100 cu inch or 91 cu inch S&S engine ?

[whitebuell]

I am thinking to put a 91" S&S engine into my S1W Buell, the standard engine(1250 cc) puts out 110 RWHP now but keeps destroying himself after 15.000 miles of hard riding and traveling across Europe with the bike.
Weak spot in the engine is the crankshaft, keeps going out of true, piston pins start hammering the clipses out as a result of that crank shifting issue.
We fixed the crank three times now, every time diffrent and very competent people rebuild the crank, same results everytime...so it is not the builder's fault but the crank's weakness that makes the whole deal go bad.
Is there anybody out there who has this S&S engine in his Buell/sporty and what are the results of this engine?
What horsepower numbers come out and most of all, how realiable is this engine?
I personally think the 100" engine is too big and the lower end will not survive very long .
I have to say i don't know the size of the pinion/sprocket shaft but they will not be the size of a TC engine and the EVO is know for his weak crank,the sporty engine is weak in the same place.
Second thaught is to build a engine,starting from Special App S&S cases, but i should want them with EVO bigtwin size sprocket/pinion shafts and that's a difficult and long road too make it work .


Correct me if am wrong please ;-)

[milmat1]

This is one for Arron................BUMP

[dashadow]

You're talking about a lot of expense and work. Do you love the S1W that much? Why not just get another bike that doesn't have the reliability problems?

[biknut]

Have you thought about the reason this keeps happening to you, but not others?

Have you thought about welding the crank in an effort to fix your problem??

[milmat1]

Originally Posted by biknut

Have you thought about the reason this keeps happening to you, but not others?

Have you thought about welding the crank in an effort to fix your problem??

This might be a solution, Where does the crank fail ??

[wilbur]

Originally Posted by whitebuell

I am thinking to put a 91" S&S engine into my S1W Buell, the standard engine(1250 cc) puts out 110 RWHP now but keeps destroying himself after 15.000 miles of hard riding and traveling across Europe with the bike.
Weak spot in the engine is the crankshaft, keeps going out of true, piston pins start hammering the clipses out as a result of that crank shifting issue.
We fixed the crank three times now, every time diffrent and very competent people rebuild the crank, same results everytime...so it is not the builder's fault but the crank's weakness that makes the whole deal go bad.
Is there anybody out there who has this S&S engine in his Buell/sporty and what are the results of this engine?
What horsepower numbers come out and most of all, how realiable is this engine?
I personally think the 100" engine is too big and the lower end will not survive very long.
I have to say i don't know the size of the pinion/sprocket shaft but they will not be the size of a TC engine and the EVO is know for his weak crank,the sporty engine is weak in the same place.
Second thaught is to build a engine,starting from Special App S&S cases, but i should want them with EVO bigtwin size sprocket/pinion shafts and that's a difficult and long road too make it work. Correct me if am wrong please ;-)

What cranks are you using? There have been some revisions on the cranks in recent years.

[whitebuell]

The S1W is the best handling american made bike i have ever owned, not one Harley can handle corners like the Buell, that's why i want to keep riding this bike.
Welding the crank is a solution i think, i maybe try that .
Wilbur ,i have the standard S1W crank with S&S supreme rods, it is also made ligther and balanced .
More people have this problem in Europe when they race or do some hard riding on Buell's .
Just had some info from S&S, those engines seem to have the same pinion/sprockets then the H-D factory engines,nothing stronger on this side.
So the 91" or 100 cu inches wil destroy the crank the same way it happens to me now, i think.
They don't have oil squirters in the cases also, that engine will get hot too .
I was just curious if some people over here do have an engine like that and what the results are .
My engine now has oilsquirters, 1250 cc nikasil kit ,dual plugs,mikuni 42,home made race exhaust ,thunderstorm heads heavy reworked,red shifts 585,pro-flow pump, 5 liter alum. oiltank,zippers ignition etc.... only the cases are stil standard H-D ,and parts of the crank.

[biknut]

Doesn't sound like you've over powered it, so the problem must be over reving.

Which I already knew.

[seajay]

There is a member with a 100 inch S&S. http://www.xlforum.net/vbportal/foru...%26s+sportster

[aswracing]

The S&S crank assemblies as you state use the same size pinion shafts and sprocket shafts and crank pins. It's no better than the factory crank in terms of staying in true.

I'm really surprised you can't make the crank live at that mild horsepower level. I have to think there's more to the story.

How far out is it going on you and in which direction? Is it spreading, or are you fighting scissoring?

You mention wrist pins pounding out. Were the wrist pin bushings reamed square to the case decks? That's really important. There's a tool to do it.

There are a number of things we do in the preparation of a race crank to keep it in true, because this is an enormous problem on motors making north of 150hp. NRHS could do a full race prep for you if you'd like, but damn, I can't figure out why you'd be having this issue at your power level. There has to be something else going on. I'd hate to see you do all that and just have it happen again.

A crank with a 1.5" crankpin makes them much stronger but good luck finding Sportster rods with a matching big end at stock length.