What happens if i run 7.400 isntead of 7.425 on the gm asa cam?
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well im asking cause im running the stock size 7.4 pushrods on my head and cam ls1 and i just now found out i needed 7.425s. Is there a power loss? if so how much ? any potential problems in the long run?
ive been running like this for like 2000 miles
ive been running like this for like 2000 miles
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i used stock ls6 lifters, i asked on here what pr s i needed and some guy said stock size, but come to fine out everyone running the cam is running 7.425s
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Get one of your rockers at the top of the stroke, turn the motor while watching the rockers, find one that goes up as yuo turn and when it stop use that one. Now loosen it a little bit, tighten it while moving the rocker up and and down with your hand, and get it to where it just stops rocking back and fourth. Now mark your bolt and tighten it to 22 ft. lbs. Count how many turns it takes, each turn is worth .050", so you should get a little over 1.5 turns or close.
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Get one of your rockers at the top of the stroke, turn the motor while watching the rockers, find one that goes up as yuo turn and when it stop use that one. Now loosen it a little bit, tighten it while moving the rocker up and and down with your hand, and get it to where it just stops rocking back and fourth. Now mark your bolt and tighten it to 22 ft. lbs. Count how many turns it takes, each turn is worth .050", so you should get a little over 1.5 turns or close.
Huh? what am I missing
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Search Vettenuts for the best post descibing how to set lifter preload.
If your valvetrain is not excessivly loud you are prolly ok though.....
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have the heads been milled? stock thickness head gasket?
a quick and easy check for you is to loosen 1 IN & EX rocker... use a sharpie and color in the tip of each of the two valves... bring the rockers down to zero lash and notate how many turns it takes to torque the rocker bolt to 22lb ft... like electric said, each full turn is approximately .050... now rotate the engine two complete turns...loosen the two rockers of the valves you marked... look at the imprint left from the rocker tip to the valve tip... it should be close to square in the middle... never coming close or off of the valve tip...unless you milled a lot off the heads you should be in a fairly safe zone with the 7.400 pushrod and a ground base cam...
your preload will be fine anywhere from .06 to .10, but ideally you will want to be between .075- .085... most importantly you want a clean centered contact patch on the valve tip with proper preload to match
a quick and easy check for you is to loosen 1 IN & EX rocker... use a sharpie and color in the tip of each of the two valves... bring the rockers down to zero lash and notate how many turns it takes to torque the rocker bolt to 22lb ft... like electric said, each full turn is approximately .050... now rotate the engine two complete turns...loosen the two rockers of the valves you marked... look at the imprint left from the rocker tip to the valve tip... it should be close to square in the middle... never coming close or off of the valve tip...unless you milled a lot off the heads you should be in a fairly safe zone with the 7.400 pushrod and a ground base cam...
your preload will be fine anywhere from .06 to .10, but ideally you will want to be between .075- .085... most importantly you want a clean centered contact patch on the valve tip with proper preload to match
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Get one of your rockers at the top of the stroke, turn the motor while watching the rockers, find one that goes up as yuo turn and when it stop use that one. Now loosen it a little bit, tighten it while moving the rocker up and and down with your hand, and get it to where it just stops rocking back and fourth. Now mark your bolt and tighten it to 22 ft. lbs. Count how many turns it takes, each turn is worth .050", so you should get a little over 1.5 turns or close.
1.5 X (1.25/25.4) X (2.7/1.7) = 0.117" of preload at the pushrod.
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Internet math sucks for building engines. If the op wants to actually have the correct length pushrods he'll need to purchase an adjustable pushrod. Which he can get for around $20 new. Then simply measure and add the desired preload (I wouldn't recommend over .050").
Internet math isn't going to get him anything but a bunch of guesses at what the engine actually wants.
Internet math isn't going to get him anything but a bunch of guesses at what the engine actually wants.
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Internet math sucks for building engines. If the op wants to actually have the correct length pushrods he'll need to purchase an adjustable pushrod. Which he can get for around $20 new. Then simply measure and add the desired preload (I wouldn't recommend over .050").
Internet math isn't going to get him anything but a bunch of guesses at what the engine actually wants.
Internet math isn't going to get him anything but a bunch of guesses at what the engine actually wants.
#15
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Internet math sucks for building engines. If the op wants to actually have the correct length pushrods he'll need to purchase an adjustable pushrod. Which he can get for around $20 new. Then simply measure and add the desired preload (I wouldn't recommend over .050").
Internet math isn't going to get him anything but a bunch of guesses at what the engine actually wants.
Internet math isn't going to get him anything but a bunch of guesses at what the engine actually wants.