Topic: Rocker Shaft Assembly Orientation

[suskeenwiske]

Can you imagine having to tear this back down? It suddenly hit me that I never checked the Piston Ring End Gaps.

Question: does anyone know if it matters which way this Rocker Shaft Support is oriented? I rebuilt it the way I found it, in the front, but have since seen photos of the same Support on the back of the Shaft.

Thanks

Ray

[C5ZZ]

Ray, here are some pictures, hope this helps.

[suskeenwiske]

Thanks Steve.

Your photos show the support on the front of the Shaft and turned 180 degrees compared to mine. My problem is...should it be on the front of the shaft or on the back and turned which way? I've seen it both ways so maybe it doesn't matter, but because its position potentially affects the oil flow to the Rockers and the return of oil, I want to make sure that I have it where it belongs.

Frankly, I don't even know why it's there at all. I do know that it dumps oil back onto the head through a large hole at a good rate. Is it meant to be a pressure relief of sorts to prevent oil from squirting out of the Rocker Arms? Is it meant to drain the Shaft after engine shutdown for some reason? In which case, should it be on the back since the Engine is slightly tilted? Then again, placing it on the front seems better since it will fill the Shaft first before draining out of the hole which would get oil to the Rockers faster. Is it designed to help prevent sludge buildup by flushing the oil under pressure? In that case it would be better at the front.

I was hoping that we had an engine builder on this site that would know, so far no luck. If I never find out, I'll just have to try both positions to see which provides better oiling to the Rockers.

Thanks again...Ray

[WT8095]

The '75 MPC illustration shows the washer on the front support. In section 60.2 it's listed as p/n C0DE 6A508-A. The description reads: "COVER - VALVE ROCKER ARM FRONT SUPPORT OIL PASSAGE". Application is "Before 5/4/66".

A PDF of a vintage Mitchell manual also shows it on the front support:

http://vintage.mitchell1.com/PClubData/chassis/den81/V2D816068.pdf

[C5ZZ]

I agree, it should be on the front support, with the way the rockers
are oriented in the picture thats the only way it would go on.

[C5ZZ]

Ray, its in the front in other pictures I have as well.

[suskeenwiske]

Thanks as always Steve...haven't steered me wrong yet. And also thanks to you for the Link WT8095; just the kind of thing I've been looking for, not just for this but any number of other things.

I won't mention where or who but a nationally known supplier as well as magazine both showed their how-to rebuilds with the Shaft Support on the rear; hence all my confusion.

Thanks again to you both.

Ray

[WT8095]

You're welcome. Glad to help!