VW conversion economics

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Vigilant1

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A Fournier RF-4 powered sailplane flew across the Atlantic ocean powered with a 39 Hp, 1200 cc, VW engine. Cruising at 3200 rpm.
Good story.

Pops,
Thanks for that, I hadn't read it before. Things were a LOT different before GPS, small cheap satellite comms, etc.

More people may know the story of Jack Lambie flying an RF5B from California to Paraguay. That plane was powered by a Turbo Revmaster.
Originally I'm Sport Aviation, reprinted in Contact! magazine's 100% Revmaster issue. Pat Panzera, you are missed.
Special Issue 104.5

Matk
 

Pops

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The 1200 cc, 40 hp , VW engine is my favorite. It develops the 40 hp at a lower RPM from the larger VW engines. So when using the straight drive driving a prop, 1200 cc engine is not a lot less in power than the 1600 cc engine as one might think.
I built and flew a 1200 cc VW engine in the SSSC for the first 32 hrs. If my weight was 150 lbs instead of the 235 lbs, I would have never taken it out and put the 1835 cc engine in its place. Great little engine and very smooth. Cruised at 3200 rpm burning about 2.8 gph.
I have another 1964 1200 cc , engine rebuilt except for the new cylinders. You can buy the 83 mm oversize cylinders instead of the stock 77 mm for an extra 5 hp. That would put it very close to a 1600 cc in HP when used with a prop. Also the engine is lighter in weight.
 

cluttonfred

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Pops, for those of us without our own personal stock of air-cooled VW engine parts, what do you suggest for building up a basic VW for a single-seater like a Volksplane or FRED? Start with a short block, long block, or complete engine? I was thinking that a rookie like me would probably start by ordering from one of the big VW engine part suppliers (GEX, MOFOCO, etc.) but maybe you have other suggestions?
 

Pops

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Pops, for those of us without our own personal stock of air-cooled VW engine parts, what do you suggest for building up a basic VW for a single-seater like a Volksplane or FRED? Start with a short block, long block, or complete engine? I was thinking that a rookie like me would probably start by ordering from one of the big VW engine part suppliers (GEX, MOFOCO, etc.) but maybe you have other suggestions?
Not an easy answer. If you have built other engines I would say buy the parts and assemble one. But, getting past all the junk parts out there is not easy. All it all, the prices of the ready built engines from Scott Casler at Hummel engines is hard to beat. He isn't making much money over the cost of parts. And you will be getting the best parts on the market. I know Scott from when he used to live in Ohio and he is a very nice honest person and would not hesitate to buy from him. Local friend just received a 2180 from Scott a few months ago and at the time there was a 8 month lead time. Think new engine cases are getting hard to find do to the shipping problems.
 

dwalker

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Not an easy answer. If you have built other engines I would say buy the parts and assemble one. But, getting past all the junk parts out there is not easy. All it all, the prices of the ready built engines from Scott Casler at Hummel engines is hard to beat. He isn't making much money over the cost of parts. And you will be getting the best parts on the market. I know Scott from when he used to live in Ohio and he is a very nice honest person and would not hesitate to buy from him. Local friend just received a 2180 from Scott a few months ago and at the time there was a 8 month lead time. Think new engine cases are getting hard to find do to the shipping problems.

The supply of cases dried up for at least the last year, but are slowly coming back. I saw Empis case, which I think is made in Brazil, is back in stock in some places. I think the Mexican cases are not going to be available for a while.
 

Vigilant1

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A common sentiment among newbies to VWs and other engines is that they want to build their own engine from parts or a kit so they'll understand it and be able to maintain it.

What do you guys think about that?

My (uninformed) opinion: Building an engine from a kit of new parts is educational, but also a fairly "rote" process. When you are maintaining and fixing an engine, diagnosing the problem and addressing it requires different skills than building it. What goes out of adjustment elsewhere when I remove this cylinder head? Which of these parts can be re-used? Hey, I didn't expect that unrelated thing to look like that, is it okay? While I'm in here, what are the other things it's smart to swap out? Even disassembly and assembly is different with a "live" engine.

I could be way off. Comments?
 

ToddK

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The supply of cases dried up for at least the last year, but are slowly coming back. I saw Empis case, which I think is made in Brazil, is back in stock in some places. I think the Mexican cases are not going to be available for a while.

The case you want is the Autolinea new Universal magnesium AS41 bubble top case. Its a new casting, perfect for strokers, and is cast filled behind #3 cylinder, no welding. Its also pre-clearanced for an 82mm stroke, and can be opened up just fine to 84 and 86mm They have been out of stock for over a year, but should show up eventually. When they come back you can order them pre machined for whatever cylinders and crank you want from CB Performance.
 

