engine case restoration and or welding

[Finster66]

Hey all, I'm a new member and this will be my first post.

I have a 61 TR5AC that is in the tear down stage of a full restoration and man and I going to need help on this one!!
SO...to the point; the crank case internals are pretty good and will just need the usual restoration work. The transmission and primary internals however are shot due to water getting in and sitting for years. I can replace the mechanical bits but my real problem is with the left engine case.

It has had significant damage from the drive chain ripping through it and its been repaired at some point. I think I may leave the repair alone HOWEVER, this same case also has some significant aluminum corrosion inside the primary and bellow the oil line that in some places is nearly through. This bike is quite rare, the numbers match and the case in question has the serial number so i really need to salvage it in some way.

My question is this; have any of you had this kind of aluminum corrosion repair work done and if so is there anyone you can recommend that can handle this sort of engine case restoration work.

I'll post pictures of the damage later.

Thanks,
Tom

[BoschZEV]

I have a 61 TR5AC ...
My question is this; have any of you had this kind of aluminum corrosion repair work done...

Tom, welcome to the Forum. I have a '61 TR5AR so am happy to hear another one of these bikes will be on the road again.

Unfortunately, I can't help you with a recommendation of a shop to do the repair work. I do my own welding so can tell you British alloy welds nicely. As long as the corrosion can be ground away without causing a structural issue (here, photos would help) building the metal back up shouldn't be a problem.

[Finster66]

hey BoschZEV,
Thanks for the response. It's good to know it welds nice. Here's what i'm working with.
Warning; these pictures may disturb some.
Don't faint.
tr5-primary2.jpgtr5-primary-pitting.jpgtr5-primary-weld.jpg

[BoschZEV]

It's actually not as bad as I feared from your description. The top (bottom) of the primary case easily could be built up and re-profiled and the corrosion of the vertical portion of the case basically ignored because it isn't that deep. However, is that JB Weld that someone has used? Whatever it's covering should be straightforward to TIG, although removing the epoxy (if that's what it is) will take some time.

If it were mine I'm pretty sure from your photos that a day in my garage would have it as good as new... OK, maybe not quite as good as new, but completely functional.

[Finster66]

well that's good to hear. i was afraid this type of corrosion damage would be impossible to repair and id have to run a belt drive conversion. the gob of material in the upper right side of the picture is a prehensile boss with no propose - not JB weld.

[BoschZEV]

the gob of material in the upper right side of the picture is a prehensile boss with no propose - not JB weld.

The material that looks like epoxy in the photos is at the center of the 1st and 3rd photos. It's on the the front side of the portion that supports the plate behind the clutch. In addition to its texture it has a different grey color and texture than the Al of the engine case.

[Finster66]

yes, that's the old repair. i bead blasted everything as clean as i could and it appears to be aluminum but you may be right. how could i tell for sure? as long as it holds oil and doesn't affect it structurally i'll leaving it alone. but if it's JB weld i would assume that wouldn't be strong enough to last very long and i'd have to have it re-repaired.

[BoschZEV]

yes, that's the old repair. i bead blasted everything as clean as i could and it appears to be aluminum but you may be right. how could i tell for sure? as long as it holds oil and doesn't affect it structurally i'll leaving it alone. but if it's JB weld i would assume that wouldn't be strong enough to last very long and i'd have to have it re-repaired.

You should be able to tell if it's epoxy -- which I'm betting it is -- by comparing how it feels with a file to that of the Al next to it. Even though it may plug the hole (but, are you sure it does?), it would be a shame to go to the trouble of restoring this case without removing the epoxy and filling it in with metal. It also would be a shame to discover after assembling the engine that the epoxy doesn't completely plug the hole since it would be a LOT harder to deal with the issue after the engine is assembled.

The repair near the gasket face is going to require machining after welding to restore the gasket surface and that is going to take time (a lot of time to get it set up on the mill, followed by 15 sec. of actual machining) so the extra couple of minutes it will take to weld whatever the epoxy is hiding will be a minor additional cost to the overall repair. That's assuming you're the one who does all the preparation, i.e. removing the epoxy.

As a general rule, whenever you come across a repair done with epoxy or duct tape it's a good assumption that whoever did the repair didn't know what they were doing, so the repair will need to be re-done. There are exceptions to this "rule," but the exceptions are rare.

[Finster66]

OK, finally an update to this post. So the old weld repair is actually a weld repair not JB. It looks like some old arc weld or possibly gas? Probably done in the old days. I used a box cutter to scrape off some material and its nice and shiny underneath. A friend at work suggested I bring it to Bill Bune for his evaluation. He's a local guy that my friend goes to for more specialized motorcycle work. if He can't help me I'm sure he'll know where to send me. As for machine work I'm a machinist by trade and have access to a Bridgeport. Wish me luck. More to come later. by the way here's the scary other side of that weld repair.

0406161743.jpg

[BoschZEV]

here's the scary other side of that weld repair.

I see a nice crack at the lower left of the weld, just waiting to ooze oil...

[Finster66]

yup. and gaps here and there...it may end up leaking a little more then your average old triumph but I'm driven to save it one way or another.