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vw diesel engines

the4ork

Member
im a vw nut... currently im building a vw 1.6 diesel engine for an 82 jetta

ive built these engines before, and you can get some good power out of them at 3k rpm


some of the 1.9 engines came with VNT turbo's which would be very easy to control in a plane with just a lever... and they have even bigger and even twin cam diesel engines...

my 1.6 complete with oil weighs in around 280lbs or so, and produces about 150hp /w 25psi on a high performance injection pump. which is not bad! fuel burn in the car is about 42-44mpg so in a plane i think fuel burn would be very good.

the 1.9 engines make more power down low because of the larger displacement, they make 150hp engines from the factory in europe (pd150) and with just a turbo upgrade, light modding from the fuel pump, and more boost these are 225hp engines pretty darn reliably...

i'd imagine the 1.9 engine would wiegh the same since the block is for the most part the same casting...

anyone look into this at all?

may not be the lightest and fastest engine in an RV, i've been thinking about building a drgonfly, which uses a 250lb engine, so this would be a little on the heavy side but it would make pretty good power, they even make engines as small as 1L
 
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One TDI fan here

Only one problem with using this engine.

Add to that 280 lbs the radiators, pluming, PRU, ECU, and all accessories and you have exceeded the weight of an O-320 by a good amount.

However, if you want to build one up for your RV, that would be great!

One thing regarding the turbo. Auto turbos don't tend to hold up well in aircraft because they not designed to run under boost 100% of the time.
 
radiators and plumbing weigh next to nothing... no ecu, everything is mechanically fuel injected and the glow plugs only need to be on a few seconds before starting (when cold) and only holds around 4 quarts of oil...

i'd like to bring a scale out into the garage and weigh all the pieces... bock, head, manifolds, turbo, stock radiator (obviously huge for an airplane), accessories...

should be very interesting...
 
Don't think about it, go weigh it!!!

What does a 0-320 weight with carb, intake and exhaust manifold, mags, baffles and oil?

Weigh up the VW engine, manifold, turbo, rad, oil, water (what? 7lb/gal?), injection system, whatever engine management is needed, and intake manifold

The difference in those should give you the difference in installation weight b/w the VW and the Lyc. Might could save a little weight on the VW by going to an aftermarket rad and oil cooler, a fabbed steel exhaust mani (I assume it's cast iron now?) and a lightweight intake mani.

Do you have a source for anymore info (power curves, turbo maps, dimensional information, etc.) on the VW Diesels? Are they iron block and heads? (surely not!) I've been thinking about these for a while, but can never find any info.

(as far as the turbos, I'd tend to agree that it'd be bad to use the stock (Garret, at least on the recent ones) turbo, but there's surely plenty of upgraded turbos available in that range (alot of motorcycle racers use turbos in the flow range, for example))
 
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I drive a 02 Golf TDI. Absolutely love it, 48mpg and an amazing amount of torque for an engine rated at 90hp.

I don't believe it would be good choice in an aircraft, for a couple of reasons: weight due to it having a cast iron block; single timing belt, which requires periodic replacement. Also having a single injector pump would make me nervous, a bit like running on a single mag...
 
I drive a 02 Golf TDI. Absolutely love it, 48mpg and an amazing amount of torque for an engine rated at 90hp.

I don't believe it would be good choice in an aircraft, for a couple of reasons: weight due to it having a cast iron block; single timing belt, which requires periodic replacement. Also having a single injector pump would make me nervous, a bit like running on a single mag...

Not sure about an 02 VW, but i think the later VW/Audi TDI's are direct injection (like, no "injector pump", just a high pressure fuel pump.) So, go with that setup, and run a backup pump and ECM.

As far as timing belts requiring "periodic replacement"....what is the interval on the car? 90k miles? Quick calc: 90k miles at 90 mph is 1000 hrs. So why not set the interval at 500 hours, and change it (instead of sparkplugs!! :) )

I'm not arguing that this is a great choice at this point, but I'm not willing to count it out on these marks. Any idea if the newer engines are ally block?
 
here is the pd100 engine before and after a chip upgrade (this is the electronic/mechanical pump)

dyno%20on%20pd%20vw.jpg


here is the 2.0L TDI with the common rail injection

grayson1.jpg


1.9 engine with just a chip

torque.txt


1.9 engine with a bigger turbo upgrade, vnt-20 @ 25psi

dyno2.jpg


another vnt-20 upgrade on a 1.9
dyno_run_corrected.JPG


anywho, i have seen PLENTY of 200+ whp dyno's for the 1.9 engines with vnt-20 or vnt-22 turbo upgrades and bigger injectors ect...

question is making the power/weight ratio
 
you say you've seen plenty of 200+whp, yet you show us three graphs which alledge around 160-170 flywheel hp (using some usually dodgy correction factor fiddling)

VW put out an engine at 150ps or so that they know will last under normal driving conditions - getting this to 200+ps is going to take the materials to their very limits (and probably over). How is this going to allow for TBO's anywhere close to the 2000hr of a Lyclone?

