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

[akflyer]

I have lots of hours in a model I and II. I cant see how one could possibly say they flew terrible. I think it is one of the more enjoyable planes I have flown to date! Yes it has some adverse yaw but nothing close to terrible. If all you have ever flown was a spam can with rudder / aileron interconnects, then I can see it being an issue to transition, but a few hours and all should be sorted out.

Floats wheels and skis I think the early model Avids and kitfoxes are about as much fun as you can have with your clothes on.

[DBVZ]

Funny what people will do with a Kitfox IV-1200 though. In my shopping I recently inquired about one with a Subaru 100 HP engine, and the seller reported the empty weight as 817. I asked him to check that since he was not the builder (estate sale I think), but he seemed sure that was it. Someone bought it since.

[rogerh12]

The original builder of my Zenith had a Subaru engine on it, with the redrive. It was fast all right, but weighted a solid 100 lbs more than the VW 2180 he later installed. It was a simple installation, true, but 100 lbs of extra wight over an already heavey engine was kind of crazy. However, he did the engine swap, not because of the Subaru weight or perfomance problems, but becuase he could not sit and watch the tac turning 5000 rpm all day, it just made him nervious.

Roger

[Av8r3400]

Link

As for the VW engine it covers, he’s still testing a fat-fin modification he hopes will solve its hotheadedness and keep him flying until he saves up enough for a Rotax 912S.

“The VW has its place in aviation; the Sonex and other planes prove that,” Clagg said. “But based on my experience, the 701 isn’t one of them.” Keeping the engine cool is one problem, and weight is the other. His CH 701 weighs 742 pounds empty. The engine, complete with baffling, alternator, vacuum pump, Ellison injector and dual ignition (12-volt and Slick mag), weighs 223 pounds.


Drawing on his past VW racing experience, Clagg had hoped to develop a cheap, reliable powerplant with mass appeal. With a local source of high-performance parts, he wouldn’t have to pay freight, and he believed he could overcome any problems. Putting 90 hours on it in less than two years, he has overcome problems for the most part, but, “Sometimes, you know, you’re just not too smart,” he said.

From the mouth of a 701-VW owner and builder.


Problems he has:

• Lack of power
• Inability to keep CHT down
• Lack of performance
• Lack of reliability
• Excessive weight

All of these will apply in a Kitfox as well. Why reinvent the wheel? I don't understand.

[rogerh12]

I agree, the VW is not good for the Zenith 70, I have heard that from my 701 builder buddy as well, and he is on the 701 group forum. The problem is these guys are nunts !!! The climb out is at something like 20+ degrees noise up, and they hold it only moving along at like 45-50 mph.
In fact, I think the top speed on this plane is only 75-80, even with a 80 HP rotax.

The 2180 75+ HP VW needs at least, well based on my experience over 5 years, 75 mph on the 601 to get proper cooling in a steep climb. At 85 mph and with an outside temperature of 80 degrees or less, I could climb at full power until I ran out of sport pilot ceiling. It would never get too hot, oil or cylinder heads.

I think the 701 guy must have installed a redrive on the front of the VW. Did it have a 3-bladed prop, or a composite or metal prop?

233 lbs is more than even a Corvair installation, I could carry my VW engine across my garage (without intake or exhaust), and I am no body builder. I would estimate my engine to weight about 155-165 lbs, based on the load on my back !!!! The redrive adds weight, but it depends on which one, so I don’t know how much.

The VW conversion is very popular here around Kansas City, both Aero vee and Great Plains VW are only about 3 hours away, and you can drive up and get engine parts same day, if needed !!!
As a result, we have 4 Sonex’s at my local airport, all of them have the VW conversion (3 are areo Vee) and they tell me their heads run on the cools side. Of course, that’s a true 130 mph plane, but the air intakes look awful small to me.

