Oz,
While I'm not working on a bike, I feel your pain. And being from Great Britain, you may understand my quandary - I certainly do yours.
I'm working on a BMC 1275 inline engine for my MG Midget. Plenty of parts and racing parts still available - but . . .
I'm destroking it to ~1000 cc's, and while there is a factory precedent for this - the 970 Mini Cooper - BMC never made an inline 970, only a transverse version. Therefore, the crank - unavailable - has to be made from scratch. Additionally, due to age, rods become a problem - nothing in the books is still available. It took me a year to find out what length stock 970 rods were. So you spend countless hours with notepad and pencil, checking out other manufacturers, be they automotive, motorcycle, snowmobile, hoping that you might be able to stumble across a piston with a 1.785 deck height, 2.700 in diameter, or hours scanning for parts on e-bay, or trying to find a parts house that still uses books, not a database out of some faceless warehouse in Birmingham (GB, or Alabama). You calculate whether or not you can make the Triumph piston work, whether or not there's enough meat left on a stock crank if you go with Subaru Justy rods (there isn't), how much you can shave off of the block, how you're going to make a 4 cylinder 4-port fuel injection system work on a 5 port head where only two of the ports are intake. Oz - is there anything I've missed?
And then you get into the literature. Stroker kits - no problem - I can site chapter and verse on the do's and dont's of increasing a 1275 to 1450 cc's. Destroking? You'd think I was asking to borrow a family menorah from a Rabbi during Hanuka to illuminate my garage.
Help at the parts store? I'm quite certain the weekend flunky at the counter could give me a solid opinion as to which tire glaze won't muck up my wire wheels, but if it isn't in the computer, he can't order it - and if he can, it's a crap-shoot as to whether or not it's the right part.
Emailing an inquiry to a parts supplier? Seldom worth the effort, with few exceptions, and usually only if you have a contact name.
All that said - shame on you if you bail on this now.
Two years? You've already got too much invested.
Nobody knows your project better than you.
Just about anybody can screw together a small block Chevy that will make sick horsepower, and if it breaks, have a replacement part overnighted to them anywhere that Fed-Ex delivers. The Busa? I've heard it said that it's the SBC of the 21st century.
But damned few people have the patience to take on a project like what you're doing and make it work.
What I'm sensing in your post is not so much the enormity of the endeavor, but perhaps a loss of faith in your ability to do it. And while it will be expensive, the only reason I would bail now is if it proved prohibitively so. If you want to, you can do this.
If you simply want to go fast, that's great. It can be done, it can be done inexpensively, and there's nothing wrong with that.
But if you want to go fast on a CBR 1000 Honda, as I do in a 1 litre MG Midget, then your going to have to do it by yourself. You will find allies, you will find support, you will find help, and as I've found, you will make some great friends who know what you're trying to do. These are your assets.
I understand your frustration, but encourage you to make it work.
Best of luck to you!
Sincerely,
Chris Conrad
