Distributor shaft and gear end play
Connecting rod to cam clearance
Proper hydraulic lifter pre-load or lash clearance
Proper valve train geometry
proper spring load rates
rocker to retainer clearance

 

[Zfan]

Trying to get correct push rod length

I am having some issues trying to get the correct pushrod length. I am using a pushrod checker only and am doing it the old fashion way, painting the valve tip and dialing out the pushrod to get the correct length. The problem I am having is the pushrod gets close to center on the valve and the roller rocker lifts off the valve stem during the rotation, this cannot be correct yet it's at that point that the mark gets closest to center of the valve stem.

Some info on my sbc 385 build, it's a new Comp cams custom grind hyd. roller, standard base with Comp retro fit hyd. roller lifters and scorpion 1.6 roller rockers, heads are AFR 210 eliminators, pushrods measure out at approx. 7.420, am I missing something in the mix?

 

[grumpyvette]

Re: Trying to get correct push rod length

the rocker is basically a pivot point between the valve and push rod roughly centered on the rocker stud, if the rocker is not running smoothly thru its intended arc theres an excellent chance you've got clearance or rocker geometry issues,you will need to verify the correct rocker geometry then order the push rod length to match the correct rocker geometry and clearances in the valve train.
as most guys find out push rods generally come in lengths that vary by .050 this is mostly because any time you measure push rods and need to get the correct geometry you generally try to get the ideal length, and you can make changes to the effective rocker geometry ,valve length with lash caps and valve shims, etc. but once you get to 1/2 of that .050 or with in .025 your close enough that the rocker geometry won,t change significantly getting the push rod length closer, so if you find your within, .025 your close enough to have a functioning and durable engine.
keep in mind that on hydraulic lifter the rocker thread pitch generally allows you to tighten the rocker from 1/4 to one full turn during adjustment, thus the rocker pivot point moves over about a .040 range ,making the length difference of less than .025 all but meaningless.
you will also find that on solid lifter you have some ability to change the lash clearance, and thus the effective geometry so don,t worry once you get the push rod length to within .025 or less.
keep in mind you need to check all clearances also, simply having the correct length push rod is NOT all that required, check, spring bind,retainer to valve seal, piston to valve and rocker stud to rocker slot clearance and don,t ignore the retainer to rocker arm clearances either.
youll need to verify you have enough valve train clearance at full valve lift to both prevent the retainer from getting closer than .060-.090- from the valve seals and .060 minimum from spring bind or having the spring fully compressed

you need .090 clearance between the retainer to valve seal and a TOTAL of .060 clearance MINIMUM on the valve spring coils from spring bind, or solid stacking the spring coils

http://www.wallaceracing.com/rockercalc.php

http://www.pontiacstreetperformance.com/psp/RockerArms.html

graphing out the change in lift at the valve with a
1.5:1 vs 1.6:1 ratio rocker valve lift diagram would look similar too this
Rocker Arm Ratio Explained
You've heard of 1.5:1 ratio and 1.6:1 ratio rocker arms. What does that really mean? How can you make more horsepower by using the larger ratio rocker arms?

The ratio of a rocker arm refers to the amount of movement on the valve side of the rocker arm in comparison to the pushrod side. A 1.5:1 rocker arm will move a valve 1.5 times the lift of the cam, assuming all things are in proper working order. If your cam has a lift of .4 inches, multiply by 1.5 to get .6 inches of actual valve movement. With the same cam lift of .4 inches: If you do the math on a set of 1.6:1 rocker arms: Multiply 1.6 x .4 inches of cam lift. You get .64 inches of actual valve movement. Essentially, changing to a larger ratio rocker arm is the same as increasing the lift of your cam the same amount. Opening both valves further usually is a benefit in the power department as your engine is capable of moving more air and exhaust through it.

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

once youve got that correct you use the valve spring/rocker geometry check tool to get the APPROXIMATE LENGTH REQUIRED, and

http://www.theengineshop.com/products/b ... hrods.html

an adjustable length push rod

thats why they sell push rod length checkers, you slide it on the rocker stud and it should touch BOTH the tip of the valve and the tip of the push rod if the rocker and valve train geometry's correct

http://www.summitracing.com/search/...d-length-checkers?autoview=SKU&ibanner=SREPD5
Proform Pushrod Length Checkers 66789 SBC 3/8" rocker studs

Proform Pushrod Length Checkers 66790 SBC 7/16" rocker studs

Proform Pushrod Length Checkers 66806 BBC 7/16" rocker studs

http://static.summitracing.com/global/i ... -66789.pdf

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

just a few points

actually verify clearances and rocker geometry

READ THESE THREADS and SUB LINKS
viewtopic.php?f=52&t=4957&p=13739&hilit=spring+bind#p13739

viewtopic.php?f=52&t=196
at
seated valve

mid lift

full lift

witness rub mark should be narrow, having it close to the valve center line is not as critical as having it narrow but try to have it close to center

if your confused I'm reasonably sure you failed to read thru the links in this and other threads, so lets look at the basics

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

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




ACTUALLY READING links WILL help

viewtopic.php?f=52&t=181

viewtopic.php?f=52&t=528

http://trendperform.com/measuring/

viewtopic.php?f=52&t=697
READ THRU THIS LINKED THREAD[/color]

correct length..................too short............................too long

WATCH THE VIDEOS, READ THE LINKS

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

http://www.youtube.com/watch?v=5GBNLlsi ... re=related

http://www.use-enco.com/CGI/INSRIT?PMAK ... TPG=INSRHI

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

Pushrod Too Long: Notice how the pattern is wide, and shifted to the exhaust side of the valve tip

Pushrod Too Short: Notice how the pattern is wide, and shifted to the intake side of the valve tip.

