To all engine type gear-heads, I have a DLE55 that was taken from a E.F. Extra and put in a E.F. Edge. After the transplant, the vibration appeared. Prop has been balanced, different props used that had been used before, dial indicator used to check run-out of prop shaft .001" very good. Ignition and pickup has been changed because of problems with dead-sticks and such. Engine makes good power, spools up good, bearings feel smooth, no prop strikes. I DON'T HAVE A CLUE what to do next. Any thoughts on this?

If it starts out lumpy down low, then gets better as the rpm's increase, the only thing I can think of to say is fly it.

If you feel like trying, for what it might cost performance wise (very little), it might be worth seeing if there is a notable difference by retarding the timing. Just retard fully/as far as the screw slots allow, to see if that changes anything.

Not a lot to add. If it did not vibrate the same on the previous air frame then I would look at what was changed and what is different in the mounting on the Edge. You may have to go step by step to isolate it.

It could even be as simple as the air frame itself absorbing and showing it more than the other one did. Some air frames will suck up a lot of vibes and others will shake like no tomorrow. They should be about the same, yet since it is now vibrating something has to be different.

I'm thinking along the same lines as Luchnia. It could just be a combination of that engine and that airframe. Did you change anything such as the standoffs? Is the vibration most apparent at idle, midrange or full throttle? You are running the engine with the wings on the airplane I hope. Tell us a bit more about how the airplane is acting. Shaking the control surfaces, the whole tail, cowl or whatever you might note.

Truckracer, good point...you gotta have the wings on. I remember starting a plane once without the wings and it vibrated so bad some of the covering came loose!

A bit more; standoffs were changed from .625'' Dia. @ fire wall / .500'' Dia. @ engine to .750" Dia. solid. Was hoping this change would result in less vibration. Reason for changing was to shorten standoffs for better spinner fit. Yes, wings were on, it flew better that way. Vibration comes in @ 2500-4000 RPM & consistant. Have not played with timing. At idle, very smooth running, surfaces are smooth, but when you start bringing RPMs up , everything starts, and peeks @ about 3000. If it had glow fuel it would foam I'm sure. Don't know anything else to add at this point, TRUCKRACER, didn't mean to be a smart--- just joking, good to see people trying to help others & it looks like I can use a lot. Think I'm going to put engine back on the EXTRA & see what happens. THANKS

No doubt Truckracer was considering that newbies often write in all freaked out about their brand new engine jumping all over the place, only to find out that installing the wings settled everything right down. It does happen...

"Yes, wings were on, it flew better that way." Funny! Nice to have a sense of humor while scratching your head over something like this.

Last, potentially noteworthy is the fact the ign. module is in the process of advancing the timing in the rpm range you mention - from the fully retarded/start position. Probably doesn't have anything to do with this issue. More likely is the difference in harmonics mentioned.

Regarding the wings on or off, didn't know if you were just running the engine for a test or were flying. Of course wings are needed for flight but I've certainly seen people running their engines on planes as if they were test stands and wondering why there was so much vibration.

As a rule, the 55 is a fairly smooth running engine so I'm betting there is some kind of resonance that is just common to that engine on that airplane. Not sure what to suggest or what to ask going forward. But, does the vibration change in any way when the needles are adjusted? How about with a different prop? I know I have a 61 on a plane that vibrates quite a bit with a 23 inch prop but runs quite smooth with a 24. Maybe you could try a 22 and 23 inch prop on that 55 to see if there are any differences.

Thanks for all the replies. At one point I had the needles all over the place and could not get any results (well, within reason) , tried different props. but all were 23'' think I have a 22'' I'll try. Prop of choice is a 23'' Falcon , others I tried were wood. Might try changing the timing (ok D.T.) but biggest change will be , putting engine back on the EXTRA, again thanks to all who replied.