Hi all!
In the cylinder head of my 1937 Model 9 there is a hole which apparently is to lubricate the inlet valve guide (feed.jpg). It is supplied with oil by a needle or better cone valve in the rocker box (valve1.jpg), which is adjustable (valve2.jpg). At one of our online club meetings, Chris Odling mentioned that the Marston works changed this design frequently in the 1930s. Some machines have such tubes for both guides, others have only one, and still others have none. It seems that the engineers searched for a good valve lubrication, tested various designs, but could not find a final solution. Now I have discovered a lot of oil in the three central head grooves between the four upper fins. As a result, the hot engine steams like an old steam engine.
I had new valve guides installed some time ago, and I'm pretty sure my engine shop didn't put a lubrication hole in the inlet valve guide. So this line is blocked and it could well be that this feed is overflowing and the oil is leaking towards the head grooves. I suspect that the inlet bore needs lubrication, while the outlet bore is lubricated by the exhaust gases. However, my old guide did not have a corresponding hole either.
So my question: was there originally such a hole in the inlet valve guide for lubrication?
Cheers, Thomas
Hi
My 32 M9A already has holes in both guides. Oil comes in 2 tubes from the box. I renewed both guides. It is a bit difficult to place the holes in front of it, but it is possible. Later models are certainly more mature and I think they also have the lubrication in them. Would be very bad if not.
greeting
Claudius
Thank you, Claudius! Yesterday I talked to Chris Odling and he confirms that there should be a lubrication hole at least in the inlet guide. He also mentioned the tiny amount of oil passing along the piston is sufficient for the exhaust guide and that the soot in the silencer should be somewhat oily/greasy.
Cheers, Thomas