Pushrod Length Correct: Notice how the pattern is narrow and is centered on the valve tip.

viewtopic.php?f=52&t=181

viewtopic.php?f=52&t=9815
"
"The problem I am having is the push rod gets close to center on the valve and the roller rocker lifts off the valve stem during the rotation,"

the only way the rocker lifts off the valve tip is if some other component is binding or clearances or the valve train geometry is wrong, a retainer hitting the rocker, the push rod binding in the guide plates or cylinder head head push rod guide slots or the adjustment nut binding in the rocker or the rocker stud binding in the rocker body are common problems
replace the valve springs with test springs, and move the rocker thru its arc carefully by hand while inspecting it closely

these come in different designs but you'll want ones matching your application
http://www.summitracing.com/parts/PRO-66789/
http://www.summitracing.com/search/Part ... -Checkers/

TAKE THE TIME AND EFFORT TO READ ALL THESE LINKS, THERE'S A TON OF GOOD USEFUL INFO IN THEM

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

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

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

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

http://www.pontiacstreetperformance.com ... ngeom.html

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

when the push rod geometry is correct, this is what the rocker rub marks look like on the valve tip

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

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

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

http://www.thedirtforum.com/pushrodlengths.htm

http://compcams.com/catalog/278.html

http://compcams.com/Technical/Catalogs/ ... L/297.html

http://www.compcams.com/technical/Catal ... 07/264.pdf

http://www.summitracing.com/parts/CCA-7901-1/

test springs
http://store.summitracing.com/partdetai ... toview=sku


reading these links might help



viewtopic.php?f=52&t=528

viewtopic.php?f=52&t=697

viewtopic.php?f=52&t=198

viewtopic.php?f=52&t=181

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

self aligning rockers have ridges to prevent the rocker from moving off the valve stem

if you need to adjust solids more than about once every 3-4 months, after the first month, you've probably have valve train geometry , wear or clearance issues.
On my old big block camaro with a 496 and on my corvette with a BBC 496 , I can,t remember ever needing to adjust the valve train after the first two weeks, now being the type of guy I am I did adjust it as part of the maintenance procedures when I changed oil, but that proved to be an un-needed waste of time as they didn,t need it, and went back exactly as before

keep in mind I groove the lower 1/3rd of my left lifter bores so I have good oil to the lifter/lobe contact areas, and used quality roller rockers

viewtopic.php?f=54&t=2187


be sure you get a push rod checker designed to fit your rocker stud diam. (3/8" or 7/16")
http://www.summitracing.com/parts/CCA-7702-1/
viewtopic.php?f=52&t=1376&p=3030&hilit=pushrod+length+checker#p3030

REMEMBER TO CAREFULLY CHECK THE PUSHROD TO CYLINDER HEAD GUIDE AND CYLINDER HEAD CASTING CLEARANCES,IF IT BINDS IT MAY CAUSE A LOSS OF OIL FLOW FROM LIFTER TOO ROCKER

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

small block chevy adjustable push rod guide plate

BBC ADJUSTABLE PUSH ROD GUIDE PLATE


its rather common to have push rods rub or bind when swapping to the higher ratio 1.6:1 rockers so its mandatory you carefully check EVERY one through its full arc for proper clearance and use a louis tool to extend the push rod guide holes is thats required
this is mostly a matter of carefully checking clearances and verifying valve train
geometry,and use of quality parts rather than selecting the cheapest crap available, in many cases the simple swap of components can be done with few issues ,BUT its rather common for parts too bolt in, but not fit correctly, but LESS-experienced mechanics don,t see the indications of potential trouble,and wonder why parts failed later as a result!
parts that rub or bind and were thought too be correctly functioning only to be found later too be causing rapid wear or even a cam or lifter failure as a result of the parts installer, NOT verifying the correct clearances and geometry, so take your time and read the links and check, never assume a darn thing, fits correctly until you verify the clearances over the full range of movement.
read thru the links and sub links they may open your eyes


youll want too use a .060 clearance too the push rod to cylinder head slot clearance CHECKED CAREFULLY OVER THE FULL ARC OF THE ROCKER TRAVEL FOR A FULL TWO ENGINE ROTATIONS
if you need a LOUIS TOOL to lengthen the slots in the cylinder head I generally lay a section of plastic wrap in the lifter gallery and be sure to place two magnets on the blocks lifter gallery wall, to hold the thin plastic wrap in place firmly, below the cylinder head while drilling to catch the metalic debris the drill will generally produce, between the plastic sheat and the magnets youll generally catch 100% of the trash the drill generates

http://www.magnet4less.com/product_info.php?cPath=3_27&products_id=254

obviously having adjustable push rod guide plates to center the rockers on the valve stems and push rods in the cylinder head slots is almost mandatory.
as is verifying all rocker geometry and valve train clearance issues

http://www.summitracing.com/search/...d-length-checkers?autoview=SKU&ibanner=SREPD5
Proform Pushrod Length Checkers 66789 SBC 3/8" rocker studs

Proform Pushrod Length Checkers 66790 SBC 7/16" rocker studs

Proform Pushrod Length Checkers 66806 BBC 7/16" rocker studs

viewtopic.php?f=52&t=126&hilit=louis+tool

http://garage.grumpysperformance.com/index.php?threads/upgrade-choices.11416/#post-52423

viewtopic.php?f=52&t=528&p=45493&hilit=+long+slot#p45493


http://garage.grumpysperformance.com/index.php?threads/rocker-push-rod-wear-issues.9815/#post-54088

http://garage.grumpysperformance.co...-rockers-and-the-pushrods-rub.198/#post-46839

http://garage.grumpysperformance.co...all-block-chevy-guide-plates.2839/#post-12739

http://garage.grumpysperformance.co...-rockers-and-the-pushrods-rub.198/#post-46839

Proper push rod length is absolutely critical for peak performance, minimizing bent or broken valve stems, guide wear, and energy-wasting valve side-loading friction.
With the lifter located on the round base circle, position the Push Rod length Checker (make sure you have the Checker with the proper diameter hole) over the stud. Ideally the Checker should contact the top of the push rod and the valve tip evenly at the same moment, should the Checker contact the push rod first, measure the gap between the front of the checker and the valve tip, and purchase a shorter push rod of the correct length. Should the Checker contact the valve tip first, measure the gap between the back of the Checker and the top of the push rod, and purchase a longer push rod. you do this with no load on the lifter seat and the seat fully extended out to its max length, the push rod weight is not generally enough to compress the seat as theres a spring inside the lifter that provides some seal resistance holding the seat extended
remember if your not getting a near constant flow of oil at the rockers on a running engine,you might have the rockers adjusted too tightly not allowing the lifter push rod seat to fully extend upward as the cam base circle slides under the lifter base, oil is pushed up thru the push rods when the engines pressurized oil fills the lifters at the point the lifters on the cams base circle then the lifters push rod seats get compressed as the lobe lifts the lifter compressing the valve spring.
the push rod ends MUST line up with the oil feed holes in BOTH the lifter and the rocker, if you use 1.6:1 ratio rockers or don,t get the valve train geometry correct or fail to verify the push rod and rocker oil feed holes line up or if theres crud in the push rods blocking oil flow youll need to correct the issue slowing oil flow.
If your not getting oil flow, youll still need to verify the oil feed holes line up and are not blocked and the rockers adjusted correctly, try backing off on the adjustment nut as the engine idles to the point the rocker clicks noticeably then slowly tighten just to the point the noise stops , then add only a 1/4 turn, and see if that doesn,t cure the oil feed issue

you might want to verify rocker geometry and oil feed hole alignment

the only real difference between a flat tappet and roller lifter is the roller on the roller lifter design, and the roller lifter has some added design features or method to prevent rotation, the roller requires the lifter to be longer in total length so most roller engine blocks have taller lifter bores
READ THESE LINKs
http://www.ratwell.com/technical/HydraulicLifters.html

viewtopic.php?f=52&t=181

viewtopic.php?f=52&t=1489

viewtopic.php?f=52&t=90

Parts of a Hydraulic Roller Lifter

A hydraulic lifter has a spring inside it. A metal plunger sits on top of this spring. On top of the plunger is a thin metal shield, upon which a round piece called a pushrod seat covers. The pushrod seat is what the bottom of the pushrod rests on top of. A single snap ring is inserted into the lifter just above the pushrod seat to keep the entire assembly together. Roller lifters also feature a metal wheel and axle assembly at the base of the lifter. Each pair of roller lifters are connected together with a metal bracket, of some design which prevents the lifters from rotating in their bores keeping them aligned with the lobe center-line

ok once you have the basic push rod length to start testing with from the push rod checker, and adjustable push rod ,your only part way home., you then use the machinist blue or marker on the valve tip and rocker wear marks to find the final length, yeah! it seems complicated but after doing it dozens of times its really NOT difficult and in many cases the checker length is remarkably close to the final used length

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

Pushrod Too Long: Notice how the pattern is wide, and shifted to the exhaust side of the valve tip

Pushrod Too Short: Notice how the pattern is wide, and shifted to the intake side of the valve tip.

Pushrod Length Correct: Notice how the pattern is narrow and is centered on the valve tip.
HAVING the mark perfectly CENTERED is not NEARLY as important as a NARROW wear mark thats reasonable close to centered on the valve tip so don,t get crazy if its not exactly centered.
in an ideal world the rocker pushes strait down the valve stem center line to reduce friction,but having the rocker wear pattern centered on the valve tip is far LESS important than having it rather narrow indicating less side thrust or drag on the valve
and having the rocker geometry a bit off as long as the clearances are correct, is unlikely to cause noise issues as much as long term valve guide wear issues
Ive never had an issue re-using old push rods on new roller rockers with a good dose of moly cam lube on the tips , AS LONG AS the tips looked like they were in decent condition and not obviously worn,after, they passed a close inspection before they were used, most good brand name aluminum roller rockers have pressed in hardened steel push rod seats that are far less likely to wear than the tips of the push rods.

