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VW VR6? (alt engine musings)

jcaplins

jcaplins

Well Known Member
For those who have considered an auto engine...
Have you considered a VW VR6 engine for use in your RV. (If you had an RV6, it seems the VR6 would be fate)

I have a 2000 VW jetta with the VR6. This is not a normal V6. the "vee" angle is 15 degrees rather than the standard 45-60 deg. This essentially gives you a v6 in a slightly over-sized I-4 package (meaning narrow). Overall it's been a great engine for the road, and I wonder how well it would do in the air.

basic info:
2.8 L
174 hp @ 5800 rpm
181 Tq @ 3200 rpm
10:1
I'm guessing around 300 lbs.
(it's got AC :D)

Aaannnnd Discuss.


Really I'm in the process of replacing the alternator, and it is such a PITA with all the other **** jammed into the engine compartment, that I would rather remove the engine and scrap the car than try to get the new alternator in there. :cool:
 
If you look into some of the reliability of these engines, they do have some problems that are not very exciting to deal with if you are in the air.

I think they may be a little too high strung to be good in an airplane. Good engines - Yes, Dead stone reliable for airplane use - I think No.

Just my opinion is all...
 
Most auto engines nowadays are extremely reliable...

...but for airplane use, a whole new batch of problems arise....cooling issues and cowl modifications and worst of all, a reliable PSRU, which has been the downfall of many auto conversion attempts.

Best,
 
Can you be more specific, Richard? And what do you mean by high strung?

I don't want this to be a "if you want to fly, get a lycombing..."

It seems all engines will have cooling issues to work out and anything other than an O-3xx will need cowling mods.

The Rotax engine is liquid cooled, requires a gear reduction unit, and has 2 carbs that need to be balanced, and people seem to love them. How is any auto conversion different?


(I should also note that I'm years away from finishing and my VW has over 100K on it, so I won't be using this engine anyway (maybe ;) ). Just thinking out loud here.)
 
VR's are sweet sounding engines, but I think the iron block (at least of the earlier VR's) would be a deal killer. I think a W-12 out of a Phaeton would make a SWEET engine for an RV-10 though:D

Did you remove the front end of your Jetta to get access to the alternator, or are you trying to remove it with a shoehorn?;)

(Jetta and Scirocco 1.8T owner here:))
 
Development

jcaplins said:
The Rotax engine is liquid cooled, requires a gear reduction unit, and has 2 carbs that need to be balanced, and people seem to love them. How is any auto conversion different?
Click to expand...

Bluntly, the diference is several millions of dollars spent on engineering and development. Given enough time and money most any internal combustion engine could be converted to aircraft use, time and money that few of us have to invest.

John Clark ATP, CFI
FAA FAAST Team Member
EAA Flight Advisor
RV8 N18U "Sunshine"
KSBA
 
1:1 Scale said:
VR's are sweet sounding engines, but I think the iron block (at least of the earlier VR's) would be a deal killer. I think a W-12 out of a Phaeton would make a SWEET engine for an RV-10 though:D

Did you remove the front end of your Jetta to get access to the alternator, or are you trying to remove it with a shoehorn?;)

(Jetta and Scirocco 1.8T owner here:))
Click to expand...


Yup, the Iron block is heavy. Doesn't a lycombing have an Iron case? I'm not real sure about the weight. the internet is telling me the VR6 weighs anywhere from 300 to 700 pounds. It seems a bit too tall also.


I got the old alternator out the bottom. pulled the PS pump, pulled the AC compressor, removed the dogbone, removed passenger side engine mount. wiggled, pushed, pulled, raised and lowered the engine till I could drop it out the bottom. Still not sure how I am going to get the new one in.




Bluntly, the difference is several millions of dollars spent on engineering and development. Given enough time and money most any internal combustion engine could be converted to aircraft use, time and money that few of us have to invest.
Click to expand...

Is this true, or just what we assume to be true? Rotax has been around a long time, working from 2-stroke to 4-stroke and putting engines in may things; planes, snow mobiles, ultralights, motorcycles. the LSA market has seemed to really spike their popularity.
I'm sure millions and millions of dollars have been spend on R&D, but they also seem to work off the tried and true, if it works don't fix it philosophy that lycombing and continental have used. There is not a whole lot of innovation there that I can see.

Auto makers spend a ton of money on engine R&D. They are tested in the harshest of conditions. I don't think the flight environment is any tougher than driving; excluding aerobatics and racing. The gear reduction unit would be the only thing left for new design/testing/research/etc. for auto conversions.

