What modifications needed for a Diesel or an LNG-fueled SL-C?

Yes, Fran, I know that the answer is: "Bring the money and you can do anything you want."

Now that we have that out of the way, what kinds of modifications to the SLC would be necessary to install a small diesel engine or an engine fueled by LNG?

(Sample small diesel engine Audi twin turbo V12 from Q7. Image c and courtesy Audi. Your small diesel engine may vary)

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Okay, so I admit I introduced this topic with levity. I actually want a serious technical discussion. Putting a diesel engine into an SL-C is not as easy as slipping a penny into your pocket.

All kinds of connections: cooling, fueling, electrical, and electronic, already exist for a gasoline fueled SL-C. What would need to change if one had a diesel fueled SL-C?

Cooling and fueling

What connections would need to be changed? Added? Deleted? What different materials and processes would be needed to install these connections? To make them work and to make them reliable?

Electrical and Electronic

Granted, diesel engines are compression-ignited, so what differences does that make to the SL-C's electrical system? To the electronic systems? What would need to be added, deleted, or changed, so that it would work properly with a diesel-fueled powerplant?

This is going to be great: to see the team of out-of-the-box thinkers that comprise the SL-C community come up with novel and innovative solutions to all the challenges of a diesel-fueled SL-C!!

THE DREAM

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Randy V

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I think that he additional weight of diesel components over that of gasoline engines shuld be taken into consideration. Certainly you can beef up suspension, but the weight & balance of the car may not be as good as that of the gasoline powered version.

TDI is some very good stuff with lots of performance goodies and tech...
 
With its compacted graphite iron construction, that Audi V12 TDI doesn't weigh all that much more than engines that have already been put in SLCs -- we're not talking about a heavy truck or marine engine, but rather one that gave the R8 TDI performance similar to that of the gasoline-powered version. Essentially, we're looking at a weight comparable to what you'd have with an iron-block LSX if you added turbos. At 26.9" in length, the V12 TDI also probably wouldn't be all that hard to fit into the SLC engine bay.

To me, the biggest problems with using this engine in an SLC look to be centered on availability and cost more than engineering issues once you've got the engine in your shop -- and on the need for a compatible transaxle in terms of torque and gearing.
 
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To me, the biggest problems with using this engine in an SLC look to be centered on availability and cost more than engineering issues once you've got the engine in your shop -- and on the need for a compatible transaxle in terms of torque and gearing.

I agree with you on this. MY main thing with Euro diesel's what happens when some thing breaks. Or some thing worst your in the middle of the sticks and some thing breaks. It will cost you a lot of money and time. Its not like if you have a problem with a American motor. You can go to the local dealer or shop and you have it fixed in a few days.
 

Howard Jones

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This is going to sound "smart assed" but IF I was going to do this I would buy a running car with the chosen power-train in it. Maybe one with a lot of side impact damage, and use EVERTHING.

You might need a custom fuel tank but otherwise I believe that's what it would take, everything related to the powertrain thats in the car. The gearbox is just the beginning. Until that was solved I wouldn't even consider going forward.

Big $$$$$$$$$$$$$$
 
I was asked to answer this thread and will try to do so from an electronics perspective. Beyond the electronics, the only thing I'd assume is that a V12 diesel will way too long for the engine compartment, but that's mainly guessing based on knowing that the Audi R10 TDI Le Mans car had to have a longer wheelbase than it's R8 gas-powered predecessor.

So about the electronics. I gave a broad overview of some of the challenges of more unique modern engines and their associated electronics in this post about AMG engines. Bottom line: you need to go full custom ECU and wiring, sensors on up. I poked around a little and the only major manufacturer who clearly states support for diesel engines in their ECU range is Bosch. Prices for a 6 cylinder engine is EUR 5000 (about $6500), EUR 6000 for 8 cylinders and for 12 cylinders you have to ask them, so it's likely to be around EUR 7000-8000.

Then you'll need to find an installer who carries Bosch and is willing to get this hooked up. I think that is much more plausible in Europe, where Bosch as a lot more of the market and while the diesel experience might be lower, I'm sure there are a bunch of Bosch installers with gas knowledge. You might want to just get in touch with Bosch directly though.