The short answer is, it's not!

A
 
the 150ps engines have pretty much the same sized turbo's as the 90ps engines and with just a simple turbo upgrade and a tad more fueling, 200hp is easy to achieve without stressing the engine

anything over 250hp you have to start worrying about the headgasket and egt's

the twin cam 4v per cyl engines would be ideal for 200hp use, but are hard to come by in the states because they were only available in europe... but the 1.9 tdi's can get 140 hp @ 3k rpm pretty easily and are available in the states. however i woulnt mind spending the extra $ to have a euro motor imported if i had some extra cash.

im going to look into using a 1.9 TDI-M engine, which is basically a tdi long block but with the older style mechanical injector pump... so no electronics to mess with. the only upgrades i would do would be a "giles pump" which is the best upgrade for the buck you can get on these little motors (im putting one on my 1.6TD) and a VNT-20 turbo. this is because it has variable vanes in the turbine housing instead of a wastegate, and can be controlled via mechanical linkage. this way you can really dial in the hp when you need it, and at cruise you could pull the rpm's back a tad and pull the boost back easily..

still though, weigh is an issue, im going to weigh my 1.6 engine complete and that should give me a ball-park figure of what the 1.9 will weigh
 
Thrust bearings?

Another point that has not been addressed is whether or not the thrust bearing can even stand being continually loaded by prop pull, assuming you intend doing direct drive.

In cars, the thrust bearing only takes periodic pressure from your leg when you push in the clutch to shift, if it's a manual transmission.

Really, what's wrong with a good used Lyc anyway? I suppose if you want to "experiment" then do so....or would you rather fly?

Regards,
 
My first inclination is that the motor does not have sufficient torque to go direct drive, and not enough hp (high rpm) to use existing redirive setups. You cannot ignore the weight of auxiliary parts if you want to compare with similiar, i.e. O-320/360 powerplant. You will need to get delivered power up to 160+ and weight including cooling, manifolds, redrive, pumps, motor mount, etc under ~350lbs. Unless the installed motor is significantly more reliable, cheaper, or has some other advantage over existing motors; it is probably not worth the effort. With diesel selling for more than mogas these days, Id be surprised if the cost savings would be a factor over other automotive offerings.

fwiw, there are some folks experimenting with diesel powered rotary engines that might eventually work..l.
 
you say you've seen plenty of 200+whp, yet you show us three graphs which alledge around 160-170 flywheel hp (using some usually dodgy correction factor fiddling)

VW put out an engine at 150ps or so that they know will last under normal driving conditions - getting this to 200+ps is going to take the materials to their very limits (and probably over). How is this going to allow for TBO's anywhere close to the 2000hr of a Lyclone?

The short answer is, it's not!

A
The first two dynos were done on chassis dyno's, so those numbers are less than you would see at the crank, add 12-15% for a crank # estimation. I'm not sure what the third dyno is from, but the fourth dyno that claims "flywheel HP" is another brand of chassis dyno called a dynapack that actually bolts to the wheel hubs, so those numbers aren't crank HP/TQ numbers either. The correction factor would be slightly less since you don't have the rolling resistance of the tires.

I'd love to have an engine that produces peak tq down around 2000rpm and just cruise there all day long, but as Pierre mentioned, the thrust bearing could be an issue.
 
TDIs

I'd love to have an engine that produces peak tq down around 2000rpm and just cruise there all day long, but as Pierre mentioned, the thrust bearing could be an issue.

Another issue that needs some thought is the thrust line, the centerline of the propshaft/crankshaft. With an inline engine like the TDI the thrust line would be way too low for an RV. The two common fixes are a belt/gear drive, which could cure the thrust bearing problem but add weight or, like many inline aircraft engines, turn it upside down. Major issues with that, lubrication being one.

John Clark
RV8 N18U "Sunshine"
KSBA
 
I'd also mention that the typical SAE correction factors used on DynoJets are invalid for turbocharged engines. Best to use uncorrected or observed hp. The difference is substantial if the facility is well above sea level.
 
the 2L engine appears to be making 160whp at 2700 rpm, which seems to be about the limit of what a 2 blade prop that's big enough to absorb ~200hp can spin up to efficiently. If you used a 3 blade (or 4?!?) you could get a little more (engine) speed (and power) at the cost of some efficiency; that'd make a nice simple optimization problem.

