ok i think if anyhting I'm just gonna build it with this motor and build a good solid motor to turbo. That way I can build me a good strong motor that I can turbo to 20 lbs. if I want to. I will mount the turbine anywhere really when I get the frame put together I'll probably see where I can get it. Do you know where I could find good cheap used engines. What sort would you recommend. I think you said over 1000cc right? I will probably keep the shaft drive I heard they were stronger than the chain. Can you use the stock carbs I haven't been able to find any parts for this engine I couldn't even find cams. You will be sitting in it like a car. I will probably just use some vw front tires they are good enough and wil fit with the front end. It was about the 70-80 hp. If I were to try and strengthen this engine I would probably spend enough for a new engine with the crank and everything right? Thanks for all the advice I didn't realize this engine had so many problems. What about the vf1100. Same problems? Let me know. Thanks for all the advice I really appreciate it. I have done a lot with cars and I really want to build this to be unique and I appreciate it.
If you want to run 20psi you will need to reduce compression considerably, which will make it fairly gutless when it's off boost. I'd prefer to run stock compression and lower boost, so the bike performs normally when off boost. If you've ever driven a turbo car with a dead turbo you'll know what I mean.
I'd suggest probably around 9.5:1 at most for that amount of boost and I'd do it with pistons rather than gaskets.
As for mounting the turbine, I would be trying to run it off all four headers which probably means mounting it alongside the engine (left side so you can still access the clutch easily) with the compressor feeding up into a plenum chamber above the V - you will need a plenum to contain that much boost.
I didn't say about engine capacity, but if the weight you mentioned is in the ballpark I'd suggest 1000cc minimum. No idea where you might find engines in your area but Ebay is always a good start. I'd strongly suggest the Blackbird engine if you can find one within your budget. Same weight as the VF700 engine but more than twice the power, and it's a solid base for performance work. Another good choice could be the early CBR1000F engine as that was in production longer than the Blackbird was. The ultimate choice for any car project would be the Hayabusa engine I would think, but for that very reason they're not cheap if you can even find one.
Something that may be of interest is the 929/954 engine. It already has the swingarm attached to the transmission so you don't need any of the bike's frame at all.
I would probably consider a chain drive to be stronger than shaft drive, especially on a boosted engine. Trying to put big power through two ninety-degree gearsets is asking for trouble. There's good reason why shaft drive bikes aren't generally known for big power.
You can use the stock carbs but as you would have noticed on the engine you have they're pretty cramped up which is going to make for a painful jetting exercise while you're setting it up. You may want to go with an injection system purely for the ease of tuning.
Rebuilding the engine yourself back to stock will probably cost you more than double what you would pay for the engine itself, building it for 20psi boost will probably double that again (a piston kit is probably around US$600 alone and good rods could go close to US$1000). All the VF-series were weak. A mate of mine had the VF1000R and had to rebuild it twice after engine failures just from normal road use (a stunningly gorgeous bike crippled by a crap engine design). I think they built the VF-series for maybe five years but the VFR-series went for twelve years without including the VFR800 that is still going another twelve years after that.
Since it doesn't sound like the trike is going to be small maybe just build it around a nice roomy engine bay and then you can swap any engine in as and when you find one.