Author Topic: Solid copper rocker box gaskets  (Read 2497 times)

Offline TT John

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Re: Solid copper rocker box gaskets
« Reply #15 on: 18.06. 2015 11:08 »
Clive.
I do not sell my gaskets through e-bay, I only sell to people on forums or at motorcycle shows and I have not had any complaints yet.
However, I have just discovered another place where oil is leaking and I thought was the rocker box but I found it was leaking from where the dynamo is located, same symptoms as leaking from the rocker box but with the turbulence when going along at speed carried the oil over the head and it was splattering the mag & carb, so I had to strip it down renew the cork in the breather timing cog, plus all the other gaskets on the timing side. I am hoping that it will be okay now.

Regards TTJohn

Offline Gasket4450

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Re: Solid copper rocker box gaskets
« Reply #16 on: 17.08. 2015 14:33 »
Hi John.
                        Just a word or two in praise of the copper gaskets. I have an A10 and an A7 ( the latter having caused me no end of problems over the last year or so, all documented elsewhere on this goodly forum ), both fitted with copper rocker box gaskets, and both heads are leak free. I don't think they are yours, but they certainly work for me. Also, so much easier to fit the rocker box after maintenance, even with the ubiquitous BSA ' comb ' . Just my opinion.

Norman 
1960 A10, alive and thriving. 1959 A7 living on borrowed time !

Offline Phil

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Re: Solid copper rocker box gaskets
« Reply #17 on: 05.09. 2015 11:34 »
Thanks John received Mine this morning, just in time for the head to be refitted.

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Re: Solid copper rocker box gaskets
« Reply #18 on: 05.09. 2015 12:23 »
Just make sure they are well annealed and the rockerbox face is flat. just re-did mine yesterday, no leaks.
Cheers
'51 A7 plunger, '57 A7SS now A10CR,  '83 CB1100F, 88 FXST .
Australia
Muskys Plunger A7

Offline jjbsa

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Re: Solid copper rocker box gaskets
« Reply #19 on: 16.09. 2015 22:29 »
Hi,  I'd like to contribute about these copper rocker box gaskets.  I've been making and selling these under the Ebor Bikes badge for a while, both from my website and eBay UK.  From what I've read on this thread, many people but not everyone have found joy with them.  When problems occur, I believe they come from the annealing which to date has been done by the customer, and it is possible that if significant amounts of oxide have to be removed as a consequence of prolonged heating, that the gasket thickness may no longer be satisfactorily uniform. 

So as from now, the gaskets I sell are both made from C106 copper (as before) but are now also vacuum annealed after the laser cutting.  These are about as soft as you can get copper, a Vickers hardness test of them is typically 42.5 on the Vickers HV1 scale.  Remember that, as supplied, C106 copper has an allowed hardness range of 40 to 160, so the annealing is necessary to get them really soft.  That it is done in vacuum means that no clean-up job is needed.

Copper is a good gasket material for this application.  It's used with success on Triumph twins and triples too.  It is able to withstand the lateral forces imposed on the BSA twin rocker-box well.  It does pay to have the two joint faces in good condition. Flatting the faces down with abrasive paste on such as a sheet of plate glass can work, though it may end up with a joint face that is smooth but not very planar.  My favoured way is to run the end of a really sharp end-mill over the joint faces on a milling machine, removing just a thou or three till it's cut all over.  If the engine has a light alloy head, and this is not done, attention should be paid to ensuring that the cast-in bronze inserts in the head for the rocker box bolts have not been pulled slightly out above the joint face surface.  If this has happened, they can be flatted back using a smooth file very judiciously. 

I think that generally there's no harm in using small amounts of a sealing compound with the copper gaskets.  This will seal any minute nicks in the joint faces, but if the faces are in really good condition I don't think it's vital.