OBVIOUSLY that assumes you have no valve train clearance issues, binding or geometry or lubrication issues, and you set the lash or lifter pre-load on the valve train correctly and use the correct oil, and it certainly would help any engines durability to have provisions for adequate valve train oiling and a bit extra valve train cooling can be helpful on an engine designed for higher rpm use.

READ THRU THE LINKS


viewtopic.php?f=52&t=181

viewtopic.php?f=52&t=6491

viewtopic.php?f=52&t=1489

viewtopic.php?f=52&t=399

viewtopic.php?f=52&t=1376

viewtopic.php?f=52&t=528

viewtopic.php?f=52&t=697

viewtopic.php?f=52&t=126

viewtopic.php?f=52&t=9815

 

[marv02]

1.6, 1.5 combo or use 1.6 on Both Intake & Exhaust

I have done a lot of reading and read a lot mix opinions on what to use.

I have a Mild SBC 357 build in my Vett and using a cam with these Specs

Compression 9.575 to 1

Valve Lift .447/.447 Duration 290/290 Lobe Center 111 Intake C/L 107 Cam gross Lift .298/.298 Duration @50 214/214
As you can see it a single patten cam,

I also and Using Trick Flow Heads Super 23 with 195 runners.

A Edelbrock High-Flow Intake Base and SPL runner 24# Injectors.

I want to get a upgrade set on Quality full Roller Rocker Arm I have a set of cheep ones now 1.5 Ratio.

After reeading you said I going SS this time around It's a everyday DD street car.

If going to buy some new RRA mite as well get the most bang for the buck should I go with 1.6 Intake and 1.5 on the Exhaust, 1.6 on In & Ex or go to 1.65 ??.

The valve springs on the heads now are rated at Max Lift .480 If I have to upgrade to anouther valve spring that no big deal.

I also read small cams like I running can have great results by using high ratio RRA.

 

[grumpyvette]

Re: 1.6, 1.5 combo or use 1.6 on Both Intake & Exhaust

your most effective compromise on a mild cam like thats more than likely going to be a the 1.6:1 rockers on both sides simply because it increases the lift a bit without major changes, the 1.65:1 ratio rockers almost always require a bit more clearance work for almost no noticeable improvement in power.

 

[marv02]

Re: 1.6, 1.5 combo or use 1.6 on Both Intake & Exhaust

Thanks
I will order the New RRA after the holidays.
1.6/1.6.

I know It wont be a rocket ship but upgrading might get the best bang for the buck.

 

[grumpyvette]

rockers won,t line up on valve tip

I have a problem with my 87 caprice. I torn apart the engine, and IMHO I found something unusual. The side aligment of rocker arms have a huge side allowance. The rocker arms are moving from side to side, even using just using just pushrods, although they were adjusted. One side of the engine is better then other.

I feel the new rocker arm kit is a solution, but what could cause this behavior and what allows it?

Please check videos below

that problem, and its cause, and the solutions, ARE all so obvious its comical, but its also ALL TOO COMMON to see it done incorrectly.

IF your cylinder heads are not precisely drilled to act like push rod guide plates like these heads pictured above are ...
MOST head castings are NOT machined like that and require either push rod guide plates or self aligning rockers.
stock chevy stamped rockers come in two basic versions,in the videos above the heads are installed without push rod guide plates OR self aligning rockers, you must use one or the other method to maintain rocker alignment
rockers must EITHER use PUSH ROD GUIDE PLATES, that keep the push rods aligned with the rocker stud and valve tip,like these two pictures

OR you use SELF ALIGNING ROCKERS
self aligning rockers have ridges stamped in the tip that prevent the rocker from moving off the valve stem alignment center line to prevent the rocker from moving off the valve stem

Anytime your tracing a failure to get oil flow you'll generally start at the oil pump and oil pump pick-up.
if you have good steady oil pressure readings on the gauge, yet the rockers don,t seem to flow oil well and especially if they are aftermarket rockers, you might be dealing with badly set up rocker geometry, defective rockers or restrictive clearances, but one very common cause is simply not correctly adjusting the valve train clearances. simply backing off the adjustment nuts on the rockers while the engine idles until they click audibly at idle, then slowly tightening just until the clicking stops then adding an additional 1/4 turn of pre-load as the engine idles works well on most engines.

http://garage.grumpysperformance.com/index.php?threads/basic-info-on-your-v8-lube-system.52/

http://garage.grumpysperformance.co...l-pumps-pressure-bye-pass-circuit-works.3536/

http://garage.grumpysperformance.com/index.php?threads/installing-an-oil-pump-pick-up-tube.1800/

check the oil passages m and cam bearing alignment

http://garage.grumpysperformance.com/index.php?threads/cam-bearing-install-tools-install-info.1479/

http://garage.grumpysperformance.com/index.php?threads/oil-system-mods-that-help.2187/

http://garage.grumpysperformance.com/index.php?threads/oil-filters-related-info.2080/

http://garage.grumpysperformance.co...oil-passages-on-a-new-engine-or-cam-swap.985/

