Crank welding needed with big bore kit?

[jknappsax]

Back in the day...

... a friend of mine bought a 1978 Skunk after he rode my 750 and liked it a lot.He's a great rider, and spun the crank TWO WEEKS into ownership. He called Suzuki and said "It malfunctioned.", and they repaired it under warranty. And that was a totally stock bike!

[rapidray]

I hear you on that. Here's some pics of my CB450 engine bottom end after I blew up a piston at 9,000 rpm!

That's NOTHING! You could still reuse those parts. I will try in the next couple of days to find some pics I have somewhere of stuff I have seen people blow up! If that happens with a GS1100 or 1150, the block, cases, & sometimes head & clutch hub are JUNK! If a piston were to break on a GS at 9000 RPM like that it would saw the cases & block on that rod & be history. Those cases didn't even look hurt & you could resleeve that cylinder. The crank was probably another story but you get the idea. Ray.

[lecroy]

I will try in the next couple of days to find some pics I have somewhere of stuff I have seen people blow up! Ray.

Now that would be a funny thread!!!! These are my own favorites...

These were from the Shark after making a few to many 7 second passes. The parts hit Underhills bike and put some nice marks in the fork tubes. No one was hurt. One reason you would be smart to use a blanket. Cheap insurance to keep oil off the tire.



My stock GS1100's output shaft bearing...


Oil filter blow out on the Raptor...

[lecroy]

My dragbike after running low on fuel ...


I was always told the stock GS gears were good into the high 8's was all. I guess that's true.


Some times I am not the fastest learner in the class room and need to repeat my mistakes.
Last summers low fuel melt down.

[lecroy]

Sometimes the bikes are not the only parts that get broke. I had them do this with a wrap (you know, they wrap up the entire limb to remove the blood the tie it off) and watched the whole thing. Very cool watching them drill holes.

[robertob]

And how pray tell did you manage to run out of "head-to-piston clearance"?

BTW, nice photos.8-[

Basically the rod grew enough to eat up the .028" squish clearance I had used. In hindsight it was waaaaaay optimistic on an old air cooled engine to use that little clearance. It would have been fine if I had used more like .040". The next build will use more clearance, of course.

Ray, you're right that it wasn't so bad. The crank is trashed, and the sleeve is bashed into the cylinder so it can't be removed. It also took out an intake valve, wiped a cam lobe and destroyed the cam follower.

But the cases are fine and the head's fine (but there is melted aluminum all over it).

This is a motor that will make 40 horsepower on a good day, though.

[robertob]

Yikes! I've never heard of that procedure. My wife got some pins a couple of years ago from a skating accident and it was a full OR-type surgery.

Sometimes the bikes are not the only parts that get broke. I had them do this with a wrap (you know, they wrap up the entire limb to remove the blood the tie it off) and watched the whole thing. Very cool watching them drill holes.

[rapidray]

Basically the rod grew enough to eat up the .028" squish clearance I had used. In hindsight it was waaaaaay optimistic on an old air cooled engine to use that little clearance. It would have been fine if I had used more like .040". The next build will use more clearance, of course.

Ray, you're right that it wasn't so bad. The crank is trashed, and the sleeve is bashed into the cylinder so it can't be removed. It also took out an intake valve, wiped a cam lobe and destroyed the cam follower.

But the cases are fine and the head's fine (but there is melted aluminum all over it).

This is a motor that will make 40 horsepower on a good day, though.

Usually I have been able to save peoples big blocks with killed sleeves like that by cutting them off at the very bottom with a cut off wheel on a die grinder. Ray.

[TurboChris]

My 83 1100E that I had in 84 twisted the crank at 12,000 miles......luckily still had factory warranty back then, the dealer even let me send out the new crank to be welded.....new cases and everything....then 6000 miles later (and out of warranty) I got that horrible death rattle AGAIN......pushed the bike in the corner and figured I was screwed......still making payments on it......after a month or two of being depressed (and not having the money) I took it to Action Fours in Santa Ana (anyone remember them?) Turned out to be the CLUTCH BASKET.....bought a V&H Welded basked and I was up and running.....funny......

[tkent02]

Just got a '79 GS1000, not going to do any real drag racing, just blasting up the mountain roads around here. Not taking the crank out to weld unless it needs it.
What causes "The Bends"?
Speedshifting with a little messed up timing in the clutch hand?
Over reving the engine?

Something I need to worry about if I'm not racing?

[rapidray]

If you are going to redline the engine much or put sticky tires on it or start modifying it at ALL, I would weld it. It is VERY cheap insurance. BUT..... it is your bike & your money. Ray.

[gshub]

cranks

so why Did pop yoshirmira recomend them not to be welded as it can make the metal brittle
two differant crank rebuilders tell me the samething I could under stand it for drag or racing
but for just a wiseco 1085cc with stock cams ridden on the road.

[rapidray]

I don't know why anyone said what they said TWENTY + years ago but I know what works NOW & what can happen if these things aren't prepped correctly for what we do with them. Do whatever you want, it's your bike but when I build one for a customer & they don't want to weld the crank or do CERTAIN things for longevity, they get NO waranty! Ray.

[lecroy]

Ah, the horse beating continues...

so why Did pop yoshirmira recomend them not to be welded as it can make the metal brittle two differant crank rebuilders tell me the samething I could under stand it for drag or racing but for just a wiseco 1085cc with stock cams ridden on the road.

Why don't you call the people who do this for a living? Two very good sources were given. Then you hear it right from the person doing the work.

[rapidray]

Thanks Mark! I know you know what needs to be done to make these things live but I guess some people just like to argue. Ray.