Mauiblubandit

I have a 90 formula 350, I put a hot cam in it, and I was wondering what length pushrods to use if anyone knew????

New2Chevy

iTrader: (11)

Use the stock length and just make sure your rocker arms are all adjusted for zero lash. I'm assuming your engine is still a roller and therefore using hydraulic lifters.

3rdgenmaro

iTrader: (9)

zero lash? i thought you only referenced lash while talking about solid cams. Ive always heard "preload" with hydraulic. If you just go to zero lash, you still need to preload the lifters.

Mauiblubandit

3rdgenmaro it says you have a hotcam. Did you use stock length pushrods?? Do you have 1.5 or 1.6 rockers? What kind of springs did you use?

3rdgenmaro

iTrader: (9)

I used the stock pushrods that came in my motor. I started with a 97 vortec motor. Im using GM LS6 "yellow" springs. Currently Im running the stock stamped 1.5 rockers, but whenever money allows, Im going to go to some COMP 1.6 pro magnums.

JakeJr

The term "Zero lash" may seem like a misnomer, but it's actually the term that's used. It has a dual meaning - "Zero lash" and "Zero Preload" - they both mean the same thing. Sort of like "lifter" and "tappet".

However, Zero PRELOAD is the more accurate way to my way of thinking.

Jake

West Point ROCKS!

3rdgenmaro

iTrader: (9)

gotcha, thanks for the info

five7kid

iTrader: (14)

Zero preload implies you have not tightened them beyond contact, which is also not correct.

1 turn down of preload beyond zero lash is the factory recommended setting.

AT9305RS

i am currently helping MauiBluBandit get his car going, we tried using the stock length pushrods that came with the motor, which is a rebuilt L98.

The stock L98 pushrods were 7.200? They were WAY too long, so we have a set of stock LT1 pushrods in there now, and they seem to work much better? can anyone explain this?

rx8ss

There could be several reasons.

Base circle of the cam could be different, deck hight differnences, valve stem hight differencs between heads, and others. That is why when changing a cam you should always check push rod length with an adjustable push tool. Just makes life easier.

New2Chevy

iTrader: (11)

[quote=JakeJr;4258485]The term "Zero lash" may seem like a misnomer, but it's actually the term that's used. It has a dual meaning - "Zero lash" and "Zero Preload" - they both mean the same thing. Sort of like "lifter" and "tappet".

However, Zero PRELOAD is the more accurate way to my way of thinking.

Jake

Thanks for clearing that up for me Jake. Zero preload could be taken wrong, however, and a guy might not adjust the rocker arms down enough to zero lash or the point where there is just a bit of resistance and it becomes harder to turn the pushrods with the thumb and forefinger....zero lash, to me, means just that--tightened up against the top of the lifter and the bottom of the rocker arm. Some guys might think, "There's no lash, therefore, there must be space between the pushrod and rocker arm cup....not good. And to all who may have questioned my post, the guy wanted to know about what length pushrods to use and didn't ask about adjusting valves...that's why I didn't include more information on adjusting valves.....To add, once there is no lash, and the proper pushrod length has been determined, then the rocker arm nuts are to be turned 1/8 to 1/4 of a turn....any further could result in valves not closing all the way because these are hydraulic lifters we're talking about.