1951 diesel beetle...maybe a modern reality?

[srgtlord]

I was borrd last night and was reading through some old posts about the 1951 diesel bug. They used a porsche 365 block and bearings. Now it appears they used newly forged 22:1 compression pistons and rings. Now In the article it stated the only real difference between a stock beetle and the diesel beetle was the heads and the injection pump. The mercedes 220d injection pump looks to be very similar to the diesel beetles pump. I think the only difference is the pumps shaft length and the timing gear. Soooo in theory if you had a set of racing pistons and rings and bearings in a racing crankcase, tapped the head to fit vw rabbit injectors and some sort  of pre cups and custom lines...would this work...in theory?
http://superbeetle.kaeferpiloten.de/bilder/showimg.php?file=/technik/berichte/dieselkaefer/dieselkaefer.JPG
http://www.thesamba.com/vw/forum/viewtopic.php?p=3662048&highlight=#3662048
http://mercedesforum.com/forum/diesel-performance-49/injection-pump-fuel-adjustment-mw-m-pumps-pyrometer-install-46097/

[rabbitman]

What about the firing order? Isn't it sorta different than most IP's are?

[8v-of-fury]

I'm sure you could make the injector lines up so that the corresponding injector would be receiving fuel.

1342 is the beetle no?

[nathan_b]

true, but it had a 59s 0-60mph and only made 30-35mpg.... might as well be a gasser, I used to squeaze 39 out of my '68, probably one of the few to go over 400 miles on a 10.5 tank haha.

[8v-of-fury]

How is it possible to get such a low mileage count?? They have to be more aerodynamic than a rabbit/jetta.. And weigh like 800lbs less.

Was it just the design of the engine wasting fuel??

[R.O.R-2.0]

How is it possible to get such a low mileage count?? They have to be more aerodynamic than a rabbit/jetta.. And weigh like 800lbs less.

Was it just the design of the engine wasting fuel??

beetles are low LOW geared, and carburated..

[8v-of-fury]

Never heard of a Carb'd diesel kev .

Which is what is under discussion is it not? A diesel bug??

Which I'm sure would have been much better geared for torque.

A beetle with an AAZ would be pretty awesome .

[bajacalal]

How is it possible to get such a low mileage count?? They have to be more aerodynamic than a rabbit/jetta.. And weigh like 800lbs less.

Was it just the design of the engine wasting fuel??

We're talking about 1940s diesel technology vs. 1980s diesel technology. Just look at how far diesel technology has come since our early 80s cars were made.

[8v-of-fury]

What made them so ***ty then? They were idi, a rotary pump?

They used a 22:1 comp ratio, so its not like they weren't being efficient. Just doesn't make sense.. It could be half as good in that small light car and probably still pull some good numbers..

So for it to be that miserable.. I want to know why lol

[nathan_b]

the engine was also undersized I believe: 1.0L if memory serves. So it was probably WOT 90% of the time.

I have always wanted to take a vanagon diesel gear box, put it in a karmann ghia, and put a 1.6td in it.

Beetles are also NOT aerodynamic at all. .49 drag if I remember right, ghias were about .27.

I actually think that the bay window bus had a similar drag efficiency at all. Ghia was designed in a wind tunnel, bugs just thrown together, also not THAT light, usually with gas ect, around 1800-2000, so not much below a rabbit. I am a firm believer that if VW would have put a 1.6d/td in a (slightly beefed up maybe) old beetle, it would have changed the world. air cooled motors dont last well, water cooled diesel last forever, along with torsion suspension, it would be a million mile machine!!

[rabbitman]

My rabbit actually weighs between 1800-1900lbs w/o the rear seat and with a long forgotten amount of fuel in it so not really any more than a bug.

Reasons for low economy: the diesel bug was probably full power all the time and aircooled engines just aren't as efficiant, aircooled gassers need a rich mixture to keep combustion temps down since they didn't cool very good but in a diesel we know that adding fuel only raises combustion temps which would spell disaster in a aircooled engine.

I doubt they would've lasted very long either, diesels clack and really pound on the rods, crank and bearings and the aircooled motors can't take that kind of beating, the case would probably pound out waaay sooner than a gasser.

[RadoTD]

A beetle with an AAZ would be pretty awesome .

I know someone thinking about doing this, except with a TDI

The whole rear end of the car is set up a bit odd; you need to make a full tubular rear end to mount the motor to.. unfortunately it's far from a simple swap

[Toby]

I suspect that the real reason it was not produced is because of some real serious problems making the motor live. Gas Bug motors pull studs out of the case. What do you think a 22/1 compression diesel would have done? You could have run very long studs from head to head to take most of the load, but that would have been pretty cumbersome. I also doubt that an alloy block could have taken the pounding and what would you do to make a head gasket live?

Making one run as a test vehicle is certainly possible; making one run more than a few thousand miles is another.

[rabbitman]

I suspect that the real reason it was not produced is because of some real serious problems making the motor live. Gas Bug motors pull studs out of the case. What do you think a 22/1 compression diesel would have done? You could have run very long studs from head to head to take most of the load, but that would have been pretty cumbersome. I also doubt that an alloy block could have taken the pounding and what would you do to make a head gasket live?

Making one run as a test vehicle is certainly possible; making one run more than a few thousand miles is another.

That's another reason right there.

[stewardc]

Here's a picture of the test mule 1951 diesel Beetle.