3100 Adjustable rocker arm Studs

[LELeach]

I just had the heads reworked on my 95 Buick Century 3.1. I read somewhere that the rocker arm studs have to be replaced when reinstalling the heads to allow for valve adjustment. Anybody have confirmation on this? I generally adjust the valves by turning the pushrod and tightening the rocker arm nut until the pushrod just feels friction then tighten 1/4 to 1/2 turn more. Will the nut stay tight using this method?

[SappySE107]

The stock setup is non adjustable. If you need to adjust it then you will have to replace the studs. The stock setup will not stay put unless its torqued down. Only other option is to get custom pushrods.

[LELeach]

Thanks Ben, I assume this means I just torque them down to 18 ft. lbs and let the lifters do their thing? LELeach

[SappySE107]

Yup, but if the pre-load is too much you would want to get custom pushrods. I dunno how much you had the heads decked, and the valve seats cut. You might be fine with it how they are.

[LELeach]

Thanks again!!! I just had the heads cleaned up, pressure checked and surfaced. The valve seats were in very good shape and were very lightly cut. I think it will be fine. I really appreciate your help and so does my college student daughter who's car I am repairing. LELeach

[jhill98]

Ahem, if you have a 1995 3100SFI, it should have the 10MM treaded holes in the head, and you CAN use 1986 IRON head studs that are 10MM/10MM with 10MM jam nuts. I did this on my 1990 3.1L V6 when I installed the CompCams, 1414-12 1.6:1 rockers. I got the studs for $1 and change each and then I purchased, the matching jam nuts.

Just talk to your GM Dealer, and get the adjustable studs, and nuts for 1986 Z24.

I took the intake off, installed everything, put it all back together except for the valve covers, and i adjusted the rockers until they stop making noise and then preloaded them about 1/8 a turn. If they didn't make noise I loosen them a smidge until they clicked while running, and then tightened until they stopped and then 1/8 turn more.

If you don't have the 1.6:1 factory roller tip rockers, this would be a good time to install the CompCams 1414-12's, and if you get that kit you just need the studs, it comes with the rockers, pivot balls, and nuts.

[SappySE107]

Adjustable rocker arms need more maintenance as well, so that is also worth thinking about. If it was decked just enough to make it flush, and the seats weren't cut a lot then you should be perfectly fine with the current system. I know I wouldnt be concerned with it on a basically stock setup with the stock cam and stock rockers.

The roller tips rocker arms arent much improvement over stock, and it doesnt sound like you are too concerned with a performance build up. If you were, I would go with the full roller setup using harland sharp rocker arms with the adjustable stud setup

[geoffinbc]

Even if you decked the heads .015 I still would not worry about the preload. I will still be within the range of the hydraulic lifter. I am almost certian they are not decked that much unless someone went crazy.

Do you know how much was removed?

[LELeach]

Thanks to all for the informative replies. I hope to crank it up this evening and I'll let you guys know how it goes. LELeach