Add 10% for losses and that works out to something like 176hp net at the flywheel (conservatively). Run an electric water pump(s!) and toss the p/s pump in the trash and you're probably looking at 185hp avaliable to the prop, call it 180. You'd want to do some thrust load analysis, but it wouldn't be difficult to add a thrust bearing. The issue becomes installed weight, and sorting out the electronics. I'm willing to bet the (inevitably) Bosh system on the stock 5 spd euro TDI's could be tricked into thinking it was in a car, or better yet, re-flashed to ignore things like neutral safety switches, wheels speed sensors, etc. All you really need for a diesel is injector pulse and timing as a function of rpm and load (boost).

The crank centerline issue would be tough, I'd be interested to see a drawing or really good straight on picture of the rear end of one of these engines with a ruler in the pic (and something similar for a lyc). More than likely this would be unacceltable for a (stock) RV airframe, but I can imagine alot of different configurations where it would be fine (or even desirable!). If they're shorter than I think they are, you might be able to lean the cam cover over to the passenger (co-pilot ;) ) at a 40ish degree angle to gain some height, of course that would involve fabbing a funky oil pan and pickup (no biggie).
 
yes but ur talking about using an electronic TDI pump...

if you search for TDI-m they are taking newer TDI engines and installing the older style bosh pumps that are completely mechanical. they need 1 positive wire to operate the fuel shutoff valve and thats it, talk about simplicity!

there are also companies that can seriously trick out these pumps with little to no affect in fuel efficiency but are the BEST bang for buck in hp/tq... a stock 1.6 turbo diesel (mine) had 40% more power just by changing the pump and adding 5psi more boost, the 1.9 i would imagine would be the same or higher jump in power

also, the mounting in an RV-x woulnt be a problem for me, as im thinking about using this engine in a dragonfly... although i'll probably stick with an aircooled vw engine for simplicity/cost/faster to get flying

but i would like to experiment later down the road maybe on a 2nd project... i dont think a repositioned prop with a belt would be too hard for anyone with fabrication skills... and good idea on the 3/4 blade props...
 
I agree with Andy's assessment in an earlier post. People assume that diesels can take unlimited boost and last for a very long time. There are subject to the same mechanical issues as a gasoline engine. Boosting power a street engine via more boost in unlikely to affect longevity since full power stresses only last for a few minutes out of each hour of operation. Torsional vibration/ fatigue levels in the crank would be my biggest concern on a highly boosted aircraft diesel.

I once turboed a naturally aspirated Toyota Landcruiser diesel with about 9 psi. It was way faster than stock. The owner commuted about 120 miles per day on the highway with it. Lasted about 2 years and the crank broke one day. This crank was absolutely massive compared to a TDI crank and heat treated alloy steel to boot.

Thielert has found out that successful auto diesels do not always work the same on aircraft. While I encourage experimentation, just don't forget the underlying physics here. Get one flying and let's see how it works!:)

The propeller longevity might be another issue with a direct drive diesel.
 
The bad news for using this engine in aircraft is that you need the OEM ECU and it is heavily tied into the chassis with sensors, anti-theft interlock codes and other nasties. It will be a mess to decipher all this junk to make the computer run just the engine happily without the car attached. No option to install a mechanical pump and injectors easily on this engine unfortunately. Apparently Bosch is able to sell a programmable ECU for common rail diesels now- the bad news- you need $25K.:eek:
 
Two serious considerations come to mind when evaluating an auto engine for airplane use.

1. How do you deal with the thrust load generated by the propeller pulling the airplane through the sky? Auto engines transmit torque to the transmission and have very little thrust loads. On air cooled VW auto engines converted to motorglider use, Limbach in Germany makes major modifications to the crank and case to incorporate thrust bearings.

2. Airplane propellers can only turn about 2700 rpm efficiently because the tips begin to go supersonic if you rev them higher, unless you have a very small diameter prop. So, how do you make the auto engine make the horsepower at low rpm? Or you need a gear reducer which only adds yet more weight and complexity.

What will it really cost when figuring the entire expense of all the parts, motor mount, cooling, cowling, etc as compared to a tried and true Lycoming? Looking at the Eggenfellner? Subaru conversions sold to the RV market, I see no cost savings anywhere, but I do see a decreased resale value.


Just because it can be done does not make it a good idea. Consider Iraq today. I rest my case.
 
The real world

Unfortunately political may overshadow the practical. Shutdown the lead additive plant in England and many aero engines become expensive museum pieces. It might be easier to cobb up a bearing package for the subie diesel than train your high compression lycon to run on nolead. I am very happy with my lycon, even with paying a performance price for having low compression pistons.
Mogas will at least keep it flying, Jet-A might be the only future.
 
