ok. then we know what YOU think it should be.

Having been flying helis from 50 to 90 size for 5 years or so, and following the Heli sites that long as well, I think I can safely say that I think we know what EVERYBODY BUT YOU thinks it should be . . . . I have never heard any other recommendation . . . .

Sorry, not trying to "jump on the pile" here, but you DID get excellent advice . . . .

- Tim

Thank you Tim.

Yes.. That was everybody. HAHA. Is funny that you pulled the "everybody"card.. actually it gives me great confidense that you ladies dont know nothing about engines and RPM, and how to get the highest RPM to one of the nitro enigines. Got more of you friends out there Evan?.. You seems so desperate to find someone that are agree with you that you called you friends to make them write a reply. Really sad... but you should get a life. HAHA...

Wow, kind of shooting yourself in the foot if you want any other advise aren't you?

Actually these temp are what everyone else in these posts have said, no one has said 200-220 is wrong except you. A few people had issues with my comparison of r/c engines to cars and motorcycles (though not to much of an issue with their temperatures). I have to think that you are fairly new to this or you wouldn't be asking. I've been flying helos for 17 years, airplanes for over 40. I remember when Tim and Barracudahockey were new to the forums and asking questions. Hopefully when you are older and wiser and someone asks you a question you don't have your answer thrown in your face with a personal attack.

Granted, 200 - 220 will NOT give peak RPM, but then again, you DON'T WANT peak RPM in a heli! The motor will FAIL prematurely if you do! The peak and back off a tad is only for plane apps that don't run at pretty much full power and RPM constantly . . . .

And, BTW, I have never met evan-RCU (or conversed with him) before now . . . . I just didn't want anyone else to fall for your bad advice, when the "standard of the hobby" was being offered to you . . . . do whatever the h**l you like, but don't whine when you start blowing up engines . . . .

- Tim

He went away Tim, should we tell him about the secret hand shake?

A water cooled RC heli engine is not as daft as it seems maybe.

You've only got to look at the evolution of small motorcycle engines over the last 2 or 3 decades. And then. it was only a few years ago that no-one would have dreamed of having water flowing through your PC to cool the CPU, then it was only the nerds, now it is quite commonplace. With the right facilities, it wouldn't be too difficult to experiment.

With more consistent cooling, it should be possible to wring more power out of the engine. Whether this would be be enough to offset the weight penalty is another matter.

Does anyone know if marine RC engines use different piston / cylinder clearances or do they just bolt a water cooled head on and leave it at that?

All the water cooled model motors I've seen use the same parts as the air cooled ones. There have been a few instances were application changed some things. Like OS had the old .32 in helo and aircraft and other than heads they gave the airplane version ABC and the helo version a ringed piston. Water cooling would be beneficial to keep a more consistant temperature throughout a flight. Helos used to have cooling problems before efficient fans and big heads came along. Designers could have just as easily gone to liquid cooling though a radiator of some sort would have probably been fairly expensive.

Take a look at the power rating from this little screamer


http://www.osengines.com/engines/osmg1627.html

2.5hp at 33,000rpm from a 3.46cc (0.21 size) engine

Yeah 2.5hp out of the .21's is pretty common now adays. It's all in the rpm. These high rpm motors make crazy rpm but no torque. This is a rc car motor turned water cooled. 10mm carb throat is about what .32 and .40s use. I like how the water cooling goes around the glow plug. I wonder what temp it runs at?

I have Paris modified Picco .21's from 1994 or so, it's rated at 2.5 and that was a lot then.

watch your language ladies. :-) .. You got to chill.. If you dont have any other answer then 200 - 240 its ok. I dont mind. I need more accurate temp. So if you are going to tell me 200 - 240 again; dont bother...:-)

^--- Watch it, buckwheat.

It's your call to refuse advice being offered by experts in the hobby, but it's not your option to attack your betters. I've been doing my best to hold my tongue through this thread, but if I see you go after anyone again, I'm getting Barracuda in here to settle it once and for all.

We treat one another with respect or "we" find a new place to troll.

Good luck!
- Chaz

I never said 200 to 240, it's always been 200 to 220 with 240 being the upper limit. You'll get better power at 240 but you'll find at that temp your .37 will start surging and your tail will start swinging out. The best way to check the temp is with a calibrated IR temp gun at the back of the cylinder and head.

OleC, try setting your engine this way you will like it set using these temps as a guideline.

Here's the info from post #2 again...

Allright kids!