Page 1 of 1

Rocker shaft seals

Posted: Wed Jul 24, 2024 6:15 pm
by EK DAZ
Hi All, What do grey motor owners use for the seals between the oil feed union and the rocker shafts?. Any substituted part that any one knows of ?. Mine are all hard and probably wouldn't seal stuff all.
Also on all of my spare motors and spare rocker shafts, the oil relief hole in the oil feed union have been blocked off with a screw. Any ideas why there is a relief hole there at all ? Regards Daz.

Re: Rocker shaft seals

Posted: Wed Jul 24, 2024 6:28 pm
by Blacky
Blocking the relief hole is a common trick to supply more oil to the rockers themselves - can't help you with the seals though

Re: Rocker shaft seals

Posted: Wed Jul 24, 2024 8:28 pm
by ardiesse
The relief hole in the oil pipe union is there so that there's just enough (but not too much) oil to lubricate the rockers and valves at highway speeds. But "just enough" is only the case for new rocker shafts and bushes. Once they wear, the oil leaks out too fast and none gets to the rocker tips or valve stems, number 1 exhaust valve being the coal-mine canary. This is why the self-tapping screw has been fitted to so many grey motors.

And the seals - if they're still in one piece, they're fine. Doesn't matter if they've gone hard. I think you could probably use the 1/2" tap O-rings as replacements, though.

Rob

Re: Rocker shaft seals

Posted: Thu Jul 25, 2024 2:23 am
by EK DAZ
Thanks for the info Blacky and Rob ,much appreciated. Regards Daz.