computermonkey

My Feedback: (90)

Can someone provide an update on the 15GX and 20GX as to props and rpm readings?
Thanks.

rhd-RCU

My Feedback: (36)

That is the engine I plan on putting in mine.

rhd-RCU

My Feedback: (36)

My 26 went in the Decathlon.

giddyuperic

What's the poop on the 10cc put one on lay away for a 60 size fiberglass stick? Can I run the same oil for break-in and from then on?

rhd-RCU

My Feedback: (36)

Yes

Fidelity101

My Feedback: (13)

Does anyone have any rpm numbers to share for their 33gx? My engine is running reliably, but I'm taching 6050rpms with a 17x10x3 biela and 7400 rpm with an 18x8 Xoar. These numbers are from the bench and after the engine has warmed up...but they seem much lower than expected.

also, it's 32:1 fuel with 87 octane gas and klotz oil. The engine is broken in with a good 12-15 flights and a gallon of fuel, hence the 32:1.

AA5BY

Not sure when I'll fly mine next time but will get some numbers and post. Think I'm running an APC 18x8w. Whatever it is turning, it's hauling the 78" aerobatic plane well.

BTW... one of the things noted is the LS needled seems different than the typical gas engine where it is leaned until stumbling on spool up and then backed out slightly. That doesn't work on the 33GX as the engine never stumbles and the effect seems to introduce air that doesn't allow the engine to idle down with a fully closed throttle.

miker49

My Feedback: (4)

right now,i'm not happy with my 33. 1st gal of fuel at 20:1, 2nd gal at 32:1 with pennzoil.using a zoar 17x8 prop in a dynaflite pt19.can't get a reliable idle.i set the trim where it idles but a bit fast,plane usually comes in too fast.tried a zinger 18x8,idle was better but 3 flights yesterday and 2 were dead stick at landing.engine guys at the field have tried working with it and we are gettin no where.i will check the screen and needle valves for dirt and see how that goes.any ideas? thought this engine was a good idea with the front mount carb for the narrow cowling,maybe should have went with zenoah.

Pete Bergstrom

Miker49,

A higher than desired idle as you describe usually means the low speed needle is still too rich, requiring a larger throttle plate opening to run and thus a higher speed. When you try to close the throttle plate to slow it down the engine is too rich and will quit. Try leaning out the idle screw but be aware as you do this you might need to richen the hi speed needle because the idle fuel circuit is always in use and as you lean out the bottom end you will also take some fuel away from the top end.

Pete

miker49

My Feedback: (4)

thanks pete,will give it a try on sun.also will try a prop with less pitch.[18x6 versus 18x8].might help with the landing speed.

Chewy 76

Well just out of sheer luck I guess when I modified the mounting plate to allow me to fit the G26EI in my H9 Taylorcraft, the top holes on the 33GX when inverted line up perfectly. My only issue is that the centre line of the crank is now 2 or 3mm higher then that of the Zenoah - which was spot on in line with the laser etched marks on the firewall.

I guess I can run a bit larger dia drill through the top 2 holes to allow me to lower the engine a little, but really only want to do that as a last resort.

Is this going to pose too much of an issue?

Also I haven't had a good look at the carb setup, but would it be possible to flip it around 180 degrees to get the throttle lever on the other side?


Thanks

jspauld2

Chewy,

It would be difficult to rotate the carb so that the throttle arm is on the opposite side. There is an internal pressure hole that gives crankcase pressure to the carb pump which would not work when rotated. You would either need to make a modified carb spacer, or route a separate pressure line from the crankcase to the carb, neither of which would be easy to do but are possible.

I hope it's not too difficult to move the throttle servo.

Jimmy

Chewy 76

Thanks Jimmy,

I found that out when I pulled the carb off to have a look

Engine install is complete and now waiting on the weather to play its part so I can get it up in the air. It ended up being a fairly easy install replacing the Zenoah - just moved the throttle servo to the left cutout already available in the fuse and used a sullivan brass plated cable for the throttle as it was the easiest option to thread between engine and muffler. The only real effort I put in was cutting 10mm off the Bisson inverted muffler and recapping so it would fit under the cowl.

jspauld2

Glad it all worked out for you! The install looks nice and clean. Nice work on the muffler also, did you weld it yourself?

Chewy 76

Yeah the install was fairly straight forward which was nice for a change. Now I am itching to get it in the air and see how it flies against the old Zenoah. Nah I have a mate who is a sheetmetal fabricator so I took the plane around to him one arvo and we sorted it out.

AA5BY

Significant contrast between the power of the G-26 and the 33GX.

Luckster

howdy, I am building a 1/4 scale Gary Allen Bucker Jungmeister. Looking at the 33ccEvo. I have the DLE 30 on an Aeroworks Edge 540, unreal power. have high hopes the Evo 33cc is comperable. DLE will not fit in cowl on Bucker. Kit calls for a Zenoha 23, but that is not an option for me. has anybody had the Evo 33 on a big scale bipe. 65" wings?

AA5BY

The comparison I can offer is between a Saito 125 and the Evolution 33GX is stark. The Saito 125 provided adequate power for aerobatics for my 78" Akrobat II but vertical was not unlimited. Vertical with the 33GX is unlimited and with authority. I'm running an 18x8 because of ground clearance otherwise I'd rather use a 19x6.

cymaz

Chewy, how did the modified muffler work out? Did it sound too loud or OK?
I would like to put a 33gx in a 1/4 scale Stampe but we have a strict noise limit at our site - 84dB at 7 meters.

cymaz

Well I have gone an ordered a 33gx for my 1/4 scale Stampe. Weighs in at 17 lbs.

Thanks to Pete Bergstrom for his help with my questions about noise. He did mention that I might save 2db as there is quite a bit of noise from the carb, and that I should fit a bit of foam over the inlet.
Anyone have any ideas in how to go about this? I thought about a trumpet/ velocity stack and wrap it in foam.
Would anyone know where I could get this sort of thing.
I will post further with the installation and measurements if any one wants them.

velottatv

Haven't seen any responses to this question/post. Does anyone know why Evolution does not recommend Amsoil?? Sure makes it inconvenient to have another fuel can to carry around. Was trying to eliminate that by getting away from nitro and changing everything over to gas.

Pete Bergstrom

Amsoil can be used but only at the recommended mixtures in the engine manuals, not what may be detailed on the side of the bottle.

Pete

Chewy 76

Hi mate,

Sorry its taken me a while to get back to you, I moved cities during the Christmas break and have not long got the net connected to the new place.

The modified muffler works just fine, I am lucky in the sense that my club doesn't have any noise restrictions....well none that I am aware of aside from the usual complaints from the old fossils that fly in the club and are dedicated methanol burners (hopefully none of them are adept at navigating RC Universe otherwise I may pay dearly for that comment..hehe)

I have a OS 95AX with the same brand and style of muffler and while its obviously a different note, I believe its no louder on my ears when warming them up in the pits and that same when its up in the air flying. But I have no way of giving you accurate information to back that statement up I'm sorry to say mate and I haven't run the engine with the standard muffler supplied.

That being said, I love the engine. I just need to sharpen my tuning skills up a bit and get familiar with it and everything will be sweet. It pulls the Taylorcraft around pretty well with a 18 x 6 prop.

Regards

Chewy

cymaz

Cheers Chewy,
Still waiting for my 33GX - it will be arriving at the beginning of Feb.

cymaz

Engine delayed, delivery date now start of March. Nooooooooooooooooo