I'm building my Dominator 88 engine. A couple of issues have arisen:
- I fitted the pistons and rings, and ring clamps (cases in frame) and wriggled the barrels + head into the frame. On offering the barrels to the pistons, the rings refused to go into the barrels. I repeatedly re-set the piston ring clamps, tight, but free enough to slide down the piston.. The refusal of the rings to pass into the barrels led, eventually to a broken ring.
The barrel has been sleeved, so I suspect that the issue is insufficient chamfer / lead-in at the bottom of the barrels. So, what should the lead-in be (size, angle?)
- I want to check the pressure relief valve. It frees off, so I can remove it, but what I want is to make sure the relief piston will move. How do you do that?
Paul
Paul, I hope you did set t…
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Yes, I did set the ring ga…
Yes, I did set the ring gaps before attempting re-assembly.
I have previously assembled twin top ends using your method - fit pistons to barrel, then set barrel up on blocks and insert gudgeon pin and circlip.
One of the reasons I am doing it this way is that the pistons are made very tight on the gudgeon pins, and I have had to use lots of heat from a blow-torch. No idea why, they are original Hepolite and came from a friend's 1956 Model 88 circa 1965. Only light wear after wearing out the bores.
Paul
Previously jim_hill wrote:
Paul, I hope you did set the piston ring end gaps before attempting to fit the barrel, I usually find it much easier to fit pistons into bore on the bench then lower the barrel with pistons fitted onto a couple of blocks across the crankcase mouth,where they will sit wile you fit the gudgeon pins and circlips, ( the inside clips can be fitted to the Pistons beforehand) lift the whole assembly slightly to check no debris at the joint, remove blocks and lower away.hope this helps ! Jim.
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Paul, I hope you did set the piston ring end gaps before attempting to fit the barrel, I usually find it much easier to fit pistons into bore on the bench then lower the barrel with pistons fitted onto a couple of blocks across the crankcase mouth,where they will sit wile you fit the gudgeon pins and circlips, ( the inside clips can be fitted to the Pistons beforehand) lift the whole assembly slightly to check no debris at the joint, remove blocks and lower away.hope this helps ! Jim.