Best engine
 

I am interested in your ideas comparing the MVVS .77 to the OS .61 or OS .91 FX. I am looking for the best engine for a Vector Flight 66" Extra which will weigh about 8#. I plan to mount the engine sideways with a Pitts style muffler under the cowl. Any bad habits I should consider with any of these engines? Thanks for you thoughts. :D

Cata

RE: Best engine
 

Charles:

Too many unhappy users of the 91 FX for it to get an upcheck. The 81 FX has gotten a lot fewer complaints, but I think you'll be unhappy with it from the start, you will want the power it does not have.

The MVVS engines are good, but there have been complaints on the carb. Maybe Dar Zeelon will comment on that.

I'd just get either a Magnum XL 91 or hang a Saito FA-100 and enjoy the plane.

Bill.

RE: Best engine
 

Things to consider:
OS .61FX is not the most powerful, reliable, or cheapest engine in it class. Now that the .46AX is in production we might expect a .61 AX in the next year?
OS .91FX is plenty of engine but still retains the nickel liner, not the best for high nitro. Quite costly.
The MAN shootout stated that the Tower .61 and the Fox eagle .60 were the highest performance .60 size engines tested. Both are less expensive alteratives. The Tower .75 is not much more expensive yet promises better performance than its little brother.
The K&B .61 twist (not in that shootout) turns every bit as much prop as the Fox and turn small props about as fast as the Tower .61 but is less expensive than either. The K&B and the Fox are both made in North America using non-slave labor if that means anything to you.

RE: Best engine
 

YS YS YS 110 cant go wrong especially at the 8 lb mark, Saito 100 awesome engine but wont impress you as much at 8#. saito 150 would be nice but I love YS's and they are powerhouses.

RE: Best engine
 

My Fox 74 pulls a 13x6 MA K-Series to 11,500 RPM after about 2 gallons through it. This is with an idle bar Fox plug, 10% Wildcat blended+2oz of castor @ 1000' ~75F day. Pulls the US-60 straight up.

The tilt down Fox muffler work really nice with the side mounted installation and the engine is one of the lightest in it's class.

btw - it hands starts really easy, shuts off on command and transitions well.

** BUT ** for the first 1.5 gallons, this was quite a dog, it takes patience to break it in, and run it RICH. I'm one click lean from the top end starting to crackle a bit. The first 1/2 gallon was at ~8500 RPM with a 12x7 Zinger wood. Fox does not like to be leaned. I broke it in with 5% Morgan pink + 3oz of castor.

RE: Best engine
 

I second Bill
Buy a Saito 1.00 and enjoy your plane!

RE: Best engine
 

Take it to the bank man !!!! If your plane is at the 8# mark with the engine on it the Saito 100 wont do what you would expect it to do. You WILL need more power. Anything under 7.5 and it will be OK. I am speaking from experience.