Rotax Rick's 670 engine

Rotax Rick

Newbie
Joined
May 17, 2010
Messages
31
Location
Naples Fla
Aircraft
Quick Sprint 2
Total Flight Time
13000
THANKS EVERYBODY.
I want to add one thing. It was the comment to how I can build a better engine than Rotax , in my garage while Rotax spends millions on engineers.
I would love to be able to get credit for all the improvements I do to my engines but the truth is, I just copy what Yamaha & the other manufactures having been doing since the seventies. Rotax engines was developed from a Snowmobile engine. You can't run a Snowmobile flat out very long or you will be wrapped around a tree. They back off the throttle a lot & this gives the engines time to replenish the bearings with oil. To show my point take the 670 SkiDoo. At the end of the 670 series in 1999 the engine was 132 hp. Now take the SeaDoo 720. This is the same rotary valve engine like the 670. Even the intake manifold will fit the 582 & the 670 but they were only 85 hp. WHY ? Because 2 guys can be going to a diving hole 5 miles off shore & the one guy say's " last one there buys dinner " Now you have an engine that is going to be ran flat out for a long period of time, just like our Aircraft engines. Rotax knew that the 720 at even 132 hp would not last, so they derated it. Thats why the best high quality custom parts builders sell rods with 2 oiling slots, Just like Yamaha does & Just like I do. I have never had a single lower rod bearing fail on any 582 that I rebuilt the crankshaft. Considering every 3 out of 5 582's that I seen fail was because the lower rod bearing failed do to lack of oil.

I want to make one last statement , I think Gyro Jake is a good guy & is very talented & loves ( like I do ) to help people & doesn't expect anything in return. I have always love talking with Jake & I been to his shop many times & I have always been impress with the things I seen him make. I feel very bad that I got so upset, SORRY JAKE !!!
I love my engines & all of my customers & do my very very best to build them a perfect engine.
Thanks again to everybody !!!!!!!!!!!!!!
Rotax Rick
 

Vance

Gyroplane CFI
Joined
Oct 30, 2003
Messages
15,939
Location
Nipomo,California
Aircraft
Givens Predator
Total Flight Time
2400+ in rotorcraft
I want to add that if you are building a Gyro that requires more power than a 582 has in flight , don't buy a 670. I developed the 670 for heavy Aircraft, heavy passengers, short strips & float planes to clear the trees. Not for Gyros to run at 90% full power all the time. The 670 will not provide even 75 hp continually. Every 3 out of 5 Rotax 2 stroke water cooled engines that fail is because the lower connecting rod bearings fail. I have never had a single 582 or 618 lower rod bearing fail & the ones that did fail on the 670's (6 out of 432 engines ) was mostly on abusing engines in Gyros . I don't want to hurt anyones feelings but I rather not sell a 670 for a Gyro. I just don't need the 670's name ruined by using a 670 where it shouldn't be used . This is where I had 80% of all 670 problems. Kirt Grover flew his 670 for years @ 4 gph & didn't have a problem. That's the way I meant it to be flown. The 582 for the same thrust would of used 5 gph & been overworked. I have no control of how my 670's are being operated so I hope everyone understands this. Also with 432 670's built if they were not a great engine I believe everyone would know this by now. Peoples always happy to jump on a bad thing but never respond to all the good things. Sincerely Rotax Rick
Getting back to the original posters question Rick; if I am understanding you correctly; you do not recommend one of your 670 Rotax engines for a gyroplane?

What Rotax two stroke engine do you recommend for a gyroplane?
 
Top