Best diesel setup

[hogrocket]

I was just reading the thread on gas mileage improvements and I started thinking about diesel conversions--again. Just wandering what the concensus would be for the best diesel engine /transmission/gearing swap(and out of what) for our trucks. Keeping in mind something that would give good gas mileage (hopefully around 20mpg or better) and able to be a decent tow rig--say able to tow up to 10000 lbs with little difficulty. Anybody up for the challenge?

[Longhorn Man]

If this is mainly for MPG, then you'll never see the profits. You'll spend 5 grand easy in doing this... that'll buy a whole lot of premium unleaded.

[krue]

Well, let me be the first to say....
"Let's get ready to rumble!!" This question usually starts a heated discussion, seems like people are passionate about their diesels.
Here's a link to the results of a search for diesel
http://67-72chevytrucks.com/vboard/s...earchid=232333

[Boog]

Hmm. Link not working for me.

[hogrocket]

Boog--way to step up to the challenge. M

[72freak]

Yep.......these diesel questions get all sorts bent out of shape!!!!!!
Longhorn is dead on it...Diesel is NOT cheaper in the long run....it all works out to be about the same. I currently own 20+ running,driving and working vehicles and have had 100's in the past. The only time a diesel saves me money is if its on a work vehicle with a GVW of over 10k and is used for heavy lifting, moving or hauling. A good rule of thum I have found is this.....If you are not loaded/hauling or have a trailer on the back of your vehicle for 75% of the time...it is NO cheaper to have a diesel.
Now...with that said...yes....diesels can be fun, there loud, billow cool smoke and you can do lots with them...My next project is will be a 72 Dually with custom bed and a 12 valve Cummins and 6 speed.

As far as preference...mine is the 12 valve Cummins

If you want good diesel info go to the TDR..Turbo Diesel Registry site. Most of those guys are diesel freaks!!!!

Have fun with all the OPINIONS you wil get from this post...remeber thats all any of this is.....opinions.

[glock35ipsc]

Remember when diesel use to be waaaay cheaper that gasoline??

[motocrosschump]

Supply and Demand

[TP from Cntl PA]

Diesel will pay in the long run.................BEEN THERE

I am going to use a 2 stroke Detroit in my K-20 WHEN I do my next conversion. I haven't been able to find the right 4-53 or 4-71 at the right price yet and that is the only hold up. They are very noisy, but are tough as nails, run cheap, and you can put the real Jake Brake on them and that is worth its weight in gold if you ask me. I drove a few Jimmy powered trucks growing up and I like them.............Slam your hand in the door jam and drive them ticked off all day and they'll hike a load over the road in short order. I am going to tweak mine and add rpms, 92 series injectors and some other mod's............She'll be a screamer no doubt.

A 6BT(AKA 5.9) is a great engine to use as well, a 4BT(4 cylinder version of the 6bt) would work possibly if you geared it right for what your gonna be doing with the vehicle.

I'd like to try using a 354 Perkins(It has been done by a few), DT-414 International..........They make awesome torque and are plentiful and parts are cheap, a Deere 404.............And if it was possible a 466 Deere would be awesome.

I got a 6AT3.4 Cummins in one of mine............For only being a whimp(Small compared to a 5.9) it blew the doors of the 454 I had in one of my other ones on the hills here in PA...........I like diesel for these main reasons.
-Longevity, they'll go FOREVER between OH's.........Unlike a V-8 gasser which doesn't get anywhere close
-Simplicity, face it, not to much to go wrong on a mechanically injected diesel
-Fuel Economy.........Yeah it is better, although price differences is making that less of a factor.
-A biggie for me.........Its different from 97.7% of everyone else
-Another big one for me.............Torque on the low end out the rear, unlike a gasser, you can pull a good diesel down and it'll take ALOT before it gives up.

About the only thing I don't like is running one in the cold of winter........Gelling fuel and getting one running can be a bear when it is COLD out. Fuel conditioner and block heaters(Or tank heaters) can make these problems relatively small.

Whether it is for you or not you'll have to decide. I don't even have my '71 Completed 100% yet and it has paid for itself...........Other than driveline reliablity I am very happy with it, I plain on swapping in a HD ZF-6spd with an oil cooler along with a heavier driveling to end that headache.

I kept my expenses small with my conversion, I saved alot by using a stock GM transmission/driveline that held up behind anything GM made............Don't make the same mistake I did, they DON'T behind a real diesel. Ok, ok, they might if you didn't load the heck out of the truck, and let the engine peak out on the torque curve something has to give..........