(I'm not bashing Lycombing, Continental, or Rotax. Just thinking about... experimenting.)
 
Jeff, you are free to install whatever engine you wish.

BUT....

Why an auto conversion? In addition to the anecdotal info that they just don't perform well compared to a Lycoming, you have the PSRU, running at 5000 RPM which is not a normal car operating regime and VERY FEW people will buy the plane should you ever sell it.

My biased opinion: Stick with a Lycoming equivalent. Keep the auto engine in a vehicle with four wheels.
 
Actually, the flying environment requires near full power for hours at a time. This is a big deal.
 
to quote (more or less) one of our VAF members: "Build the plane YOU want, not the plane others want."
A lot of water will have gone under the bridge before you reach the point of actually buying an engine. you have a long time to scheme and dream. ;)
 
Jeff, you will get the usual answers from the Lyco crowd here and the usual hostility for wanting to experiment. Few people here on VAF are true experimenters and have little or no first hand experience in this field.

Most people here don't understand car engines and in fact apply little logic or evidence when they attack them in aircraft.

As a moderator, I'm not going to let this thread degenerate into the usual attack. Jeff has asked some legit questions here so let's be civil.

I'll state this first off- If you just want to go flying with the least likelihood of problems and extra time spent and if resale value is high on your list of important things, install a Lyco and forget the alternative engine. If you want to experiment and have the background in engines, tuning, structures, fabricating and welding and a few hundred spare hours and plenty of patience to devote to a project like this, then this MAY be for you. For most people, alternative engines are not the right choice. You must realistically evaluate what you want from your project.

The VR6 engine is probably not as well suited as some other sixes having aluminum blocks like the Subaru, Suzuki and Honda which have many thousands of flight hours on them plus a wide variety of available gearboxes. These are all much lighter and in most cases more powerful at lower revs.

The modern auto engines are much more extensively tested and validated than traditional aircraft engines as the standards are much higher before acceptance into production. This includes running at full rated power for many hundreds of hours so we don't worry too much about core engine reliability if the engine is essentially stock- with certain things understood at least.

If you are building a 7, 8 or 9, all auto V6s will be heavier than a standard Lyco so be prepared for that. A four may be more suitable weight wise. For a -10 you would want to use one of the larger V6s- at least 3.2 liters. Weight is more competitive with the 540 Lyco and several modern designs are over 300hp stock at reasonable rpms.

Be aware that there are many challenges to installing an auto engine from engine mounts, exhaust, reduction gear, propeller, fuel and spark control, fuel system design, electrical system, oiling and cooling.

It is a real challenge to get everything right but that is how we learn. Just be very aware of the realities before going forward with this project and do plenty of ground testing first.
 
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rv6ejguy said:
As a moderator, I'm not going to let this thread degenerate into the usual attack. Jeff has asked some legit questions here so let's be civil.
Click to expand...

Got your back, Ross.

rv6ejguy said:
I'll state this first off- If you just want to go flying with the least likelihood of problems and extra time spent and if resale value is high on your list of important things, install a Lyco and forget the alternative engine. If you want to experiment and have the background in engines, tuning, structures, fabricating and welding and a few hundred spare hours and plenty of patience to devote to a project like this, then this MAY be for you. For most people, alternative engines are not the right choice. You must realistically evaluate what you want from your project.


If you are building a 7, 8 or 9, all auto V6s will be heavier than a standard Lyco so be prepared for that. A four may be more suitable weight wise. For a -10 you would want to use one of the larger V6s- at least 3.2 liters. Weight is more competitive with the 540 Lyco and several modern designs are over 300hp stock at reasonable rpms.

Be aware that there are many challenges to installing an auto engine from engine mounts, exhaust, reduction gear, propeller, fuel and spark control, fuel system design, electrical system, oiling and cooling.

It is a real challenge to get everything right but that is how we learn. Just be very aware of the realities before going forward with this project and do plenty of ground testing first.
Click to expand...

Good advice. Good honest advice.
 
I hope my comment that cars and planes have different power requirements was not perceived as an uncivil attack, as that was not my intention. At the risk of painting with a broad brush, I think its fair to assume that many alt. engine inquiries are driven by major sticker shock at the $25000 price tag on what appears to be an overgrown Beetle motor. I hope we can agree that a car motor will not save you money, especially if you factor in resale. I felt sick writing that check to Superior, but got it all back when I sold the plane. I look at it now as simply a place to park some money and won't cry as much when I do it again.

Now, if the desire to go alt. is driven by recreation, education, research, wanting to be different, etc., then I'd have to say go for it. Modern auto engines are soooo good compared to the crud we drove when I was a teen, it's real hard not to want one in a plane.
 
