Rocker shaft. Whats the max clearance?

[rich112]

What clearance would be OK on the rocker shaft?

I can feel some ridges on mine. I'll measure up tomorrow and see, but rockers feel a bit rattely!

Replacement shafts seem pretty cheap but I have volvo rocker arms and I'm not sure where I can get them or if they can be rebushed?

[rich112]

This is a volvo shaft as its 22mm.

I'm measuring 0.13mm clearance worst case, so they are a bit worn.

I would guess 0.05mm would be the right clearance?

[ChrisJC]

It's a good question. I have no idea as each time I rebuild an engine, I buy new shafts and rockers as they are so cheap.

It means I have quite a few old rocker shafts though!

Chris.

[paul c]

There are no figures in any of the Rover manuals that I have seen, they only tell you to inspect for wear, if any is present I guess that they expect you to replace them. I replaced my shafts and rockers, though the replacement rockers I got were steel rather than the expensive alloy ones.
Is there any benefit to having adjustable rockers if you are using hydraulic lifters? I would have thought it of no purpose if the pedestals have been shimmed anyway.

[rich112]

There are no figures in any of the Rover manuals that I have seen, they only tell you to inspect for wear, if any is present I guess that they expect you to replace them. I replaced my shafts and rockers, though the replacement rockers I got were steel rather than the expensive alloy ones.
Is there any benefit to having adjustable rockers if you are using hydraulic lifters? I would have thought it of no purpose if the pedestals have been shimmed anyway.

I have no idea why this motor was built the way it was, but for some reason they went with adjustable volvo rockers and shaft. I doubt I'll find find new volvo rockers and shaft anywhere? Might just have to revert to stock, which means new pushrods and pedestals too...

[SuperV8]

This might be a useful thread, I had some issues a few years back with some cheap rockers being a very loose fit on the shaft.

Took a while to find it as the forum search wasn't picking up older posts!

http://www.v8forum.co.uk/forum/viewtopi ... c&start=15

[Richard P6]

Is there any benefit to having adjustable rockers if you are using hydraulic lifters? I would have thought it of no purpose if the pedestals have been shimmed anyway.

They allow you to get the same pre-load on all cylinders, which depending on how far they are out, does make a positive difference. My 4.0L has adjustable push rods, which amounts to very much the same thing.