Box Stock

Clone Rockers Jam Nut To High

Assassin

Assassin

New member
Rebuilding a clone for local use. Im having an issue with the jam nut on the rocker arm stud being to high up with only half the nut being on threads. Setting valve lash at 0, 0.10 head gasket, same pushrods, lifters, cam that originally came out of this engine that ran very well. Any help would be great!
 
Did you remove a guide plate? Or mill head?

Either way, you can put a washer between stud and head to raise bolt to rocker. If you milled head, check for binds, rocker stud to rocker at full lift.
 
95 shaw said:
Did you remove a guide plate? Or mill head?

Either way, you can put a washer between stud and head to raise bolt to rocker. If you milled head, check for binds, rocker stud to rocker at full lift.
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That is one way but not legal if he is running a rules program
 
I've done a normal rebuild. Piston, rings, rod, seals, gaskets. Everything else is the same from the original. I will be running AKRA.
 
If I go with a 0.15 it would help but not alot, and I'm trying to keep everything in exact spec as it was. Very odd issue I have on my hands
 
Lash cap on wrong side ?
Lifter stuck up ?
Something physical has too cause it .
The other one is perfect ?
You rotated engine to be sure valves closed .
 
Everything moves freely, engine is at TDC. Rotated multiple times. Lash cap is on exhaust side for compression release. Maybe original head gasket was 0.15 before installation and 10 races. But I don't think 0.05 would help me significantly.
 
Assassin said:
Everything moves freely, engine is at TDC. Rotated multiple times. Lash cap is on exhaust side for compression release. Maybe original head gasket was 0.15 before installation and 10 races. But I don't think 0.05 would help me significantly.
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Go back and set valves again, by rotating engine in the direction it runs. Set intake valve when exhaust valve just starts to open. Rotate on until intake just starts to close. Set exhaust.

.005 of an inch will not correct what you are looking at.

Did you grind valves and cut seats?
 
Yes everything was cut and seated properly, funny thing is (not being an ass) I did the exact same thing you just said. Clones don't have compression during initial start, setting valves at 0 close to -0.05 from what I was told.
 
Have you checked valve spring installed height?
Did you have to shim to get to the minimum?
Grinding the valves, and cutting the seats moves the valve tops upwards relative to the tops of pushrods. Cutting the deck and head lowers the head relative to the top of pushrods.

Setting using the method I gave insures you get on the base circle of the cam. Lots of engines get valves set during overlap when using the tdc method.

The compression release holds the exhaust valve open during the compression stroke to allow easier starting. When the rpm increases enough, the release quits interacting with the exhaust lifter.
When the engine warms up, the block and head (aluminum) expands more than the pushrod and valves do. Therefore, more lash on a warm engine vs a cold engine.
Setting valves to 0 on a warm engine will hold the valves open when the engine cools.
 
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