tyler99

iTrader: (2)

I'm in the middle of a cam / lifter swap and all other necessary parts of course.
I'm going with the ms4 cam, using stock 98 ls1 heads, which I had cleaned and decked... I'm a bit worried that having these heads decked was a bad idea when trying to use such a big cam.

Now im in the process of using clay to check PTV clearance. I've never done this before but it all seems quite simple, lay the clay down, tighten the head, turn motor over, check measurements..

Now for my question, as I read more into this I need to use a "solid" lifter. Ive read where I need to fill a lifter with metal to prevent it from "plunging" when motor is turned over. I have 2 lifters taken apart but not too sure what to throw in there to make it not plunge at all, anyone know what I should use?

Also, I bought all new ls7 lifters which I will be using to replace my ls1 lifters, as 1 had a tick. I'm told they are slightly different size than the ls1's, will this mess with my readings as i'm checking clearance using the ls1 lifter?

Exidous

iTrader: (11)

You could have a shop tack weld the plunger.

tyler99

iTrader: (2)

in that case, ill do that! Any idea if my measurements will be different because im using the ls1 lifter to do the checking but going to be running ls7 lifters once I go in for the install?

Exidous

iTrader: (11)

They should be exactly the same. There were stories about the LS7 lifter being .050" different but it's not. You can verify if you have a digital caliper. Use a pushrod and the lifter and measure total height.

tyler99

iTrader: (2)

Thanks exidous! Anyone have any possible good news so I can get to sleep tonight knowing that I may still be able to use my stock heads without fly cutting since I had them decked with the ms4 with the already close clearance issues?

ckpitt55

iTrader: (4)

here's what i did

take the lifter apart and remove the spring, then reassemble with the parts as shown

-(2) M4 standard thickness washers
-(1) M6 screw, ~12mm long.
-optional: (1) snap ring for retaining it all. Mcmaster PN# 99142A370. The original wire retainers shot across the garage never to be seen again when I was taking it apart so I needed a replacement.
**Disclaimer: While these are sufficient for retaining everything in this state, I would NOT recommend using these snap rings to retain the lifter innards on ones that you plan to run. They don't seem to have enough spring rate to keep them from shifting around.

Order of assembly:

tyler99

iTrader: (2)

I really liked this idea, and went and bought the parts, but it seems as though you did this to something other than an ls1 lifter because it dont seem to fit correctly unless im not getting something. I guess ill go back to the weld idea and give it a shot. Thanks for the idea though!

JakeFusion

iTrader: (7)

What are you guys doing for Morel lifters?

badazz81z28

iTrader: (6)

The lifter height has no bearing on PTV clearance. All you are concerned about not having the lifter bleed off. Any variance from lifters would be taken up by the length of the checker push-rod. I measured mine by installing small washers in the lifter.

tyler99

iTrader: (2)

When I am checking ptv clearance, should i use a stock 7.400 pushrod? I bought 7.375 hoping they will be right, but I still need to measure... Should I measure the pushrods at the same time as im checking ptv or just wait until I have my motor fully assembled to check for that?

01ssreda4

iTrader: (96)

Buy the comp checker springs. Not enough pressure to collapse the lifter. Y'all really over think **** sometimes.

tyler99

iTrader: (2)

I would do that, but the comp spring compressor I bought bent so I ended up having to pay to get my springs put on, so im going for the clay method.

badazz81z28

iTrader: (6)

Agree....one step at a time, its not that hard. Check PTV with a solid lifter (home-made or not, or Checker springs) using the adjustable comp push rod. Once that's good, measure for pushrods using the comp tool after it is all together with the real lifters.

ckpitt55

iTrader: (4)

it's possible your washer thicknesses were slightly different than mine. did you also remove the spring from the lifter?

badazz81z28

iTrader: (6)

He needs the adjustable measuring push-rod. Unless he welds the cup exactly in the stock position or exactly the right thickness of washers, its not going to be exact. I don't recommend using the real push-rods unless you are using checker springs.

2000PewterT/A

^^^ x2