or maybe the brass cam follower although they were rising and falling of their own weight without the valve train pushing them. The camshaft is ETC 7128 and can be used on all the petrol and diesel engines up into about 1994. It has slightly more lift but will work in SII and SIIa and SIII engines as well as some others that are newer as I understand it. But it required a shorter pushrod which I have. It still begs the question since I had the head milled that 100 thousandths perhaps the pushrods are a wee bit too long. Okay so they will go in and can be lashed properly, but that doesn't guarantee they are the right length for the rocker geometry does it?
I am waiting to hear back from Turner Engineering and Cradock to see what they say.
 
Cradock said their pushrods are 7 inches long. I returned a note to clarify if they are actually 7 inches or like mine 7 3/16 inches. I'm holding on returning the rocker assembly to the engine until I have more information on pushrod length for my situation,
 
I hate to ask again.
But the "slack"?
The valve is off cam and the rocker moves, its the valve that is stuck?
I cant get past this.

Is the head off at the moment?

J
 
I hate to ask again.
But the "slack"?
The valve is off cam and the rocker moves, its the valve that is stuck?
I cant get past this.

Is the head off at the moment?

J
You're good. When it has jammed the rocker is in the valve max open position. The rocker is not free it is still compressing the valve spring. I don't really know about the pushrod. It seemed okay,but I did not try to rotate it. I just tried to put a 1/2 inch box wrench on the adjuster nut and that amount of movement released whatever was causing the jam and the valve snapped shut. No the head is back on. I took it off in desperation and dismantled each valve. They were all free but I spun them in a hand drill with some 400 wet/dry paper and hand lapped the valves just for good measure but they were fine. Seals good and in place.
 
Can you replicate this everytime when you turn the engine by hand?

How many valves stick?

If you can then try very carefully to push the rocker, it should move with hardly any pressure.

Need to read back, but I believe you have totally disassembled the rocker shaft. Are the rockers “handed” (inlet, exhaust) have you mixed some?

Just chucking questions I know but maybe someone will have a “light bulb” moment.

J
 
Can you replicate this everytime when you turn the engine by hand?

How many valves stick?

If you can then try very carefully to push the rocker, it should move with hardly any pressure.

Need to read back, but I believe you have totally disassembled the rocker shaft. Are the rockers “handed” (inlet, exhaust) have you mixed some?

Just chucking questions I know but maybe someone will have a “light bulb” moment.

J
no I can't replicate it. only happened a few times when I turn it over by hand. Beyond that it has been the engine running very rough, dying rather than idling, vacuum gauge reading ~5 psi indicating late valve timing or sticking valves. Rockers are handed and on the right and left way.
 
You're good. When it has jammed the rocker is in the valve max open position. The rocker is not free it is still compressing the valve spring. I don't really know about the pushrod. It seemed okay,but I did not try to rotate it. I just tried to put a 1/2 inch box wrench on the adjuster nut and that amount of movement released whatever was causing the jam and the valve snapped shut. No the head is back on. I took it off in desperation and dismantled each valve. They were all free but I spun them in a hand drill with some 400 wet/dry paper and hand lapped the valves just for good measure but they were fine. Seals good and in place.
Ok, let's isolate the problem. Get one to stick. Feel the pushrod for movement before doing anything else. If the valve or rocker are stuck then it follows that the cam has moved on and the pushrod should be in danger of falling sideways out of the tappet.
 
Okay, that is about where I am. Cradock said "std 7 inch pushrods". Turner said the pushrods they use for engines 7:1 going to 8:1 are #546798 and they work. My pushrods are 546798. So I will put the rocker assembly back on the engine and very slowly turn it over by hand to see if one sticks and go from there.
 

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