Twin head gasket

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Leejm
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Twin head gasket

Postby Leejm » Tue Sep 10, 2019 3:32 pm

My engine is already to start going back after hours flatting the gasket surface on the barrel and head . . I see that the gasket is a composite gasket are solid copper ones available? And what was used originally?
1948 NH, BSA D10 SPORTS. 1953 VHA, 1951 KH rigid project.

john.whiting
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Re: Twin head gasket

Postby john.whiting » Tue Sep 10, 2019 11:58 pm

The original A10 gasket was composite,and you wont get one the same ,because it was asbestos.

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Re: Twin head gasket

Postby Simon.Gardiner » Wed Sep 11, 2019 1:13 am

NOS Payen gasket I've got lying around (for '1948-on' KH/KG - must be very very old stock if it doesn't know about the change in 1954!) is copper/asbestos.

SG
'55 Huntmaster, '56 VH, ' 51 VH, '80 R100RT, '00 Sprint ST (but all those Ariel parts can only make one running bike...)

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paul.wirdnam
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Re: Twin head gasket

Postby paul.wirdnam » Wed Sep 11, 2019 7:13 am

Lee, Andrew Jackman (on FB Ariel page) and I had great trouble sealing our heads with brand new, annealed, laser cut, solid gaskets on our '48 KG/KH Ariels. We both gave up and reverted back to NOS composite gaskets, which took a bit of time to track down. In my case, I found two: one from Malaysia and one from Australia but both took so long to arrive that I ended up annealing the original that came with the bike and fitting that. I've now done 800 mile since going back to this old gasket and no sign of any leak whatsoever.

I think half the problem are those ridiculous thin head nuts between the fins. With a solid gasket, there was no feel of squashing down a gasket, unlike the composite gasket. You're welcome to have my second, unused laser cut solid gasket.
Last edited by paul.wirdnam on Wed Sep 11, 2019 8:05 am, edited 2 times in total.
'28 Model B (future project), '30 Model F, '31 SF31, '35 4F, '38 VB (abandoned project), '39 4G (current project), '46 VH, '48 KG

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Leejm
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Re: Twin head gasket

Postby Leejm » Wed Sep 11, 2019 7:40 am

Hi Paul I found that the gasket faces were completely not flat . After a very long time they are now ! The faces were so bad I can’t see it would ever seal anything. Maybe that was the problem if it not sealing on yours too ?? And thank you yes if you are not using it I will give it a go Lee
1948 NH, BSA D10 SPORTS. 1953 VHA, 1951 KH rigid project.

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adrian.hannam
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Re: Twin head gasket

Postby adrian.hannam » Thu Sep 12, 2019 1:00 pm

Hi Lee, I have had lots of trouble sealing the head on a 48 iron twin. My problem was not with compression but untolerable oil leaks around the pushrod holes. I have had the head and block finished flat at the machine shop. I have rubbed them flat with wet and dry on glass. I have tried the block both ways. I had solid gaskets made, as above laser cut and annealed, tried them after trying composite gaskets from different suppliers, but I have had trouble with all. I have gone back to a composite gasket from Draganfly with loctite sealant, the one the guys use on Sq4's. As recommended in a post here somewhere, after the initial tightening, start the engine and heat it up. let it cool and re-tighten. Do this three times or more before taking it on the road and then repeat regularly. Bit too early for me to to call a it a success yet. In my case, a solid gasket with black silastic lasted about 1500 miles, which was longer than the first two composite ones with black silastic on one and copper spray on the other.
'48 KG outfit, '51 VH, '51 4G (in bits)
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Leejm
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Re: Twin head gasket

Postby Leejm » Thu Sep 12, 2019 1:53 pm

Looks like I have no opinion then to use that type thanks for the input on this Adrian
1948 NH, BSA D10 SPORTS. 1953 VHA, 1951 KH rigid project.


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