ls7 lifters and pushrod length
03-12-2012, 10:33 PM
#1
ls7 lifters and pushrod length So I tore my motor apart last weekend getting ready to put in my ms3 cam, springs, etc...I also got ls7 lifters to replace my stock ones as well and I have already bought 7.4 prs. I have not checked the length yet and I really dont have time to order a checker and then order new prs. Should I just be patient and order a checker or should the prs work fine? Stock heads and gaskets and everything else.
03-13-2012, 03:59 AM
#3
Stock are shorter than 7.400". The recommendation for use of 7.400" is to make up for the smaller base circle of aftermarket cams as compared to the stock LS1 cam. While your 7.400" pushrods may be OK, best to measure. Unfortunately if you run the 7.400" and they are not correct then you will end up buying a second set. That being the case you can sell the 7.400" pushrods. Guess its your call.
03-13-2012, 10:24 PM
#4
What brand pushrods? 7.400" gauge length or flat-to-flat, depending on brand.
What you should at least do is do one or two cylinders and see how many turn you end up getting on the rocker arm bolt from zero last to 22 ft-lbs. It will at least give you a close answer.
Bolt turns to 22 ft-lbs vs. lifter pre-load:
Rocker Bolt ... Lifter
Turns .......... Preload
1 ................ 0.052
1-1/4 .......... 0.071
1-1/3 .......... 0.078
1-1/2 .......... 0.091
1-2/3 .......... 0.104
1-3/4 .......... 0.110
2 ................ 0.130
What you should at least do is do one or two cylinders and see how many turn you end up getting on the rocker arm bolt from zero last to 22 ft-lbs. It will at least give you a close answer.
Bolt turns to 22 ft-lbs vs. lifter pre-load:
Rocker Bolt ... Lifter
Turns .......... Preload
1 ................ 0.052
1-1/4 .......... 0.071
1-1/3 .......... 0.078
1-1/2 .......... 0.091
1-2/3 .......... 0.104
1-3/4 .......... 0.110
2 ................ 0.130
Last edited by ZeeOSix; 03-13-2012 at 10:30 PM.
