Diesel engine swaps

-
Btw it's not just about the mileage I would also get a huge kick out of having a diesel C-body. I could save the big block to build into a hot street/strip engine and plunk it in an $800 4-door Valiant, IMO that's the only logical use for big blocks these days aside from maybe old-school tow rigs.
 
Interesting, no I have not driven one but I subscribe to Deboss Garage on YouTube, he swapped a 4bt into a 2000s Suburban and after a while it wasn't all that worth it. He said it was noisy and vibrated quite a bit and you could definitely hear it clearly in his in-car videos. This coming from a guy who is currently swapping a Caterpillar engine out of a dump truck into an OBS Ford. Said it got up to 28 mpg though...

Like I said I'll gladly swap a 12v 6bt into my D200 at some point but for a C-cruiser I'd much prefer something quiet with at least 6 cylinders in the 3.0-4.0L range. We do own a 2005 VW Passat with the 2.0L TDI 4-banger and that thing is as loud and shaky as I will tolerate in a passenger car. That particular engine is a tad small to push around a C-body though our Passat weighs about the same as a 4-door A-body.

The early mechanical Mercedes diesels are super easy to swap but don't have much power and can't handle a lot more boost and fuel like bigger truck diesels. It's also really hard to find those in the U.S. in 6-cylinder form, they were almost all 5-cylinders. A friend of mine just got a 1982 Mercedes turbodiesel and even in perfect tune it takes 18+ seconds just to get to 60 mph. And I don't think that car even weighs 2 tons it's the mid-size model (forget the name).
It also heavily depends on the year of 4BT or 6B that you use. the mid 90s to late 90s one were notoriously loud. the ones from 89-93 werent near as loud. and then the 03s and newer when the switch to the common rail injection system quieted them down a ton. You can swap from the electronic CP3 pump to the 12v mechanical P7100 pump or even the A pump for the 4Bt. Course that'll add substantial cost but would give you the mechanical injection system without the noise of the early and mid 90s cummins.

I've also found that sound deadening really does help a ton as well. Also, most people when they are swapping in these things, are welding up solid mounts, often because the factory cummins mounts are HUGE. about a 6 inch diameter rubber mount, and then probably another 6-8 inches for the bracket.. Dodge and Nissan as well as the box trucks and such are designed for that extra width and height. But non designed cummins vehicles don't have that room in MOST cases. It is also one of the reasons why Ford declined the 6B, too wide and too long and they didnt want to change the frames or engine bays to accommodate it. But without that mount, its gonna shake the crap out of you
 
Interesting, no I have not driven one but I subscribe to Deboss Garage on YouTube, he swapped a 4bt into a 2000s Suburban and after a while it wasn't all that worth it. He said it was noisy and vibrated quite a bit and you could definitely hear it clearly in his in-car videos. This coming from a guy who is currently swapping a Caterpillar engine out of a dump truck into an OBS Ford. Said it got up to 28 mpg though...

Like I said I'll gladly swap a 12v 6bt into my D200 at some point but for a C-cruiser I'd much prefer something quiet with at least 6 cylinders in the 3.0-4.0L range. We do own a 2005 VW Passat with the 2.0L TDI 4-banger and that thing is as loud and shaky as I will tolerate in a passenger car. That particular engine is a tad small to push around a C-body though our Passat weighs about the same as a 4-door A-body.

The early mechanical Mercedes diesels are super easy to swap but don't have much power and can't handle a lot more boost and fuel like bigger truck diesels. It's also really hard to find those in the U.S. in 6-cylinder form, they were almost all 5-cylinders. A friend of mine just got a 1982 Mercedes turbodiesel and even in perfect tune it takes 18+ seconds just to get to 60 mph. And I don't think that car even weighs 2 tons it's the mid-size model (forget the name).
I dug this up from my files. This is my 6BT, 5 speed. HP to the rear tires on a chassis dyno. This is a 4th gear pull. 1:1 with a 3.55 rear gear. Starting at 50 mph going full throttle to redline (mine was set with a limited at 3200) with a load similar to road conditions simulated by the dyno.

120 mph in 4th gear at redline.

357FABE9-2CBF-4E8B-85E0-A6AD6C27B453.jpeg


360148E3-E837-4863-9155-9A7E3DF0B689.jpeg
 
It also heavily depends on the year of 4BT or 6B that you use. the mid 90s to late 90s one were notoriously loud. the ones from 89-93 werent near as loud. and then the 03s and newer when the switch to the common rail injection system quieted them down a ton. You can swap from the electronic CP3 pump to the 12v mechanical P7100 pump or even the A pump for the 4Bt. Course that'll add substantial cost but would give you the mechanical injection system without the noise of the early and mid 90s cummins.