Be aware that there are many challenges to installing an auto engine from engine mounts, exhaust, reduction gear, propeller, fuel and spark control, fuel system design, electrical system, oiling and cooling.

It is a real challenge to get everything right but that is how we learn. Just be very aware of the realities before going forward with this project and do plenty of ground testing first.[/QUOTE]

I too have flown behind an alternative engine, and I too would like for us to have choices besides the Lycosauras, but as Ross pointed out there are a lot of things to engineer for an auto engine to perform well in an aircraft and in my mind the problem becomes one where we cannot test some of these things without flying the plane. If our initial engineering was not on the mark, we are faced with dead sticking it back to the airport, if we can reach one.

I have lost several friends and known of more folks that were sure that their designs were going to pass muster and went off flying only to have one of the periphal items fail and the motor quit.

What is needed is a good safe way to test our creations before flying. Lots of aircraft and lives could be saved if we could test completely on the ground before committing to flight.

I am afraid that some folks are motivated by $$ only to later realize that the savings potential was a myth. They then are left with the motivation being educational. Without a good safe way to test over a long period of time, some have paid the ultimate price for that education.

Gary Specketer
Tech Counselor, Flight Advisor
 
jcaplins said:
The gear reduction unit would be the only thing left for new design/testing/research/etc. for auto conversions.
Click to expand...

Do a lot of reading, and you'll find that "cooling" is also very high on the list of problem solving. Much of the time, it's required quite an aray of cowl modifications for both the inlets, and outlets.

L.Adamson --- RV6A
 
Gary is quite right. Saving some $$ initially should not be the the only reason for installing an alternative engine. In many cases, people have found that they spend more by the time they are done and they still may not be happy with the results. Many end up replacing their auto engines with Lycomings after a few years of frustrations.

As I said, for most, writing that killer check for a Lycoming or clone is the best choice.

Regimented flight testing in the safest environment (over the airport, with a long runway and no ground obstructions) is something you should spend a lot of time at. At least the RV airframes are well proven so you are mainly testing the powerplant system. Combining a new engine and new airplane design would have to be approached even more carefully. Using an alternative engine statistically increases your chances of of forced landing.

As far as cooling issues goes, most of these can be traced to poorly thought out cheek mounted installations. Under pan and belly mounted radiators with proper ducting more often than not work well but this is even more work of course- usually in the plumbing and fiberglass departments. Some RVs do not lend themselves to easy belly rad installations.

In short, the whole concept of auto engines in airplanes is not as simple as it might seem at first look. If it was, many more airplanes might have something different under the cowling.

All this is not to discourage you but rather to give you some insight as to the possible pitfalls of rolling your own FF installation.
 
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There is nothing sweeter then a Chevy LS2 engine purring in a RV-10. When I build again it will be another Chevy powered RV-10. No doubt about it.
 
jcaplins said:
Can you be more specific, Richard? And what do you mean by high strung?

I don't want this to be a "if you want to fly, get a lycombing..."

It seems all engines will have cooling issues to work out and anything other than an O-3xx will need cowling mods.

The Rotax engine is liquid cooled, requires a gear reduction unit, and has 2 carbs that need to be balanced, and people seem to love them. How is any auto conversion different?


(I should also note that I'm years away from finishing and my VW has over 100K on it, so I won't be using this engine anyway (maybe ;) ). Just thinking out loud here.)
Click to expand...



When I say high strung, they seem to be more of a high performance engine that requires extra special care and feeding. The cam chain guides are prone to failure when run hard or run hot, and in an aircraft, it is very likely they will get hot, and they will definitely be run hard.

The ones that I have seen (Granted only a couple) have needed more frequent oil changes than most other cars would need and this was not the driver's fault. The drivers for the ones that I saw were fairly mild. I don't think frequent oil changes in an auto are going to translate into acceptable oil change intervals in an airplane.

One of the engines I took apart had literally 1/4 inch of sludge on the topside of the valve train. This was not even after extreme use. The oil changes were drawn out a little longer than they should have been, but the car was used primarily for long distance commuting.

I am by no means trying to say that Lycomings are the only thing that should be in a plane. I am all for getting some modern technology in an aircraft engine, but from what I have seen, this is not one I would consider for a project of my own.

Some may have not seen the same things with a VR6, but this is just one persons experience.
 
Different engine, but.......

the VW 1.8T is supposed to be prone to sludge, and this is what mine looked like when I pulled the valve cover off after 125,000 miles making more than double the stock power, Mobil 1 from 2500 miles on:
DSCF1550.jpg

DSCF1552.jpg

DSCF1551.jpg


Just a data point......
 
