Anyone had to have a small aluminum cased engine welded to fix a crack? A motor i'm looking at has a small, 2" crack where the motor bolts to a frame of a motorcycle. The area where the bolt hole in the case is, is raised up, off the main case housing. The crack runs length wise, with the bolt, perpindicular to the threads. I know it would be hard to say without seeing the motor itself, but do you think it could be welded up?

Thanks

 

I dunno if I understand it right but here goes..My guesss is the frameside has threads as well if so..Weld the part thats cracked/sticking out,put a cylindrical shim inside the hole..Put a stud that threads to the frame and a nut to hold the casing tight..What was the cause of the crack in the first place?this would determine what kind of weld and the kind weight is has to support..BTW give me call,I dunno if you still have the tank and interior if you do I have the $$ now..

daz

 

I know what you mean, just weld it and ream the hole out after.

Just make sure you have a good welder do the work.

If you're near TO try JB Alloy weld, off Hwy 7 and 400. They did a fantastic job on my T56 tailshaft for the mechanical speedo gear drive assembly.

 

Here is a pic to kind of show where the crack is. The crack is actually on the opposite side of the motor i'm looking at, but it shouldn't effect anything.

 

Just my uneducated 2 cents, but I say get it welded up, retap the hole and away ya go. What have you got to lose?

 

You be fine mon,

Make sure you have a pro do it that specialized in welding alloys, not some JA with a TIG!!

 

That shouldn't be a problem for a pro. what so ever. Looks like a easy spot to get at. Go for it, it'll be fine..

Keiran

 

Thanks for the info guys. I went back and had a look at it again today, and I'm pretty sure i can get it fixed up. Hopefully in the next week or two I'll have a new project to work on

 

glad to hear that its gonna work out kevin. did you get another bike?

 

Well, I may be. A bike shop in Kitchner has a 99 Ducati 900 SS in. It was in an accident, but its not damaged all that bad. The crack in the case is the worst of it, but it will need some minor stuff as well. If i get it, I'll be trading my ZX6R straight up for it. I should know by the end of next week if i'll have it.

 

holy crap...i saw that pic of the motor was a Ducati , but i thought you were using it for reference. wow..that sounds like a pretty sweet deal. i dont know much about bikes, but i do know ducatis are pretty damn nice. i hope the deal pans out for you. how much faster is this bike than the ZX6R ?

 

Truth be told, Ducati's aren't all that quick. The ZX6R would beat the 900 SS hands down in most areas, except maybe on a track like Shannonville, but even then it would be close. My 6R has about 100hp and 45 ft/lbs, but the 900 SS makes only 85hp but closer to 60 ft/lbs of torque. Ducati's excel at having a great frame and suspension setup, and are more designed for handling.

You might find this intresting. Ducati's use a unique way of opening and closing the valves in the motor. The cam shaft actuates lifters that open and close the valves. It does not use springs to apply tension to keep the valve closed. Its pretty crazy, but it works. Here's a pic of the valve train. If you want to see what it takes to check the valve lash on one of these things check this out

http://www.ducatisuite.com/valves

 

hmmm.....that is a strange setup.......different from what i am used to.

 

I've read about the Ducati valve train when I was researching alternative valve train technology....

If you are interested in that stuff, you should check out the camless and EMV stuff that's coming out.

the coolest by far is the CSRV http://www.coatesengine.com/eGallery/G1.html

 

Kevin, I work in a small custom precission metal fab shop in Newmarket, we're all riders (road race, flat track, ice race, etc.) We can do the job for you and do it right. Contact me if you'd like.

 

Oh, BTW, that valve actuating system is called a Desmodromic valve system, Duc has been using the "Desmo" system for decades (I think since the late 50's). Briefly, the cam opens AND closes the valves, not relying on a spring to close them. Result - higher RPM, and NO valve float.

 

Actually you can see a spring in the valve train pic. However, correct me if I am wrong, but I think the spring ensures the rockers follow the cam. This is a very reliable system, while in Austria back in 98 I had an opportunaty to go to a World Super Bike race. Needly to say....the Dukes dominated.

I also read something about GM experimenting with valves being operated by solenoids.

88AstroMan
I have a spare RZ500 motor, from my parts bike, that blew a rod and but a crack in the bottom of the case. It was repaired and was working when I got it. What I would like to do is weld the crack, but I am worried about distorting the case. Can you guys do this, or have you

 

Everything's repairable. We've done cases before with no problems. If you could post a pic I could give you a cost, or send it to corptec@corptec.net. My main concern here is the previous repair, what was used and how it was done.

 

88AstroMan
Unfortunately I do not have a digital camera to post a pic.
The previous repair is some sort of adhesive. The total length of the cracked case is approx 70-80mm and C shaped. The case is displaced a maximum of 2mm. Short of showing you that is about all I found.