[m1ll10n]

At this point I am pretty interested in building an inline 5 turbo diesel. I understand how the diesel works and all for the most part. I'm doing research right now, and I'm sure there are others that are and have done research prior to this post. Basically here is the low down. Later in fall or winter I am going to pick up another audi probably a pre-96 one. Not quite sure what yet though. I'll probably drive that around for winter and then next year I'd be interested in swapping in a diesel. Here's a few questions...

1) Are there any differences between a gas & diesel short block in the way they are designed?

2) I know sizes can be different, but would using a normally "gas" engine block with a diesel head work as a diesel?

3) Is what makes a diesel engine a diesel engine in the head design (no spark plug holes?

4) If so, does that mean everything else is the same?

5) Also, I understand why diesel can run such high compression, but how do they obtain it?

6) Are there any 20v head (designed for diesel) that I can put on a 5 cylinder short block?

7) If audi doesn't make a 20v diesel (and if there is no way to make your own :wink: (by lets say sealing the spark plug holes>?)) Would a volvo or mercedes (if they made one, which I'm not sure of yet) directly bolt on an audi transmission? I know volvo is horizontally mounted so it'd fit different in the engine bay.

I'm going to keep looking things up, I'd thought I'd start a post to help with the search and for anyone else that is interested in a diesel.

Actually I guess there is another question,
Is there any limitation in turbo'ing a NA diesel (anything to worry about). Knowing that'd you have to have an exhaust manifold, maybe oil lines, or custom things built to accommodate the addition of a turbo.

Sorry for the long post. Thanks

8)

 

[EES]

I have to admit I know almost nothing about VAG Diesels, but I think you will need to find yourself a factory original unit. The knocking you hear with a Diesel is just that knocking. As a result they are significantly stronger engines. Typically Diesels are all cast iron (again don't know much about VAG stuff).

1) Like I said above the Diesels are typically significantly stronger. They also tend to be "stroker" motors since they typically turn about 50 to 60% the RPM of a similar gas engine.

2) Probably not. First due to strength, second due to getting enough compression.

3) Diesels typically have very different combusion chambers. They have no spark plug, but they do have a glow plug and the injector goes straight into the combustion chamber or into a small pre-chamber.

5) My GM 6.5 turbo Diesel does it with flat top pistons and a VERY shallow combustion chamber.

6) Don't know

7) I don't think an aluminum head would last very long.

Another very important thing to consider is engine speed. If your car is geared for 3000 rpm at 75 mph remember this will be close to red line in a Diesel. You will likely want to search for the lowest numerical final drives you can find. I don't know the 87.5 ratios, but if they are 4.11 you will want to search for turbo drive train parts to get the 3.89? parts.

Oh yeah on turboing a NA engine you can do it, but you might need higher cracking pressure/flow rate injectors and maybe some injector pump tweaking (again near zero knowledge on VAG stuff).

I understand the desire to go Diesel. I would consider trying to find a TDI and spend yoru time sorting out the adaptor plate to the transmission and such. Then you have the next generation of technology as well as a current engine that parts are easy to come by and DIY aftermarket support exists. Those 1.9 TDI engines can be made to fly.

 

[cuatrokoop]

VAG's 5cyl block is virtually identical between the gas and diesel versions. However, the rods and pistons are definitely different. Heads can be aluminum. VAG never made a 20v 5cyl diesel to my knowledge. The 5cyl diesels Audi did make are old and not very powerful at all. Honestly, I'd rather get a 1.9L or 2.0L TD/TDI from a Passat and drop that in. A 2.0L TDI with it's transmission shouldn't be too terribly hard to find, or even a 1.9L. It'd have to be from the newer Passats, as they would be the only longitudinal VAG TD's in the US worth using, if you wanted the transmission too. Otherwise there are loads of 1.9L TD's in Beetles, Jettas and Golfs.

 

[m1ll10n]

So the early 1.9l TDi engines were tranversely mounted? I'd want to use a pre-96 quattro transmission, not sure what car yet, but it will most likely be an audi 90 or 100 quattro. Whats the power to money ratio out of these things (the TDi 1.9l & 2.0l VW 4 cylinders) I know a diesel is alot torquier, but 100 hp is depressing. Thanks for the answers guys!

 

[cuatrokoop]

You can chip the TDI's, both 1.9L and 2.0L. This is assuming that you have good low-sulphur diesel in your area, and can get a chip from Europe.

 

[EES]

Do some google searches on TDI and you will find quite a few people making a good bit more than 100 hp here in the US.

 

[thrash]

AFAIK, All of the VW diesels are transverse _except_ in the B5.5 passat.

