I am trying to decide on the best engine for my new Vector Flight Extra 66". I would like to use the pitts style muffler to keep the installation under the cowl. I am considering the MVVS .77 but others suggest I go with the .99. Are there great advantages to the .99 and I would also appreciate advice on the muffler selection.
Thank you
Charles

Charles,


With the Pitts, muffler and a big prop, the MVVS .91 has a definite advantage in power.
On the other hand it is more expensive.

The best power system for the .91 is to mate it with the full length tuned pipe #3250.

The .77 responds very well to the shorter, lighter mini-pipe #3253.

Contact David Moen, representing MVVS in your country.
You can find him here and I remember he is actually flying with such an engine.

Hallo,

last time I visited my local dealer I have seen a new MVVS .77. I must confess that they look much better than in earlier days. I have also read about new carburetors (seemed to be a copy of Webra's carburetors). Also the pipes looks very well, so it becomes harder and harder to buy an OS at double price.

Are they reliable and is it possible for normal users to get them runnig fine with the new carburetors? I also have heard that they are made to run without nitro; is this correct?

Thanks in advance

Werner

Werner,


The MVVS carburettor is not a copy of the Webra carburettor, but the 13 mm spigot models are a drop-in replacement for Webra carburettors, which may also improve the performance.

MVVS engines are set up tp run on 0-5% nitro, but there has been talk here that some models, destined for the USA, have a larger combustion chamber, making them suitable for 15% nitro.

What you buy in Austria is, no-doubt, set up to run no-or-low nitro.

I also consider buying a MVVS91, and tuned pipe # 3250 for my new pattern plane (Winter project).
But I am a bit confused. http://www.mvvs-nl.com/MVVS/main_bestanden/glow.htm Say #3266 is the right one for this engine.
Can both tuned pipes be used on a 91? ....If so how would they compare?

Micro,


The #3266 is the tuned pipe intended for the #3094 26 cc engine (glow and gas).

It adds power between 6,500-9-000 RPM and although there is no physical barrier to prevent it fitting, (with the right #3251 side header; not the 26 cc header #3265/26), your engine is designed to spin faster, so the pipe will be inefficient.

Use the #3250 and don't forget the header (they come separately; #3252 for rear exhaust setup; the cylinder and sleeve must be rotated before the engine is run).

You can also ask Jan Karlsson (JAKA) as the Swede dealer.