Combustion chamber caps - sealing

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agroman
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Combustion chamber caps - sealing

Post by agroman »

Project is progressing all be it slower than I would like.
Just waiting for the engine to return from the machine shop. It is all stripped down just needs cleaning and building back up.

One of the combustion caps was leaking before refurb. What is the best way to reseal these?
1958 Dexta with loader crying out for TLC. Now getting some
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Tubal Cain
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Re: Combustion chamber caps - sealing

Post by Tubal Cain »

Originally the caps were sealed using a copper ring, and if the three nuts were overtightened it was possible to distort the cap in way of the holes. Check to see if the caps are distorted, preventing them from seating properly. Also anneal the copper ring by heating it to a bright red and quench in water. This will soften the copper which hardens with age, this will work on any copper joint ring, it also applies to copper pipe which after annealing is more pliable and can be bent easier.

The combustion cap copper joints which are now supplied are full face with holes to fit over the studs. Again if the caps are distorted it will prevent then from seating properly and forming a seal. You can use a straight edge to check for distortion, which can be removed by a file with a safe edge being careful not to damage the face adjacent to the boss.

Gerald

agroman
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Posts: 103
Joined: Wed Dec 11, 2013 10:47 pm
Location: Truro, Cornwall, UK

Re: Combustion chamber caps - sealing

Post by agroman »

Thanks for info. I will check for distortion when head / block are back from the machine shop - possibly tomorrow - ooh exciting!
I have got some new copper gaskets and sort look for / flatten any distortion and try the high temp paint wet option and see if that does the trick.
1958 Dexta with loader crying out for TLC. Now getting some
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