Kitfox-4-1200 : 2180 VW power Performance Data Available !!!!!

[rogerh12]

a. did you use the belt reduction put out by great plains...?????
NOPE, JUST DIRECT DRIVE.

b. what is your dry weight when you mounted the vw... not counting the engine mount...??????????????? THE TOTAL PLANE WEIGHT WITH OIL WAS 654 LBS, THAT IS THE ONLY TIME I ACTUALLY WEIGHED THE AIRCRAFT.

thanks for the moment.... a kitfox iv... about 90% done...

[rogerh12]

Hey Guys;

I am looking at a couple of good used VW's for the kitfox, and got my first pricing. I thought I would pass it along for reference to a used Rotax 100 HP. This engine is a Great Plains 2300 cc engine, direct drive with less than 50 hours on it (nicely broken in). Here it is:

Basically a running 2300 cc, dual plug engine with all the extra stuff like oil cooling, baffling, remote oil filter, super HD oil pump, remote oil drain, and some engine instruments. Also, intake, exhaust, and Ellison Injector carb, but no motor mount, prop, spinner. $6000.

Well, would still need an engine mount, cowling and prop to finish the Kitfox-4-1200 with the 75 HP VW aero engine, (shimmed out to run on car gas). which would set me back another $1500 or so. So for about $7500, I have an "almost new" FWF package ($8000 will be budgeted) that can run on car gas.

This is fairly cheap, for comparison my buddy put in a factory rebuild 0-time rotax 100 HP for about $17,000 (minus the cowling) , but of course he gets an extra 25 HP and less weight. Still, I would save almost $10,000 bucks over that, and the real saver is the rebuild cost of the VW. It’s only about $500 in parts and I can do it myself, if needed.

Anyone know what Rotax charge for a rebuild?

Hope this helps.

Roger

[Av8r3400]

$8k for a converted auto motor with very questionable reliability and performance in an airframe like a Kitfox.

My good friend, Dave, just bought a complete, running 912UL (80 hp at a usable prop RPM) for $6500, 150 hours TT and a fresh tear-down inspection from LEAF. (The motor was involved in a crash - fuel exhaustion, no sudden stop.) Combine this with known performance & reliability and a supported FWF package with cowling from Kitfox. This would make for maybe $10k total FWF.

Personally, I would gladly pay a $2k premium for a motor that I would be totally comfortable trusting my own and my passenger's life with.

Roger, you are obviously sold on the VW conversions. At one time, I was too. I hope your plans work out for you. But, just stop and think for a moment, if this experiment does not perform (and I truly don't believe it will), you will have, at best, a plane that needs to be re-powered, at worst a wreck (that hopefully has not injured you or a passenger). Either way you are back to square one.

One man's opinion and my last input on the subject. Good luck to you.

[rogerh12]

Wow, 10K for a Rotax 80HP FWF is great deal !!!!. My pricing of 8K for a used VW FWF is conservative or course as it includes 6K for the engine (it's only his asking price). I am sure there are folks out there that will point out that I should expect to pay 1/2 that for a used VW Aero Engine, but these numbers are REAL and can be used for a direct comparison, and that's what I was shooting for.

Of course, I too would prefer the Rotax, but for a person like myself that buys and sells aircraft and engines occasionally for the past 10 years, I have never been offered such a smoking Rotax deal myself. However, I do run across smoking VW deals on a regular basis (I saw 4 over the winter on Barnstormers for cheap) and that means it’s possible to “low ball” and get your engine for even less (low ball a Rotax 912? Good luck !!!).

VW reliability questions aside (this is a factory build VW aero conversion, not one from "Bob’s airboat emporium") , we do now know the real performance of a VW powered aircraft, which is what started this thread:


N53RJ KitFox IV Speedster

Weights:
Basic Empty Weight = 700lbs
Max Weight = 1200lbs
Usefull Load = 500lbs
Fuel Capacity = 27 Gallons
Wing span = 28.8 ft.
Fuel Burn = 4 - 4.5 Gallons an hour
Cruise speed (economy setting) = 90 to 95 mph at 1500 feet (3000 rpm).
Cruise speed (high setting ) = 110 mph at 7500 msl.
Max speed (At full power) = 115 mph at 7500 msl.
Rate of Climb (two people) = 700 fpm
Rate of Climb (One ) = 1000 fpm
Take off roll at Gross Wt = 300 feet
Landing roll at Gross Wt = 300 feet
Stall speed (with vortex) = 37 mph
Approach speed = 60 mph

I personally call these figures "good" for a small low cost aircraft, beter than the Ercoupe I use to fly, that's for sure !!!!

