Push rod length
07-07-2011, 09:24 PM
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Push rod length Ok i done some seaching and i think have it but just want to make sure. Putting another set of heads and cam in car. I have a set of 7.400 push rods pulled them down to 0 lash then start my turns. I am only getting 1/2 a turn before they are tight. So from what i have seen i need 7.450 to have the right preload.
How does this sound?
How does this sound?
07-07-2011, 09:49 PM
#2
Most on here shoot for about .080 lifter preload for a moderately quiet
valvetrain. I believe that is around 1.5-1.75 turns from zero lash to
22 ft./lbs. rocker torque. Are you sure the one you checked had the
lifter on the base circle of the cam ????
valvetrain. I believe that is around 1.5-1.75 turns from zero lash to
22 ft./lbs. rocker torque. Are you sure the one you checked had the
lifter on the base circle of the cam ????
07-07-2011, 10:26 PM
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Yes it kind of hard to check with the YellaT rockers but pretty sure it was right. I put the trickflow heads on that call for 7.500 push rods. The heads were cut down .030 I think the 7.500 is going to give way to much preload.
07-08-2011, 08:20 AM
#4
Counting turns with the YT's is not a good way to go because of the design. The first step should be to verify the wipe pattern as they "may" need to be shimmed. Once that is done, you can measure. Best way with the YT's is the adjustable pushrod so they can be tightened snug and use the adjustable to obtain zero lash and add preload. They rockers have to be tightened in pairs, so the GM procedure can't be used. You must rotate each cylinder to firing position then install the rocker pair while both lifters are on the cam base circle.
07-08-2011, 08:43 AM
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Counting turns with the YT's is not a good way to go because of the design. The first step should be to verify the wipe pattern as they "may" need to be shimmed. Once that is done, you can measure. Best way with the YT's is the adjustable pushrod so they can be tightened snug and use the adjustable to obtain zero lash and add preload. They rockers have to be tightened in pairs, so the GM procedure can't be used. You must rotate each cylinder to firing position then install the rocker pair while both lifters are on the cam base circle.
I put #1 in firing position and slowly pulled both to 0 lash. Then started my turns. I done it about 5 times. Each time i came up with 1/2 a turn. From the seaching i have done .025 will be about 1/2 a turn. So 7.450 should put me at 1 1/2 turns.
07-08-2011, 08:48 AM
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http://www.ls1howto.com/index.php?article=21
I found this but they are talking about 1/4 to 1/2 a turn for preload. Are the turns diff for the YT rockers?
I found this but they are talking about 1/4 to 1/2 a turn for preload. Are the turns diff for the YT rockers?
