Hughes500E

My Feedback: (16)

I'll be running an MVVS 26IFS (red head) engine shortly. I would like to hear what mufflers and prop combinations work well for quiet performance, G23/26 inverted wrap around pitts fit? Evolution etc? Did many have to install shims under the head?
Any hints and tips that would be useful for me, I would appreciate!

Thanks

apalsson

My Feedback: (1)

The Evolution Pitts muffler is nice and fits perfectly.
The DLE30 Pitts muffler is what I have on my 26cc but I had to modify it a bit by brazing a flange on the exhaust port to clear the cooling fins and then widen the hole spacing from 34mm to 36mm
I believe OS160 mufflers also fit and quite possibly some Moki engines have the same pattern.

Sorry - forgot to add - I'm running a 19x6 wood prop and it's a very good combination

Rocketman_

The OS 1.60 muffler doesn't fit the MVVS 26cc.

The Bisson Pitts muffles effectively but my rpm was 7450 with an APC 18x6 wide prop. If you cut off the rolled tips of the Bisson Pitts exhaust pipes you can gain around 300 rpm but it gets louder.
The MVVS tuned pipe is an excellent muffler and it allowed my MVVS to reach 8800rpm with an APC 18x6 wide prop.

Hughes500E

My Feedback: (16)

I actually have the tuned pipe but I can't use it on this airframe.

I wouldn't want to modify too much :-)

pe reivers

On the MVVS tuned pipe 18x8 20x6 and 18x10 props do a good job. Restrictive mufflers do well on 16x12, 16x10 18x6 and 18x8
If your engine is of year 2008 or later, no extra shims are needed if premium gas is used. The infamous US regular gas (87 PON) needs shims added to avoid pinging.
If you fly at altitude of 4000' or more no shims work as well.

Hughes500E

My Feedback: (16)

Hi Pe,
I would guess that this engine has been around for awhile, pre 2008 but it has just had its first two tanks of fuel through it.

I am below 4000 feet (1200') with Canadian Octane equalling 91

I guess I should order some shims from you!

pe reivers

shipping is no problem, but from Horizon would be a lot cheaper. Dutch TNT is expensive, and I only ship registered mail. Shims by themselves cost next to nothing.
The chinaman's food trays also are good to snip a shim or two from. So are aluminum mousse cans! You would need about 0.4mm added shim.

Hughes500E

My Feedback: (16)

Thanks Pe!