 

[Henka]

A buddy of mine tuned his 2.5Tdi. Ran pretty well. Stock hp was 115 at the crank, his made 160hp at the wheels. All he did was change the turbo to a K25 (stock K14!) and then he used a KCR piggyback for a Iveco truck to tune it. Crazy car. That engine, with a better exhaust and a better tuning will make 200hp easily. His main problem was that he kept blowing hoses causing the turbos to blow up. I think he went through 2 or 3 turbos in a very short period of time. But then again, it was all on a budget. I made the adapter to fit the K25 to the stock EM and then I ported the EM end turbo to match up. Looked pretty neat. Anywho. To anser some of your questions:

No, there is no 20v head avaliable. Early Volvo 850 and V70 used Audi TDi engines so they are interchangeable. It's funny though, the Volvo version made 140hp with a K14 and the corresponding Audi version made 115hp with a K16! The crank and block are commonly used here in Sweden and Norway on gas engines making up to 1100hp (Jonus!) so they should hold up to some abuse. Don't bother with a 4-banger - the sound from that IL5 tdi of my buddy was just crazy!

I think this would be good cheap fun. A B3 or B4 quattro and then a tuned diesel. The KCR piggybacks have their limits and the biggest problem is injectors. If you can crack that, well, serious hp should be possible. It's a matter of getting the fuel into the engine - that's the real problem...

 

[m1ll10n]

That's sweet! So I'd imagine I'd have to have one shipped over from europe. What's the market price for those engines used? I thought the 2.5l audi turbo diesels were v6's not inline 5's? Maybe if I took on a project like that it'd be time to go 034 efi. Thanks

 

[Henka]

Yeah, I haven't really figured out how to use a standalone on those TDi's. I mean, they aren't like gas engines in the sense that you don't have any throtte and the injectors are a bit weird - I don't even remember what the deal was. It was quite a few years ago! Those engines are cheap over here. However, they all have loads of miles on them and unfortunantly they were sensitive to timing belts. If you didn't change them when you were supposed too - kaboom! I'll talk to my buddy and see if he can post a bit here on what he did and his thoughts on tuning diesels.

Found a couple of engine that are about $800 complete - pretty fair price I think. Then again, you'd probably want the ECU and such. Definantly under a $1000 though.

 

[cuatrokoop]

They have two 2.5L TD's. One is a 10v and one is a 12v. Both single turbo.

The Eurovan MAY have come with a 2.4L or 2.5L 10v diesel in the US, can't remember.

 

[m1ll10n]

Yes eurovan did come with them in the US, just found it. I only thought they had the 2.5l gas engine, but they did come with diesels as well. http://www.sjmautotechnik.com/bentley_manuals/bentleyvw.htm ..scroll about half way down and they list the engines available for the eurovan. If I could get one in the US it would deff save on shipping costs. Also Henka, yea I'd be interested in hearing what your buddy has to say about what he did.

 

[m1ll10n]

ahhh, nevermind Canada got the diesels, US only got gas!!!!!!!

 

[scotty33]

Audi did the 140hp tdi as well, came in 10/'94 on A6 models (which was a facelifted Audi 100 here) I think there were quattro and 6 speed versions available.
also found there were 151hp VW type 4 tdis available, (Eurovan) engine code AHY 98-2000!

 

[EES]

If you get the Euro engines I would get the tranny and rear diff also. Does anyone know of a US market quattro drive train that would turn low enough rpm to make a Diesel highway cruiser?

 

[m1ll10n]

Yea you're probably right, just get an engine + tranny/rear diff combination all in one. This is prolly going to get expensive especially with shipping, but hey thats not to say it's not worth it! I-5 TDI is deff what I prefer.

 

[cuatrokoop]

The 10vt Type44 cars have pretty long gearing...Significantly higher (longer) than the CQ's thats for sure. The 5HP19 and 5HP24 5-spd auto setup may not be a bad option either.

 

[Wizard-of-OD]

The 5cyl diesels Audi did make are old and not very powerful at all.

Eh?
the 2.5TDi found in the Audi A6 over in europe was pretty powerful to me especially with a chip.I would be quite happy with 500+Nm of Torque thanks.
Just like the 4 cylinders the 5 cylinder Turbo Diesels saw an evolution going from TD short block (220mm) to TDi tall block (236mm).The 2.5TDi also founds it way into the Volvo 850TD,Eurovan as well as some other vehicles.I think everyone in here is familiar with this little deamon from VW.

Woops whats in here?

Yeah, I haven't really figured out how to use a standalone on those TDi's. I mean, they aren't like gas engines in the sense that you don't have any throtte and the injectors are a bit weird

From what I have been reading over on clubtdi and tdiforums,the only difficult part to figure out when integrating TDi & an SEM is the DBW pedal.The problem with the B4 and down frames is that none of them ever came with a DBW accelartor pedal so you will have to adapt an Audi A4 (b5) pedal into whatever older frame your using.Once you have accomplished this,the accel pedal becomes your TPS and everything else is the same.
VR sensor,Injectors,etc etc

 

[maRS2]

The new VW T5 eurovan and the Touareg have a TDI I5 174 Hp

 

[cuatrokoop]

The 5cyl diesels Audi did make are old and not very powerful at all.

Eh?
the 2.5TDi found in the Audi A6 over in europe was pretty powerful to me especially with a chip.I would be quite happy with 500+Nm of Torque thanks.

I was referring to the ones that the USA did get, you know, in the early 1980's. Notice the lack of "turbo" when referring to them.........