Dan -

I've ridden Tom Metty's 88" bike, and our 100" race bike (S&S aftermarket case that's wider on the cam side to accomodate a 4" bore). We DID fit the 100" engine in a stock frame, but, couldn't get the rear rockerboxes in w/out unbolting the motor mounts and lowering the engine to get clearance.

BOTH engines were simply phenomenal. Tom did an excellent write-up on costs/process/problems. In the 88" displacement, in street clothes, we got 160MPH outta the QC88 (goin' from memory - the SCTA/ECTA records should be more accurate). In race trim, I wanta say that Tom's guy from Hell, MI got above 165 w/the same engine. (Tom went on to try all kinds of wildassed stuff w/that engine - he's quite an amazing fella!)

The big-bore engine, done right, will be expensive, but, should be quite streetable. Starting from scratch, though - you'll spend close to $3K to do a 1250 up properly.

To those considering a climb up the HP mountain - you can get 80HP out of a 1200cc Sportster fairly easily - the costs and work required to move up expand exponentially beyond that point.

Is it worth it? Only you can tell, but, *I* certainly think so.

:-)

 

100" has a certain ring to it......

 

Ah!

 

Yup - it's not cheap. The cases alone are close to $3K, bottom end about another $1500, and we haven't bought heads/cams/pistons/transmission/ignition/fuel delivery or exhaust yet. The Zippers' billet heads we had worked well, but, I've gotta wonder whether or not current offerings would be just as good and a bit less.

We had Red Shift make up a set of cams - and when that engine got to the top of its torque curve - it felt like it wanted to jump up off the track. It was FUN!!!

 

Don't forget that high flow oil pump.