E: Engine Diagnosis

vibrac

Well Known and Active Forum User
VOC Member
Well the problem with the Road Comet was that the old racing 90 bore barrel needs replacing as does the piston. I have a number of standard barrels and pistons and a top hat to fit the crankcase so I think that's the most economical thing to do. I have too many costly rebuilds on at the moment thanks to increased workshop time and decreased outside events this year, but I will replace the big bore at some point when the Comet racer gets on the bench so if you know of a suitable supply of 90 bore pistons and liners I shall need some sometime in 21.
The other anoyance was the continual oil leak at the base of the push rod tubes, I have some Flash works push rod tube assemblies but found that they would not accomodate the angle I needed at the head (they may fit on the new head and barrel). I tried a number of methods to seal the standard tubes including the two O ring solution but I think the solution will be found in the curing of the piston problem (ie perhaps it was excess crankcase pressure). Also the sugestion of getting new pushrod tubes with perfect cirtcular ends is a good one. I also need to revise the wiring and switches to control the electric start better and get a small lithium battery to fit a dummy case as the big (12Ah)gel I have at the moment starts it OK, but according to the ammeter afterwards it would not stand a bout of repeated starts, and the suggested one(18Ah) is huge and nearly reaches the final drive chain on the other side, and its weight doesnt bear thinking about. Ah wel! another busy workshop in lock down, Heck I may even get some work in over Xmas! Its not all bad news is it!
 
Last edited:

vibrac

Well Known and Active Forum User
VOC Member
Well this thread has been marinated for 72 hours (bit like my snail mail:)) but it does not look like there are not any purveyors of 90mm barrel and pistons around, not like 1995 when Ron Kemp said in MPH "Forged 90mm bore street pistons first batch sold" please let us know on here if a possibility appears especially if later next year
 

timetraveller

Well Known and Active Forum User
VOC Member
Well I hope that was not a joke but if not then good luck with that Martyn. I had my run in with the big C seven years ago and lost a kidney and adrenal gland in the process but am still here and causing trouble. So the diagnosis is not the problem. It all depends upon where it is and how long it has been there. Just remember that treatment for cancer is remarkably better now than it was even ten years ago.
 

Peter Holmes

Well Known and Active Forum User
VOC Member
Martyn, when I saw your post I was going to comment, but Norman was far more eloquent in choosing his words, and he talks from experience, Sue joined this cancer club that no one wants to belong to about twenty years ago, and is still going strong and enjoying life. Good luck with any treatment that you are prescribed, and I look forward to meeting up again at the next International Rally. Peter
 
Top