Bill-Higdon

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A Fournier RF-4 powered sailplane flew across the Atlantic ocean powered with a 39 Hp, 1200 cc, VW engine. Cruising at 3200 rpm.
Good story.

Mira Slovak did it twice he damaged the first one so he bought and other one on the "Fly Away" plan
 

Vigilant1

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Its a new casting, perfect for strokers, and is cast filled behind #3 cylinder, no welding. Its also pre-clearanced for an 82mm stroke, and can be opened up just fine to 84 and 86mm
That's good news, and will make it a little easier to build stroked aero VWs. How super would it be if they (or CB, etc) would bore the HVX oil passages for us (hard for a home mechanic? Maybe not, but it would sure be easier and far less drama for a real shop with customized jigs and long bits).

Best part: if they've invested in new molds they obviously believe they'll be cranking out cases for many more years. I recall there was a scare about 10 years ago (ill-informed rumor) that VW case production was stopping worldwide. Nope. The Type 1 will be around for a long time.

Are good 84mm cranks available/not crazy expensive? If it's not hard to fit one in this new case, it's something to think about. Revmaster's "stock" aero engine is (the "R-2300”) is an 84mm stroke x 94mm bore = 2331cc. They claim 80hp continuous (well, we'll see how hot it gets...), but at just 3000 rpm. That'll allow for a more efficient and/or quieter prop than we typically see with an 82mm stroke.
 
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karmarepair

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How super would it be if they (or CB, etc) would bore the HVX oil passages for us (hard for a home mechanic? Maybe not, but it would sure be easier and far less drama for a real shop with customized jigs and long bits).
The oil passage drilling is Semi-Tough. The case is a bear to hold and fixture accurately with the tools, clamps, and workbenches most of us have. I tried it on a junk case, and could not pull it off. I think a VW specific engine stand would have helped.

All the OTHER HVX mods (enlarging the oil passage behind the main bearing, grooving the rocker shafts and the rockers and the lifters) are pretty simple with a dremel and a drill press or a little lathe, a grinder, and some diamond points. Doing everything BUT the oil passage will produce a substantial increase in oil flow, at low risk.

Bob Hoover's Blog Keep scrolling down to get all the good stuff.

The machine shops that specialize in VWs (CB, RIMCO) do a good job on what they do, and WILL NOT do anything outside their experience and tooling, in my trials with them.
 

Vigilant1

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The oil passage drilling is Semi-Tough. The case is a bear to hold and fixture accurately with the tools, clamps, and workbenches most of us have. I tried it on a junk case, and could not pull it off. I think a VW specific engine stand would have helped.
Thanks, it looked challenging to me. And high-stakes: screw it up and you'll be buying a new case. Worse would be to screw it up and not know it (come really close to popping out, but instead just leave a paper-thin wall on the passage that eventually cracks in use).

This would be a service that wouldn't be hard with the right tools/jigs/experience. I'd think many folks would find it worth paying for.

I wonder if Scott Casler offers the HVX mods as an option, or at least a case with the chamnels bored.
 
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karmarepair

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The best bang for the buck appears to be the 1915cc 65 hp full VW with the lowest price per horsepower of any of them and right in the middle of the pack in terms of weight per horsepower.
The 1800cc no machining combination should be used more. It should be a couple of hundred dollars less than a 1915, all other things being equal. 1800cc VW Engine - Budget Big VW Engine by Aircooled.Net VW Parts

Suitable new and used cases can be had from TheSamba at various price points. TheSamba.com :: VW Classifieds
AS41 is good. Type IV should be avoided.
 

Pops

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I didn't find drilled the case hard. Bought the long drill and marked the bit for the desired depth. Drilled a little at a time until about an 1/8" short. Then drilled down the front cam shaft bearing stand slowly . Tried to just break into the beginning of the long hole. Them finished drilling both.
That way I just drilled the needed length for the long drill bit.
Have done 3 cases with no troubles.
 
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Vigilant1

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ToddK

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Thanks, it looked challenging to me. And high-stakes: screw it up and you'll be buying a new case. Worse would be to screw it up and not know it (come really close to popping out, but instead just leave a paper-thin wall on the passage that eventually cracks in use).

This would be a service that wouldn't be hard with the right tools/jigs/experience. I'd think many folks would find it worth paying for.

I wonder if Scott Casler offers the HVX mods as an option, or at least a case with the chamnels bored.

I could be wrong, but I don’t think Revmaster or Aerovee do the HVX mods. While the HVX mods make sense to me, there is a lot of debate about their real world utility in the VW community.
 
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TFF

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The question is were the mods or similar work arounds incorporated? .002” off the center band on the lifter would let oil pass just like a channel cut out. Rocker and shaft mods can be done a different way and get similar results. The bigger case mods are the scary stuff. A picture of the Aerovee rockers on their parts page have the ball adjusters, so they got something going on.
 
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