[Thomas]

There is a significant difference between the inlet and outlet sides of my rocker arms and bushes. On the inlet side, the bearing is installed plane-parallel in the housing and the arm has a washer.  On the exhaust side, the bearing is shifted inward and the arm has a second washer (spacer ring?). Has anyone seen this on their housing? Is this correct at all?

[Thomas]

The rocker arms/shafts are out. Chris Odling explained that the nuts should be turned only once or twice so that the shaft/keys can not be pushed into the bush. The procedure is highly "aggressive" and does indeed need brute hammer force. Later I will write a text about it because such force won't be applied without knowing how to proceed...

I am now in touch with Chris about new bushes.

Cheers, Thomas

[klaudius]

I'm sorry that I misnamed the rocker arms. I meant the inside lever. If everything is resolved and the shaft is ready to be pulled out, caution is now required. If the safety wedges are still in and a bit sharp-edged, the shaft will be stuck halfway. The safety wedges rub a pattern into the bush. It all depends on the wear and tear of the whole. Greetings Claudius

[singleminded]

Another point to remember is that to get oil to lubricate the rocker arm and bushes there has to be SOME clearance, maybe only 0.001" ( 0.0254 mm) so the possibility of leaks exists.

[singleminded]

The external rocker arm is outside of the rockerbox.The arm that has the Woodruff keys is inside the box.
By loosening the nut that holds the inside arm and hitting it with a hammer the arm should come free of it's taper. You then remove the inner arm, and the rocker shaft should be able to be pulled out of the rocker box..You will only then find out if the rocker shaft will come out without having to remove the Woodruff keys, or remove any burrs to make it slide out..
If you think that the bushes are so badly worn that they are allowing too much oil past you should be able to feel the play in the rocker shaft without stripping it apart..PLEASE fully inspect it BEFORE you strip it down. I have excess play in my M90 inlet rocker bushes and it leaks a little oil..It is almost impossible to stop the top end from leaking a little, as I found out from Chris Odling.
Also the bushes may not be bronze or oilite..Mine are hardened steel in the 1932 rocker box, not so easy to replace..

[Thomas]

I am really sorry, but I just do not understand. The wedge (key) is on the right side, the rocker arm is on the left. How and in what order do I take all these things apart? I suggest we just continue in German. And who wants to have it translated can simply use this: https://www.deepl.com/translator

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Es tut mir wirklich leid, doch ich verstehe es einfach nicht. Der Keil sitzt auf der rechten Seite, der Kipphebel auf der Linken. Wie und in welcher Reihenfolge nehme ich die ganzen Sachen denn nun auseinander? Ich schlage vor, wir machen einfach in deutsch weiter. Und wer das übersetzt haben will kann ganz einfach das hier nutzen: https://www.deepl.com/translator

[klaudius]

The gentle blows that would be something is always good to release the rocker arm from the shaft. Now the shaft is still in the box, the safety wedges still sit on the conical shafts (mostly bombproof). Actually, they fit through the box. If, however, the wedges have formed small edges that no longer fit through. It helps either to rework (smooth) the wedges or to expand them.
I hope that my horrible English is a bit understandable. I can't do better than that.
Greetings Claudius

[Thomas]

Well, I will now first dismantle the box and see if the leak really comes from there.

Yes, I have the spring washer on there too. But you say that hammering out is correct. On the other hand, you warn about a sharp edge on the wedge that can damage the bush. If I just knock the axle through, I can't control that at all. I still don't understand this.

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Na ja, ich werde jetzt erst einmal den Kasten abmontieren und schauen, ob das Leck wirklich dort herkommt.

Ja, die Federscheibe habe ich auch da drauf. Aber Du sagst, dass das herausschlagen richtig sei. Andererseits warnst Du vor einem Grat am Keil, der die Buchse beschädigen kann. Wenn ich die Achse einfach durchschlage, kann ich das doch gar nicht kontrollieren. Ich verstehe das noch nicht.

