forged rockers w/bushings

[MST0118]

Checking to see if anyone know if the forged rockers on the old 911 engines (65, 66 & 67) that had bushings had holes drilled in them for oil circulation purposes similar to the newer cast iron rockers? I've looked on this forum and see different varieties of forged rockers, like those of early 911s and rsr, etc.. If someone has a stock set with original bushings, can you post a picture of the inside of the bushings? Thanks.

[DRACO A5OG]

I would contact John at DRC, he would know for sure.

[MST0118]

Yes, good idea. Was just hoping that someone could just post a picture of one that came with bushings originally as I thought there may be different varieties out there including some that had no bushings. Think the oiling system was different in those engines. That made me think that perhaps the bushings and rockers weren't drilled but I'm not sure and I've seen some pictures of forged rockers with holes for oiling but not sure if that was a subsequent modification.

[chris_seven]

Original forged rockers in 1965/66 engines did have Glyco Bushes fitted and they were drilled with oiling holes in the same position as all subsequent rockers.


The photograph below is an original 65 part taken from a 901/01 engine that has centre-lube cams.



The centre lubed cams were designed to lube the cam to rocker faces and not the shaft bore.

The first rockers without bushes were the 906 'solid' rockers used in Carrera 6 and 911R engines.

They had no bushes but had oil retaining grooves machined into the lower half of the shaft bore.

They were also used with a 'Motorsport' Rocker shaft which had a hardened surface.

I believe these rockers were also used on the ST, RSR, 934 and 935 engines.

In 1967 the forged rocker was replaced with an Investment casting which had oil feed holes but no groove and no bush.

They were used with stock shafts without any treatment and do have a tendency to gall and damage the shaft.

They were replaced in 1969 with a cast rocker using the original style of Glyco bush which stayed in production right up to the 964 although there are several slight variations.

We have re-manufactured the early style of forged rocker, specifically for use in FIA Appendix K Period 'F' Race Cars as good used parts are increasingly hard to find. They will have a much better fatigue life at high rpm than a cast steel component.

We have forged these parts from 300M-VAR, heat treated and stress relieved, shot peened, REM surface finished and Plasma Nitrided rather than chrome plated the wear surface.

We have also extended the 'pad' length to the same dimension as was used on the 906 engine which is more appropriate for use with a high lift cam

The bush is supplied by Glyco and precision honed after installation.


We have also re-manufactured a rocker shaft which is surface treated using a ferritic nitrocarburising treatment.

[MST0118]

Thanks Chris. That's exactly what I was looking for.

[Ultrafast993]

Originally Posted by chris_seven

Original forged rockers in 1965/66 engines did have Glyco Bushes fitted and they were drilled with oiling holes in the same position as all subsequent rockers.


The photograph below is an original 65 part taken from a 901/01 engine that has centre-lube cams.



The centre lubed cams were designed to lube the cam to rocker faces and not the shaft bore.

The first rockers without bushes were the 906 'solid' rockers used in Carrera 6 and 911R engines.

They had no bushes but had oil retaining grooves machined into the lower half of the shaft bore.

They were also used with a 'Motorsport' Rocker shaft which had a hardened surface.

I believe these rockers were also used on the ST, RSR, 934 and 935 engines.

In 1967 the forged rocker was replaced with an Investment casting which had oil feed holes but no groove and no bush.

They were used with stock shafts without any treatment and do have a tendency to gall and damage the shaft.

They were replaced in 1969 with a cast rocker using the original style of Glyco bush which stayed in production right up to the 964 although there are several slight variations.

We have re-manufactured the early style of forged rocker, specifically for use in FIA Appendix K Period 'F' Race Cars as good used parts are increasingly hard to find. They will have a much better fatigue life at high rpm than a cast steel component.

We have forged these parts from 300M-VAR, heat treated and stress relieved, shot peened, REM surface finished and Plasma Nitrided rather than chrome plated the wear surface.

We have also extended the 'pad' length to the same dimension as was used on the 906 engine which is more appropriate for use with a high lift cam

The bush is supplied by Glyco and precision honed after installation.


We have also re-manufactured a rocker shaft which is surface treated using a ferritic nitrocarburising treatment.

Interested on a set, please PM me a price, cheers.