Bumping this to the top for you guys that are milling your heads, changing your lifters, etc. There's been a few questions about pushrod length lately....I think that the proper lifter preload should be examined

*EDIT* IMO this info should be a sticky...seems like every day somebody asks about pushrod length...

 

Hey Budhayes3, thanks for bumping this one to the top.

I saw you used the new style LS7 lifters and had your heads milled .030". I'm about to assemble a similiar setup (Patriot Stage lll's milled .030, GM MLS 5 layers .051" and a new set of LS7 lifters) and was wondering what size pushrod did you end up with?

Also, did you soak your new lifters before they were installed?

I'm going to pick up a pushrod checker but I might order pushrods at the same time (if they are returnable) and cross my fingers they are the right length.

Rick

 

Stock48 is correct. You need about .100 preload on the factory lifters. Rule of thumb is usually about 1-1 1/2 turns on the plunger with an LS style bolt.

Rick

 

Hey Rick, I got your PM Glad that folks are getting good use of this info I'm a ways away from assembling my engine yet, have to pay off, then swap my trans and get the truck back on the road first...but it will happen eventually (all I really need are gaskets, head bolts, lifters, and pushrods and my LQ9 will be complete ) I'm guessing that I'll be needing 7.35's, but my pushrod length checker will tell the tale for sure

I will be soaking my lifters also, you don't want to run em dry. I'm thinking that finding a way to stand them up in a tupperware container should do the trick.

Be sure to post up what length pushrods you end up with and what your pre-load ends up to be

 

Its not that important to make sure they are standing up in an oil bath IMO. I just let them sit for a while, shake the container every once in a while and after I put them in the motor, I pour a quart over each side and Ive never had any problems with lifters pumping up or anything doing it this way.

 

If the oil pump is working properly, they will pump up in just a few short seconds.

That said, I always stand them up (in a coffee can) full of oil for overnight. Probably overkill, but that's just the way I am.

 

I've always soaked them from way back in my sbc and bbc days with flat tappets, to a couple of sbc's with rollers also, so I'll keep doing it that way as it definitely couldn't hurt anything.

*EDIT* I soak them over night also...

 

So after 05 GM started using the new style lifters in the trucks and is that the ls7 lifters?

Thanks
Kyle

 

 

Yes and Yes