[amc49]

You're talking a solid patch some 2 inches wide X maybe 4 inches long, there is no such survivable epoxy patch on earth that can do that. If the pieces aren't there even the best welder on earth will pass on the work, there is too much material missing. Looking at enough heat replacing it to warp nearby surfaces, the last thing you should be doing. The split line crush stress alone wrecks the idea. That area is already a known weakness point on SOHC 750 cases, they broke plenty of them there.

I've both welded and epoxied race heads at $20,000 each to recover them to use again; I got a pretty good idea of what will work and what won't.

 

[NHDad]

You're talking a solid patch some 2 inches wide X maybe 4 inches long, there is no such survivable epoxy patch on earth that can do that. If the pieces aren't there even the best welder on earth will pass on the work, there is too much material missing. Looking at enough heat replacing it to warp nearby surfaces, the last thing you should be doing. The split line crush stress alone wrecks the idea. That area is already a known weakness point on SOHC 750 cases, they broke plenty of them there.

I've both welded and epoxied race heads at $20,000 each to recover them to use again; I got a pretty good idea of what will work and what won't.

So you think he needs a new engine?

 

[Unkle Krusty]

Wot about cutting a piece of aluminium to fit. Then glue or weld or bolt it in place. Why I suggested getting a pro to look at it. Ultimately a spare engine is the answer.
A ******* farmer would have a fix. UK

 

[amc49]

New cases = new engine in difficulty level.

Yes, farmers have a 'fix' for everything and I would have gone further but wiped what I was going to say. I note the lack of the word 'good' put in front of 'fix' though.

 

[amc49]

Honda CB750 F1 SOHC engine rebuild. Part 1.

www.gazzz-garage.com

Go down to 3rd or 4th big pic on the left and does it look familiar? That one not as bad as here onsite. Read the text, the split line killed them, the fix leaked and wrecked rest of engine when it ran out of oil.

That kind of damage CAN be fixed but in no way are you going to without a complete engine teardown. And the plate fitment and welding will have to be top shelf stuff, no farmer work. The split line machining will have to have an expert on how far to cut the plate down for crush. You're talking within .002" for SURE, that is too much error itself.