[flyingearly]

On my rebuild, I've received two VW engines: the one that I've taken off the aircraft and a spare.

On stripping the 'A' engine, we've learnt that the Barry Smith interference-fit prop hub was potentially forced onto the crankshaft a little inappropriately; undoubtedly it may never have been a problem had it stayed there, but the act of removing it has revealed the damage and means the crankshaft can't be re-used, nor the hub, in all likelihood.

On stripping the 'B' engine, the crankshaft looks usable. Fortunately, the prop hub on the 'B' engine is also another Barry Smith job.

I am slightly apprehensive, knowing that I've got a quality prop hub that's hard to find these days, but needing to remove it without damaging the prop or hub. I won’t be doing it myself anyway, but for my own intellectual curiosity: are there any dos or don'ts about interference prop hub removal? Tips or tricks? I assume that targeted heating of the prop hub wouldn’t help and it’s just a case of “pull and hope”?!

[Lefty]

With most interference fits, the general principal used to be : heat the outer - and cool (freeze) the inner. It's been a few years since I did one, but I've not heard of any magical new alternative.

[Nick]

Yes, the use of correctly applied heat, helped along with a suitable hydraulic puller is the normal way of removing difficult/interference fits. Definitely not beating the sh 1t out of it with a big hammer!

Nick

[flyingearly]

Thanks all - it came off without any damage and is in good nick. As a bonus, the machinist managed to salvage the other hub without taking too much material off, so things have worked out well.