[klaudius]

A spring washer sits behind the rocker arm. At least that's the case with 32 models. Your idea is good. That's what I did too. If the rocker arms are off, it is now necessary to check whether the wedges fit through the hole or have to be removed.
With me they passed. Sometimes they form a degree on the cone that is sufficient that the whole thing cannot be removed. It is best to remove the entire box.
It is built in a simple manner but very well thought out. That's what i appreciate so much about english motorcycles. Greetings Claudius

[Thomas]

I opened the rocker box again and unscrewed the rocker arm nuts. I can see two gaps probably containing the mentioned Woodruff Keys. When watching the attached graphic one tends to hammer with a brass punch onto the axle to drive it out. However, that seems a delicate affair with the risk of damaging something. Do you have any idea for the next step?

Cheers, Thomas

[Thomas]

That was my experience when I tried it. As I said, I had the feeling brute force is required. But how without damaging something??? A special extractor?

I just try to contact the 1937 Model Interest Group but can't find the email list (where can I get it from?). Or I better send a message to Chris Odling.

[singleminded]

The rocker arms are a taper fit with Woodruff keys to maintain the correct alignment..The arms can be difficult to remove from the tapered rocker shaft.

[klaudius]

It is exactly. If the securing wedges of the rocker arm are not removed from the shaft or if they are properly deburred, they simply remain in the socket in a certain length. Greetings Claudius

[Thomas]

When thinking your idea over I see a problem to explain the oil flow: If the bush is worn it would have to be very worn to give the 'additional' valve clearance - if there was too much oil then it wouldn't wear so quickly either. Additional oil would also end up going down the valve guide and give a smoky exhaust, which is not the case. The rocker arm/bush assembly appeared good on inspection. But yes, we cannot ignore any possibility. I have to find the leak...

I am not sure if the rocker arm removal is really that simple. I've tried it but wasn't successful. In fact, my problem was "remove the rest and pull it out". There was nothing to pull out – it blocked. I felt I had to apply brute force and better stopped at a certain point. Unfortunately, a reasonably understandable description is missing in the club site and forum. Checking the bush requires removal of the box (the rocker arm shows no play, when testing manually in situ). Before I start doing it, I'll talk to my engineer in a local engine workshop.

Cheers, Thomas

[klaudius]

At 32 it's simple. It will certainly be the same with your model. Unscrew the screw, remove the rest and pull it out. You have to be careful with the safety wedges (are they called in English?) Of the rocker arm. They form a sharp edge after years of work that do not fit through the bronze bushes. Should be better developed. Most of the time the beasts sit bombproof. Then it's better to remove the edges with a lot of love, rinse well and then pull out the waves. The bronze bulls suffer with violence and get reefs.
As I understand it, the oil on your model comes from the nozzles of the lid onto the rocker arms. The overpressure created in this way is compressed through the two bores. Good simple solution.
Greetings Claudius



.

[Thomas]

Yes, Claudius, there are three nozzles in the rocker box cover. They are fed by the puipeline coming from the timing case. I believe that the oil then finds its way through the holes (I have only one active hole) as indicated in my last post.

I agree and already thought about the rocker arm bushes, too. For checking I would need to dismantle them but don't know how.

[klaudius]

I don't know the model in detail, but could it be that the spray nozzles for oil mist are located directly in the lid? The holes in the head are only for pressure relief.
The rocker arm shafts run in bronze bushes. Could that be responsible for the strange color of the oil?
Greeting
Claudius

[Thomas]

Thanks a lot together!

There are two (feeding?) holes visible inside the rocker box but I do not have two tubes under the box and no corresponding holes in the head. On the exhaust side they are missing. I also do not have felt pads. There is a supply line from the timing case to the rocker box, as I have shown, but no ball spring.

All this doesn't explain the excess oil at the exhaust valve, especially since lubrication is missing (no tube) and even if the (new) guide is now worn (why?). The excess oil has a strange colour but there is no water in it (checked it). Blow-by at the piston rings would introduce dark oil and the plug looks perfect. But something is wrong since I overhauled the motor. I didn't have this problem before.

Yesterday I discovered a valve gap about ten (!) times more than recommended in the manual. I must have been drunken when I did it.  Hopefully that explains the nailing noise. I will check it this week. Today it's cold and raining. 

