Author Topic: Need New Head Gasket  (Read 212 times)

Offline Billington

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Need New Head Gasket
« on: July 17, 2018, 10:04:39 PM »
After riding my BSA in attempt to diagnose the poor running issue the engine note change and it lost power significantly then stopped. I was then unable to feel any compression through the kick start, hence I pushed the bike home again.

On further investigation I discovered that the cylinder head gasket had a hole in it. I now suspect that the poor running of the engine was a sign of pending failure of the head gasket. At lower revs in 3rd and 4th gear while riding along there was not enough compression for the engine to function properly. Please see my earlier post titled “Losing power when in high gears” link http://classicmotorcycleforum.com/index.php?topic=5764.0

I’ve kept the old gasket as a template or reference for a new gasket that I can purchase.

Could you please help me? Where can buy a head gasket for a 1932 BSA W32-6, or where could I get one fabricated.



Offline chaterlea25

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Re: Need New Head Gasket
« Reply #1 on: July 17, 2018, 10:57:38 PM »
Hi
My opinion is that a solid copper head gasket is the best solution
It is relatively easy to make one yourself cutting it out of some copper sheet say 1mm thick
sandwich the copper between two pieces of plywood, mark out the holes drill through then cut the inside and outside with a jigsaw, anneal before fitting
Alternatively
https://coppergaskets.us/
Lani will make you a gasket from a dimensioned drawing or sample
I have used his products and they are very good value (as well as making my own)

John

Offline Billington

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Re: Need New Head Gasket
« Reply #2 on: July 17, 2018, 11:09:24 PM »
Thank you John, this is helpful. I've got a gasket on order from this company, a 1937 BSA M20 gasket which is another 500cc side valve and very close to my bikes head gasket. However I closer inspection I know believe they are different.

Offline john.k

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Re: Need New Head Gasket
« Reply #3 on: July 18, 2018, 05:52:18 AM »
Save your money,simply lap the head to the barrel.Then a very thin smear of silastic to stop oil creeping out.....and you will never blow another gasket.....There wont be one....It also ups the compression a bit to improve performance.

Offline iansoady

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Re: Need New Head Gasket
« Reply #4 on: July 18, 2018, 11:00:09 AM »
That would be OK with an OHV engine with an annulus but I don't believe it would work with a side valve.

Copper (well annealed) would be my route, as well as making sure that all the head studs and nuts were in good condition. It may also be worth flatting the head (I assume cast iron) on some fine wet and dry neld on a flat surface (I find MDF is flat enough).

I also use a very thin coat of Wellseal despite people telling me I shouldn't. It was the only thing that stopped the weep from the pushrod tunnels on my Commando.
Ian
1952 Norton ES2
1982 Moto Guzzi V50