It seems to me, that basically if a kitfox can climb well in the 75-85 mph range, then it will not overheat the heads or oil at any temperature below 80, even at full power. I say this as the kitfox has at least as big an air opening (with the round cowling) as my 601 did. However, something besides the stock top mount oil cooler may be needed for higher air temperatures. I say this because when I found that I could not run full power in a climb endlessly at air temperatures over 80 degrees with the 2180 VW, that was because I was still using the stock top-mounted oil cooler, and not the under engine one like use on the Revmaster and Aero Vee engines. I would recommend only installing the larger bottom mount oil cooler on a Kitfox.

Note: This winter, I saw 4 Revmasters listed on Barnstomers, used, but otherwise all listed as “complete and ready to install” for between $3000 and $4000 (though I bet they would have sold for less). The Revmaster 2100D makes 70 HP. Now that’s cheap power !!!!!!
Roger

[szicree]

I mean no offense and don't wish to hijack this thread, but it seems that price is the major knock against the Rotax. I've not seen it mentioned that when it comes time to sell you might actually come out ahead with the Rotax. I sold a VERY nearly done RV-4 with a Superior 360 and got my money back quite easily, with multiple cash offers the day I listed it. Meanwhile I've seen a lot of similar projects with Subarus and such languish unsold for months. Whenever I have doubts about the cash outlay for this project I just remind myself that I can always get my money back out as long as I build to suit the typical buyer. That means mainstream engine and panel, conservative paint job, and good workmanship.

[rogerh12]

Howdy All;

This is off Great Plains VW web site, and outlines the engine weight. This spec is very similar to what Revmaster and AeroVee state as well.

ENGINE DISPLACEMENTS: TYPE 1 - AIR COOLED (The big boy ) 2276cc

Take off HP, 3600 RPM (MAX)........... 80
HP @ 3400 RPM .................................76
Displacement, in CC ........................ 2276
Compression Ratio ........................ 8.0:1
Minimum Fuel Octane ................... 96
Weight in Pounds ......................... 165

Note: The above weights are for engines that include the Diehl Accessory Case package and Generator, intake manifold, Single Slick ignition system and oil cooler. (I think the Battery, exhaust, fuel system and secondary ignition would add another 20-25 lbs, but using a light weight wood prop would help the installed weight). Aluminum cylinders aid in cooling, and reduce engine weight by about 10 lbs.

Reducing Compression to 7.5:1 allows the use of Car gas, but decreases horse power by about 4 HP.
I would expect a total firewall forward kit to add less than 200 lbs to a bare Kitfox Airframe (bare with cowling attached). This would be the total installed weight, with oil, prop and ready to fly. Using Aluminum cylinders would give you an installed weight 10 lbs less than that, and a light weight ATPs UltraStart-Red battery will save another 5-7 lbs (this battery worked with my old VW install, it was a lower compression engine). Probably yielding a true installed weight of about 185 lbs, ready to fly.

Anyone know how much the Rotax 912 80HP version adds to an airframe, with fluids prop and battery (ready to fly)?

Hope this helps

Roger

[whitewulfe]

On a somewhat related note, do they mention how that octane is measured? I ask because I find it somewhat odd an American company would use a RON octane rating when in North America we use AKI ((RON+MON)/2) ratings (which would put such as 91-92 octane fuel in North America, if such is the case)

[rogerh12]

I have not seen it listed definitively, but I think the 96 octane is with respect to 100LL.

I tried to cut my Avgas, on my high compression engine, with 92 car gas. It would run at full power the same, but the exhaust temps went through the roof (cloud cover ). The 7.5:1 compression for car gas is determined by experience I think. In the winter, you can just run 87, but in the summer 91+ would be in order (oh so I have heard). Around here, we have 92 octane with no Alcohol, so this what I will setup my engine for. Right now, I have two guys wanting to sell me there used factory VW conversion, but no prices set yet (am hoping to pay about $2500 on a used one, then spend another $500-$1000 and have it rebuilt to my specifications)

Note: On the VW, if your compression is still a bit too high, cylinder or head shims can be added to adjust it down, for your particular fuel requirements (Like the new 94LL ), it’s not a problem.

Hope this helps
Roger

[JRLAMB]

what i would like to know...

a. did you use the belt reduction put out by great plains...


b. what is your dry weight when you mounted the vw... not counting the engine mount...


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