An article in the technical section about building the engine includes a reference to a rubber O ring being used on the oil stud to the valve gear if the latest gasket type is used. Which particular gasket would this be? The article is not specific why a gasket would need an O ring. What would it's function be and is it absolutely necessary?
Nick
Head Stud O Ring
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Nick Webster
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Head Stud O Ring
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Re: Head Stud O Ring
This particularly applies to the New Zealand manufactured gaskets which are made from a composite material, rather than asbestos copper. The O ring prevents high pressure oil seaping into the water jacket.
viewtopic.php?p=44416#p44416
On other makes of gasket the copper fold over is probably sufficient to seal around the stud.
viewtopic.php?p=44416#p44416
On other makes of gasket the copper fold over is probably sufficient to seal around the stud.
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David Morris
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Re: Head Stud O Ring
Hi Nick,
Happy New Year! If you are using a head gasket from NZ ( and in my view, you shouldn't use anything else ), then the correct 'O' ring should be taped to the gasket from new. If your 'O' rings are missing, then I suggest that you find a local supplier, but ask for a Vitron ring, not nitrile, because of the heat. You have the internal diameter, which is the diameter of the stud, and I think the cross-section of the 'O' rings were about 3mm. They are quite reasonable, and you should get a packet of 50 for a couple of pounds.
All the best and Happy Jowetteering in 2024!
David
Happy New Year! If you are using a head gasket from NZ ( and in my view, you shouldn't use anything else ), then the correct 'O' ring should be taped to the gasket from new. If your 'O' rings are missing, then I suggest that you find a local supplier, but ask for a Vitron ring, not nitrile, because of the heat. You have the internal diameter, which is the diameter of the stud, and I think the cross-section of the 'O' rings were about 3mm. They are quite reasonable, and you should get a packet of 50 for a couple of pounds.
All the best and Happy Jowetteering in 2024!
David
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David Morris
- Posts: 837
- Joined: Thu Feb 09, 2006 9:23 am
- Your interest in the forum: Jowett Javelins since 1964. Now a Jowett Stationary engine owner and club member since 1964.
- Given Name: David
- Location: Sunny Bristol
Re: Head Stud O Ring
Hi Nick,
As a postscript to the post above, if you are using the NZ gaskets, you must follow their fitting instructions to the letter. Also, I would recommend that you don't exceed 0.004" liner protrusion, if you want to prevent the block cracking. The manual recommends much more protrusion, but just ignore it.
Also, once the engine has the NZ gaskets and has settled down after a 1000 miles or so, go back and recheck the 35lbs/ft torque settings on the head studs. I am sure you will find they have eased off and I have found engines where there has been a subsequent gasket failure in service and the head nuts are down to being almost only finger tight!
All the best,
David
As a postscript to the post above, if you are using the NZ gaskets, you must follow their fitting instructions to the letter. Also, I would recommend that you don't exceed 0.004" liner protrusion, if you want to prevent the block cracking. The manual recommends much more protrusion, but just ignore it.
Also, once the engine has the NZ gaskets and has settled down after a 1000 miles or so, go back and recheck the 35lbs/ft torque settings on the head studs. I am sure you will find they have eased off and I have found engines where there has been a subsequent gasket failure in service and the head nuts are down to being almost only finger tight!
All the best,
David