What prop, exhaust and RPM's are you getting out of your MVVS .91's

Thanks

nobody ?

Hughes, I have one that I have run very little, mine has the carb with the blade in it instead of the normal drum, I use the Silent muffler, which really is. It is smoother running than most engines its size. I'll have to go to Pe's website and run it with some of the recommended props. What size would you like to know about?

Hi!
14x6 ,15x4W or a trimmed 15x6 (less blade area, not less diameter)...all APC of course.
Silencer MVVS steel muffler and mousse can for quiet runs...all around 10000rpm.
Airplane: Great Planes GEE BEE R-2.
Glowplug: Enya 3.
Fuel: 15% all synthetic oil (Motul "Micro" ) and 5% nitro
Regards!
Jan K

Hughes,


The numbers stated by Jan are right for the non-tuned exhausts.

With the tuned exhausts, you will get 700-1,200 RPM more on these props, or spin larger props at the same RPM.

The MVVS engines are timed for tuned exhausts ab\nd respond to them very well.
The .91 with the full length pipe is particularly strong.

Thanks guys,
I am hoping to run it in what could be an 8 to 10 Lb 72 inch Sukhoi. Was hoping to spin a 16-6 or better. I may be asking too much.
May wrap this gem up and look into the 1.60 gas by MVVS

Hughes,


This .91 engine should be powerful enough for an 8-10 lb plane, to hover at 1/2-2/3 throttle.
And you can spin a 16x4-16x6, with a tuned exhaust.

Take into account that the 1.60 engine, with the Walbro and the ignition system, would be about twice the weight of a bare .91...
The weight of the exhaust must be added to both.

Heavier planes generally don't fly as well as lighter ones, so over-powering your plane can only be good if the weight stays the same.

If this plane becomes about 750 grams heavier (don't forget the balance in the tail, the fuel tank for gas can stay the same size for the larger engine), it may just fly like an anvil...

Follow the model manufacturer's engine size recommendations.

That's good advice but the general opinion for this craft is based around the 1.50 4 stroke etc.
I think I will be installing a larger engine!
I have seen Dave's Stick fly with the 1.60 and it was definitely not over powered. Very similar specs etc. I am not one for over powering but I do need to pull out of a hover etc

Steve,

Not overpowered....as the Rolls Royce guys say, power is "adequate". The 1.60/tuned pipe/ 18x8 combo hovers my 10.5 pound airplane at about 1/2 throttle or so. 6' take-off runs to vertical climbs are childs-play.

Did you get the .91 from the guy at your field that had it in a Sukhoi? I heard from someone else that he was having problems getting it to transition. I have not been happy with the Bisson exhaust on this engine, not enough exhaust pressure to the tank I think.

I have run 14x6 (not enough prop) 15x6 (better) and 15x8 (seems better yet, but need more time on it) APC props on mine. The 91 is rated to go as big as 15x10!!!

If need be I can hook you up with a 1.60 gas or glow engine.

Still need a tuned pipe for your SE?

Oh boy Dave,
Is there a market for you LOL
I really need an engine from you bud I am screaming for you over at RCC
Al was going to rattle your cage about the SSE this week. I just let Bill D down today. I did put my name on that 91 out of that Sukhoi but as you and I know these are gems, I want to break my own in. Funny how the word gets around eh [8D]
When you get a minute, shoot me an email! I would love to hear some pricing!
Would really like to get into a 1.60 and show these guys how it's done!