Mode Zero

My first successful ! Rc flight was with a veron Decon ,using a vintage MacGregor s/c set (it was vintage even then in 1975 !) The first flight was excellent until I pressed the control button ! No response ,hadn’t bothered with such a thing as a range check .Of course it had a full tank of fuel,after all it was radio controlled I could land it at my feet Anyway the question I’ve never had a response to is why the silencer on the Enya 09 was on the opposite side to nearly all other engines ? Anyone know ?

I was told many moons ago that engine exhausts were on the engines right-hand side (starboard) so that when most modellers hand-launched a model the noise and exhaust goo were pointing away from them, this assuming most people are right-handed and this was when many (most?) engines were not fitted with a silencer. I guess nobody told Enya! Or for that matter, the Mills brothers as my Mills 1.3 had exhausts on both sides, as did my ME Snipe that I started R/C with, but both were so quiet that it didn't really matter.

There were more engines with the exhaust on the LHS in the 50s and 60s, supposedly to suit inverted installations in control line models.

I have always liked the Enya engines of all sizes. Very well made and will last seemingly forever.
The Enya .09 up to and including the .09 III had a left hand exhaust with an optionally available strap on muffler.
Starting with the .09 IV they switched to a right hand exhaust with a very nice bolt on muffler.

Both engine run very well and are at least as strong & have more torque than my OS 10 FSR.

My Enya .09 IV is slated for my 80% Executor, hopefully it warms up enough soon so I can finish off the paint job.

Actually the first Enya 09 (model 3001) had a right hand exhaust.

I don't know if there is any truth in this but I have always thought that a right-hand exhaust would be more eficient (= a bit more power) because of the direction of "swirl" of the mixture in the crankcase. Because of the direction of rotation of the crankshaft/disc the transfer port would get "upgoing" mixture whereas if the transfer port was on the rhs of the engine it would get downgoing mixture......? Of course I have no way to test this theory and my old Enya with LH exhaust seemed to run well enough but it was just a thought....... What think you?

Paul

Here is an excerpt from a post from an engine expert: John Shannon

"I think crankcase swirl does have an effect. The engine in question is a “mini Dooling” layout. The other main layout of this time frame would be what I think of as a “McCoy” layout. The Dooling layout scavenges from the case cavity to under the piston, through matching slots in the piston and sleeve, loops through the case transfer channel, through the sleeve intake port, deflects off the piston baffle towards the head and then back down towards the exhaust port. The Mccoy layout scavenges from the case cavity into the case transfer channel, through the sleeve intake port, deflects off the piston baffle towards the head and then back down towards the exhaust port. Both start in the case cavity and get to the sleeve intake port. The only difference is the journey path.

I have made a sketch of both journeys. Don’t laugh. I believe in both instances the intake charge is cavorting around in the case lower end in a circular motion mainly driven by the connecting rod motion. In the Dooling layout the swirl is most helpful when positioned to take advantage of the tangential release directly into the waiting piston port. In the McCoy layout the swirl is most helpful when positioned to take advantage of the tangential release directly into the waiting transfer channel. Both arrangements are about equally efficient (in my opinion). You will notice one very important difference. The Dooling layout is best served by a left-hand exhaust and the McCoy layout is best served by a right-hand exhaust. Is this really true?

There are a few hints. The 1957 MVVS 15 and MOKI-S1 15 are both left-hand exhaust Dooling style engines. They are also World Champions. But, what about the Dooling 29/61 and K&B 15R? They seem to be wrong. I can only relate my limited experience from this time frame. I had seen the pictures of the MVVS and MOKI engines in the European magazines. Additionally, at the tether car racetrack in my hometown many of the competitors had their Doolings “backwards”. I went home and reversed my Dooling 29 to be left-hand exhasport engineust and found it did run better that way. Additionally, it was common knowledge that the K&B 15R ran better “regular”, that is right-hand exhaust. Mine did, too."


So for a typical cross flow engine like the Enya 09, the exhaust is best on the right side. However, John is writing about speed engines, and any difference might not even be noticeable on a sport engine like the Enya 09.

Thanks for that Richard, I was standing by to be shot down but it seems it may not be a totally idiotic idea.......

Paul

Thanks for the great reply’s recently bought one on flea bay , fitted it in a KK marquis . The silencer looks in the right shop with the engine inverted !
Tony