DLE 20 Advice

I'm currently building a Great Planes Extra 300 kit and considering powering it with a DLE20. This would be my first foray into petrol engines and I would welcome some advice from the experienced gassers in the club .

I gather from comments on various forums that the DLE 20 with stock exhaust is quite noisy. Would an engine with the stock exhaust be too noisy to fly at Cashmoor?

I've seen, on the web, an exhaust restrictor device which plugs into the muffler outlet which apparently reduces noise somewhat at the cost of a few hunderd rpm. Anyone know how effective they are?

An alternative would be to get a Just Engines pitts style muffler. Does anyone have any experience of these and their effectiveness?

I'd ideally like to get the DLE 20 RA ( rear exhaust ) but I suspect that the choice of after market silencers would be limited as it's a new engine.

Any thoughts or experiences on achieving a noise level suitable for flying at Cashmoor would be much appreciated.

I have a DLE55RA that I flew in my P47 on the last scale day at Cashmoor with the supplied pitts style exhaust and had no complaints from those present. I even had to do some ground running as it was the first start up of the motor.
Ron.

I have a DLE20 and with the stock exhaust it is LOUD!!!!!!!

I have a DLE20 in my YAK 54, ok, its only flown twice at Cashmoor but it has a Pitts In Cowl style muffler on it and I thought it was very acceptable in terms of noise...I bought it from the chap over near Bearwood who runs a model workshop from his bungalow! (sorry his name has totally escaped me)

The standard and pits style exhaust in my opinion are only good for deflecting what little residue petrol engine produce!!
They are LOUD and I believe if they keep getting used there wont be many flying sites left in the uk!!
Being a kit built model you have the perfect opportunity to adapt the fuselage for a canister or even a tuned pipe! :evil:
Yes it's more expensive and may take longer to get flying but the long term benefits are fare greater in my opinion,
No bleeding ear drums
More power!!
and the main thing you keep the flying site!!

Take a trip to Probuild they have a good selection of pipe/canister's and manifold's, will also help you install them.

Thanks for the replies chaps.
Ok the stock exhaust is a definite no.
A Pitts muffler would be the easiest to fit , it would be interesting to hear how loud your YAK is James. Was the exhaust home made or was it a commercial one he sold on?

But re-reading your post Chris is sounds like I need to have a stare at the plans to see how a canister would fit and then have a chat with Probuild.

Personally I would have a chat with Probuild, if you took the plans with you I am sure Phil would be able to suggest the best option. The Pitts are a bit better than the standard exhaust but they are still pretty loud

I have a DLE-20 on my Flair Leo. It has a £25 pitts muffler and is acceptably quiet.
I have been using the model as my main plane for 3 years now.
The motor runs best with a 15x8 prop and sips fuel. Only problem has been a crankshaft replacement when the big-end got noisy. The engine has had several hundred flights without any other problems.

That's interesting John, thanks for that.. A pitts exhaust is the simplest solution if I can find an effective one. My thought was to fit a 3 bladed prop as I will have plenty of grunt from the DLE. I understand they produce less prop noise at the cost of some efficiency and provide a better braking effect. (All info gleaned from the web but no practical experience. )

AlanF wrote: But re-reading your post Chris is sounds like I need to have a stare at the plans to see how a canister would fit and then have a chat with Probuild.

It may be easier than it looks!! Done a few over the years most of witch were ARTF's :blink: