I've decided to start a custom motorcycle build and would like to use a VFR-800 power plant and transmission. I've got some detailed questions about them before I get started.
1) Is there a preferred 800 motor? What should I look for when buying a motor, either faults or benefits?
2) What are the general dimensions of the motor and transmission assembly? What is the overall length and width?
3) Are performance parts readily available for these motors? Has anyone turbo'd one, and with what success?
4) What is the offset of the chain? (Millimeters offset from dead center on the bike)
Thanks a bunch. I know these are advanced and obscure questions, but I'd like to know as much as possible going in.
1. VFR800 engines were produced from 1998, in two major versions. Until the 2002 model year they featured "gear-driven cams", which means no cam chains to worry about and a noticeable "gear whine". From 2002 the engines featured a kind of mechanical variable valve mechanism (VTEC), which only operates all of the 16 valves under certain conditions. The VTEC engine has been essentially the same ever since (it is used in the "8th generation" VFR800 from 2014-on). So, the earlier engine is less complicated, but the later engine is much more common.
3. Not really. Several years ago A&A Performance produced Rotax supercharger kits for both versions of the VFR800 engine, but not any more. And a very long time ago, Dynamo Humm in Canada produced "big bore" kits that took the displacement up to 870cc, but that was pre-VTEC and the company no longer exists. VFR engines are usually not hot-rodded--except by a select few dedicated lunatics lurking on this very forum. With a decent exhaust, they do sound good, though: like a small V8 (if you like that kind of thing...)
If you go with a 750 engine from a 1997 or earlier model, you can forego the electronics - might be a simpler install in your project. Highly similar architecture and output but carb'd rather that FI.