http://garage.grumpysperformance.co...k-after-a-cam-lobe-rod-or-bearings-fail.2919/

verify oil flow enters BOTH the lifter gallerys under pressure

http://garage.grumpysperformance.co...g-up-oil-feed-holes-in-bearings-shells.10750/

http://garage.grumpysperformance.co...oil-passages-and-improved-oil-flow-mods.3834/

verify oil leaves the lifters and flows through the rockers

http://garage.grumpysperformance.com/index.php?threads/not-getting-oil-to-rockers.4537/

http://garage.grumpysperformance.com/index.php?threads/block-prep.125/

and drains back to the sump, quickly and withh minimal restriction to flow

http://garage.grumpysperformance.com/index.php?threads/valve-train-shrapnel-screens.1458/

http://garage.grumpysperformance.com/index.php?threads/locating-the-source-of-that-noise.15694/

http://garage.grumpysperformance.com/index.php?threads/cleaning-a-short-block.7697/

http://garage.grumpysperformance.com/index.php?threads/whats-a-windage-tray-do.64/

http://garage.grumpysperformance.com/index.php?threads/valve-train-clearances-and-problems.528/
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

 

[grumpyvette]

Re: getting custom pushrods and the correct valve train geom

I have already find a lot of threads about it, nevertheless I'm still not sure if I'm on the right way.
Which "pattern" is acceptable, which not anymore?

Please have a look to the pictures and let me know your opinion.

(402BBC, stock push rods, roller rockers, hydraulic lifters)

Picture 1

http://garage.grumpysperformance.co...rect-custom-length-pushrods.14241/#post-72366

http://garage.grumpysperformance.co...sh-rod-length-checker-tools.13735/#post-70650

thinking about putting roller rockers on my 327.

IM seriously considering/ thinking about putting roller rockers on my 327.do i have room to put 1.6 ratio or just stay with 1.5s http://garage.grumpysperformance.com/index.php?threads/louis-tool-swapping-to-1-6-1-ratio-rockers.14761/...

garage.grumpysperformance.com

GrumpyThe Grumpy Grease MonkeyStaff Member

https://www.crower.com/clearance.html?cat=1541

you might want to buy a few of these
while they are on sale at a reduced price

heres a bit of useful related push rod length info (POSTED HERE) youll want to select the correct set or SETS for your shop

Big Block Chevy, Standard Length Big Block Intake 3/8" / .080" 8.275"
295-7941-8 Big Block Chevy, Standard Length Big Block Exhaust 3/8" / .080" 9.250"
295-7969-8 Big Block Chevy, Standard Big Block +.100" Long Intake 3/8" / .080" 8.375"
295-7979-8 Big Block Chevy, Standard Big Block +.100" Long Exhaust 3/8" / .080" 9.350"
295-7951-8 Big Block Chevy, Standard Length Big Block Tall Deck Intake 3/8" / .080" 8.675"
295-7961-8 Big Block Chevy, Standard Length Big Block Tall Deck Exhaust 3/8" / .080" 9.650"
295-7800 V8 396-454 Retro Fit Pushrod Set, Intake & Exhaust, 1965-Present
3/8" / .080"
3/8" / .080" 7.725 Int.
8.675 Exh
295-7913-16 Small Block Chevy, Standard Length Small Block Chevy 3/8" / .080" 7.800"
295-7984-16 Small Block Chevy, +.100" Long 3/8" / .080" 7.900"
295-7934-16 Big Block Ford, Standard Length Ford `72-'78 429-460 3/8" / .080" 8.550"
295-7951-16 Big Block Ford, Standard Length Ford `69-'71 429-460 3/8" / .080" 8.675"
295-7582-16 Oldsmobile, Std Length 455 5/16" 9.550"

• 
  Reduced
  Part Number: 70463-2
  Checking Pushrods
  Checking Pushrods 7.975 +-.250 (Pair)
  Learn More
  Regular Price: $28.13
  
  
  Your Price: $13.99
  
  
• 
  Reduced
  Part Number: 70461-2
  Checking Pushrods
  Checking Pushrods 7.150 +-.250 (Pair)
  Learn More
  Regular Price: $28.13
  
  
  Your Price: $13.99
  
  
• 
  Reduced
  Part Number: 70465T
  Checking Pushrods
  Checking Pushrod Kit (1) 8.150 +-.250 (1) 9.150 +-.250
  Learn More
  Regular Price: $28.13
  
  
  Your Price: $13.99
  
  
• 

http://www.summitracing.com/search/...d-length-checkers?autoview=SKU&ibanner=SREPD5
Proform Pushrod Length Checkers 66789 SBC 3/8" rocker studs

Proform Pushrod Length Checkers 66790 SBC 7/16" rocker studs

Proform Pushrod Length Checkers 66806 BBC 7/16" rocker studs

If your thinking you can swap to the 1.6:1 rockers without checking clearances carefully, ...probably not, your certainly going to need to check and verify clearances , and yeah, youll find a dozen guys that say they did it with zero problems......many could also tell you that in a few months they experienced a cam lobe /lifter or rocker failure as the push rod binding in even only part of the rockers arc, tends to cause excessive wear on the valve train, it might take some time but it will result in component failure over time if parts can,t move freely as designed.
http://garage.grumpysperformance.co...o-rockers-and-the-pushrods-rub.198/#post-3033
http://garage.grumpysperformance.co...swap-in-1-6-1-ratio-rockers.10671/#post-46039
http://garage.grumpysperformance.co...e-train-clearances-and-problems.528/#post-664


Picture 2

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Picture 5

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Picture 6

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Picture 7

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Picture 8

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Picture 9

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Second issue, what I'm not sure about:
Do I create the right pattern?
When I adjust the roller rockers, I mean preload, zero lash etc., the plunger inside the lifter stays not stationary. Clear... --> hydraulic
So, after I turned the engine several times, will I get the correct result?
Which level has the plunger in operating condition?
Maybe the valve contact will be different then?

