fourthgen9534

I have a 85 oldsmbile motor the block casting # is 3161 i was wondering if this is an actual 85 or if not what year is it ?

replaced the entire valve train and i can tighten the rockers all the way and there's still huge valve lash and i cant figure out the problem ?

Timberwolf

I'm not familiar with Olds engines, but are the rockers pedestal mount or adjustable? If they are pedestal mount, they will be torqued in place. Hydraulic lifters need to be pumped up before you can set the lash as well. Empty lifters will not allow for an accurate lash setting.

angel71rs

Are you sure it's an Olds? Gm did a lot of mix and match in those years. If it is an Olds, it will have bridged pivots that tie two rockers and two tiny bolts that hold it down. These take a miniscule amount of torque, I think like 25-30 ft/lbs. I've seen guys crack the bejezzus out of the pivots cause they thought they must take at least 50-60 ft/lbs.

Here is a good site for Olds tech:

http://realoldspower.com/

fourthgen9534

yeah, it's got those wierd bridges. Actually the car belongs to a friend of mine, we've been messing with it for quite a while now. it just puzzles me that with all new oem rockers, bridges, and pushrods, and a new lunati cam, even with the bolts screwed all the way down, there's probably 1/4 inch valve lash. This the first time i've ever even seen these type of rockers, so i don't know what's going on with this. any help is greatly appreciated

angel71rs

Performance cams run a smaller base circle so that there is a greater distance from the base cirlcle to the lobe tip, giving you greater lift. If the cam has only a little more lift, differece isn't much, so you can just adjust the rocker a little on engines like small block chevys. Not the best solution, but it works. But the Olds isn't adjustable, so it throws things off. Even a valve job or shaving the heads can screw the valve preload. You need to get longer pushrods or adjustable rods. But the 1/4" clearance sounds excessive.

With offbeat engines like the Olds, a lot of times you are better off dealing with a specialist like Joe Mondello. His stuff isn't cheap and the guys at realoldspower dog him (refer to him as mondildo), but he knows the engines. When I ran Olds engines in the past, I bought from him and didn't have problems.