Best twin cylinder engine for tiny turbo?

So, I bought a tiny VZ21 turbo from Ecotrons.com, which is a copy of IHI's RHB31 unit. By the numbers, it looks to be good for about 80-100HP, which seems just about right for a fairly ridiculous go-kart sized vehicle I'm pondering...

The question is, which engine to attach it to? Here are my initial, ideal requirements...

-twin cylinder

-4 stroke, OHC

-approx 400-500cc

-water cooled

-approx 9:1 or 10:1 compression ratio (possible head gasket spacer to achieve)

-all aluminum

-integrated sequential transmission (possibly optional)

So, the closest candidates that satisfy all of that are likely found in the Motorcycle/Quad/Side-by-side world, which is where you guys come in...

Which engine would you chose???

-Mark

Is the EX500 Kaw liquid cooled?

Yes, EX500 is watercooled it seems... Not a bad place to start for sure. I should also consider some V-twins in the 500cc range it seems. Little baby turbo might nestle nicely in the cylinder valley...

stroker wrote: Is the EX500 Kaw liquid cooled?

That was the first thing that came to mind for me too. Honda CX500 as well if you'd prefer a V-twin.

GL500 honda would be perfect. 50HP stock, with a little boost, 70-90 HP would be right in line.

The CX500 is an amazing little power plant, with a very compact 5-speed shaft drive transmission attached. It has already been turbocharged from the factory, and comes in 500cc and 650cc versions.

That's a picture of a model of the engine, holy cow!

In reply to pinchvalve:

I came in to mention the same bike/engine.

Are there any smallish snowmobile engines that meet the criteria? They would be good because they have reverse and CVT transmission is probably a plus in this application.

Suzuki SV650. Very strong bottom end, physically heavy (115 lbs), and much lower vibration than any parallel twin.

Honda Shadow is another source for liquid cooled v twin and shaft drive. Think they made them in a ~500cc version.

HappyAndy wrote: In reply to pinchvalve: I came in to mention the same bike/engine. Are there any smallish snowmobile engines that meet the criteria? They would be good because they have reverse and CVT transmission is probably a plus in this application.

I have been daydreaming about gokart with a snowmobile drivetrain for soooo long.

I've done it, with a yerfdog and a Polaris 440. It was a wheel stander... on dirt!

These are all great suggestions, guys... I've researched a few of them.

I like picking something fairly common and made in big numbers, just to keep costs down, especially if this becomes some kind of kit vehicle... I also like to stick with relatively modern tech, or as modern as possible, again without getting too spendy...

That rationale puts the EX500 engine in the lead so far... but keep the ideas coming! The snowmobile engines sound interesting too, though I'm not very keen on a CVT for this application...

In reply to mxseven:

The turbo charger will like the CVT, trust me.

CVTs in those sound awful. A weird dude built a 5/8 scale dragster with one. It was the most annoying slow car there.

BAAAAAAAAAAAAAAAAAAAA

For 11 seconds.