crainholio

iTrader: (2)

For an LS engine that has fixed-height pedestal rockers, that advice is as f#cked up as a football bat.

crainholio

iTrader: (2)

The method you used ensures the lifter you're measuring is on the base circle, so your measurements will be accurate assuming you're using the pushrod tool correctly.

Ignore the other guy's post about rocker tip contact pattern on the valvestem surface...not applicable to pedestal rockers unless you've changed valves and/or rockers.

This geometry applies to stud-mounted rockers where the rocker height is a variable that has to be accounted for in the pushrod length. Not the case w/ an LS engine running stock rockers or other pedestal-mount pieces.

allan808

iTrader: (3)

Yes i do know how to use the tool, every full turn is 50.right? lol.. ive tryed three different length pushrods! and measured 2 different ways!
The first was the eo/ic meathod wich cam out to this.
7.400 pr. int 1.6 turns exh 13/4 turns to 22lbs
7.375 pr. Int 1.35 turns exh 1.45 tuns to 22lbs

The second measurement i did was found 0 lash by slowly turning the tool and taking on and off the rocker till i could tighten the bolt snug and have 0 lash without pushing the plunger. This is what i came out with.
Pushrod length. 7.270+/- without preload. Added .80 for preload to get 7.350 pr. I then put rocker on and turned the bolt to 0 lash, then counted 1 turn to 22lbs.
the 2nd measurement confuses me.

A little info on the engine, ls3 with .40 mls gaskets. Heads have been cnced & valve job. Intake valve sits in .14 and exh .11, im pretty sure he cut the valve tips to factory height.

allan808

iTrader: (3)

Also the heads are not milled.

allan808

iTrader: (3)

And im useing stock rockers & ls7 lifters.

X-Bomb Racing

iTrader: (1)

Thanks for the advise. I am very new to the ls and i came from the old school sbc. I assumed it worked like a sbc does. The only point in measuring push rods in a sbc is to get them to ride and push down in the center of the valve stem.
I'm about to go through this myself here shortly and i have a feeling im gonna be learning something new..lol OP scratch what i was saying

allan808

iTrader: (3)

Im in the same boat, my first ls!

X-Bomb Racing

iTrader: (1)

Virgins lol

crainholio

iTrader: (2)

If you do a search on "LS7 lifter preload" you should find a long thread that has good info for you in helping select the right pushrod length based on your measurements.

allan808

iTrader: (3)

Lol, ls is a lil different.

allan808

iTrader: (3)

Ok so this is where im at! eo/ic method @7.375 pushrod i get right below 1 1/2 turns to 22lbs.
Now when i measure just to 0 lash i get 7.270+/- then add in .75 of preload i get a pushrod length of 7.350. this is whats confusing me! what one should i go with?

td1168

iTrader: (2)

That's the funniest thing I've read on this forum since becoming a member! Football bat!