Olds 455 adjustable roller rockers

[78 salon 442]

Hey all my oldsmobrothers , I picked up a 461 olds for my 78 cutlass salon. It has a jm 22 25 h cam and harland sharp roller rockers. It is also 30 over. My question is how do I adjust the rockers? Cam is hydraulic and heads have guide plates. I only worked on non modified style engines and I don't want to screw this up.

 

[bracketchev1221]

First write down the firing order you have it. Then rotate the engine by hand until you see the Number 1 exhaust valve open. Now back off the #1 intake rocker until you have lash. Now tighten the poly lock nut until all up and down play in the pushrod is gone. Once you get there, tighten the nut another 1/4-1/2 turn, Then tighten the set screw. Then give the poly lock a little tug to set the entire nut together.

Rotate the engine in running direction until you see the next piston in the firing order exhaust valve open and repeat. Continue with all the intake valves until you have gone through the firing order.

For the exhaust valves, go back to piston #1 and rotate the engine until the intake valve opens and then moves closed. About a little more than 1/2 closed, adjust the exhaust valve using the same method as on the intake. Rotate the engine and continue through the firing order until all Exhaust valves are done. If you are good, you can do the entire engine in 2 rotations.

 

[81cutlass]

I have always thought the 'one at a time' method was the only way to do it but this video describes what I think is a lot faster and less complicated way to do it.

 

[fleming442]

Why are you adjusting them? If they were backed off for storage, that's fine. If it was running good then not so good, it probably wiped some lobes.

 

[78 salon 442]

Why are you adjusting them? If they were backed off for storage, that's fine. If it was running good then not so good, it probably wiped some lobes.

Rockers were loosened up for storage. I was told zero last quarter turn. Is there any other adjustment that I need to do? Do I need to use a feeler gauge ?

 

[fleming442]

I have always gotten the rocker on the base circle (above methods) tighten until you can't spin the pushrod with your fingers, then add a 1/4 turn.

 

[78 salon 442]

Thanks everyone for the help. I'll keep everyone posted on this. Motor is going into a 78 cutlass salon. 400 transmission and a 3.73 posi. Also have a edelbrock performer and a holley dominator intake. Can't decide which one to use. Carburetor is a 850 holley, but I think the 750 would be a better choice for the street. Car is only driven during warmer days . Rocket Power

 

[fleming442]

Just my personal opinion: I would think that a vacuum secondary carb might prefer the dual plane and a mechanical might prefer a single plane. 3.73 might not be enough gear for the latter, though.

 

[64nailhead]

EOIC - Exhaust Open Intake Close. Works on every motor no matter of gas, propane or diesel. Rotate the engine in direction of running rotation and as the Exhaust valve begins to Open - adjust the corresponding intake valve, then rotate until the Intake valve is Closing and adjust the corresponding exhaust valve. This is doing exactly as Fleming described - you're putting a lifter on the base circle of the cam and adjusting it.

The twist or giggle method for determining zero lash both work. Personally, when adjusting a hydraulic lifter I do both to confirm that I've not fubar'd. For a standard lifter with either 3/8 or 7/16 thread will put a 1/4-1/2 turn of preload in spec. But be careful if you have exotic lifters - they are do not require the same preload. I have a set of Morel's that want .025"-.040" and a set of Johnson's that need .040"-.060". But most stock style FT lifters will want anywhere from .025"-.050 (1/4 to 1/2 turn.)

If someone recommends the running engine method, then I'm out on that - spewing oil all over the motor and engine bay is not for me lol. It reminds me of sitting in the front row of the class when the teacher has a lisp and spits it rather than saying it.