Bang! (loctite of the ages II)

[vibrac]

I beefed up the extractor and tried again

I turned the screw till the world went grey ... nothing moved
Time for a rethink
One of the last bits of advice before the world went off on Mini engines a P38 planes was Gary Gittlesons 'more Heat'
so I beefed up my original extractor with the two 5/16 BSF bolts with a 3/4 CEI thread to take that big screw shown above, that gave plenty of room for flames and heat
Then I took the lot to a man who builds steam engines with an oxycet rig (I doubt he would even call that a flywheel)
I wound up the screw as tight as I could then we emptied the gas tank on it, boy did it get hot!
braving the radiated heat I turned the bolt a fraction and..... hence the name of the thread
Thats me convinced..... heat is the thing
Thanks to all who gave me advice

 

[Gary Gittleson]

Whew! Glad to see it's finally off. No damage, I hope. That extractor looks pretty serious. Nice work.
I would have offered the use of my torch but there's a 3,000-mile wide pond in the way.

Gary

 

[oexing]

Applause, applause ! So would you please show pictures - and what exactly was wrong with it and why all that trouble ? Can you measure the angle of the taper, should be around 6 degrees per side usually ? So no sign of Loctite on taper ??

Vic

 

[Sakura]

I think you'll find it was me that told you oxy acetylene was the answer. As I said, the secret it to heat the object quickly before the shaft gets hot. Propane and mapp are just not hot enough. Anyway, I'm pleased you got it off, it was beginning to worry me, never mind about you! Douglas T35 or Dragonfly?

 

[vibrac]

T35/90+ hybrid Thanks for the good words, I haven't got my protractor to hand but it is shallow about 6deg There is not a blemish on the taper surfaces and the woodruff key is still in the keyway in the shaft so I havent a clue as to the problem I have been told mostly they just fall off with a little pull in fact it is a a known fault if the nut is not secured properly that they get loose on the shaft!

 

[oexing]

Hmmm, if the taper was below 5 degrees this could be the flaw in the design . As I said elsewhere the old guys from long time ago did not always decide on best practise, either due to company politics or any other mistakes made. I´d say the 5/16 bolt holes were plain wrong and too weak in combination with less than 5 degrees tapers for a puller plus hammer blow on that. A torch on components for regular disassembly would be proof of faulty design. Never had to save my day on BMW cranks for decades by using a welding torch, the seal behind the flywheel wrecked by this for sure. At this place there should be some securing part like tab washers under bolts or nuts of the crank - after a good heave on the wrench certainly. You´d lap the taper of the flywheel on the crank in case of questionable finishes there. There are lots of engines with that sort of taper joints, just the Vincenteers not so used to them it seems. But certainly this is a question of suitable pullers to use and designs to go with them which do work reliably.

Vic

 

[vibrac]

An engine like this is a really interesting challenge when it's the first you have done that unusual problem had not been encountered before by any of the people I spoke to who know the engine
The design goes back decades in effect post war that part of the engine was just rotated 90 degrees I bet the taper has always been the same since the year dot
Now for some more reading before I split the crankcase