Sonex AeroVee Engine

[MartyB]

Has anyone tried the AeroVee 2.1 Engine Kit from Sonex aircraft?
I Have a Kitfox Model IV and looking for a 4 cycle engine that won't break the bank.

[Av8r3400]

The VW debate has been beaten to death around here. Do a search to see what I mean.


Bottom line: If VW motors worked well in Kitfoxes there would be a ton of them flying. There are very few, in fact. Take that for what it's worth.

[rogerh12]

Marty;

This was on a different thread, but thought you might have a look.
Great Plains sells a FWF kit for the VW, I think this engine could be used instead and offers some advantages over the AeroVee and GP VW because it lets you turn a longer prop, used with Kitfox planes:

I was on Revmasters site today, and they are offering a new 2331 cc long stroke engine for less than $ 8,000. It is said to have larger fins on the heads to improve cooling and weighs 170 lbs dry. Probably has an install weight of 190 lbs, but lots of bang for the buck. It also developes it's cruise power at a lower rpm to allow longer props to be used, which is needed on the kitfox. Here are the specs:

R-2300
SPECIFICATIONS
HP Rating: 85 @ 3200
Continuous HP: 80 @ 3000
Fuel minimum octane: Aviation grade 91/98 – 100LL
Conforming to ASTM D910
Oil: multi-grade 20/50
Bore: 94mm
Stroke: 84mm 4 main bearings
Displacement: 2331cc
Firing order: 1 – 4 – 3 – 2
Compression ratio: 8:1
Spark plugs: 12 X 3/4 reach DCPR7E
Carburetion: RevFlow 36mm
Ignition: Quad CDI 8 coils
Timing: BTDC 25 degrees
Dual alternator: 20 amp each
Battery: 12V min. 20 amp
Crank flange: SAE #1 4-3/8″ bolt circle
Dry weight: 170 lbs.

OPERATING LIMITS
Max rpm: 4200
Cruise rpm: 3000 +/- 200
Idle rpm: 900 +/- 50
Oil temp min: 130 degrees F
Oil temp max: 220 degrees F (measured at sump)
Oil pressure min: 10 lbs/1000 rpm
Oil pressure max: 80 psi
CHT cruise: 350 – 375 degrees F
CHT climb: 450 degrees F
EGT full rich: 1250 degrees F
EGT max; 1400 degrees F

Props aside and back to the motor. Revmaster states they can produce 82 HP at 2950 rpm continuous, which sure ani't bad. Wow, that is about 400 rpm less than what I figured you would have to spin the motor to get 82 HP out of it. Should make for a good cruise speed and perhaps this motor could even be used on a float plane?

They also say that it comes with dual CDI ignition with 8-coil spark to 8 spark plugs, dual 20-amp alternators, oil cooler.

If this were a Johnny come lately company, I would not believe the engine specs, but Revamaster has been around for decades, so.... I got kinda believe it can do what they say it can. Sweet looking motor too:




Enjoy
Roger

[Judoka5051]

We have a IV (1050) with a GP 2180, 76hp engine. and today I did a climb test. I live in S Florida, so it's as hot and humid as it gets. At gross we were getting 700FPM. That's at 95 degrees and 99% humidity. The plane cruises at about 90-95mph (after some areo-mods).

Lance

[JimS]

Lance,
What is your empty weight and useful load on your Kitfox?
JimS

[Judoka5051]

The plane weighs almost exactly 600 lbs, which leaves 450 for passengers and fuel. It has been flown over gross (80 lbs) when someone fibbed about their weight. It still climbed just fine. About 500fpm as I recall.

[rogerh12]

Lance;
I am about to start mounting my Great Plains Porsche (Type-4 VW) engine on my kitfox-4-1200, and need to get a prop on order. I was hopping you could help me out with a starting point. What prop did you use? That is to say, who made it, what is the diameter and pitch? It's birch, right? Also, what is your cruise rpm at 95 mph, and what is max rpm on the ground? Thanks in advance. Roger

[Judoka5051]

Hey Roger,

The prop was made by 'Valley Engineering' (formerly Culver) and is a 62X25. I don't know what wood they used. It cruises at 3100 for 95, but will happily loaf along at much lower RPM. I was just about to comment that the pitch seemed wrong, and tried to look at the Valley Engineering site to check their pitch calculator and found that their site is no longer active,,, out of business? Anyway, 62X25 seems like a climb prop, but the plane cruises fast, and I can never get 3600 RPM even in level flight, 3400
max. It will reach 3100 static. It might have been repitched and not re-labeled You might try 'Tennessee props' I've bought several props from them and had very good luck, beautiful props too! They are very familiar with VW's.

Hope this helps, Lance

[rogerh12]

Lance;

Thanks for the input, it really helps with my prop selection. I like culiver props too, but it does seem that they are out of business now. I also agree that you have a climb prop with your 25" pitch, if your turning 3400 max in the air and 3100 on the ground. Also, my calculator says you have a thrust velocity of 80 mph at 3400 rmp, which is low for a plane like yours, so could stand some more pitch if you want to go faster.

I do have a propeller performance calculator, and it is showing that you are absorbing 73 HP through the prop. So, based on the above readings, the calculator also shows that if you increase your pitch to 27 inches, which I would call a "cruise" prop for your VW Kitfox, you will loose 100 rpm off your static and max rpm, but increase cruise speed by 6 mph. Of course, these are just calculated projections, but another flyer reported cruise speeds above 100 mph with the VW, so it will probably work for you too. However, I suspect your rate of climb will be reduced 50-75 fpm or so if you go to this "climb" prop.

Note the other VW powered kitfox-4 was a speedster, and had a Sterbra wood prop (62x32) and recorded a cruise speed of 110 mph at 7500 feet.

Hope this helps
Roger