The bad news for using this engine in aircraft is that you need the OEM ECU and it is heavily tied into the chassis with sensors, anti-theft interlock codes and other nasties. It will be a mess to decipher all this junk to make the computer run just the engine happily without the car attached. No option to install a mechanical pump and injectors easily on this engine unfortunately. Apparently Bosch is able to sell a programmable ECU for common rail diesels now- the bad news- you need $25K.:eek:

Are the sensors encrypted or something? What's to stop you from using something like an AEM unit or a modified SDS unit to handle fuel injection? I'm sure you've thought this out already, but I just wonder, beyond the added car stuff, what's so special about the mechanicals of this engine? Could you not replace the turbo with a belt-driven supercharger? The mechanical fuel pump is a problem, but could that not be solved with redundant electrics? I tend to oversimplify complex problems, but unless there's some kind of realtime adjustment for injection timing, isn't it just a question of delivering fuel to the cylinder at the right time with the right amount of compression? I would also guess that the case would fit happily together with a Marcotte or Sub4 PSRU.
 
Most new diesels do up to five injections of varying pulse width per combustion event. Right there all the programmable ECUs for gas engines are out of their league. The anti-theft interlocks on the new Sube ECUs are very difficult to get around with digital wireless codes it looks like.

You'd never want to replace a turbo on a diesel with a supercharger. Might just need a different unit for aviation use at altitude but a lot of repackaging would be required anyway and lots of issues with the PSRU unit I'd think as well.
 
Subie Diesel

I know of a suitable computer geek that would probably sort out the coding problem over lunch (he's a VW/Audi tuner that runs a DTM team in Germany and chipped my uncle's Skoda Octavia).

Having followed the Subaru scene for a while, I see this new Subie diesel as a good core. It's not yet out and running so the aftermarket tech support to do what you want with it will take some time. However, between the V-dub TDI tuners and the Subie rally crowd, I wouldn't be surprised before you saw these engines being used for all sorts of nefarious purposes (diesel rally car?)

Direct drive would worry me. A solid PSRU like the Marcotte would be a better bet. Trying to get an auto engine to take thrust/gyro loads would be an engineering mountain to climb, time that would be better spent getting a solid independant engine computer/wiring harness sorted out. Not to mention, a lot of new prop blades seem to be more efficient at much lower RPM when flying at RV speeds. This will be even more apparent to anyone who likes to climb to oxygen levels to cruise. Big slowish prop and fuel sipping diesel sounds brilliant to me.

I'm a way off an RV project as my Gyro is still not complete (can't be too greedy or my wife will kill me). However, I reckon that within a year of Subie's diesel being in full production, the prospect of it being a good aero-conversion core will look a lot more rosy!

If Thielert can do it, why can't we. Plenty of capable engineers building RVs!
 
pvansrv3??

Just a short comment about your post:-

'What will it really cost when figuring the entire expense of all the parts, motor mount, cooling, cowling, etc as compared to a tried and true Lycoming? Looking at the Eggenfellner? Subaru conversions sold to the RV market, I see no cost savings anywhere, but I do see a decreased resale value'

You are correct, the cost of a new 6 cylinder Subaru conversion is probably no cheaper than the 4 cylinder Lyconing - after all, the engine mount, the cowl, and solving the cooling issues (which is apparently soved in the latest version of rad and cowl combination) are the same in both engine types.

'Looking at the Eggenfellner? Subaru conversions sold to the RV market, I see no cost savings anywhere, but I do see a decreased resale value'

Inital investment cost, no. But factor in reduced operating costs - fuel over 2000 hours say 14,000 gals at a reduced cost of $2/gal. That's significant. Reduced maintenance costs - look at plugs, oil, filters, and I'm sure the cost over 2000 hours is again significant.

2000 hour engine overhaul. Don't do it with a Subaru, just replace with a factory brand new short block at $5,000, and that's if you need it at 2000 hours. Probably don't need it until much later, if maintained and operated properly. How much is a Lyc overhaul up to and including 2000 hours service?

Add in smooth operations, possibly more efficient and less fluel flow, great winter operations with liquid heating through car type heater, quieter, less vibration, no shock cooling issues. Why would you want to resell it so no worrying about resale value?

OK, I'm an Egg H-6 owner and flyer, and, despite my issues and tribulations with oil cooling and an older type gearbox, I still prefer it to the daily problems I see at my home base with certified/clone air cooled engines. OK, I may be slower, but I'm quieter, smoother and reliable. No price on that for me, but it is your choice, after all. Just don't knock it until you've tried it - with an open and interested mind.

If this is the wrong thread, I apologize, just responding to the post.....

Allan
 
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