Repairig cast aluminum cam cap

[liberty2701]

Here is a cast aluminum camshaft cap that i broke. The pieces will fit back together perfectly like a puzzle. I was thinking of either using low temp aluminum brazing rod (35kpsi tensile) or having it tig welded on three sides. This part just hold the bearing race. It is not the bearing surface. It s from a 2015 Honda crf250x.

 

[RoyJackson]

If you can get it clean enough (looks like a casting and might be impregnated with oil over the years), I'd go with the TIG...make sure the welder knows what he's doing so the cap isn't warped and he gets good penetration.

 

[Shield Arc]

I would buy a new one. I got a feeling once it's welded it will be warped to bad. Not sure, after welding if it could be machined good enough.
I would at least compare cost of a new one, to the cost of welding it.

 

[liberty2701]

I can get it welded for free. That is why I mentioned low heat brazing due to the less chance of warping. These parts are mated to the cylinder head camshaft individually. You cannot buy these parts separately. A new assembly is $400. Salvage parts only. it will then have to be fitted.

 

[Shield Arc]

I've never been involved in brazing aluminum.
For the cost of a new one. I would sure try Tig welding it.

 

[yomax4]

Although I could list a bunch of good aluminum solders for aluminum repairs, i think this part needs to be tig welded. I don't think you can get by with only doing 3 sides either. You may have to take it to a machine shop and have it measured so after the weld, It can be machined on the Cam side or just have them make you a new one out of a block of Aluminum. That is a fairly easy part.

 

[pmsmechanic]

I'm thinking that in the end to just get a new one made will be better. Unless you get real lucky you'll need to have the repaired one align bored.

This looks like something interesting so I'll just follow along.

 

[Oldpath05]

Tig welding is the best, I'd find someone to that if I had no mig welder, if it's aluminum for sure, piece of cake.

 

[CincyFlyer]

Here is a cast aluminum camshaft cap that i broke. The pieces will fit back together perfectly like a puzzle. I was thinking of either using low temp aluminum brazing rod (35kpsi tensile) or having it tig welded on three sides. This part just hold the bearing race. It is not the bearing surface. It s from a 2015 Honda crf250x.

As a former Honda technician, I can say a few things about this part: it's likely a high-silicon die casting, so a little trickier to weld than sand cast stuff. Welding it is gonna changes its shape, for sure; depending on the engine design it may not be under much stress, but in this case it's broken, so it may be! Sometimes this part is available separately, sometimes you have to buy the head. I'd weld it bolted to a heavy flat plate (in reality, I'm machine a new one, if I couldn't buy one.)