Thanks for your comments!
heres a bit of useful related push rod length info
Big Block Chevy, Standard Length Big Block Intake 3/8" / .080" 8.275"
295-7941-8 Big Block Chevy, Standard Length Big Block Exhaust 3/8" / .080" 9.250"
295-7969-8 Big Block Chevy, Standard Big Block +.100" Long Intake 3/8" / .080" 8.375"
295-7979-8 Big Block Chevy, Standard Big Block +.100" Long Exhaust 3/8" / .080" 9.350"
295-7951-8 Big Block Chevy, Standard Length Big Block Tall Deck Intake 3/8" / .080" 8.675"
295-7961-8 Big Block Chevy, Standard Length Big Block Tall Deck Exhaust 3/8" / .080" 9.650"
295-7800 V8 396-454 Retro Fit Pushrod Set, Intake & Exhaust, 1965-Present
3/8" / .080"
3/8" / .080" 7.725 Int.
8.675 Exh
295-7913-16 Small Block Chevy, Standard Length Small Block Chevy 3/8" / .080" 7.800"
295-7984-16 Small Block Chevy, +.100" Long 3/8" / .080" 7.900"
295-7934-16 Big Block Ford, Standard Length Ford `72-'78 429-460 3/8" / .080" 8.550"
295-7951-16 Big Block Ford, Standard Length Ford `69-'71 429-460 3/8" / .080" 8.675"
295-7582-16 Oldsmobile, Std Length 455 5/16" 9.550"

Ok, the contact pattern would be ok.
But what me concerns is a "big" gap between the valve tip and the pushrod length checking tool I have used:
[/url]

Unfortunately I have no photos, but it's a gap from approximately 0,12 - 0,15 inch on both, exhaust and intake valve.
Why?

Should I consider that tooling result?
Or is the image on the valve tip the more important value?

Or do I compare apples and oranges right now?

FIRST THANKS FOR POSTING GOOD CLEAR PHOTOS AND THOSE ADJUSTABLE PUSH ROD GUIDE PLATES ARE AN EXCELLENT ADDITION TO ANY BBC VALVE TRAIN!
"THAT PLASTIC THING" is a PUSH ROD LENGTH CHECKER, THE PUSH ROD LENGTH CHECKING, AND ROCKER GEOMETRY TOOL, ARE ENGINE SPECIFIC, so you MUST USE ONE DESIGNED FOR THE SAME STUD DIAM. SPECIFICALLY FOR YOUR SPECIFIC ENGINE, to find the correct rocker geometry and push rod length. If you for example use one designed for 7/16" studs on a SBC and used it on a BBC with 7/16" rocker studs the result would not be close to correct, if the tool designed for one engine is used on the wrong engine, so be damn sure you use the correct tool.

while your rocker wear marks on the valve tips look very close to ideal , you need to verify the push rod length, as getting that rocker geometry correct is important to durability , and a slight change in push rod length may improve that further, keep in mind that having the wear band centered is nice but not as important as keeping in narrow and close to center as possible as a narrow wear band tends to indicate minimal side thrust and as a result minimal wear results

if your seeing a .120-.150 gap between the push rod tip when the "PLASTIC THING" is inserted on the rocker stud , AND IF ITS THE CORRECT CHECK TOO FOR THE APPLICATION,and its resting on the valve tip, your push rods that much too short for the application, your measuring

viewtopic.php?f=52&t=4596&p=18401&hilit=adjustable+guide+plates#p18401

viewtopic.php?f=44&t=2839&p=7344&hilit=adjustable+guide#p7344

 

[grumpyvette]

Re: getting custom pushrods and the correct valve train geom

@ boogie & 77_cruiser,

thank you for following my topic.
I would like to ignore the pushrod length checker tool too, but I'm afraid it's going to become a problem one day.


@ grumpyvette,

If I respect the tool, the rocker arm position looks strange (from my point of view).

I mean the quite short end of the pushrod above the guide plate (especially the intake valve ~ 0,5 inch).

Furthermore it seems not to be possible, to reach the 90°-ratio --> rocker arm to valve on mid lift.
(Maybe I'm wrong and it's only a visual mistake)
What do you think, should I still follow the tool and use shorter pushrods?

Intake / Stock Pushrod

Exhaust / Stock Pushrod

Intake / Adjustable Pushrod

Exhaust / Adjustable Pushrod

Intake / Distance To Guide Plate

Exhaust / Distance To Guide Plate

Intake / Mid Lift Ratio Possible?

Exhaust / Mid Lift Ratio Possible?

