[Shorty]

Greetings peeps!

I'm considering using a PWC engine for a little project of mine and I was wondering if anyone here could point me in the direction of some of the engines with better power to weight ratios? The engine for the project can't be super bulky so some huge insane v6 would probably be out of the question, but I'd like a minimum of 100 hp.

Also, what is the torque output on PWC engines usually like? I haven't seen torque ratings anywhere for them.

 

[lsxhp]

2 stroke or 4 stroke? What's it going in?

 

[Shorty]

I'll use whichever has better power to weight ratios, normally I'd assume that's the 2 stroke, but I don't follow marine engine development closely enough to be sure.

It's hopefully going in a dune buggy, but a go cart, atv, or motorcycle are other possibilities.

 

[Arctic]

Get a 1100 Z1 turbo snowmobile engine. You'll have to get a complete donor sled. It will already have the centrifical clutch and In stock form it's 170hp and with some computer tuning you can easily go to 240hp on pump gas. There's a ton of aftermarket stuff for it.

 

[Shorty]

I've contemplated something along those lines, but the clutch and cooling system are problems, though I could probably go the tularis route and use a sport bike clutch, but that still leaves the cooling issues.

 

[lsxhp]

I'll use whichever has better power to weight ratios, normally I'd assume that's the 2 stroke, but I don't follow marine engine development closely enough to be sure.

It's hopefully going in a dune buggy, but a go cart, atv, or motorcycle are other possibilities.

I've got one of the 2010 BMS 1000cc Sand Snipers and it uses a 1000cc liquid cooled 4 cylinder. Have you thought about running a setup like that?
I was wanting more power on mine and from the research ive done its either turbo it or a lot of people use GEO motors or crotch rocket motors. The more I looked into the rocket motor idea it seems there is a lot to change though. Are you building from the ground up or does it already have a motor? That may help you decide what kind of engine to look for. Seems like the seadoo rotax motors make good power from what ive seen and arent that expensive as far as 2 strokes go imo.

 

[Shorty]

An engine like that (the sand sniper's) wouldn't have enough power, and would be a bit big (for the power level). I've considered street bike motors, but haven't been uber impressed with the power to weight ratios or cost. Small car motors as far as I've seen aren't much better than sport bike. (I could be wrong) but i have looked into the rotax. I just don't know any weight or torque numbers on them

 

[Arctic]

I've contemplated something along those lines, but the clutch and cooling system are problems, though I could probably go the tularis route and use a sport bike clutch, but that still leaves the cooling issues.

What cooling problem? Put a radiator with a fan on it and you're good. it's a closed cooling system that should be less work than getting a pwc with a open system. If I'm not mistaken, the new seadoo's are the only ones that have a closed system

 

[Shorty]

My understanding was that sled engines had small cooling veins due to the cold weather they run in. This was second hand from people on a snowmobile forum, but there seemed to be a good number of racers (both summer and winter) who knew their stuff.

 

[Arctic]

Another thing that comes to mind going off of my snowmobile knowledge is that the 1200 polaris watercraft engines were a popular motor swap.

 

[Shorty]

That's looking like a decent possibility. Guys are talking about getting over 240 hp, and 150ft/lbs with light mods and the thing supposedly only weighs 100 lbs. the only way it could be better was if it had more torque.