E: Engine Muff / Liner.
- Thread starter Bill Thomas
- Start date
To be the cause of a seizure is quite difficult to understand, I don't know how much Tony reduced the diameter of the stud holes, but there must have been sufficient clearance to allow the barrel to drop over them when assembling, are you thinking when the barrels got hot they gripped the studs somehow, there are so many other things that can lead to nipping up, piston clearance, lean mixture, timing etc.
Well don't keep it to yourself,
Tell us Who and What and we will tell you if he is Clever.
Tell us Who and What and we will tell you if he is Clever.
That was not the only thing wrong with the them,
Not happy.
Knowledge is power as they say, what was wrong with them?
Every thing.
It is worth taking the time to actually think what happens to an engine like this when you are on a lot of throttle under a load like a long steepish incline........On a single, it is working very hard as it does not have the extra cylinder of a twin to help out........however, the exact same can and will happen to a twin if you do the same. ordinarilly if the mixture, ignition timing, bore clearance is not ideal........you can and will damage the engine absolutely hands down........If you are too deaf or your helmet has good sound deadening built in and you cannot hear the engine pinking (detonation) within a not too long a time frame, you are doing damage. If the barrel/ liner diamentions are altered in a manner that they become quite thin, the ability of the barrel to transfer heat changes dramatically........having large holes through the muff as per standard, but running a bore out to 92mm the alloy wall thickness at these stud holes is very thin.......as the engine is worked hard, these skinny "towers" get hot rapidly due to their being so thin........Add to this, the piston which when worked hard, expands quickly as well.......the larger th episton the worse the problem........yes you can give it more bore clearance but that is a band aid approach that will probably in most cases still end in failure.......the larger the bore size the easier this will happen........this is exactly what happened to Zezz's engine, added to a weaker than needed mixture on the carby........When running an engine like this extreme caution should be used when running it up........If running on petrol type fuels the problem will happen way, way faster that an alcohol fueled engine.......I feel the big help here would be to add an oil jet to the underside of the piston.......the question of running thin liners/muffs is not going to end well for the user........Just my thoughts.
I was wondering if it would be better going for a thicker liner,
At the expense of even thinner muff,
I mean lots of bikes run iron barrels.
As you say , So many things can give trouble,
Going back to my first photo, Of a standard Barrel,
That is not good engineering ?,
We have all heard of Standard rebuilds going badly.
Interesting trying new things.
At the expense of even thinner muff,
I mean lots of bikes run iron barrels.
As you say , So many things can give trouble,
Going back to my first photo, Of a standard Barrel,
That is not good engineering ?,
We have all heard of Standard rebuilds going badly.
Interesting trying new things.
The heat transfer 'grease' which is referred to in #21 above is available from anywhere that supplies electronic bits and pieces. A lot of electronic devices run hot and have heat sinks attached to them. These have to be linked to the hot component via the heat transfer grease to ensure that the heat can flow to the heat sink.
Thanks for the info Bill, extremely helpful and informative.