I run into similar questions all the time, while building engines and the first thing Ive always done is to get on the phone to the tool manufacturer and ask the tech guys,if I have questions simply because asking questions beets replacing busted parts every time!
while I agree that the valve stem wear marks the rockers are making look to be correct and I see no indication the valve trains binding Id also point out that the checker indicates or at least is designed to indicate the OEM SPECS as to the rocker to push rod and rocker stud locations, I,d also point out you have swapped to AFTERMARKER ROLLER ROCKERS so that push rod check tool may no longer be valid, with those rockers in use.
what to look for and having had that issues many times in the past I can assure you that the first thing they usually ask is if the cylinder heads are completely OEM,/stock and if you have changed any component parts or altered the valve spring installed height.

its hardly surprising when getting your rocker geometry's a challenge, its not like they make it standard or easy
ERSON,CRANE and CROWER tend to have good consistent dimensions
and some of the off shore imports are a joke in consistency
comps rockers rocker angles vary a good deal between models, but all can be made to function

link to tool,
http://www.summitracing.com/parts/man-42133/overview/

http://www.manleyperformance.com/contact.shtml
Phone (732) 905-3366
heres the instructions that come with the tool, posted below and if you call them they will tell you it will only work with stock chevy OEM BIG BLOCK PRODUCTION CYLINDER HEADS, not many aftermarket heads as many have the valve angles changed or the heads deck surface rolled a few degrees

This is a very simple tool to use:

Rotate lifter to cam base circle and slide the tool over the rocker stud.
One of the ears on either side of the tool will rest on either the valve tip or the pushrod.
If the tool rests on the valve tip, you will measure the gap left between the pushrod and the end of the tool. This distance will be added to the existing pushrod length for the new length needed for correct geometry.
If the tool rests on the pushrod, and there is a gap between the tool and the valve tip, you will subtract the distance from the existing pushrod length for correct geometry.
Works great with a pushrod length checking tool.

 

[philly]

Re: getting custom pushrods and the correct valve train geom

grumpy since its kind of related do you think that theres merit to the claims that people make about using steel roller rockers instead of aluminum from an increased strength perspective? on a low (under 7000rpm) rpm motor ive always felt the savings in mass justified the potential failure but, having used roller aluminum roller rocker arms from scorpion and comp i havent had one fail... so what are your thougts on the strength to weight saving merits of that?

 

[grumpyvette]

Re: getting custom pushrods and the correct valve train geom

it comes down to the length of time and the valve spring pressure levels your dealing with, aluminum has about 1/2 the durability of steel, IE, if you cycle an aluminum part from stress to unstressed continually, the repeated cycles, if its made of aluminum,it will fatigue faster ,and it will tend to fail in about 1/2 the time at the same stress levels as long as the elastic limits are not exceeded.
put a different way,all rockers are a replaceable item, like brake pads or fan belts,if I bought good quality aluminum rockers, LIKE CRANE, or the BETTER ERSON ROCKERS, for a street driven engine and did not subject them to excessive stress and kept them well lubed, Id expect to throw aluminum rockers in the dumpster after about 60K miles as they are generally starting to show the signs of minimal fatigue stress by that time, Id feel that STEEL rockers like COMP, or CROWER could easily go 80K miles before pitching those in the dumpster, they might not be showing stress fatigue but surely any roller rocker starts to show wear and needs to be replaced by 100K as a general maintenance replacement precaution. and just as obviously ID suggest taking any set of roller rockers off and doing a close visual inspection every few months , on any street driven car or every few thousand miles during its expected life span as a standard maintenance procedure, that would hopefully allow you to find any sign of potential fatigue failure ,well before the parts fail.

http://aluminium.matter.org.uk/content/ ... 2144417131

http://www.americanmachinetools.com/ten ... rength.htm

http://www.kastenmarine.com/alumVSsteel.htm

http://www.crower.com/media/pdf/2008b/153-155.pdf

http://www.lunatipower.com/Tech/Valvetrain/HowToVerifyValvetrainGeometry.aspx
keep in mind all roller rockers do not have identical dimensions, crower offers .050 off set trunion designs ans the designs dimensions do differ slightly between manufacturers

 

[grumpyvette]

Re: getting custom pushrods and the correct valve train geom

http://www.pushrods.net/pushrods.html

http://www.jegs.com/p/Lunati/Lunati-Pus ... 8/10002/-1

http://garage.grumpysperformance.com/index.php?threads/valve-train-clearances-and-problems.528/
heres a bit of useful related push rod length info
Big Block Chevy, Standard Length Big Block Intake 3/8" / .080" 8.275"
295-7941-8 Big Block Chevy, Standard Length Big Block Exhaust 3/8" / .080" 9.250"
295-7969-8 Big Block Chevy, Standard Big Block +.100" Long Intake 3/8" / .080" 8.375"
295-7979-8 Big Block Chevy, Standard Big Block +.100" Long Exhaust 3/8" / .080" 9.350"
295-7951-8 Big Block Chevy, Standard Length Big Block Tall Deck Intake 3/8" / .080" 8.675"
295-7961-8 Big Block Chevy, Standard Length Big Block Tall Deck Exhaust 3/8" / .080" 9.650"
295-7800 V8 396-454 Retro Fit Pushrod Set, Intake & Exhaust, 1965-Present
3/8" / .080"
3/8" / .080" 7.725 Int.
8.675 Exh
295-7913-16 Small Block Chevy, Standard Length Small Block Chevy 3/8" / .080" 7.800"
295-7984-16 Small Block Chevy, +.100" Long 3/8" / .080" 7.900"
295-7934-16 Big Block Ford, Standard Length Ford `72-'78 429-460 3/8" / .080" 8.550"
295-7951-16 Big Block Ford, Standard Length Ford `69-'71 429-460 3/8" / .080" 8.675"
295-7582-16 Oldsmobile, Std Length 455 5/16" 9.550"
push rod too short
WIDE SWEEP ON VALVE TIP FROM ROCKER ADDS ADDITIONAL,
SIDE LOAD WEAR

