Would a crank weld be necessary

[Guest]

I know I've reached out to many of you privately on this forum, and I just wanted to say I really appreciate all the help so far. I'm still trying sort out final options before I begin a rebuild of my gs1000 engine. I'm looking to have a powerful street bike that rarely gets redlined, and I'm curious if I would need to go to the effort of splitting cases to weld the crank or if it is fine as is.

This is where I'm at:
1100g cylinders bored to accept 74mm 10.5:1 pistons
1000 large port head, street ported (possible have an exhaust dam built for a fake D head, entertaining thoughts on this)
web cam grind #118 .365 lift 286° Dur
Likely need to find some 34CV carbs.
Kerker pipe, not sure but probably Kerker headers, they are old.

So is this a "You need to weld that crank" kind of build? Like I said, no racing. Not likely to redline. Just looking for more torque and quick HP delivery.

Thanks for any opinions.
Ross

[Agemax]

i dont think you need the crank welded with those mods, but others may disagree.
if you were constantly redlining i would say other wise but with just mild to fast riding i dont think it is worth the expense

[rapidray]

If you are spending money to build a motor, why not make it BULLETPROOF & spend the extra hundred to get it welded? It will cost you more than that just for new gaskets if it twists after you build it. I would also do a heavy duty clutch hub while you're at it. But, that's just the way I build them & I don't like having to re-do them after the build. Ray.

[mrl1000l]

For $100, I'm assuming you are talking about me simply finding a competent welder locally.

I guess I thought the bulletproof build means me sending it off to someone who can true and weld the crank, which is more $$ after all the shipping is done.

If I can get all that done for $100, I'm in! Otherwise, I'd like to spend the money on other parts of the build if I can.

[gshub]

When I had my Gs bored to a 1085cc ,the crank was checked out first ,and then tacked, I have been told if they are welded up to much the heat can do more do more damage .......
having seen pics of a unwelded crank and what can happen is £50 worth the risk,I ask.........

[speedyandypandy]

"better safe than sorry" someone said at one point or another...
If you build a faster bike, and you should find out by yourself, that the biggest upgrade is the rider, and your skills increase, and you find yourself redlining the thing abit often, it's worth to have done it.....
just my $0.50

[mrl1000l]

When I had my Gs bored to a 1085cc ,the crank was checked out first ,and then tacked, I have been told if they are welded up to much the heat can do more do more damage .......
having seen pics of a unwelded crank and what can happen is £50 worth the risk,I ask.........

Falicon website has the service of truing and welding a crank listed for $270 BEFORE shipping it 2 ways.

I hate to sound like a cheap bastard, but who is doing this for $100? I feel like it's slightly more complicated than taking to crackpot welder, but maybe I'm wrong.

[Big T]

I had my local engine builder do mine, $50 BITD

It just needs to be spot welded, any competent welder can do it

Yes, you should do it, because for all that engine building (you're spending about $2k) splitting the cases, cleaing up the insides and checking the tranny is worth the time. Minimal expense in splitting the cases

And, you're kidding yourself if you think you won't be redlining it. You'll have to be shifting fast to use that additional power without hitting redline. My 78 motor goes past redline in the lower gears quite quickly if you open the throttle much

[Nessism]

There are better sources than Falicon for crank work. Lots of different threads in the archives including this one so you can learn more...http://www.thegsresources.com/_forum...d.php?t=121162

[BlackStar]

When I tore into my GS1000 to do a top end, I discovered that my crank was twisted, so I didn't have a lot of choice in the matter. John Pearson in West Alexandria, Ohio fixed me up.

[blowerbike]

call john........
937-839-9723

[mrl1000l]

Thanks for all the input, I called John Pearson and talked with him for a while. He explained how the crank can get twisted in street application that I thought I would try and pass on for anyone that finds this thread.

He told me that a common cause for a twisted crank is when the back wheel looses traction. In this event, the engine with spin up to high rev. If the wheel then gains traction again when the engine is free spinning at 9k rpm, dropping back to 2k rpm in an instant the crank is likely to twist.

Speaking with another engine builder, he told me another scenario is a lean idle circuit and chopping the throttle at high RPM. If the tire has enough grip, the strain is sent directly to the crank.

These are both scenarios that I've experienced with my stock motor. I'll be sending my crank to John as soon as I can tear down the motor.

[TeamDar]

John is the man. He is honest and does quality work at a reasonable price. I highly recommend him.