silly bollox

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just rebuilt my 920 commando, js pistons, rods, valve train ect. without thinking it thru. also fitted 850 base gasket. fired her up. sweet as a nut. sounded beautiful and pulled like a train. stop at a junction after a mile or three. what's that smell? oil burning. long story as short as possible.. base gasket had a tear. didn't think liner size when rebuilding. anyway. scraped as much paper as possible out between barrel and crankcase. forced in green Loctite. left over night. dry as a bone. rode it this morning. oil tight. a lesson learnt and a lesson shared. what a twat! lol
 
We call those brain farts over here. I have lots of gas also...
 
My case halves were seeping after a rebuild. Pulled head, de oiled crankcase, pulled a vacuum with shop vac and semi air tight tape and plastic. Clean and Super glue in the seams. 4 months now and not a drop. Same trick worked on my lycoming av540
 
I bet that goes a bit! I remember going to see a 920 in a damp Halifax 1982 when I was getting into britbikes. He took me on the back and I couldn't believe the torque. I spoke to Roger at RGM a few weeks ago and he said there wasnt much call for them anymore and a std motor is almost too good to mes around with but one day maybe..
 
My case halves were seeping after a rebuild. Pulled head, de oiled crankcase, pulled a vacuum with shop vac and semi air tight tape and plastic. Clean and Super glue in the seams. 4 months now and not a drop. Same trick worked on my lycoming av540

I cannot think of any reason that would not work and be reliable, but, I hope that Lycoming is in an boat and not in the sky. :)
 
The “an 850 is better than a 920” concept is a bit subjective IMHO.

Firstly, for most peoples use in classic circles, I believe it’s totally true. The stock motor is a good performer by classic standards and more than enough for club runs, touring, etc.

Secondly, a poorly built 920 is, obviously, gonna be worse than a well built 850. And back in the day, I reckon quite a few 920s weren’t really up to scratch (using Swiss Cheese barrels, heavy car pistons, etc).

But... a well built 920, that has been built ‘as a package’ is a sweet thing. My Maney / JS 920 is incomparable to a stock 850 in terms of performance, it’s also a much lighter engine unit (by approx 17lbs), and whilst it shakes about at tickover, it’s unfeasibly smooth in use.
 
The “an 850 is better than a 920” concept is a bit subjective IMHO.

Firstly, for most peoples use in classic circles, I believe it’s totally true. The stock motor is a good performer by classic standards and more than enough for club runs, touring, etc.

Secondly, a poorly built 920 is, obviously, gonna be worse than a well built 850. And back in the day, I reckon quite a few 920s weren’t really up to scratch (using Swiss Cheese barrels, heavy car pistons, etc).

But... a well built 920, that has been built ‘as a package’ is a sweet thing. My Maney / JS 920 is incomparable to a stock 850 in terms of performance, it’s also a much lighter engine unit (by approx 17lbs), and whilst it shakes about at tickover, it’s unfeasibly smooth in use.
have standard barrels with 920 liners. js 920 package. fcr 35's . runs a dream. love it
 
I bet that goes a bit! I remember going to see a 920 in a damp Halifax 1982 when I was getting into britbikes. He took me on the back and I couldn't believe the torque. I spoke to Roger at RGM a few weeks ago and he said there wasnt much call for them anymore and a std motor is almost too good to mes around with but one day maybe..
running in, but just wants to go as soon as you open the throttle;)
 
Sounds sweet.

What CR are you running? And what cam? And where are the PICTURES ?!?!
js1. and as soon as I can work out how to upload the pics I shall post circa boxing day in dining room until in frame and running last week. the missus was happy to see the back of it!!!
 
here goes
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Looks great. can't help thinking though all that motor and just standard (looking ) brakes ?
 
cnw Brembo master cylinder . I do have a brand new norvil 14" disc and grimeca caliper to go on but the brake seems to work pretty good. will dwell on it sam
 
Is it just the photos or is there more metal between the cylinders at the top of the cylinders than at the bottom?

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I think it’s an optical illusion caused by the internal chamfer on the bottom of the liners vs the flush machining at the top.
 
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