Head Gasket

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Norm Emerson
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Head Gasket

Post by Norm Emerson »

I have 1954 VH 500 engine. It has an aloy cylinder head so will it need a head gasket? I have read about grinding the head to the barrel but if the barrel is cast iron and the head aloy surely it can't be a good idea!
Any opinions on this please
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dave.owen
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Re: Head Gasket

Post by dave.owen »

No head gasket on the alloy head engines.
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Norm Emerson
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Re: Head Gasket

Post by Norm Emerson »

Thanks Dave.
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Brian_Walker
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Re: Head Gasket

Post by Brian_Walker »

Don't go too hard on the grinding, remove the head studs and put a bit of blue texta or marking blue on the top of the barrel and move the head back and forward a small amount to see if any high or low points show up if none a light rub backwards and forward with fine valve grinding paste will do a good job. MAKE SURE you have a bit of rag in the bore and wash out with solvent to make sure no abrasive gets into the engine, I like the spray brake cleaner to clean the last bits out.
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ralfpenkert
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Re: Head Gasket

Post by ralfpenkert »

Hmm, i feel a bit confused,
Obviously my 56 VH500 - also alloy head - looks like it has a copper gasket.
Riding 5 years or so without any bigger issues.
Must be done by the former owner.
Shall i leave it?
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pete.collings
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Re: Head Gasket

Post by pete.collings »

I had a problem in the past with a VHA cylinder head used with a new alloy barrel, in that the top of the liner did not mate up with the cylinder head, probably due to excessive grinding in the past. I cured the problem by placing a thin copper gasket on top of the liner lip to fill the gap (annealed it before use). It is also possible to use a copper gasket of the type meant for the iron cylinder/head combination (need to cut out a segment to clear the fifth head stud), but this did not fully cure the leak from the cylinder, hence the liner top gasket.
Basically, if there is no evidence of blow out from the cylinder (mine was a whistling when under load), continue with the present setup, but be on the lookout for any problems developing.
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Re: Head Gasket

Post by nevhunter »

Lapping with alloy and iron will result in the grit embedding itself in the softer alloy and working on the iron part. With both parts made of iron the procedure gets more pressure on the inner raised bit for sealing but contact on both for better heat transfer. It's easier to machine the alloy head with the guides out but that's just buying into trouble if you can avoid it by setting it up with the Jaws reversed in a 4 jaw chuck.. Nev
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