[special-K]

If you buy a new truck with a diesel,the money you save on fuel will pay you back for 1/2 the truck.

[hogrocket]

hey Tp from Cntl PA--great info. I agree that the little or no difference in the two fuels has pretty much ended that argument. However, the longevity and toughness of a diesel is what intriques me. The biofuel setups you see on-line (using cooking oil, etc in the diesel) are also interesting if one has the time and energy to put something like that together.

I know a conversion would be expensive if your buying individual parts from different sources, but what about using the whole setup out of some of these older cars and or trucks (pre-computor age). Of couse you still have a lot of fabrication. I know there was a lot of foreign cars (like volvo) with diesels too. Would these type engines be too small for a working truck?

[cell]

My vote would be the Cummins 4BT. This is the 4 cylinder version of what is currently in the Dodge Rams.

Cummins did a repower project with a lot of companies who used the GM P30 "step" vans (the big box vans), and replaced the gasoline engines they originally had with 4BT's. Many of these vans are reaching retirement age, and are being auctioned off. If you are interested, hit up dovebid.com and search for "4BT". They have an auction about once per month. Be sure to look for the chevy vans only, as they come with the right bell housing adapter and motor mounts.

There is also a forum on tdr1.com for cummins conversions, as well as prirate4x4.com, and the 4BT is very popular among that crowd (although they are mostly putting them in old jeeps). People on those forums claim fuel economy around 25 MPG, but that's with 33" off road tires and short gears. With the right tires and gears, you should get near 30 (a late model Ford F150 with a 4BT claimed 30mpg).

as far as transmission, I would say nv4500 or maybe the tremec tko-500.

[TP from Cntl PA]

Originally Posted by cell

People on those forums claim fuel economy around 25 MPG, but that's with 33" off road tires and short gears. With the right tires and gears, you should get near 30 (a late model Ford F150 with a 4BT claimed 30mpg).

Or maybe even a tad better.................I wise I had mine on a free way for a few hours to compare, but just running our state and township roads, and farm lanes around here we got almost unbelieveable numbers with mine..........I will only say that 5 gals will last a LONG time. We were running it and I thought the sending unit in the tank took a dump, tore the seats out and checked it..............It worked, drove it more and it did move, but alot slower than even I expected.

Key to a diesel is alot of gears.........I got a good setup, but it doesn't hold up to the Cummins, I am thinking the 6spd and a splitter from either AA, GV, or a Brownie will do the job and hold up.

[Karl Hoh]

My daily driver is an 89 5.9& 5spd. Been abused by 2 po's and myself. Got over 350K miles on it, NEVER been opened. Used to haul 16,000lbs. combined gvw. Torn up the oem 3.54 gear. Now have a posi & 3.31's does about 25/ gal. Just wish it was 4x4. This drive line will find its way into my C20 when I convert it to C30. Run it without a muffler, I get the same looks from people now as I used to with my Harley. Yes, you can tweak a gaser to get this mileage, but you'll never have this kind of power. Torque is king.

[special-K]

I agree with cell.If you`re not going the easiest route by tossing a GM 6.2 in,then a 4BT is a cheap and simple swap.The idea is,if you have to spend thousands then it won`t pay,not in an old truck.The 4BTs were installed in box vans(StepVan-style)and many were on GM chassis mounted to GM transmissions.They don`t pump the big horses,like just over 100,but can be tweeked (turn-up I/P) to around 150 real easy.Beyond that,I`m not sure.Although,they are the 6BT w/2cyls lopped-off.So,maybe other mods for the 6 can be adapted.Gettih`back into the money again,though.For around 6 grand a 6.2 can be built to put out right about 200 reliable non-turbo horses.That price includes a complete rebuild,of course.The 6.5TDs are rated @ 195 stock.I have a friend with an`82 shortbed with the 6.2 I`m talking about.

[TP from Cntl PA]

Originally Posted by special-K

For around 6 grand a 6.2 can be built to put out right about 200 reliable non-turbo horses.That price includes a complete rebuild,of course.The 6.5TDs are rated @ 195 stock.I have a friend with an`82 shortbed with the 6.2 I`m talking about.

For $6k I could buy a truck and put a 5.9 in it...............I have less than that in mine, although I'll be close to that figure IF I put a HD ZF-6 spd in it because they aren't cheap to purchase. That includes price of the truck, engine, driveline and all misc stuff which includes seats, brake booster, radiator, and other minor parts.

