texasSlick said:
As an engineer, I see the problem of liner replacement in air cooled engines being that of heat transfer. One must achieve virtually a molecular bond between the liner and barrel, in order to achieve original heat transfer characteristics. Even fine honing is not good enough, and neither will a shrink fit eliminate the micro gap between components.
Slick
Actually, this is not strictly true.
And, why would water cooling make the sleeve contact requirement any different anyway ?
Apart from that many diesels were aircooled from some makers...
Since sleeving sidevalve engines since WW2 was a VERY common practice - eeking out more miles on a shoestring budget - it is suggested in the motorcycle press that as the engine gets hotter, the sleeve can ONLY expand outwards - so the already tight fit of the sleeve gets better, heat conductivity wise.
Heat will always flow from hotter to colder, so even if the contact was only minimal, all those minimal points will flow heat - or the bloomin thing would melt !
It takes considerable muscle to press the sleeves in too, so the contact won't be too minimal !
As I said, I have an ex-WD M20 engine that has been sleeved, and done extensive miles since then.
And Mr Curzon sez he's had a number of Nortons sleeved, successfully.
Now, it is also mentioned that the early 650 and Atlas engines had rather minimal metal in the cylinder walls.
Isn't there a memo noting that the wall thickness was increased, quite early in the oroduction of these ?