krillformula

Im about to start check on PR length for my cam install. And Im gonna put some new ls7 lifters in. Does anyone know if I will be OK with making a solid lifter out of one of my stock ones to check length? If they have the same deep? Im having a little hard time to measure them
Because I dont wanna take apart the new ones if I dont have to

mdenz3

No. The LS7's have a considerably shallower pushrod cup.

Dave1980

I am going to have to do the same thing here.

krillformula

hmm that sucks.. I just tried to disassemble the new lifters and had a little bit hard time with it, the inner "cup" that sits on the spring is like stuck there. I can get it out just enough to grab it with pliers but it´s like the spring is holding it back. I had no problems disassemble the stock lt1 lifters

BUBBA

Here's a stupid question: Why do you need a solid lifter to measure the PR when a hydraulic lifter acts like a solid lifter when it is pumped.

So if you install the hydraulic lifter and assemble the rocker with the correct preload and then used an adjustable checker to see which length provides the best striking of the roller tip with the valve tip, shouldn't that work? I believe most prs come in increments of .050 +-. I.e. why does the lilfter have to be solid. You would still have to factor in the gap for a solid lifter for accuracy wouldn't you?

In addition, I figure a second method that you can use along with seeing where your roller tip marks the valve stem is to : Measure the distance between the bottom of the retainer to the top of the valve quide seal (i.e. the distance the valve travels) turn the crank until that distance is exactly half, assuming that the valve is at half lift and then check the angle made by going thru the trunion to the center of the roller tip to the center of the valve stem. This angle should be 90 degrees. Any more than 90 or less means that you either need a longer PR or a shorter PR. If the angle is 90 degrees then you have the correct length. Combinging these (2) methods for determing a length greater of lesser than stock should provide the correc geometry.

This is just an opinion, but I would still like to know why you need a solid lifter to do this if the lifter is preloaded or at 0 (just able to turn the pr with your fingers with a light drag.)

I guess, if you really need a solid lifter, you could just buy the solid lifter that replaces the hydraulic lifter for your engine. Or if you go with another hydraulic lifter, again just get the solid lifter that would replace that particular hydraulilc lifter. Just Curious, since you rarely see the requirement for using a solid lifter when purusing methods of measureing PRs.

mdenz3

You need a solid lifter because the valve spring will colapse the lifters. You can use a normal hydrualic if you use checking springs which have just enough force to hold the valve up and wont compress the lifters.

You can't buy a single solid lifter because it can have different legnth from the roller to the bottom of the cup.

BUBBA

OK: so when the cam is on the base circle and the valve is closed and there is no proload, you are saying that the lifter is depressed? Wouldn't that mean that you have already preloaded it in order to depress it? I guess, I just can't get the picture in my mind staight. So bottom line, you need to remove the intake to insert the solid lifter. What about removing the intake and observing the hydraulic lifter to ensure that it is not depressed or is the lifter automatically depressed at all times as long as the spring is installed properly to ensure that the valve is fully closed?

Again, just curious, since I, personally have not read where it is necessary to use a solid lifter to check PRs. I have seen it once in awhile, but not as a rule. Thanks. Also, would you direct me to the steps for using a solid lifter as suggested by any of the major valve train component vendors.

mdenz3

Well you need to turn the engine over to check the wear pattern on the valve stem to determine Pushrod legnth. Seeing as there isn't oil pressure while your turning the engine over by hand the lifter will collapse.

Dave1980

So using a checking spring sounds like the way to go here. Where is a good place to get them? I don't want to hassle with lifter disassembly if I can go another route.

mdenz3

Summit sells them.

Also some guys have been able to find suitable ones at their local hardware stores.

krillformula

I think I will give it a try with a non-solid lifter first because I have som test springs from the cam degree kit and the intake is off so I might be able to see if the lifter bleeds down. Would be nice not to have to mess with making a solid lifter

ENRKyle20

(First, Sorry to bring this back from the dead)

I had that exact same problem.. and I got it to sit about 1/4 out, but now it does not sit down on its own.. I can push it in.. but it pops back out (wont come completly out).. I think I just streched the spring wich will be ok right?

Also. I did endup just taking the cup off and putting shimms in until it bottomed out the spring, then I put the cup on and a old clip (just incase the pressure were to mess up the clip).. that worked for making it solid. turns out my pushrods are to long.. grrrr

z28_4life

Wouldn't you have to remove the original springs and install the checking springs though. Seems like just as much work if not more than to use a solid lifter. I have these on order and would like to know the simplest method as to check the pushrod length. I was under the impression that I could just rotate the crank and check it like was suggested but it sounds as though that would "collapse the lifter". Wouldn't adjusting the rockers in this way also collapse the lifter then?! Since many suggest adjusting the rockers with the car not running.