I also briefly looked into Motec, but it doesn't look good, at least right now. See this thread in their forums. Looks like they're working on a brand new system and can't piggyback this on their existing units, but info is contradictory in their forums. Their new M1. Next Generation that they just came out with has GDI support, but it doesn't look like Diesel is supported. Maybe that's just a software upgrade away... I have no idea.

So basically from what I'm seeing is that you're looking at a big spend on a Bosch ECU. I would be curious to see if anyone knows of any other suppliers for diesel. You might also try to get in touch with Apex Speed Technology and ask them. Tell Neel I sent you - they're the guys I'm using for my system.

DO IT! :)

Tim
 
A lot of people are going the route of taking over the components needed to run such engines/ECU's such as gauge clusters/etc, it's 'easier' than hacking things around but more of a problem if you don't also have all of those components.

I've seen this done a couple of times with Audi transplants but for the life of me I can't think where.

To be honest if you intend to be economical, why have such a hulking great diesel lump? Why not go for something little smaller...
 
I have a Touareg V10 TDi and have measured it to see if it would fit in the SLC engine bay. It looks like it would fit, especially if you could relocate the turbos on the sides.

The V10 is a very short engine, with no external front dress- everything is driven from the most elaborate gearset I've ever seen on the front of an engine. The V10 is also a very light engine- it is the first large diesel engine ever manufactured in volume with an aluminum block. The technology was developed with the help of Mahle, IIRC.

As Tim points out, the biggest problem is engine management. Since it is a Vee engine, another solution would be to treat it as two separate 5-cylinder engines for purposes of engine management. In fact, this is precisely how the engine is managed on the VW- there are two ECUs, each responsible for one bank of the engine.

Related to the engine management issue is the topic of finding a tuner who is familiar enough with diesel technology to create a map that works well everywhere, as VW has done in the Touareg. I'm sure that didn't happen over a few lunches. :)

Finally, the transaxle issue is a serious one. There was actually a VW V10-powered car that ran at LeMans one year under Caterpillar sponsorship that ran well until the transaxle broke from too much torque. Even the stock V10 has 553 ft lbs in a conservative, emissions-friendly tune; I would guess that twice that wouldn't be out of the question with the proper tuning and turbos.
 
Aluminium diesel.... interesting!

Like I said, I'm sure there was a guy somewhere who took the engine out of an S5 or something and brought with him the gauge cluster, keys, etc over from the donor vehicle to the one he was transporting it into but I can't remember where I saw that?
 
Beyond the electronics, the only thing I'd assume is that a V12 diesel will way too long for the engine compartment, but that's mainly guessing based on knowing that the Audi R10 TDI Le Mans car had to have a longer wheelbase than it's R8 gas-powered predecessor.
The Audi V12 TDI, at 684 mm, is almost 2" shorter in length than an LS1, and it has a tighter V-angle. It almost certainly can be made to physically fit into the SLC engine bay without extreme contortions.
 
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About the same as a gasoline-powered, OHV, iron big block. Significantly more, but not outrageously more, than an LS3 or LS7. This is not a hulking lump designed for heavy equipment that we are talking about.
 
Okay, guys: what about this engine?

Inside The Banks VM Motori 3.0L 630T V6 Diesel Engine - Diesel Power Magazine
Inside The VM Motori 3.0L V6 Diesel Engine
Text By David Kennedy, Photography by David Kennedy
Diesel Power, August, 2012

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VM Motori’s 3.0L diesel is manufactured in Cento, Italy and is available in various power outputs from 190 to 268 hp. The engine was originally developed for passenger car use, which means it offers a much broader power curve than the medium-duty truck engines we’re used to. Fiat (Chrysler’s parent company) owns a 50 percent stake in VM Motori: General Motors owns the other 50 percent. So (they) should be able to keep the costs of this high-tech engine down to a level we can all afford. (Furthermore,) the Banks Powertrain division of Gale Banks Engineering is developing this VM Motori engine for use in extreme applications by our military. Banks calls this engine the 630T.