Cheers, Thomas

[klaudius]

Am I correct? Thomas head has the 2 tubes under the box and corresponding holes in the head. Perhaps the supply is regulated differently inside than the 32 models. Why should Sunbeam go to the trouble if it hadn't worked? Perhaps the supply line and its spring, ball spring, could have something to do with the malfunction? Look in here. Greetings Claudius

[singleminded]

The felt pads in my rocker box control the amount of oil that feeds to the guides, i found that the density of the felt makes a difference to the amount of oil going to them..i eventually found that 2 pads made from a felt leadmakers apron about 3/16"(about 5mm) works fine.I have the same in both my 1932 9A engine and my 1932 M90 engine.
You can see the oil feeds to the head and from the rockerbox,the tubes are missing in the picture, and the guide is drilled in exactly the same way..
The reason for saying the leak could not be from the exhaust guide oil feed is because there is no feed to it, and the head looks like it was not drilled for a feed.
The guide in the photo is an old one i used as a pattern for the 9A, the 90 head is drilled for an oil feed the same as the 9A.

[klaudius]

The 32 heads have felt plugs in the channels. I renewed mine because they were quite dirty. Valve guides also have a hole for oil. Of course, later construction is also a little different. It is best to search everything point by point. Please excuse my english.

[Thomas]

Aha, my exhaust valve too squeaks sometimes and I then need to give a shot of oil. You say it was an easy fix. Did you install a second tube? If yes, how? And what exactly do you mean with "it is not leaking from then". What part leaked? There is no breather in myrocker box but only in the timing case. Would all that explain my leakage at all?

[singleminded]

That is surprising,my 1932 bike has them on both valves guides, in fact i had a problem with the exhaust valve squeaking because it was not getting oil. It turned out to be an easy fix.
Well thats one place it is not leaking from then.
The 1937 parts list mentions a breather in the rocker box is that OK?.

[Thomas]

Ah, ok, I get it.

No, there is only one tube. I was a bit surprised, indeed, during dismantling because I too expected one on the exhaust side. But strangely there is only one on the inlet side and a blind plug at the exhaust valve.

[singleminded]

look at the picture of the rocker box you posted..There is a small tube on the inlet side which I am sure goes into a hole in the cylinder head to lubricate the valve guide..I could not see one on the exhaust side of your rockerbox..i may be wrong and you bike doesn't have them but if there is one for the inlet I would think that there should be one for the exhaust..

[Thomas]

What and where is the valve guide oil tube? I am lost. 

[singleminded]

I can only see one valve guide oil tube..Is the other one in the head? if it is not there then you might possibly get a leak from it.

[Thomas]

Yes, the oil shouldn't come along the rings (although I have no better explanation for the strange colour as if from rust). But I see no possible leak and I do not see it coming from the exhaust... very strange. I'm completely lost.

[singleminded]

If you had oil coming past the rings the exhaust would be smoky..Is the oil around the valve stem or from the exhaust port/ joint.
You may have some sort of leak in the rockerbox area..My earlier engine suffers like that if i get too much flow to the rockerbox,but it is a different design to yours.

[Thomas]

I am still not sure about the barrel/head surfaces. They both look nice. I have a 1937 Model 9 and checked the breather. It looks fine, too. But I found excess oil at the exhaust valve. It has exactly the same color as the oil on the cover plate in front of the barrel. It seems as if the valve spits oil.
But what exactly might that be? Oil passing along the piston rings and the valve guide? If yes, how?

[VicYouel]

The head and barrell do need lapping together with grinding paste just like you do with valves and the seats. Otherwise they will leak and sealant will not do the job,

Most models have a breather for the crankcase..... cannot  recall your model but it is usually bhind the magneto chain case and on 1932 models  for example a pipe lead to the rear chaincase
Hope this helps
Vic

[Thomas]

Hm, both not, Vic. I just cleaned the surfaces but left them untouched then. Lapping? What about Wellseal and such? Breather spring and plate? What and where are they? Do you have pictures?

[VicYouel]

Just wondering whether you "lapped" the head and barrell with grinding paste?
Also did you replace  the breather spring and plate?
Vic

[Thomas]

Hi all!

During and after a recent run I noticed two things which I like to hear your opinion about.

First, there is a slight nailing noise at low thrust and at idle. Because of the noise at full power I cannot say if it is there then or not.What can it be?

Second, I have the impression that oil mist on the motor is increased after overhauling it. In the pictures one can see it on the oil tank, the barrel fins, the horn and on the support plate in driving direction. It seems that it comes from the head-barrel connection (there is no gasket). Is it possible that I need to tighten the head bolts again after a recent overhaul?

All ideas are appreciated.

Cheers, Thomas