Lot's of good info rolling in.

Ross-
Thanks for the support.


Richard-
Thanks for clarifying . Basically your saying the engine is already tuned for the minimum requirements needed for the plane and can't be de-rated for reliability and still perform well enough.

Todd-
Did you consider other engines vs. the LS2? or are you a corvette guy, and that was the only way to go. As suggested by Kelly the VW W-12 looks pretty sweet.



As far as data points. I think we all need to look at where that data point comes from (no insults intended).
For example: If I try a VW engine and fail miserably, This is no indication that the engine is a bad fit for the RV, since I don't know what I'm doing.
I think there are many failed alt engine installs that fall into this category.

If many people with lots of engine experience can't get a engine to work well, then perhaps it wasn't meant to be.

Looking at the Subaru engine; everyone complained that the weak point was the PRSU and had cooling issues. But they all used the same PRSU's (then gen 2, 3, 4..) and all the cooling setups were very similar. So if there was a problem it manifested itself in all of them.


In conclusion: The VR6 is probably not a good fit for an RV, but I'll keep thinking about one that will be.

Thanks for the responses everyone.
 
Yes Jeff, you pulled the right conclusions out of all this pretty much. If everyone uses the same gearbox or radiator layout which has problems, everyone has the problems and the package or engine as a whole gets a bad rap. The devil is in the supporting system details- a problem with any of these can cause a power loss just as surely a rod or jug failure so they are all important.

Many have learned the hard way not to stray too far from the proven. This is a main reason why the Lycoming setups are more reliable statistically. People use the same proven system layouts and components for the most part.

Reliable gearboxes, electrics, fuel and cooling system layouts are available today and if these are implemented properly, people are having good success. Titan aircraft in particular is embracing the Suzuki and Honda V6s for their P51 replicas and there are many flying with these engines now despite a few initial setbacks with PSRUs or improperly tuned EMSs.

I have a number of clients who have 500+ hours on their auto engines with either no issues or minor ones. That being said, others are still working through significant problems over quite a time period so you often need some fortitude to succeed in this choice. Often people who have gone the Alt route do not have the mechanical background to diagnose and fix problems and they are forced to give up which is why I caution people in this category about their choices.

The VR6 would work fine of course as there are billions of hours on them collectively and a lot of those are at high revs and high power in Europe. It's just that it would be more work to mate a gearbox to one and payload would suffer a bit compared to some lighter choices.

If you decide to go Alt, I can direct you to some resources which might make your journey less painful.:)
 
jcaplins said:
... Doesn't a lycombing have an Iron case? I'm not real sure about the weight.
...
Click to expand...
No, they have aluminum cases. Figure around 282 pounds for a 180 HP O-360 engine, ready to bolt on your airframe. Source: http://www.aviator.cc/aircraft_engine_weights.html

FYI - 180 HP at 2700 RPM equates to 350 ft-lbs of torque. See this website. (I add the torque because most car guys think in terms of torque and HP whereas airplane guys only think in terms of HP.)

szicree said:
... engine inquiries are driven by major sticker shock at the $25000 price tag on what appears to be an overgrown Beetle motor.
...
Click to expand...
If you are going through the trouble of developing an auto engine conversion, then you probably know something about engines or are willing to learn. A brand new ECi kit engine costs around $15 to $16K, less accessories and assembly is required.

The VR6 has always been an intriguing engine and if you go that route, please keep us updated on your progress.

One thing that no one has mentioned, auto conversions in a two seat RV typically come in about 100 pounds heavier than a comparably equipped Lycoming powered RV. Watch your weight and you should be OK.

A good friend who built the 2nd rotary to fly tells everyone who is interested in auto conversions that they are for people who like to tinker. If you just want to get in your plane and fly, put a Lycoming in it. The other thing he often tells people is that you can tell a conversion was successful if the airplane shows up year after year with the same engine installed.

BTW, he now has around 450 hours on his rotary and has more RV glider time than any pilot I know. The engine has never failed but the systems that support the engine have. Plan your systems carefully and you will be fine.

Keep dreaming, reality was created by those who start with a dream.
 
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Jeff,

For myself I would only stick to the Chevy LS series and only because that is what I have worked with for the past four years. I know what needs to be done and how to keep it running. I am not an expert on engines so I wouldn't want to clog my brain with to many options. After seeing the destruction an LS2 can take and continue to run as far as I am concerned there isn't a more reliable engine out there.
 