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Overall, the Banks 630T version of this engine is a very tightly packaged powerplant that is more power dense than any diesels we usually work with, and that means two things: It’ll make a great swap for vehicles that can’t fit a large truck engine, and whatever this engine goes in it’s sure to be a rocket ship.

The 3.0L’s oil pan is a piece of cast-aluminum beauty. Using aluminum aids in cooling the engine oil, acts to quiet the engine by adding additional structure, and provides an additional area for the transmission’s bellhousing to mount to—which, believe it or not, is key for vehicles that see high-speed driving.

The aluminum heads on this engine are unlike anything we’re used to in this industry. The DOHC configuration means there are separate cams for the intake and exhaust valves, there are no pushrods to flex, and the engine will love to rev.

There are four camshafts in the engine. The exhaust cams are driven off the front of the engine by a chain, and the intake cams are then geardriven from the exhaust cams. The round plastic piece on the intake cam (arrow) is part of the engine’s closed-crankcase ventilation system.

Plastic valve covers are used to reduce weight and provide a layer of sound insulation in passenger-car applications. (And we can replace them with extremely costly and ego-soothing carbon fiber - B et P :) )

On the 240hp version of this engine, Banks uses a Garrett variable-geometry turbo mounted to the rear of the block. Gale Banks told us the 268hp and 421-lb-ft version of his engine will use Garrett’s latest ceramic ball-bearing turbo (capable of handling 1,500 degree EGT) and Banks’ new exhaust manifolds.

That turbo will send compressed intake air through an intercooler and then into this two-piece Banks intake manifold that’s being developed to suit a range of power levels. Though not discussed during our visit, this manifold would also be suitable for a twin-turbo application, and we suppose the top half could also be replaced with a supercharger.

Getting an all-new engine like this to run in a standalone configuration requires a special engine controller. Thanks to its close ties with Bosch, Banks has developed its own programmable ECM called the AutoMind that it has already used for its Duramax motorsport and military engine programs.

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Banks AutoMind engine controller

The guys at VM are located in (Cento, Italy) the high-performance automotive equivalent of the Silicon Valley, with Lamborghini, Ferrari, and Ducati close by. The design of its V-6 is intended for firing pressures up to 2,940-psi, and the engine freely revs to 5,000 rpm. VM Motori has a passion for its engine designs, and according to Gale Banks it was, “the excellence of this engine [which] convinced me that it would be a rugged basis for what I have in mind for these new Special Operations vehicles.”

(Gale) Banks went on to say, “We (fired up the engine for the first time) in our engine test cells on Friday May 4th, 2012 and my first impression was about the sound...this thing is sweet! The low-end response is excellent and it revs freely, which worries me. We've already designed a high-rpm capable aluminum intake manifold for it but, our Banks AutoMind diesel engine controller is only good to 7,800 rpm in its current form.

(Aw, poor baby - B et P :) )

A Banks version of the 3.0L VM Motori V-6 engine will be also be available to the general public as well, according to Banks. “Our initial build will be 240 hp and close to 500 lb ft of torque with an engine weight under 500 pounds,” reports Banks.

When asked what other applications we might see this engine in, Banks told us, “We have a stepped power development plan in the works and racing versions will emerge as well."

"The 630T has the potential to make more than 600 hp in race trim," Matt Trainham, Banks Powertrain Engineer

