Whilst browsing eBay for rotrex superchargers (as you do), I came across some significantly cheaper similar superchargers from a Seadoo jetski.

After a bit of searching I found that the Seadoo uses a Rotax 1503 and new 1630 engine.

Now these look prety tasty on paper - 3 cylinder, 4 stroke, revs to around 8K, the 1503 (cc) comes in NA form but more interesting in supercharged 215, 255 and 275hp versions and the new 1630 is 300hp all in an 80kg small package.

So questions for the forum -

1) the supercharger looks similar to the rotrex so any issues with running one of these in a car (can't seem to see oil in/out on them, are they water cooled)?
2) given the use in a jetski (works at extreem angles) what stopping you using one of these in a car?

answers on a postcard.......

The first thing i would like to add is regarding cooling.

Boats have an unlimited supply of consistently cold water. Something that is hard to replicate in a car.

Another as i think before i type is power bands. Not 2 stroke style but delivery. These engines drive propellers so they just sit at high revs. Something that would not happen in a car.

my immediate thinking cant think of many reasons other than cooling of how the SC would be different

Look for a vortech instead

I have often had the same thoughts.

With respect to cooling do they really pass cold water through the engine or do they have heat exchangers like most marine engines? If heat exchanger used then easily replaced by a radiator.

One possible risk is that I doubt if the motors are designed to do the number of hours that automotive motors do but then they are most probably designed to live at much higher constant revs than automotive ones.

Gearbox...

And do they have the torque?
And are the cranks strong enough? They're designed to push water rather than a few hundred kg on land

[Edited on 17/10/15 by blakep82]