Potential upgrade for 587 engines?

[- BiRkS_]

Coming from a sled background, almost all Rotax skidoo engines have RAVE's the 470, 583, 650 and up all have raves. (the 470 bottom end is the same up to the 650)

So thinking of the 580 engine. It has the same cylinders either pwc, or sled, the heads are different (sled has a thermostat in top of head) Only difference is the cases and the sled engine has a different case (RV shaft goes to other side of engine to power the waterpump for cooling)

So that being said... I'm thinking those looking for a little upgrade to their 580/650 engines, find a pair of skidoo cylinders with RAVE's. On a skidoo, there is a very big power difference, and you can feel them open at ~6000 rpm on a sled. exhaust tone changes and you can feel the boost in power and rpm.

If my 91 GT ever shits the bed, I may consider doing the swap. (BTW you can pick up a good USED sled engine for under 400$ running and cylinders go for about 80$ machined) Unfortunatly, after all the abuse that ski goes to, it still has 153 psi per cylinder:thumbsup: this thing just wont die. I guess I will be waiting a long time!

If anyone has a 580 that is dieing/dead already, maybe someone will be willing enough to take the chance? Parts would be cheaper for sure..

 

[Crofoot50]

I am a sled guy myself . I own 6 currently. The RAVE conversion sounds interesting I dont know how much more power you would get outa installing them. Would it be worth it ?

 

[Matt Braley]

I don't think those cylinders are gonna fit. If they did the pipe and carb(carbs) would need to be changed also. The best upgrade for a 587 imo is a 717 but that takes a lot of other things as well to make happen(basically a 717 donor ski).

BRP did make upright RAVE engines for skis. They were made at the factory for racers only. They used the 670 bottom end until they were called out on it not being production stuff so they had to switch it to the weaker 717 bottom ends. All of them were 785cc because that was the class cc limit. This in the last couple years before the 787 came out.

I have a couple that I've found but they are rare. I have one from the Big Red Racing and one by Novi. I also have a brand new 785 from Rossier but they didn't use the RAVEs. I also have a cylinder from VE that makes a 717 a 785(looks like a mini 951) with Yami 760 pistons.

Sorry to get way off topic here but I just think if the jugs really swap then the racers of the time would have done it and I would find the evidence on the used market.

 

[- BiRkS_]

My sled is currently stored up north, but I think it does have a very similar exhaust manifold bolt pattern. I'll compare them. As for there being no evidence, maybe they figured they wouldnt get enough power out of them to consider doing the swap. The 587 was a good bulletproof motor, but any improvement on 60 hp would be a blessing.

 

[Strizzo]

since the 657 came out in the 93 xp it might explain why there wasn't a ton of performance development for the 580 platform. the next year the xp had the 657x which is even more similar to the 717 so that platform was used for a lot of years in racing, which is why there were so many parts available for them.