Copper rocker box gaskets

[A7JAY]

Hi all

does anyone know where I can get copper rocker box gaskets here in the UK please?

[rocker21]

there used to be a guy on this forum who sold them, i bought a couple from him, but cant remember his name

[A7JAY]

all sorted, Ebor Bikes to the rescue

[sean]

not in UK but there is a place in USA that will make copper gaskets to your pattern ....Copper Gaskets Unlimited....he also stocks copper gaskets for several makes including BSA

[Black Sheep]

Tried them and couldn't get them to seal despite annealing. Went back to normal paper ones and all was well.

[BagONails]

Replaced my leaking copper gaskets with conventional ones, re surfaced the boxes and the cylinder head so all joint faces as flat as I know how to do. Initial signs were encouraging but now after about 500 miles and a couple of good hoons there is a weep appearing again on the left hand side. Boo!

I will have to revisit the idea of re-engineering the head steady attachment ala John CL's posts previous, I'm pretty sure that is the culprit here now.

[Rex]

Always seems to me that even annealed copper gaskets are still too unforgiving to be pulled down sufficiently with the existing size studs etc.
Nice in theory, but I prefer a material here which is more squishable.

[CheeserBeezer]

Replaced my leaking copper gaskets with conventional ones, re surfaced the boxes and the cylinder head so all joint faces as flat as I know how to do. Initial signs were encouraging but now after about 500 miles and a couple of good hoons there is a weep appearing again on the left hand side. Boo!

I will have to revisit the idea of re-engineering the head steady attachment ala John CL's posts previous, I'm pretty sure that is the culprit here now.

Yes, I'm building something a bit different at the moment so not wedded to originality and I was considering using suspension rubber mounts which have limited movement, enough to allow the rocker box to move slightly, but still stable enough to function as a head steady. The problem is, as discussed on the forum many times, that the original head steady rigidly attaches the rocker box to the frame so the vibration of the engine sets up a 'wriggle point' where the rocker box is fastened to the cylinder head. Eventually the rocker box creeps backwards and forwards and destroys the gaskets. I'm wondering if people have the same problem with plunger models. Theoretically, they should be better because the steady is actually attached to the cylinder head at the front mountings for the rocker box. Therefore the 'wriggle point' is at the barrels base and the rocker box should not be as badly affected. However, the rocker box still suffers from the valve spring tension which is trying to lift the rocker box off the cylinder head. I used to have a plunger and don't remember having leaking issues with the rocker box on that bike, maybe I was just lucky!

[Roger (Doomtrainbarx)]

 I wonder what the effect would be if the head steady was removed altogether ?
 More vibration ? - more stress to the frame around engine/gearbox mounts ?

[RichardL]

Recommend going way back in time and reading this thread spawned by Chaterlea John’s invention of the shock-absorbing head steady. Late in the thread I pay homage by copying the idea. Resists large displacement movement while reducing the higher frequency vibrations being transmitted back into the rocker box joint.

http://www.a7a10.net/forum/index.php?topic=2912.msg19633#msg19633

Richard L.

[berger]

roger when i were a lad my mate owned betsy and she didn't have the head steady , we could see the engine dancing

[Joolstacho]

Yes that head steady arrangement has always been crap. I contemplated adapting a Commando type (sprung) head steady at one stage. But a mount to the crankcase would be better.

[Triton Thrasher]

Does anyone sell the modern composite gaskets for these bikes’ rocker boxes?

I mean the gaskets with an aluminium core, sandwiched in rubbery stuff.

[Bsareg]

There's a firm in Redruth that will cut any gasket to your patern, any quantity from many materials excepting copper. They can offer good advice on the choice of material and their prices are not extortionate. Ram Gaskets, 35/36 Cardrew ind est, Redruth.

[JulianS]

Copper gaskets did not work for me either.

The joint surface on the head and the rocker box do not quite match each other . Then the often supplied gaskets do not quite match either which can give some quite narrow sealing surfaces. I was particularly concerned about the front joint of the inlet compartment and had the joint widened to closer match the head by ali welding and then machined back to flat. I then ground the head to rocker box joint with fine valve grinding past. This has improved sealing. It can be interesting to bolt the box in place less gaskets and then shine a torch inside and see how much light you can see in the joints.