Any news of the 2005 Evinrudes with exhaust valves?

[Markus]

Weren't some '06 Evinrudes going to get exhaust valves?

Any news on the topic?

[Scream And Fly]

All of your questions will be answered at the Miami Boat Show - and I'll report on it the very same day with photos. :)

Greg

[RBT]

2.5l 200 has powervalves.
Was announced a long time ago. I don't know how they run though.
On the more up and up. Bombardier has signed a deal with Petronas to build hi performance engines!.

RT

[Scream And Fly]

Yes, press release posted here (http://forums.screamandfly.com/modules.php?name=News&file=showarticle&threadid=97382). Looks like 2006 will be a great year!

[Riverman]

I remember when first two-stroke street bikes came out - specifically the Yamaha YPVS. That was a sweet running motor at the time. Sure took the peakiness away from the RD350.

In case some of you don't know, two-stroke street bikes hung around a little longer in Canada. I think in the US they tried catilityc converters but you can imagine how well that worked.

[Tom Foley]

I was just going to say, the first RZ 350 's with the powervalves and the RZ 500's were awesome ! All current 2 stroke moto crossers and road racers use this technology to make a very broad ,usable powerband . Imagine a wildly ported 260 with a powervalve setup to make it idle like a 150 !!

[chynewalkr]

why don't the outboard manufacturers do away with reeds and go the a rotory intake valve (RAVE) similar to what the older ski-doos had?

[Riverman]

Imagine a wildly ported 260 with a powervalve setup to make it idle like a 150 !!Probably a lot more low end grunt too.

[Riverman]

why don't the outboard manufacturers do away with reeds and go the a rotory intake valve (RAVE) similar to what the older ski-doos had?Good question John. Kawasaki also used rotary valves on their earlier twins like the Avenger 350 and Samuari 250, circa 1969.

[Markus]

Bombardier has signed a deal with Petronas to build hi performance engines!.

Yeah, but it does not say anywhere that it is about outboard engines, does it?

[1BadAction]

Yeah, but it does not say anywhere that it is about outboard engines, does it?

nope. for what its worth i think it means some bad ass jet skis and snow machines, possibly quads.

The best thing for mercury racing would be a BRP High perf division. There is nothing to compete with Merc in that arena, and as long as thats the case, they will keep raising prices for the same stuff. as far as BRP high perf outboards, there has been nothing even hinting other than heresay and bullsh1t. With the Miami boat show this close, they would have been putting some form of teaser out there to get the people to the show, IF they had an unveiling planned...

[BarryStrawn]

Nope. For what its worth, I think it means Rotax will design and build some cycle engines for Petronas.

[JWTjr.]

Ski-Doo's RAVE valves were/are variable height exhaust valves; they had nothing to do with rotary intake valves. Rotary intake valves are not new; well before Ski-Doo/Rotax used them in their high-performance snowmobiles (beginning in the early 1970s), Johnson used them in outboards in the 1930s. They are not used much today because they are more expensive to incorporate and manufacture in the design of an engine, whereas reed valves are easy and cheap to design and build.

JWTjr.

[Riverman]

Aircraft engines? Before BRP split from their parent company several years ago they were already building certified light aircraft engines. I've always thought Bomb was on the verge of offering a larger line of engines, the market sure is ripe for something new. Hmm, their website down right now...

[Mark75H]

why don't the outboard manufacturers do away with reeds and go the a rotory intake valve (RAVE) similar to what the older ski-doos had?

Rotary valve motors tend to be "peaky" and only have really good power in a narrow rpm band. You can't get low end grunt that a lot of boats need with rotary valve timing that would significantly improve top end.

John left out that reed valves are automatically variable from idle to wide open - a rotary valve usually has fixed timing

Even the 200hp, 30 ci racing outboards use reeds these days (some of them have also been power valves) In the past there were experiments with variable rotary valve timing with variable exhaust tuning and some combined power valve/exhaust tuning on racing outboards

[bigbore]

as far as i know the rotary valve engine is no more they still use the r.a.v.e.valve (exhaust)and note that all the sled engines eventually copied this design its a proven 2 stroke boost the idea of the rotary valve was to control the intake also (hints 4 stroke design)it held in gas and air to the cylinder jug through each revolution obviously(most you guys know this)but the reed valve was a good idea an today they have prety much perfected it they still need to be replaced after long use though.the idea of the exhaust valve is to make a performance engine able to run like a stocker also without the lean condition.its a good idea.as far as the .low engine torque goes its not afected thats up to the engines ability to perform just for what it is displcement and porting intake and exhaust from the manufacturer.

[H2OPERF]

I was told the 60 deg E-Tecs do not have blade type power valves in the exhaust ports.They have a 2 stage tuner with a diverter door in the exhaust that directs the flow depending on rpm.Dave

[Markus]

So that is what is was all about.

Thanks for the info, Dave.