Jeff...FWIW...

....even Van himself has stated, "The best conversion for an RV is converting your dollars to a Lycoming."

Reckon he just might know what he's talking about?

Best,

ps I know where theres a Subie FWF package with a little over 200 hours since new for 1/4th the original price.
 
Let's read what Jeff wrote here originally:

"I don't want this to be a "if you want to fly, get a lycombing..."

"I'm not bashing Lycombing, Continental, or Rotax. Just thinking about... experimenting."

While the Lycoming might be the best choice for most folks here, it is not the choice for some people who want to experiment and learn some new things.

He's probably got enough advice here now on the downside to an alternative engines, including from me. Sorry if we sound like a broken record. I like the earlier post from JDanno " build the plane that YOU want... etc.":)
 
Pierre!

You still trying to get rid of that FWF Subie? I see that you mention it periodically!:D:)
 
rv6ejguy said:
I like the earlier post from JDanno " build the plane that YOU want... etc.":)
Click to expand...

Of course, the original "build the plane you want" slogan, is from a builder/ owner who seen the light, when his original.... one size too small engine was destroyed in an accident. For a replacement, he actually went "two" sizes bigger in cubic inches.

Which only proves.....................that sometimes what you think you want, isn't what you'll want in the future. And that's why wer're here to help! :)

L.Adamson --- RV6A
 
L.Adamson said:
Of course, the original "build the plane you want" slogan, is from a builder/ owner who seen the light, when his original.... one size too small engine was destroyed in an accident. For a replacement, he actually went "two" sizes bigger in cubic inches.

Which only proves.....................that sometimes what you think you want, isn't what you'll want in the future. And that's why wer're here to help! :)

L.Adamson --- RV6A
Click to expand...

I think most people who have gone the Alt engine route have learned many things and probably at some point had second thoughts along the way. Sometimes is has gone more bad than good and what we thought we'd get does not happen. Such is life and learning and hard lessons.

For those with the true experimental spirit, the satisfaction of of doing your own FF installation and making it work well is at least equal to building the airplane itself. For me, it is more important. Almost anyone can build an RV, not too many do the other stuff themselves.
 
L.Adamson said:
Of course, the original "build the plane you want" slogan, is from a builder/ owner who seen the light, when his original.... one size too small engine was destroyed in an accident. For a replacement, he actually went "two" sizes bigger in cubic inches.

Which only proves.....................that sometimes what you think you want, isn't what you'll want in the future. And that's why wer're here to help! :)

L.Adamson --- RV6A
Click to expand...
Larry,

I don't think you are talking about me, but just incase you arde, I will respond.

Had I been able to locate the parts to OH my O-290-D2, I would have. It is a great match for the -9.

Once I found out the price of an OH for that engine was north of 30K, I elected to go with a current production engine. With only $500 difference in price and 12 pounds in weight, I couldnot not put the 360 in the plane.
 
rv6ejguy said:
For those with the true experimental spirit, the satisfaction of of doing your own FF installation and making it work well is at least equal to building the airplane itself. For me, it is more important. Almost anyone can build an RV, not too many do the other stuff themselves.
Click to expand...

Getting the FWF working and flying was by far one of the most satisfying things I have done in my life.
 
Yep...

JDanno said:
You still trying to get rid of that FWF Subie? I see that you mention it periodically!:D:)
Click to expand...

...it's ready to go, WITH the three-bladed electric prop. The airplane now has a 180 horse Lyc, Catto prop and MGL Oddysey.

PM me and I'll send you Ray's contact info, 24 miles from me.
 
Experimental tinkering

I'm with Todd and Ross on this. I enjoyed doing my WAM 120 diesel FWF more than any other part of my project. Now that it's done, there's a little bit of tinkering to do, but most of the time I just fly it - how boring! I find myself daydreaming regularly about how to do it better, or how to develop a lighter, more powerful diesel.

I've been all over the Subaru boxer diesel alternative, which really sounds like it might be viable. It's sure more complicated than it needs to be for an airplane, and most likely too heavy. The WAM is SO much simpler (a fraction of the moving parts, no gearbox, no electronics, etc). But the Sub's still worth a look, so I'm on the hunt for one. Can anyone out there help me lay hands on one? I've scoured the 'net, and can't find anything.... I'd love to buy one and do a lot of testing with it. Ross, do you have any contacts??

Kurt
 
I was hoping you might be dreaming about this one Kurt. You are the right man for the job here with your background. No contacts yet but I have my ears open. If I had a bit more time, I'd be interested as well.

The new ECU gives this real possibilities.:)
 
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