I've also found that sound deadening really does help a ton as well. Also, most people when they are swapping in these things, are welding up solid mounts, often because the factory cummins mounts are HUGE. about a 6 inch diameter rubber mount, and then probably another 6-8 inches for the bracket.. Dodge and Nissan as well as the box trucks and such are designed for that extra width and height. But non designed cummins vehicles don't have that room in MOST cases. It is also one of the reasons why Ford declined the 6B, too wide and too long and they didnt want to change the frames or engine bays to accommodate it. But without that mount, its gonna shake the crap out of you

Wow cool, I guess it's kind of obvious when I think about it now but Cummins did the same upgrades over the years to the 4bt as the 6bt? I know the 6bt's made after about 2010-ish are almost totally silent I'd love that in an old cruiser.

How are the earliest ones quieter than the mid-90s ones though? Different injectors?

Also no way in hell I'd solid- mount a diesel in anything lol that's just punishing yourself and the chassis of your vehicle. My Duster has a solid mount on the driver side and even the gas 360 in that transmits quite a lot of vibrations through the car.
 
Wow cool, I guess it's kind of obvious when I think about it now but Cummins did the same upgrades over the years to the 4bt as the 6bt? I know the 6bt's made after about 2010-ish are almost totally silent I'd love that in an old cruiser.

How are the earliest ones quieter than the mid-90s ones though? Different injectors?

Also no way in hell I'd solid- mount a diesel in anything lol that's just punishing yourself and the chassis of your vehicle. My Duster has a solid mount on the driver side and even the gas 360 in that transmits quite a lot of vibrations through the car.
Usually the 4B was a year or so behind the 6Bs but not always. A lot depended on emissions requirements and the application.

So in order to understand why things got quieter, you gotta understand how the diesels worked. Both the VE injection pump of the 89-93 & the P7100 pump of the 94-98.5 were mechanical. The VE pumps injected fuel at a lower PSI where as the p7100 hit it with a LOT MORE. Diesel fuel regardless of the pump is injected at several tens of thousands of psi. The higher the injection psi, the bigger and hotter the boom. Which then adds to the noise. The 89-93s are much much quieter than the 94-98.5.
Then in 98, roughly half way they the model year, the epa requirements forced the introduction of the 24 valve using the VP44 injection pump. This pump tried to combine timing, volume and PSI. This made things even louder as now you had twice the lifter hits and just as cam over lap affects sound and lope of a V8 gasser, those three things inside the pump made things lope and do so loudly. One thing people run into when turning up a VP44 is if you go too far with timing or volume, you can get a shuttering effect on the fuel. Not a good thing.

in 2003, Cummins switched to the CP3 pump, which supplied a single rail injection system at a constant And consistent injection psi. That’s all it did. The injectors were then controlled directly by the ecm. Which controlled the pulse and timing, this adjusting the volume and timing at the cylinder instead of an injection pump. This greatly eliminates psi variations and quieted the injectors and the subsequent ignition down. They also changed out lifters and upgraded valve springs and added valve spring dampeners. All those things resulted in the quietness compared to the 90s Cummins.

If one does swap to the mechanical p7100 pump in a 03+, the noise level will increase, but it will be somewhere between that of the first gen Cummins and the common rail Cummins and no where near as loud as the VP44 era engines
 
Usually the 4B was a year or so behind the 6Bs but not always. A lot depended on emissions requirements and the application.

So in order to understand why things got quieter, you gotta understand how the diesels worked. Both the VE injection pump of the 89-93 & the P7100 pump of the 94-98.5 were mechanical. The VE pumps injected fuel at a lower PSI where as the p7100 hit it with a LOT MORE. Diesel fuel regardless of the pump is injected at several tens of thousands of psi. The higher the injection psi, the bigger and hotter the boom. Which then adds to the noise. The 89-93s are much much quieter than the 94-98.5.
Then in 98, roughly half way they the model year, the epa requirements forced the introduction of the 24 valve using the VP44 injection pump. This pump tried to combine timing, volume and PSI. This made things even louder as now you had twice the lifter hits and just as cam over lap affects sound and lope of a V8 gasser, those three things inside the pump made things lope and do so loudly. One thing people run into when turning up a VP44 is if you go too far with timing or volume, you can get a shuttering effect on the fuel. Not a good thing.

in 2003, Cummins switched to the CP3 pump, which supplied a single rail injection system at a constant And consistent injection psi. That’s all it did. The injectors were then controlled directly by the ecm. Which controlled the pulse and timing, this adjusting the volume and timing at the cylinder instead of an injection pump. This greatly eliminates psi variations and quieted the injectors and the subsequent ignition down. They also changed out lifters and upgraded valve springs and added valve spring dampeners. All those things resulted in the quietness compared to the 90s Cummins.

If one does swap to the mechanical p7100 pump in a 03+, the noise level will increase, but it will be somewhere between that of the first gen Cummins and the common rail Cummins and no where near as loud as the VP44 era engines

Very nice thanks for breaking that down! 4BT New Yorker is now on my radar lol
 
So a couple things that come to mind here.

You can hear a V8 in a performance street car. Are we looking for a quiet engine that makes big power? I can say my 24V's are quieter than my 440 with full exhaust.

The early Mercedes were hot boxed (no intercooler). There are places with them to make more power besides simply adding boost pressure. Fuel, larger turbo, intercooler, exhaust, intake, timing are some of those. (HX40 chargers, intercooler, replace head bolts with studs and 8mm fuel components)
 
So a couple things that come to mind here.

