Rotary outboard?

[RiverDave]

 

[BingerFang]

“World’s First Rotary Combustion Powered Outboard Racing Engine” | Boating Mag

The interesting history of rotary combustion outboard racing engines.

www.boatingmag.com

 

[azsunfun]

I think it was mazda early 80's had rotary motors. And it was a screamer.

 

[old rigger]

Back in the day, mid 80's to '90ish, when I was at Advantage the daughter of the owner married a guy that used Mazda engines and adapted them to existing Merc outboards and also used them in off road buggies. He ran his biz doing this in the old Fiberglass Concepts building, where Advantage evolved from. I never got to ride in a boat with one of his engines hanging off the transom but was told they hauled ass. He might still be there?
I think you could stack those Mazdas right? I seem to remember reading an article about them.

 

[OLDRAAT]

265 hp ain't too shabby in '74. Wonder how much it weighs?

 

[Berdes]

265 hp ain't too shabby in '74. Wonder how much it weighs?

From internet search: Its 183 lbs is what I heard a few months ago. and like crj said, with accessorties and what not, at or around 350 lbs.

 

[TPC]

Poor mans turbine.
Suzuki made a rotary Motorcycle too.

 

[Hydroman55]

There’s a YouTube video that runs down the whole story.

 

[BabyRay]

My sister had a Mazda with a rotary engine when she was young. The oil wasn’t changed even once, and it ran forever. I think she had around 100k miles on it, and it was still running fine when she sold it. I don’t know anything about rotary engines, but that always made me wonder why they weren’t more popular.

 

[OCMerrill]

My first wife had a Mazda RX-7 of the 1980 vintage. Reliable with decent power.

My step brother had a Mazda Rotary truck for a couple years.

 

[50onRED]

Rotary engines can make huge horsepower and the already cylindrical shape would make them a great option as an OB. There has to be something wrong with their viability or they would still be used today.

 

[LargeOrangeFont]

They use a stupid amount of fuel compared to a regular engine, and make very little low end torque. They are however compact and rev very high.

To live they need to be kept cool, which on the water is easy.

 

[Bajastu]

With stack-ability, HP was never the issue, it was heat and fuel consumption.

Imagine a four stack Mazda, 1,500 hp and 10,000 rpm. What drive could live at 10-13k rpm?

 

[attitude]

This video is a good watch.

 

[OCMerrill]

The problem is the Apex seals. The engines cannot be lugged around because because they build heat like crazy fast and the Apex seals go away quickly.

15 on the highway and like 12 in town on the 1980 RX-7. I later changed the engine to an Imported Jap engine because the massive use of oil.
They were oil injected like a 2 stroke and this 1980 variant had a Jap version of a Holley 4 Barrel carburetor.

 

[coolchange]

Brother had a bridge ported one in a RX2.
2 power bands. Started pulling around 4k to 7k then fell off until about 9k to 11k like a RM 450.
Motor went in his Baja but was detuned on the porting.
Sister in law raced a spec RX 7. Fun class