Repairing a damaged aluminum engine case

[MatBirch]

I have an aluminum motorcycle engine case with a damaged bore. It's for the oil pump. It's machined as a blind bore, but the has passages out the bottom connecting to the oil filter housing behind. Something caused the oil pump rotor to drag and gouge up the bore. I've replaced the pump rotor parts, but it still won't build pressure.
In this scenario- is it reasonable to think that the damage can be repaired by a reputable machine shop? Welded and re-bored? Bore it oversize and sleeve? Bore it oversize and a larger pump rotor??
If anyone has experience, including costs involved, that would be helpful. I haven't lived where I do for very long and don't know anyone, so every day I spend blindly wandering around researching, is a day that an eBay motor can be on it's way.

 

[dirt t]

My thought is could you bore it out and sleeve it back to factory?

 

[kbs2244]

I would go with the "fill it in and re-bore" idea.
I don't know how well the HF AL brazing rod would stand up to the rotor.
But is a cheap try before trashing it.

 

[Chevy-SS]

Go to a motorcycle forum for that particular make/model and throw this question out there. Someone may have better answer for you than you'll ever get here. I am on different forums for every vehicle I own and I have received lots of invaluable help on those types of forums. Good luck!

 

[oldmxracer]

What bike are You working on ?

Would need more information to try to figure out the most cost effective repair !

 

[38Chevy454]

Assuming you have enough material around the bore, then bore it oversize and put a sleeve to bring back to std.

 

[adam728]

It's an older BMW. All the advice on ADVrider has mostly been "junk it and buy something newer".

 

[The Cobbler]

any repair will not be inexpensive , depends if it's worth the $$$ to invest .
I suspect the bore oversize & sleeve it would be the best option .

 

[oldmxracer]

It's an older BMW. All the advice on ADVrider has mostly been "junk it and buy something newer".

Ok, BMW in My opinion will definitely raise the price and skill to have it done correctly !

Is there any chance to a buy a good used set of cases online ?

 

[BillK]

Matt,

First question would be "how much can you get a used case for" ?

Without seeing what you have I am guessing on a minimum of $300 to repair, if it can even be done. Most guys in my area with a TIG welder want $100 just to turn it on. Then you have to worry about all of the oil that has seeped into the casting. You usually have to bake it for a while to get it all out. Then can you even get a TIG torch in the bore to weld it up ? Sleeving it might work but then you are talking about making a custom sleeve to fit the bore and finishing it to the proper size once it is installed.

 

[pi_guy]

Often casting are white metal so it can be difficult. You will have to pre heat and need to jig the case so it does not warp. It must be 110 % clean or it will contaminate the weld.
The best way is replacement.
The second best way would be make a sleeve and fit and machine to final dimension.

 

[Plastikosmd]

Bore and press in sleeve , post pic of your repair

 

[APEowner]

You're looking at 2 to 3 hours of labor at a machine shop to machine a sleeve, bore the case and fit the new sleeve. More if they need to do the engineering/design work on the sleeve and the press fit calculations.