I have from time to time wondered about another approach: machining a small groove round the joint face of a rocker box, to take 1mm or 1.5mm O ring cord (probably Viton).  I do know that japanese bikes using this type of arrangement do NOT exude oil!  I have a CNC mill that could do the job and it could be easily programmed off the drawing for the gaskets, but it's only about number 423 on the list of projects  *smiley4* 

I hope that helps,

Jon




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Re: Solid copper rocker box gaskets
« Reply #20 on: 17.09. 2015 08:17 »
G'day Jon, thanks for your input.
Having them already annealed is a big plus. Do you do them in different thicknesses? To allow for 50 rears of skimming.
Cheers
'51 A7 plunger, '57 A7SS now A10CR,  '83 CB1100F, 88 FXST .
Australia
Muskys Plunger A7

Offline jjbsa

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Re: Solid copper rocker box gaskets
« Reply #21 on: 17.09. 2015 09:31 »
Hi Muskrat,  good question.  I don't presently do them in different thicknesses, but I've been wondering about using 0.9mm copper instead of the present 0.7mm because the laser cutting people tell me it's easier for them.  For this reason I would quite like to make them 0.9mm and I am keen to hear peoples' views on that. 

If there is demand for still thicker gaskets I could get quotes, though this would probably for smaller sized batches which would put their price up somewhat.  What sort of thickness did you have in mind?

Best regards,  Jon


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Re: Solid copper rocker box gaskets
« Reply #22 on: 17.09. 2015 21:28 »
G'day Jon.
I found 0.8 worked OK on the cafe but I needed 1.00 on the plunger.
Cheers
'51 A7 plunger, '57 A7SS now A10CR,  '83 CB1100F, 88 FXST .
Australia
Muskys Plunger A7

Offline jjbsa

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Re: Solid copper rocker box gaskets
« Reply #23 on: 19.09. 2015 12:12 »
Thanks Muskrat,  I'll bear that in mind and wait to see what others might say,
Jon

Offline bikerboy

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Re: Solid copper rocker box gaskets
« Reply #24 on: 21.09. 2015 23:47 »
John

I got gasket from you and I did anneal them :(. Oil poured out but I found one of the front studs had stripped so the rocker box came back off and I heli coiled the thread and faced teh rocker box again just in case.

I will tell you how it worked out once I have tried it out hopefully me annealing them wont have hurt :)

Offline Gasket4450

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Re: Solid copper rocker box gaskets
« Reply #25 on: 22.09. 2015 10:34 »
Jon,
               Just purchased what was shown as 'the last one' of yours on Fleabay - I have decided to give the A10 a thorough overhaul through the winter, including an annoying little oil leak from the front left of the rockerbox, which I've tolerated up to now........ "Don't worry, they all do that, sir.....". I already have copper gaskets on the A7, no leaks so far, so I reckon yours will be just fine.
               Hope sales are on the up for you, certainly seems like an excellent product.  *clap*

All the best
Norman T
1960 A10, alive and thriving. 1959 A7 living on borrowed time !

Offline a101960

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Re: Solid copper rocker box gaskets
« Reply #26 on: 22.09. 2015 11:00 »
Quote
including an annoying little oil leak from the front left of the rockerbox, which I've tolerated up to now.".
Funny you should say that! I fitted copper rocker cover gaskets and they worked well except for the front left, and from conversations I have had with other A10 owners it seems that if the rocker cover is going to leak after fitting copper gaskets that is exactly the area where the leak will be.
Quote
"Don't worry, they all do that, sir.....
Said in jest I know, but you might be closer to the truth than you think.
John

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Re: Solid copper rocker box gaskets
« Reply #27 on: 22.09. 2015 11:10 »
I know the swinging arm bikes have an engine stay bolted to the rocker box and that is thought to possibly be responsible for leaks so I can be a little smug about my Plunger rocker box being dry. In fact the whole engine is leak free, (at the moment)!  *whistle*

Offline paulmbsa

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Re: Solid copper rocker box gaskets
« Reply #28 on: 29.09. 2015 21:25 »
My A10 & A7 Have done mega miles, on rebuild i flaten the rocker box on glass and have the top of the head skimmed (remove guides) no oil leaks mega miles together 20 years

regards

Offline TT John

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Re: Solid copper rocker box gaskets
« Reply #29 on: 30.09. 2015 12:35 »
It's good to read all the input on the gaskets and although I don't normally advertise these on any site, I have been selling these for quite a while now, I also sell the M20 head gaskets which are 0.9mm thick made from the same C106 soft copper, which I first started with. It was good to see JJBSA report which makes sense, he advertises in the Star magazine also and a fellow member of the club. At the moment I am too busy with taking the new BSA club raffle bike to shows etc, I think the next one is Copdock on the 5th October then East Sussex on the 25th followed by Shepton Mallet on the 31st to the 1st November. The Rally raffle bike is a great little show winning C12, 1956.
All the best with your sale JJ.