airborne

My Feedback: (1)

I'm hoping to get a bit of help with my MT-57. I purchased one of these from Southwest RC Engines late last year to power my new 50cc Aeroworks E-300. It came with the standard muffler, and I also purchased an elbow/canister from SWRC at the same time. From what I've seen on several forums, the MT is supposed to equal (or possibly) more power than the DLE-55, etc.

I'm just about finished breaking it in (about 2 gallons of 32-1 through it now). It's mated up with a 22x10 Pilot carbon-fiber prop and it specs out at about what the manual says on the top end (6,200 rpm). I also detached the canister and bench ran it with the muffler (jumped to about 6,500 rpm, but a touch louder).

I've flown it several times and am starting to work on the IMAC Basic flight plan. However, in the air, it just doesn't have the "pull" to get through the vertical maneuvers. Even if I approach with a ton of horizontal speed, then by the time I get to a half-roll on the vertical, it's just about out of airspeed. It weighs in at 17.5 lbs., so it's right on Aero-Works specs.

I must also admit that although not new to the hobby, I am relatively new to gas engines. But with the setup so simple, I'm not sure what's left to tweak.

Could it be that when I go to the regular fuel mix (50-1) that I'll suddenly pick-up the needed power? Seems unlikely.

Anyway, if anyone could lend some advice, I could sure use it.

Thanks in advance!

phantomdriver

Try 50-1 Redline with Av Gas 100LL / Works for me.

mrbigg

My Feedback: (21)

You'd think that engine would spin that prop over 7 grand.

closetguy

My Feedback: (13)

i don't think you will get much more than that.i got 6200 on a xoar 23-8 with the one i use to have.you can check the timing,mine was set at 24 degrees BTDC. i got a little boost in power after setting it to 28-30 BTDC, BUT not much no more than a hundred rpm's.i had two of these jewels[:'(] of a engine.first one ran same rpm's as the one you have now.the second one i got as replacement for the first,after the crank case crack around the nose where it meets the case.
that one would spin a vess 23-a at 7200 rite out of the box.this one i like for the power but it shook like a dog *****tig bones,it loosen up two airframes before i got rid of that one.
i would try setting the timing and get a vess 23-a or a 22-8 prop like a xoar.
it sounds like your engine is over prop with the 22-10.
best of luck to you.

catfish2

My Feedback: (43)

That engine should be getting a little better tha 7000 on a 22" prop. My 57 gets 6800-6900 on a 23X8 prop all day long, and i do not have the newer flat top piston. Another one that I am around gets 72-7300 with a newer piston, canister and a 22"vess, not sure what pitch. I would check timing first, set it to 28 degrees, check carb screen and fuel plumbing next, then take a good look for air leaks around the carb and engine case. If nothing found check your tuning, maybe you are off a bit.

airborne

My Feedback: (1)

Since my original post I've gone through everything. I removed the canister and ran with just the muffler. That helped. Then I went back to the canister tried playing with the length of the header and found that by shortening it (tuning it in effect) I have gained a bit more RPM. I'm now in the 6,600RPM range on the ground.

I've also checked the timing and although it isn't an exact science to measure, it seems to be in the range you mentioned. I experimented with moving it just a bit, but ended moving it back as it ran best in it's original position.

I have been running it pretty lean all along and it's had over 2 gallons through it now, so the break-in should be finished. I've switched to the 50-1 mix, and on a whim I also switched from 87 to 89 octane. In doing that I lost about 150 rpm, so I'm going back to the 87 octane after this gallon is used up.

The one thing that is really puzzling in this is the high-speed needle. Everything I've read says to creep up on this by small adjustments. I can crank the needle all the way in, most of the way out, or most anywhere in between and little difference is made on the top end. It does change the transition from mid-range to high, but that's about it.

I'm wondering if it's more of a carb problem.

closetguy

My Feedback: (13)

when i had my 57 i had a real hard time getting it started.i switch the carb out to an Evolution 58 that i already had and it started on 3rd flip.it also had the same problem of not much of a high speed needle adjustment. this was one of the first batch of engines in the US.
i also had to replace the reeds one the first engine after one broke after two gals.
you found out that it dosen't do much good using higher octane fuel unless you have higher compression. i was using a tuned pipe on the first engine and that jump my rpm to 7300 on a vess 23-a.funny but the engine respond good to a tuned pipe.