Perfect torch for your needs.
My bearing install procedure.
1: clean new bearings crank & housing with break clean
2: slide big bearing onto crank,
Pace in freezer with small bearing.
3: let freeze at least overnight.
4: I use a small toaster oven.
Heat housing/case for about 1/2 hour at 350*
5: quickly, remove from oven, slide big bearing & crank into housing/case. Slide small bearing on. Install flywheel sweadge piece, flywheel and snug up the shaft collet.
Wrap on the 4 sides with a brass hammer. Saturate with your after run oil & let set/cool to room temp.
My procedure, right, wrong!?!?
Works for me.
okay, cleaned-up crank housing, placed into oven (375 degrees, 40 minutes). Inserted crankshaft w/bearings (both slid into housing with ease). Installed flywheel w/cone. Firmly hand-tightened cable collet
(I do notice a very small amount of end-play within bearings. I can visually see the front bearing inner race float, fore and aft)
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Don’t ever go over 250 degrees when installing bearings. It causes damage. I’m certified by SKF as a machinist and pump rebuilder. We use 235 degrees actually. Do some research on this and you will see Iam correct. Jeff Lutz
He was talking about case heating temperature not heating the bearing up.
That is when heating a bearing for it's inner race to slide over a shaft.
Heating a bearing your pressing in a housing would be working against yourself. You would heat the housing of course. The temperature you use to heat a aluminum housing has no relation to the temp the bearing can withstand. The bearing is not heated to that high a temp anywhere it matters by pressing in extra hot aluminum bore.
Because this has nothing to do with heating a aluminum case you are about to put a bearing in. If you were heating bearing to get crank into it that is different. Heating the aluminum case to install the bearing you can go hotter so it opens up more to freely accept the bearing with minimal insertion force.
Those are bearing heating temps for going over steel. Not aluminum temps for opening it up to accept the bearing. That can be hotter and it is never going to affect the bearing if you cool it following insertion of bearing especially.
That heat is dissipated by the outer race and the atmosphere so fast if you merrily press it in and if you just blow it cool immediately with compressed air you are golden. 250° is not hot enough and you will remove aluminum pressing the old out as well as the new one back in.
You want case at high temp so it lasts a long time and you retain your fit indefinitely. Some aluminum engines can operate up to 250° so surely that isn't hot enough to fully release a properly fitted bearing. The interference fit is altered when you use a lot of force to remove or install a bearing in aluminum bore.
I heat aluminum cases to 350° and I can guarantee the bearing is not getting affected. Most of the bearings I use are phenolic plastic type high speed retainer. No heat makes it there whatsoever. That 100° too much for bearing is gone by the time the bearing hits home.
250° is not opening up the case and releasing or accepting the bearing like it could if heated more like you should.
And for sure NEVER FREEZE the bearing. The reason being is it does very little to shrink it versus heating the aluminum ONLY and will suck your heat out before it goes in.
What can happen is if you do not get the new frozen bearing fully seated in the bore in one quick fast motion the frozen bearing will suck the heat out of the aluminum so fast it will lock the case up on the bearing where ever it is. Now you are 100% screwed. Now you got to reheat the case with your brand new bearing in it and you have created a real problem you could have avoided by leaving the bearing room temperature always. Beside it fills your brand new bearing with water when it warms up. Bad idea. Repeat NEVER FREEZE the bearing. If anything you can actually warm it just slightly so as to ensure it doesn't suck the heat out of your case going in. A cold bearing is for sure detrimental to this bearing going in aluminum bore process.
Installed many hundreds of bearings in aluminum cases and have learned a bit along the way. Do not believe most of how the internet seems to think it should be done as they are just frigging clueless.
A good high temp heat gun is better for heating cases than the torch. You get much more even heating with the heat gun.
