Square four Mk1 rocker

[markus.nikot]

I always install the shafts with the oil holes facing downwards. That way, nothing squirts out at the top.
The force comes from below, and that is where the hydrodynamic lubrication wedge should be.

[Chris Sealy]

I fitted my shafts with the oil holes facing downwards as well, just in case it helps a bit with lubrication, but there is a groove running all the way around the shaft from the oil hole. Therefore with the incorrectly drilled rocker, the oil has little resistance to flowing straight out of the top.
The stud, mentioned by Will restricts the oil flow to a maximum; oil temperature dependant; rate. If more than one of these rockers is fitted, it may be that there is zero oil pressure in the rocker shafts. I would expect this to result in accelerated wear of the shaft/rocker bearing surfaces.

[nevhunter]

Is excess wear common? It WAS with Norton Commandos when People disconnected the Oil feed to the rockers completely. Generally a HEAD of a few inches is enough. Tapping off the return line is enough. The load is intermittent. I'd be more concerned about the camshaft and the followers getting oil. Nev

[Chris Sealy]

What we need Nev, is for someone who has these incorrectly drilled rockers fitted to come forward and tell us if they result in worn parts.
Any takers?

[nevhunter]

Yes indeed Chris. That would be helpful. Nev

[Duncan J Robertson]

A bit late on this, but I have just had a stuck inlet valve on my MK1.
Having rebuilt the engine bottom up, I started having problems with number 2 firing or so I thought, it proved to be the inlet valve sticking open.
On inspection the rocker was different from the others, did not have any oil holes drilled to allow oil to flow to the valve.
But yes shaft needs to be installed oil hole to the bottom or it will shoot out of the top of the rocker

[markus.nikot]

Duncan,
check which oil you're running.
It should have a high flamepoint.
For example and with good experiece I would recommend this MOTUL 3000 20W-50 4T 240.0 °C / 464.0 °F

Markus

[david.anderson]

While off topic and probably not the cause of a sticking valve mentioned above, a valve picking up in a guide is not always the fault of the oil, or lack of it. Stainless steel valves are notorious for picking up in a guide. Steel valves have chrome plated stems. While many stainless valves do have the stems chrome plated, there are also many where the stem is just polished stainless steel. A stainless steel stem will pick up in the guide unless the guide is made from the correct bronze. That said I have also had older stainless steel valves where the chrome on the stem has worn through and then they pick up fairly quickly.
The correct bronze for valve guides to be used with stainless steel valves is C86300 Manganese Bronze which is impossible to buy here in Australia, so I have to use a lesser grade of Manganese bronze.
David

[nevhunter]

David is spot on about the Galling. Nitriding Helps. (Black finish) Surface Hardened. NOT suitable to run rollers on. Nev