acotrel wrote:Phil Irving.... - perhaps he had never worked with titanium ?
You say some odd things.
Have you voiced your concerns to the people who sell titanium conrods?
Triton Thrasher wrote:You say some odd things.
acotrel wrote:It is common practice to fit the main bearings into Manx crankcases using steel sleeves
Snotzo wrote: but he certainly turned down Harry Weslake's 4 valve head offer
Rohan wrote:Snotzo wrote: but he certainly turned down Harry Weslake's 4 valve head offer
When was this ?
How ye know such things ?
Are there details of this anywhere.
4 valve heads would have been uncommon in the Joe Craig era,
only Rudge and Excelsior (openly) used such things (all prewar.)(?).
acotrel wrote:A question - are the guys who are using titanium conrods running plain bearing big ends or roller big ends ?
I do know this. A friend of mine gave Kevin Magee his start on Ducatis in the 70s. One of his earliest bikes was a 250 Ducati single which had as much done to it as possible - high comp. methanol fuel GP carb., factory race cams etc. At most meetings, it was very fast at first, then it always slowed. When the bike was stripped the only thing he could ever find was too much clearance on the roller big end. If the conrod is titanium and it starts to get hammered, the rod dimensions will probably change.
In Australia we have a couple of guys with grossly oversize G50s - they are not very good. The bigger motor delivers more torque, but the bikes seem to stop being nimble.
I still believe that a 500cc single cylinder motor is probably very limited in how much further it can be developed, than Joe Craig achieved with the Manx. Obviously the Molnar Manx is better than the 1962 Manx, however it is still only marginal.
The simple fact is that oversize motors destroy the whole object of the exercise - the playing field is not level. 4-valve might not be so bad, but if it comes to having the big bill every time you race just to be competitive, it can kill the race class.
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