alexandervdr

The bell housing of my 327 has a crack at the bottom. It goes from the middle of the bottom side to about 1" inwards about where the cross is.. (Seems it's been hitting the flywheel too one day). It's not through the whole thickness of the housing though (about 2/3).
Is this is structural problem? I went to welder who did not want to touch it because it's been too long in oily environment making clean alu welding a high risk thing. Or I could just drill a 1/8" hole at the end of the crack to avoid it propagating?

wraplock

Find another welder yours is a coward. I have had more Harley Davidson engine and transmission cases aluminum welded than I care to count and they are literally oil reservoirs constantly filled with oil. A good welder will "V" out the crack, clean it and weld it good as new.

Don

Y0GI

Even if you can get it welded, you're still stuck with the problem of "why is the flywheel hitting the bell housing?"
Wrong flywheel maybe?

Yogi

DansYellow66

I would have it welded without a second thought. I wonder what they were running for a flywheel/pressure plate that didn't clear?

alexandervdr

I think the car has been hoisted on the bell housing, hence cracking it on the inside only. The flywheel hit was a separate incident I believe.
Still: is this a structural integrity problem or not?

Pop Chevy

No, I wouldn't worry bout that. Look and see if something was run over and hit it. Weld it up and forget it.

redvetracr

I agree with above...drill a small hole and find another welder

DansYellow66

I think the only structural integrity problem you would ever have to worry about would be containing an exploding flywheel or clutch at high rpm - but from memory I don't think you are planning for a high-horsepower motor. But, if you think the bell housing may possibly be deformed from using it for a jacking point - I would check the transmission register opening on the engine with a dial indicator to make sure it's still somewhere within .005 inches of centered to the crankshaft. Usually GM bell housings dial in pretty accurately - but you might want to check it.

project63

If this is a 403 bellhousing, just replace it. You will spend more on a weld job.

Easy Rhino

It is a hidden blessing that your welder refused to take on this repair, as you want a real pro to weld repair this, and yes, begin with drilling out the end propagation stop, and let a qualified cast aluminum welder fix that - no problem.

The flywheel contact is unusual, but I'm guessing that it looks like a short-term contact, as the contact "patch" does not appear to be long-term.

DZAUTO

I, like others above, have had numerous bell housings------------------------and Muncie cases, welded with ZERO issues.
If that housings was mine, I'd use a 90deg die grinder and a very thin cut off wheel to cut all the way through the crack, then have it completely filled with a weld (seek out a very experience welder who has done alum welding). Use the die grinder with a sanding disc and then a 3M type buffing pad to work down and smooth the weld.

alexandervdr

I did check the bell housing centring, and it was at .005 inches max off center, on the edge of acceptable, still bought some offset dowel pins to improve that.
My engine is modest power indeed. For your update, knowing you have been following my build over the years, I bought a GM 350/290HP crate in the meantime

alexandervdr

I went to a different welder, great result
Some finishing off and it will look as new

LSUvetteguy

alexandervdr

Not sure, I payed 15€ (about 17$) and he did it in 10 minutes while I waited . I had V-grooved the crack myself, so that saved some time. That's about the cheapest thing I ever spend money on for this 64 rebuild

DZAUTO

You done good!

wraplock

I don't believe any aluminum bell housing is going to contain an exploding clutch/flywheel. This is why every sanctioning body for racing require an explosion proof bell housing (scattersheld) like the Lakewood steel bell housing. I run one of these in my modified 1956 Chevy Belair.

Don

Easy Rhino

That's good as new, and cheaply as well. I can't imagine what the shipping of a bell housing from the states would cost to you.

Were you able to confirm, and eliminate, the cause for the flywheel grinding on the bell housing? Maybe I missed it. FWIW, it would be easier to troubleshoot with the engine out and bell housing off than later. Good Luck!

alexandervdr

The engine is out, cause it's a brand new 350/290 crate I am building up.
I believe bell housing has been taken excessive load on the bottom (hoisting?) and that pushed it all a bit up.
I checked minimum clearance of flywheel to bell housing, and that's slightly more than 1/8". Would that be fine?

DansYellow66

Great - good as new.