push rod length correct
AS CLOSE TO CENTER AS POSIABLE BUT BEING CENTERED IS LESS IMPORTANT THAN MINIMAL SWEEP ON THE VALVE TIP< INDICATING MINIMAL SIDE LOADING
be aware that you need to measure BOTH the intake and exhaust push rod length as they can be different and ON the older BBC are designed to be totally different length, theres also 3/8" and 7/16" diameter BBC push rods and STANDARD AND TALL DECK SETS, and it should be obvious that the guide plates need to match the push rod diameter, being used, in each application as well as the correct length selected.
wall thicknesses vary from about .060 up through about .140 on most designs materials vary also, and larger diameters tend to be significantly more rigid resisting deflection under higher spring load rates, and inertial loads due to more radical roller cam lobe designs and higher rpms.

yes they DO MAKE ROLLER ROCKERS IN BOTH STANDARD AND SELF ALIGNING VERSIONS
any time you find the valve train producing a noise its generally a clearance issue or a worn part,
to help locate the source of the noise, take off the valve cover and, have a buddy start the engine,
press down on the rockers individually at idle with the palm of your hand,
,if the lifter, rocker or other valvetrain component is worn or mal-adjusted,
the sound on each valve assembly will change as pressures applied to the rocker with the heel of your hand on the rocker testing individually at idle,
obviously done before oil temps rise too far and
visually check for cracked valve springs,
bent or loose rocker studs and
rocker slots that contact the rocker stud
and
missing valve lock keys in the valve spring retainer
Id also suggest you swap rockers if you find one causing the noise,
burn or worn rocker balls in the rocker can cause this,
and that helps you isolate the defective component

https://www.chevydiy.com/small-block-chevy-rocker-arms-studs-pushrods-lifters-guide/

Stamped rockers use a slot cut in the base of the rocker that allows the rocker to move relative to the stud. With higher lift cams,
make sure there is a minimum of 0.050 inches clearance between the end of the rocker slot and the rocker stud at max lift.

a burn rocker ball can result from lack of volume of pushrod oil flow,
this tends to temporarily result in galling and a rough surface,
rocker balls with grooves tend to allow more oil flow to the rocker ball bearing surfaces thus a marginally lower failure rate due to galling

check all valve train geometry and clearance on any engine you assemble or modify the valve train on.

In the mid 1980s, all production small blocks began using “guided” rocker arms that use two small guides that straddle the valve tip to locate the rocker arm tip. Guided or “rail” rockers should not be used with guideplates since this could create a binding situation that would break parts.
its not unusual to find mixed sets on older engines



let us know what you find
http://www.cpgnation.com/forum/threads/ ... etry.4346/

http://www.cpgnation.com/forum/threads/ ... tech.2408/

http://www.hotrod.com/how-to/engine/hrd ... vesprings/

 

[Grumpy]

http://www.hotrod.com/how-to/engine/ctrp-0703-rocker-arm-comparison/

http://www.hotrod.com/how-to/engine/116-0101-roller-rocker-ratio-test/

http://garage.grumpysperformance.co...ch-is-best-steel-or-aluminum.3124/#post-51904

http://www.superchevy.com/how-to/vemp-0703-corvette-rocker-arms/

http://www.superchevy.com/how-to/engines-drivetrain/sucp-0202-rocker-arm-ratio/

http://www.mustangandfords.com/how-to/engine/mmfp-1101-roller-rocker-arms/

http://www.crower.com/media/pdf/2008b/153-155.pdf

http://www.lunatipower.com/Tech/Valvetrain/HowToVerifyValvetrainGeometry.aspx

file:///C:/Users/Marge/Downloads/Jim%20Miller%20Mid%20Lift%20VTG%20(2).pdf



roller TIP rockers like this are basically a total waste of time, money and effort, the tips of the valves on the rocker provide MINIMAL friction its the fulcrum the rocker pivots on at the rocker stud, that needs a roller bearing and thats where you gain most of the power gain, in reduced friction, the increase in valve lift is a small help but not nearly what the reduced friction in the valve train provides

your FAR BETTER OFF WITH TRUE ROLLER ROCKER DESIGNS
https://www.summitracing.com/parts/sum-g6991/overview/make/chevrolet

On my sons 1992 LT1 we installed CRANE 1.6:1 ratio roller rockers and gained 13 REAR WHEEL hp, (measured on the dyno)

 

[Grumpy]

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