broken engine case

[dodgediesel59]

Well just as I thought luck was looking up and PCW finally got some of my engine parts shipped I realized that was not the case. I got the upper engine case unpacked only to find the rear of the block broken where the middle gear cover bolts on. My thoughts are to bolt the engine cases together as well as the middle gear cover and then grind this out and weld it extensively. I know the casting welds pretty easy from having yo weld the front left engine mount section back on a few years back. Does anyone see a problem doing this? It's not ideal, but there is serious money involved in starting fresh with new cases. I was thinking about making a ssmall1/4 inch plate and welding it inside as there is nothing there but a fairly small diameter spacer. Any thoughts or opinions would be greatly appreciated.

 

[jedi-]

Personally I would throw them away and start again. Second hand cases are pretty cheap, but I expect you're worried about the machining expense and then possible piston/ring issues into the new cases, boring or honing, possibly new pistons etc.

Thing is, if you patch it up and it fails again when it is all together then it will piss you off even more. Also the integrity of that hole is important to locate the outer bearing. Welding **** creates distortion, it's the nature of the beast. I wouldn't trust that everything lines up as it once did.

 

[dannymax]

That sux!!

 

[Rusty McNeil]

Damn that sux!!

I'm sure you're in deep with sleeves + chain conversion etc...I'd want to fix it too.

That area is dry now due to chain conversion right?

How much stress does that area take after the conversion? Is there still an outer bearing?

How did it get broken?
Could PCW or the carrier cover the damage?



I think it could be welded quite accurately with cases assembled and bearings/shafts in place and mid gear cover bolted in place.

The assembly could serve as it's own jig.

Whether that would be strong enough is out of my skill set.

 

[dodgediesel59]

I guess in my mind I don't really have a choice but to fix it. Obviously the amount of machine work with the 1500 sleeves and chain drive makes it very hard to justify pitching it. On top of the fact it would probably take a month or better to get a replacement. There is no oil present there as its sealed on the right side of the sprocket. The only thing that really worries me About fixing it is that the 2 of the 4 bolts for the frame stiffener plate will be mounted to that ear for the chain drive.

 

[dodgediesel59]

If you look at this picture what I'm thinking about doing is grinding through the first layer of case and veeing out the bottom layer and then welding and filling that oil return hole solid. Any thoughts?

 

[twistedmax]

Are you a welder? experienced with aluminum? if so...............go for it , if your not experienced with aluminum, find someone that is.

 

[Rusty McNeil]

Along with the welding...

If it's dry and a frame stiffener goes there maybe a full plate could replace the mid gear cover?

Or maybe go under it, leaving the cover as "cosmetic"

With the amount of meat they cut out of it I can't imagine that little piece would have served as much of an anchor point for a frame stiffener any way.

Perhaps this "frame stiffener" was to reinforce that piece so it could do its job as a bearing support??

 

[dodgediesel59]

Yea very experienced with cast aluminum welding, not worried about the quality being poor as I had to weld a broken motor mount on to the front already.

 

[twistedmax]

Probably more mass upfront where the motor mount was but if you're confident I say go for it

 

[dodgediesel59]

Defenitely more mass on the motor mount and more webbing to fill in with weld. I guess like previously stated, it cant be that structural considering how much they cut out of the case in the first place. I am going to build it up considerably on the backside and add as much material as I can without interference. On the plus side I got block, pistons and head gaskets today. Should have trans output shaft, heads, and cams back by the end of the week it sounds. So maybe my monday or tuesday i can get this bike fired up and break in the new engine!

 

[Rusty McNeil]

Take your time on the bearing sizing. Don't trust the numbers.

 

[one2dmax]

Weld it up. Then you can always make up a complete mid gear plate to add more strength if you want it beefier.

Something like seen on the right side of this picture.

 

[dodgediesel59]

Well we will fire up the syncrowave tomorrow and get it welded up. If its going to break, hopefully it does it by the end of the season so I can fix it agian when I tear down to the bare frame again.

 

[alorio1]

I think [email protected] a member on here welded his and it's doing ok, but I could be mistaken about the member.