Inside The Banks 630T V-6 Diesel

DISPLACEMENT: 3.0L (182 ci)
CONFIGURATION: 60-degree, even-fire V-6
ENGINE WEIGHT: 498 pounds
BORE AND STROKE: 83 mm x 92 mm (3.26 in. x 3.62 in.)
COMPRESSION RATIO: 16.5:1
ENGINE BLOCK: Compacted-graphite iron (CGI) casting that weighs 159 pounds, featuring four 14mm head bolts per cylinder
BEDPLATE: A one-piece, 35-pound assembly retains the crankshaft and ties the bottom of the block together with six 12mm bolts per main bearing
CRANKSHAFT: Forged 4140 steel with 74mm (2.91 in.) main bearing journals and 67.5mm (2.66 in.) connecting rod journals, externally balanced
CYLINDER HEAD: Aluminum castings with four valves per cylinder
VALVETRAIN: Dual overhead camshafts (DOHC) with roller finger followers and hydraulic lash adjustment
VALVE SIZE: 28.5mm (1.12 in.) intake, 25.4mm (1.00 in.) exhaust
BASE POWER RATING: 221 to 268 hp at 4,000 rpm
BASE TORQUE OUTPUT: 369 to 421 lb-ft at 2,000 rpm
MAXIMUM ENGINE SPEED: 4,800 rpm
FUEL SYSTEM: Bosch common-rail injection with a CP4.2 pump and CRIN 3.4 solenoid injectors capable of running up to 29,000 psi (2,000 bar) and seven injection events
TURBOCHARGER: Electronically controlled variable geometry with water-cooled ball-bearing cartridge in high-power applications

So the technical side of this engine is: it's light, compact, powerful, robust, and already has a stand-alone electronic controller.

What technical changes would be necessary in the SL-C to make this engine work there?

Thanks,

Bassanio et Portia :)

All photos c and courtesy of DieselPower Magazine.
 
The above article from DieselPower Magazine was only slightly edited, from an SL-C point of view. :)

Full disclosure,

Bassanio et Portia :)
 
Makes me laugh that they say it loves to rev and then give a maximum rpm of 4800!

Doesn't matter if the controller will do 7800 or even higher the physical limitations of being a diesel limit them to about 5000rpm.
 

Randy V

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Makes me laugh that they say it loves to rev and then give a maximum rpm of 4800!

Doesn't matter if the controller will do 7800 or even higher the physical limitations of being a diesel limit them to about 5000rpm.

I've seen a GMC 6-71 Diesel run north of 6,500 RPM one time..
 
I've seen a GMC 6-71 Diesel run north of 6,500 RPM one time..

Oh yes you can get them over 5k but it gets harder and harder the more they rev as you have a fixed very small time window to inject and as you can't alter the ignition point[1] power dies off. 5-5.5k is the reasonable limit but as you point out there will be a few over that.

[1] As you can on a spark ignition engine (ie petrol) by advancing the ignition timing.
 

Randy V

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Actually I should have told you a little more about this engine. It did have a bit of work done to it to raise the compression and increase both fuel and air. However, as it was on the test stand and was to be destroyed (military surplus that was to be destroyed prior to disposal) - our instructor showed us what happens with a runaway diesel. I used a pick to puncture and slightly rip one of the blower seals. Once she got the taste of her own crankcase oil she started to hunt a bit. We went through the checklist and shut off the fuel supply.. The engine just about died as it was registering belowe 500 RPM on the test cell's tachometer. Then she started to grunt an started knocking very loudly.. Faster and faster. We shut off the air intake and a moment later the flex hose ( like that used in brake ducting ) ripped as it was very old and tattered.. It only took a minute for the engine to reach about 4500 RPM and our instructor was a bit frantic and chased us out of the test cell while he continued to try and shut her down. She held 36 quarts of oil as I recall. He finally left the cell when she was freewheeling at 5000. He applied full load to the water brake and she only dropped a few hundred RPM. God only knows how much torque she was making.
The tach in the test cell only went to 6500 RPM and she went screaming well past that before oil pressure was lost and the whole side of the block exploded. The reciprocating assembly was in a few dozen more pieces than it was designed to be in. Once the room cleared of the smoke and firefighting powder, I was one of the chosen that got to clean that mess up.

So yes, they will rev.. But they can only take soooo much... :)
 
You might also try to get in touch with Apex Speed Technology and ask them. Tell Neel I sent you - they're the guys I'm using for my system.
Tim

Neel is an awesome guy, I agree - he and his team did the ECU and wire harness for my turbo Hayabusa-powered Sports Racer...very professional and he bends over backwards to help whenever and wherever he can. If anyone can figure out the electronics for a Diesel it's Apex.
 
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