Rover V8 - rocker arm and shaft specification.Advise needed

[Austinambassador]

Hi,

I bought a set of new pattern rocker arms and shafts for my Rover V8..problem is the new rockers seem too loose on the shaft.

The shaft measures 20.53mm and the rocker bore is 20.65.

The supplier assures me that the parts are to origonal Land Rover specification. But surely 0.12mm is too much clearance on brand new parts ?

Thanks all

[donboyfisher]

They should be a fairly snug fit fit, but the rockers should be able to rotate smoothy on the shaft. Remember that oil has to pass from the shaft into the rocker and seep between the rocker and the shaft itself.

[Austinambassador]

Thanks, but does anyone know what the tolerance Leyland specified for the clearance between rocker shaft and arm ?

[Pupp]

There's loads of anecdotes on here about sloppy pattern shafts and rockers resulting in lowered oil pressure and excess oil in the rocker chest... worth a search in the TVR area

[debaron]

Austinambassador said:

Hi,

I bought a set of new pattern rocker arms and shafts for my Rover V8..problem is the new rockers seem too loose on the shaft.

The shaft measures 20.53mm and the rocker bore is 20.65.

The supplier assures me that the parts are to origonal Land Rover specification. But surely 0.12mm is too much clearance on brand new parts ?

Thanks all

YEP! Just going through this myself with a set from a well know online supplier...

What was the outcome in the end?

[Pumaracing]

I've rebuilt Leyland rocker assemblies for MGB race engines and the new bushes are reamed to almost the exact size of the shaft. Clearance is 1/2 thou to a thou tops. Anything more is shagged before it's started up.