Roger

[cainbird]

This past winter I bought a used early 912 with about 150 hours tt. It was involved in a crash caused by fuel starvation and no damage to the engine. I found it on Barnstormers and paid 6k delivered. I may have spent 1k bringing it up to snuff. I am not trying to discurrage you from your project, just saying the deals are out there, you just have to be patient and persistant. I hate to see someone spend tons of time and money on a project that turns out to be a dissapointment! If you can pull it off, buy a 912 and you will never regret it. Your resale will be about 10k better too!

Best of Luck~Cain B

[DBVZ]

I went for a demo flight Sunday in the Speedster on Barnstormer's that is in St. Louis. It has the Great Planes VW conversion. For what is it worth, the engine ran well, and operated like an aircraft engine. The carb and throttle body are the same as used on some small Lycoming engines; with a conventional mixture control and carb heat. We were unable to get up high for a speed test leaned out because of weather, but in the flat flying we were doing at full throttle the airspeed indicated 95-100 mph that his equipment translated to about 110mph TAS at the DA we had. We did not have a GPS we could use to check that against a GPS ground speed. He was still running full rich, so some better numbers at higher altitude seemed at least reasonable to expect. With the 62" X 32 pitch prop, he was turning 2900 at WOT running ROP with an oil cooler in use. Up higher with leaning it seems like 3000 or even 3100 should be possible, even though the engine power rating and the length and pitch of the prop seems to say it should not turn that fast.

Still, the resale issue is important. If the consensus of Kitfox builder believe the 912 is the right engine, and the VW conversions are not, it has got to limit the number of buyers that will even consider a VW powered Kitfox, and that ought to force down resale prices. But from the asking prices I see, the engine choice has some effect on the price; but not as much as other factors. I saw prices that range from about $20,000 to $40,000, and while the engine choice was one factor it did not command a $10,000 premium, nor did a VW conversion get a $10,000 penalty relative to aircraft near being equal otherwise. Things like the equipment in the panel, paint scheme, workmanship of the builder, TW or tri-gear, range and endurance, speed, care since finished, hours since finished, empty and gross weight, 2-cycle or 4-cycle etc, all contribute to setting the relative value of a specific plane. And then, some sellers have highly inflated expectations, and set the asking price that way,

[Geowitz]

Not trying to knock anyone's ability to make their own decision for an engine, but I simply don't believe the important number - Rate of climb. This is by far the biggest difference in a Kitfox between an auto conversion and the rotax. Also, in my opinion, besides reliability, rate of climb has the greatest affect on safety. 1000 fpm is a great rate of climb, but I just don't believe it's a true sustainable number for the VW. I think the "VW 1000 fpm climb" youtube video is misleading. When you build up your speed and get 1000fpm for 30 seconds it doesn't mean your true sustainable rate of climb is 1000 fpm. I want true pulling power and a VW with a 62 inch prop just doesn't have it. Sure, I researched the VW, but there were too many perfomance compromises that added up.

[rogerh12]

I agree, rate of climb is probably the biggest fudge factor you will see on airplane specs. Of course, it depends on many factors, such as prop, outside air temps, humidity and even thermal updrafts in the area.

As you saw, one of us got a ride in the VW powered Kitfox on barnstormers. Here is what he found (see below). This flight was made with two in the plane, but no total take off weight was noted. Also, it was done this summer, and it’s hot in the Midwest this time of year, so performance in the winter work be at least 10% better I would think.

Climb was 700 fpm with both of us in it. He did not use the flap handle at all for Take off or landing. We were on pavement, though a grass strip was available he thought it was too wet after recent rains. He did not work at a short field take off or landing, but roll was less than 500 feet for each, lift off was around 50 mph.

700 fpm is in line with my expectations, based on VW experience and performance specs for a similar (rotax equipped) plane. Less performance to be sure, but I will rate it as “pretty good”, and certainly better than a Cessna 150 with two in it.

Roger

[rogerh12]

2300 cc VW engine conversions are now available. Running avgas, 85 HP may be possible from this engine and it still wieghts in at about 165 lbs.

Roger

[SkyPirate]

I'll have to disagree with your statement about the model 11 flying terribly Roger,..my model 11 was a dream to fly,..she did everything I asked of her ,..yes it had the 582 in it ,..but then I have flown everything from ultralights to jets ( no not bragging ,..but it does help a great deal addapting to the "feel" of any aircraft in flight),..,..in any plane it's a matter of the pilot mastering the planes capability,..with co ordination