robss96dcm

I seem to be a little confused here, most people using the ls7 lifters in lsx applications are shooting for about .080 preload. When installed in lt1 applications there going about a 1/4 turn past zero which is about .010 preload if my math is correct.

Why so little in the lt1's

wrd1972

iTrader: (12)

I play it safe and go 3/4 PZL, but thats just me. If I were racing, I would do 1/4 turn PZL.

jaycenk

iTrader: (1)

I did a tad over 1/2. about 2/3rds

gregrob

iTrader: (8)

Full turn is factory spec, and LS7 lifters are factory replacement. Soooo....

SoxXpupPeT

iTrader: (34)

I had tryed that in my car. As im slowly doing them with the engine running it started to run like crap!

I have mine set at 1/4 turn. I might fool around and see how they respond at 1/2 turn

z28_theantirice

iTrader: (2)

When I initially did my motor I did either 1/2 of 3/4 cant remember, ended up going with 1/4 and the motor felt a lot smoother with the 1/4 turn.

gregrob

iTrader: (8)

Maybe they require less. It would be interesting to know what GM calls for on the LS7.

Are you guys using 1/4 turn sure your pushrod length is correct?

litch2004

iTrader: (1)

Mine was loud as Hell at 1/2 so I went with 1/4 and ran great. Not sure about why it is just is lol.

litch2004

iTrader: (1)

rrob, mine were measured three times by three different people and used a micrometer to measure test rod.

SoxXpupPeT

iTrader: (34)

same here. but do remember. not all LS7 lifters are the same. There have been alot of reports with people having bad batches iirc

litch2004

iTrader: (1)

I remember. Mine are about a 2 years old. I have only put 200 miles on them. It was my rockers that were loud. Went back redid all of them and marked a line on the oily lock to determine movement. All is good.

robss96dcm

My understanding is .060 on stock ls7 engines, in a lt1 that would be about 1.5 turns past zero lash!

speed_demon24

iTrader: (6)

It would be about half that.

RamAir95TA

iTrader: (2)

I've always done 1/4 TPZL.

jasonz28camaro

iTrader: (13)

Yep, they call for 1/4

wrd1972

iTrader: (12)

Based off of what reference?

the_merv

iTrader: (88)

LS7 Lifter perload is .080 ideal, can range from .060-.100, always go with the larger one past .080 when selecting proper pushrod size.

There is a difference in the LS7 Lifter vs. the others..different Pushrod lengths get specified if you use them , I beleive the number most are using is .025", but it would be best to measure.

Big Al

iTrader: (1)

Your math is correct, except you are moving the center point, not just one end. Think about it.

Al 95 Z28

robss96dcm

Are you saying it should be .030 = .75 of a turn? And Why?

robss96dcm

Not sure if i understand you correctly, are you referring to the change in valvetrain geometry?