So How is a Four Stroke so much better than a Two Stroke?

[John Jones]

and mine likes a big fat V-8

[Capt Matt]

Forgot how heavy those first DFI merc covers where, Took two people to lift one off and under a poling platform on a flats boat just about impossible to remove. So glad they are now light
Capt Matt

[seabob4]

Forgot how heavy those first DFI merc covers where, Took two people to lift one off and under a poling platform on a flats boat just about impossible to remove. So glad they are now light
Capt Matt

Remember the Merc guy, think it was John Litgens saying, "Well, yes, we've been working on the technology, the packaging will come later."...DDDOOOHHH!!!

[GoneFission]

Is a 3-stroke like a Wankel?

A wankel or rotary engine is actually a zero stroke engine.  The number of strokes refers to how many times the piston goes up and down to complete the Otto cycle:  intake, compression, power, and exhaust.  A rotary engine does not have pistons so it never "strokes." The rotor spins through the cycles and completes the 4-step cycle in one revolution.  This is why rotary engines can turn such high RPMs - the parts never reverse like a piston engine.  

There is a cool web site that shows how engine types work called "Animated Engines" - they include 2 stroke, 4 stroke, wankel, diesel, steam, CO2, etc:
 
 http://www.animatedengines.com/wankel.shtml  

Here's a nice video of how the Mazda R13 engine works (yes only 3 moving parts on the base engine!):
http://www.youtube.com/watch?v=6BCgl2uumlI  


See ya on the water!

[John Jones]

A friend in the Air Force bought the first Mazda Rx3 to arrive in Montana in the early 70's.  Ugly little car but it would fly.  I was with him at 9,000+ RPM/135+ MPH on a lonely interstate in Montana.  Too young to think about what might happen if we had hit a jack rabbit.     There was no daytime speed limit in Montana back then but the Trooper we blew by shook his finger at us.

I think they said there was no limit to the rpm of the Wankel design except to expect  the eccentric gear to come apart above 10K rpm.

[RickK]

I had a RX2 - quick little pup.

[Capt. Bill]

Allright guys. I'm almost afraid to wade back in here. Well, almost. Fitz, I really didn't mean to offend. I'm just a lighthearted guy and it seemed like good fun.

Boatdood,

Fear's a terrrible thing jump right back in  :P  and no offense was taken here.  These conversations take place where ever boaters congrate. This one is actually mild compared to some I've seen. IMHO motors are motors and they all have one thing in common....Theys be's espensive