The more important issue is energy density...

The units are comparative Watts per ounce...
If NiCd is 1, NiMH is 2.5, LiFe is 5 and Li-Po is 10.

Li-Po is, of all the above, the most fire-prone and LiFe is the safest.

Agreed, the 10cc gas powered planes should not have trouble with a decent NiMh. My second thought applied more to the bigger stuff - where I've found I had to run a pair of NiMh batteries to do the job as well.

Originally Posted by AA5BY

NiMh are current limited when cold... so they may work in 70-80° temps but not supply adequately at 50°..

I have been flying my yak with nimh batteries in -20c thats about -4F and never hadd any problem. We were flying before we had the lipo. and there was never a question then

Just as info.
I put another 61 minutes of flight time on my 10GX this morning.
After tweaking the hsn a bit it is turning a 13X6 Xoar prop 9400 Rpm on the ground.
Flying a 6.5 lb (dry) low wing trainer type plane I get unlimited vertical. It will trip the telemetry RPM alarm that I set at 12600 after a couple seconds straight up.
This is awesome power in a small engine, IMHO. And, I have been flying it for several days and not one dead stick.

The only small complaint is: If it fails to start instantly it floods and spits LOTS of fuel and oil all over the plane in the next few seconds of starter time. This happens seldom, but is a bit messy when it does.

Sounding better and better! What a difference from the other small engine introductions.
Edwin

Good to hear cause mine will be here Friday

Originally Posted by Fokker DII

Just as info.
I put another 61 minutes of flight time on my 10GX this morning.
After tweaking the hsn a bit it is turning a 13X6 Xoar prop 9400 Rpm on the ground.
Flying a 6.5 lb (dry) low wing trainer type plane I get unlimited vertical. It will trip the telemetry RPM alarm that I set at 12600 after a couple seconds straight up.
This is awesome power in a small engine, IMHO. And, I have been flying it for several days and not one dead stick.

The only small complaint is: If it fails to start instantly it floods and spits LOTS of fuel and oil all over the plane in the next few seconds of starter time. This happens seldom, but is a bit messy when it does.

You're saying you think the engine is turning over 12k on a 13x6 while going straight up? Seems pretty awesome to me too! But maybe turning a little too many rpm? I'd be tempted to cut down a 14x6 to 13.5" and try that?

Originally Posted by ahicks

You're saying you think the engine is turning over 12k on a 13x6 while going straight up? Seems pretty awesome to me too! But maybe turning a little too many rpm? I'd be tempted to cut down a 14x6 to 13.5" and try that?

I do not have a 14X6 at the moment. However I am limiting the throttle so as to not overspeed the engine. I only got the alarm twice... the second time I tried it just to see if it was a fluke but since it did it again I limit the time at full throttle to not punish the mill.

Originally Posted by ahicks

You're saying you think the engine is turning over 12k on a 13x6 while going straight up? Seems pretty awesome to me too! But maybe turning a little too many rpm? I'd be tempted to cut down a 14x6 to 13.5" and try that?

I'm running a 14x4 at just over 9k static and just over 10k unloaded in the air on a flat so I think your 13.5 x 6 would be reasonable but it depends upon the plane and what kind of speed one desires.

I like what you've been saying about your 14x4, but have never flown with a prop that low in pitch? I'm sure 4" would be great for all out 3D, but more concerned about sport flying with a little 3D thrown in on occasion?

Prefer take off and vertical performance over speed to a point. Just not sure where that line is? Thinking of a Yak (Chinese ARF, forget who's) I've had up in the rafters for a while. Lost interest in it when I went to gas exclusively. By the sounds of the numbers I'm seeing from you guys for this engine, I might be able to give it a second look? It would likely be on the bigger/heavier end of this engines capabilities it sounds like. I was originally going to use a 70-80 4c in it. Don't know if I could keep it under 7lbs. Even if it went over a little, a gasser that small (56"?) pretty neat!

The characteristics of the 14x4 are, less noise, more vertical line thrust (less throttle needed), more down line braking, slower speed, slower landings when no headwind exist, and very reliable idle. I've not experienced any heat issues.

The one thing that has me scratching head is the last several outings have each required a click or two more towards rich, probably 7-8 clicks all together. I don't know if that is a characteristic of ABC break in or what is going on as I've never owned an ABC engine previous.

Sport flyer here... no 3D. I'm starting to age and appreciate slower. A 4 pitch might also be good for the higher drag of a bipe such as a 40 size Ultimate.

I was doing some measurements earlier this week and think this engine may fit inside the cowls of a DS B-17,~7.1"dia. Its one of my distant dream builds and probably the first I'll do in retirement, 2.5 yrs. So I'm paying close attention to sport performance and reliability. I'm looking at using 3 blade props. I also figure by the time I'm ready to try one of these out the fuel/oil mix will be more fine tuned.
Edwin

Fokker DII

Do you feel that the engine can now power you escapade now?

I have bought the plane and I am trying to figure out which engine to use.

Originally Posted by SammyKY

Fokker DII

Do you feel that the engine can now power you escapade now?

I have bought the plane and I am trying to figure out which engine to use.

Yes, now that it is broken in and NOT running slobbering rich I am sure it will fly the 60 size Escapade.
After all I was flying that plane for a long time with a Saito FG-14 with a 13X6 Xoar, and his Evolution turns as big a prop at higher RPM so it will fly nicely . I am going to put it back into the Escapade later now that I see the power is there.

Just got mine tonight... L