transam1577

ok so i have a am wondering if any of you guys know of how much power i am lossing beacause ive got the car in my sig. and it has 1.6 rr sa pro mags, and stock lifters,pushrods,and when i set them i set them zero lash then a turn & a 1/4 (because thats what ALL DATA said to do)NOW i have driven the car about 1000 miles and runs fine,until yesterday i got it up to 6000rpm and i compressed a lifter and they only have 15,000 miles on them so i have now ordered comp lifters and chromoly push rods but i would like to know if that would cause a huge power loss haveing them to tight. Ohh and i will be setting the new to zero then 1/8-1/4 wich ever you guys recomend> THANKS

Formula350

iTrader: (3)

ALLDATA I don't think has the knowledge for roller rockers. And over-tight will result in open valves which yes, can cause power loss. Easy way to tell, do a compression test.

96capricemgr

iTrader: (1)

On a stock or stock replacement lifter 1/4 is not too much. On the current setup I have run as much as 5/8 and going back down to under 1/4 caused no noticable difference in performance.

Where guys screw up ROYALLY though is in how they find zero lash. How were you finding zero lash??

Formula350

iTrader: (3)

He's doing it 1-1/4 turn!

On stock rockers it's generally 1/2-3/4 turn past tight pushrod (where you can't turn them by fingers).

SS RRR

iTrader: (2)

Not sure what data you're getting, but most books I've read say one full turn past lash. No more. If you are really adjusting them 1 and 1/4 past lash then that is too much and yes your valves could be hanging open and your valves could burn up. As suggested you need to do a compression test.
Read up on shoebox's site on a few techniques on how to adjust valves:
http://shbox.com/1/4th_gen_tech2.html#adjust_valves

Formula96

i did it that way and had problems, make sure your lifters are pumped up (oiled), as you tighten don't twist the pushrod, go up and down with it, when you can't anymore, go another half turn and call it quits...

Slowmaro95Z28

You're not suposed to tighten until the pushrods don't spin anymore. That is way past zero lash. You're suposed to tighten until you JUST START TO FEEL DRAG ON THE PUSHRODS. Then go 1/4 - 1/2 turn or whatever your lifters call for.

SS RRR

iTrader: (2)

I've always wiggled the pushrod up/down until the play was gone to find zero lash. To me it is much more consistent and accurate.

Slowmaro95Z28

There are a ton of ways and everyone likes a different one. I used the info on Shoebox's site and it worked great. Either way, you do no tighten until the pushrod doesn't turn. That is way past zero lash. I'm sure you can agree on that.

Formula350

iTrader: (3)

If there's no oil on the rockers or lifters, then I wouldn't say it's way past zero lash.

Slowmaro95Z28

If there's no oil in the lifters they will compress a lot more easily than if they had oil pressure in them. This is why you don't go until the pushrods don't turn. I was just offering help from my experience. I'm not here to argue over it. As I said we all use different methods.

Formula350

iTrader: (3)

ON the lifters, not IN the lifters I know you have to prime a hydraulic setup before doing rocker adjustments.

Slowmaro95Z28

Sorry for the misunderstanding. Maybe I should have stated that I soak everything in oil before install and then pour some more after everything is in place.

Tricked-Out-Toy

iTrader: (4)

The ONLY way to get it right is with the engine running. friction on the push rod ends is different across the board, what feels lile drag to one person doesnt to the next. when its running the :ticking" sound is unmistakable! get a stethoscope and be done with it. you will never have to worry again. I run my Morels at about an 1/8th of a turn past Zero. when its that close you cant "feel" zero very accurately but you sure can hear it!

Formula350

iTrader: (3)

I think my buddy generally does the running motor bit, but on vehicles that are his. Since working on customers cars, time is money and the running less method is quicker (and less messy heh)

96capricemgr

iTrader: (1)

Agreed. Always do static adjustments myself and cold at that. We are talking hydraulic lifters here, the very purpose of such is to take up slack and tempature changes.

Running adjustment is not necessary, that or this is another thing I am doing wrong which is handicapping my car, Imagine what it would run if I listened to everyone on the net, I'm guessing 13s.

BattleShip

Well I used the newest desktop configuration 2099, with the LT1 rammed horn, shoe and toe and it says depending on air velocity, cross sectional area, angle of the dangle and stone heat

13.7913. It may be way off, but look how precise it is?

Formula350

iTrader: (3)

You forgot to factor in ego size.

zlover129

iTrader: (10)

i go 0 lash (no up and down movement) and 1/8th to 1/4 turn max, i had overtightened rockers before and i felt a difference between the old setup and now.

lt1-xjs

Alway's cold 5/8 plus 1/8 tweak' , work's for me. Rotate twice methed.