You can hear a V8 in a performance street car. Are we looking for a quiet engine that makes big power? I can say my 24V's are quieter than my 440 with full exhaust.

The early Mercedes were hot boxed (no intercooler). There are places with them to make more power besides simply adding boost pressure. Fuel, larger turbo, intercooler, exhaust, intake, timing are some of those. (HX40 chargers, intercooler, replace head bolts with studs and 8mm fuel components)
There is a difference between a "noisy" diesel and a loud hotrod

My 408 sounds a WHOLE lot better at idle them my 6.0 diesel
 
So a couple things that come to mind here.

You can hear a V8 in a performance street car. Are we looking for a quiet engine that makes big power? I can say my 24V's are quieter than my 440 with full exhaust.

The early Mercedes were hot boxed (no intercooler). There are places with them to make more power besides simply adding boost pressure. Fuel, larger turbo, intercooler, exhaust, intake, timing are some of those. (HX40 chargers, intercooler, replace head bolts with studs and 8mm fuel components)

This would be for a C-body cruiser not a performance build. If I kept it gas I'd put quiet mufflers on it. I have my Duster for going fast and making racy V8 noises. And yeah diesel noises are completely different than loud gas engine noises, and all you need to quiet down a loud gas engine is mufflers. Diesels make noise from the engine itself.

I know the Mercedes can be built up but one thing that turns me off is that most internal engine components are INSANELY expensive. Like a set of stock replacement pistons for an OM617 are around $1500... I know those engines run forever for the most part but if I'm going to crank it up to 250-300 HP I don't want to be screwed if something does break. The 4BT is attractive because it's super plentiful, and not European lol.

I'm still considering both options though.
 
I'd rather see an LS swapped in before a diesel

I think you're in the minority with that opinion LOL... not saying I have some kind of issue with it but I personally would rather see a Toyota 2JZ or a hamster wheel swapped in before an LS lmao

I've been convinced of the benefits of diesel engines from working on and driving my brother's TDI Passat. The combination of power and fuel economy is simply impossible to achieve with a gas engine; that thing has 247 lb-ft at 1800 RPM from a 2.0L 4-banger (stock, also I think 140 HP?) and gets up to 45 MPG on the highway, with a conventional auto trans to boot. It's also at 225k miles and runs like new (the engine, the rest of the car has been slowly starting to fall apart the past couple years lol).

With JUST a tune, no actual upgraded hardware, you can easily get an extra 30 HP and 70 lb-ft from those TDIs. Can't really do that with an N/A gas engine.
 
Last edited:
I've been convinced of the benefits of diesel engines from working on and driving my brother's TDI Passat. The combination of power and fuel economy is simply impossible to achieve with a gas engine; that thing has 247 lb-ft at 1800 RPM from a 2.0L 4-banger (stock, also I think 140 HP?) and gets up to 45 MPG on the highway, with a conventional auto trans to boot. It's also at 225k miles and runs like new (the engine, the rest of the car has been slowly starting to fall apart the past couple years lol).

With JUST a tune, no actual upgraded hardware, you can easily get an extra 30 HP and 70 lb-ft from those TDIs. Can't really do that with an N/A gas engine.
Yeah, but compare that to VWs 1.8T and that diesel falls flat on its face

(I had one in a 03 passat, I think, that car was pushing 18 PSI and a BLAST to drive)
 
Yeah, but compare that to VWs 1.8T and that diesel falls flat on its face

(I had one in a 03 passat, I think, that car was pushing 18 PSI and a BLAST to drive)

Oh the 1.8T is great but tuned up for extra power there's no way it'll get 45 MPG on the highway or make 300+ lb-ft of torque at 1800 RPM. I also don't think they're known for lasting 300k miles plus like the TDIs.

The subject here isn't max power anyway; again I want to build something with a focus on economy and just plain coolness factor. I don't see a need for more than 300-350 HP in a C-body that I want to travel the country with especially when there's 500+ lb-ft of torque to go with it. I've always had a dream of road tripping around the continent with a classic Mopar but the big-V8 gas mileage was always a turnoff; yes a modern G3 Hemi with EFI would do much better but still even so I just... want a frickin diesel lol I love them and think they're super cool.
 
Yeah, I think my wife managed to get 35mpg out of the 1.8T
I never could stay out of boost long enough to break 25mpg

I'm not sure I would consider a diesel engine cool (I always considered them a farm emplement) but I ain't funding this project either

So, if you want to do it, I do think the VW diesels would make a good candidate, both with availability, dependability and aftermarket support
 
I've never seen one, but I think the new Datsun/Nissan pickups have a V-8 Cummins in them which is lighter than their straight sixes that they put in Dodges.
 
I personally like the sound of a diesel. A cammed and tuned diesel...mmmm But to each their own. The V8 diesel with an open exhaust whistle like a rocket ship.

I also like the sound of a good running 8, a straight 6, etc.

Never heard an inline 4 I liked though.... (except street bikes)
 
-
Back
Top