EME35 vs DA35

[Chordslinger]

Not using a felt clunk, just a standard clunk on a straight fuel line. No tubing added to the clunk line, but it doesn't fall to the front of the tank.
Not running an on-board fuel filter, but fuel is filtered twice on the way to the tank. I've determined that behaviour is the same operating cowled or un-cowled, on the ground or in the air, so not an airflow or overheating issue.

Looks like rain for this coming weekend, so I'll have plenty of time for a teardown. These are simple machines, I'm hoping I find a simple answer.

[JDaly]

Jason,

Is anyone else in the Calgary area running an EME35 on a Pitts muffler that you can confer with?

A shot in the dark but what Altitude above Sea Level is Calgary? I ask because an engine will develop less power at higher altitudes.

[Chordslinger]

We're at 3550ft. The density altitude was discussed among us at the field this weekend, but I'm not sure it's that large a factor. My other gasser is a DLE 55RA, and when I look at online reports for rpm with the same prop I'm running, I'm within 100rpm of the average. If it were an altitude issue, I would expect a similar offset on both engines.

I have not yet met anyone else with an EME 35, only a previous owner. He had really liked that engine.

[akabek]

I would check the carb fuel screen.

[JDaly]

I had an EME35 on a Planebender Smooth Pipe in a 74" Extreme Flight MXS. Flew it for 3 Seasons and it had gobs of power. Was running a Falcon Carbon prop but don't remember the prop size

[Chordslinger]

Solved!

So after checking a number of things including the carb screen and much head scratching, I realized I had never run the engine on the stock muffler - only the after market pitts muffler.
A quick muffler swap without touching the tuning got me an extra 500rpm instantly on the 19x8 prop, although it was obnoxiously loud. I then installed the EME header / canister combo, retuned, and now consistently get 7400rpm on the same prop. That's a 700rpm increase - or more correctly, the pitts muffler was restricting the output by 700rpm. The engine now performs as expected with good vertical performance on the Edge, and I'm looking forward to the performance after another few gallons of fuel are burned.

I've got a Falcon 20X7 carbon prop on order and expect that this prop will kick it up yet another notch.

[JDaly]

Congrats Jason.

The only Pitts style muffler I ever had good performance was made by J’Tech for a DA85: the main body of the muffler is as made from a 2.5” axis x 4” long aluminum tube. With 5/8” dia outlet stacks. Actually pretty quite with good performance

[Nev]

I have about 5L through mine stock muffler, could never get it to idle properly. This winter I rebuilt the carb took forever to start, had to flood the carb with gas probably to be expected since it was bone dry from the rebuild. When it did finally run, thank you Gary! it ran through 1L of gas reliably. Redline 32:1, 94oct. I am running a 20x8 Xoar getting 6500/6600rpm and a reasonable idle at last ! Now I need to get out more to give this engine some time to properly break in.