Granted, all I ever did at GM's Diesels was cuss, but can you even get decent mileage numbers with them? If they get the MPG that my buddies get with their Powerstrokes, I don't think I'd be overly excited to even bolt one in a long weekend.

[Daubs]

Originally Posted by special-K

If you buy a new truck with a diesel,the money you save on fuel will pay you back for 1/2 the truck.

Hmmm, I disagree. When I was researching a new truck in 04 I calculated miles I traveled in a year / cost of diesel fuel vs. gas / cost of Duramax vs. Big Block vs. 6.0 / estimated MPG of all three.

Yes, Duramax would save me $$ on fuel, but not that much. I would have to drive the diesel for 6-7 years before savings on fuel would offset the initial cost of getting the Duramax. You can buy a lot of gas with ~$5,500

For me, it just wasn't worth it.

[special-K]

What`s the going price for a used 6BT?I didn`t think they were that cheap.The $6,000 is for a custom motor r&r and labor.Let`s not forget to figure labor in.This isn`t a used junkyard motor and a standard rebuild would be less than 1/2.I`m talking about a finely-built no expense spared motor.As far as mileage,I get 22 mpg in a 3/4t 4wd Suburban w/12.50/35x16 mud tires.The same vehicle with a 350 would be stretching it to get 1/2 that,with stock tires.
How much extra was that 8.1/Allison?What`s your mpg,if you don`t mind me asking?Besides,I was refering to the overall price of a truck.That $5,500 is at least money towards economy.What other options do anything but cost you?I drive about 25,000 miles a year.At 10 mpg and $3.00 per gallon that`s $7,500 per year.At 15 mpg,that`s about $5,100.Take five years to pay for truck,that`s $11,000 saved and you`ll have 125,000 miles on the truck.Use the truck for 10 years,that`s $22,000 you`ve saved on fuel and you`ll have 250,000 miles on the truck,which is not uncommon at all.In fact,let`s go another 5 years@ $11,000 and you`ve saved $33,000 in fuel.
I`m not negating other motors,it`s all good.I`m also not telling anyone what to do.Just presenting info.I don`t need to put anything down to justify my choices.I know lots of guys that have swapped to Cummins motors.You`ll never get the power that can be had with a 6BT from a Detroit-Allison.But,it all costs money and does require a good bit of work.It`s just a matter of time before Dodges are powered by Mercedes diesels.There will be an abundance of used Cummins6s in the future for all of us.

[409biscayne]

Don't flame me , for the past 10 years all my daily drivers have been Dodge / Cummins so you know where i'm heading . You probably don't want an extra truck hanging around but here in town i see 1990 -91 Ram regular cab 3/4 ton pickups for sale asking $4500 . So ya offer them $3500 , good to go . The key is there 2wd . Nobody buys 2wd , lol . Keeps 'em cheap. Heck you get the Cummins , auto , a/c , just keep the 67 - 72 as some what of a toy . Just my .02 .

[72freak]

Originally Posted by Daubs

Hmmm, I disagree. When I was researching a new truck in 04 I calculated miles I traveled in a year / cost of diesel fuel vs. gas / cost of Duramax vs. Big Block vs. 6.0 / estimated MPG of all three.

Yes, Duramax would save me $$ on fuel, but not that much. I would have to drive the diesel for 6-7 years before savings on fuel would offset the initial cost of getting the Duramax. You can buy a lot of gas with ~$5,500

For me, it just wasn't worth it.

I agree.......unless you are going to keep the vehicle and drive it for 300,000 miles and use it for hauling for most of those 300k.......It wont be any cheaper. It takes a long time to re-coup that (NEWER) diesel engine additional cost. Plus diesel fuel is around here is 10-12% higher than gas.
But agian...they diesels can be fun and the longevity of them is longer.

[TP from Cntl PA]

Originally Posted by special-K

What`s the going price for a used 6BT?I didn`t think they were that cheap.The $6,000 is for a custom motor r&r and labor.Let`s not forget to figure labor in.This isn`t a used junkyard motor and a standard rebuild would be less than 1/2.I`m talking about a finely-built no expense spared motor.As far as mileage,I get 22 mpg in a 3/4t 4wd Suburban w/12.50/35x16 mud tires.

6BT's aren't expensive if you know where to look But they got hundreds of thousands of miles on them..............Other than maybe rolling in bearings, they don't need much. I'd still take a 12V with 350K on it over a new 6.2 or 6.5 GM..........

[72freak]

Originally Posted by TP from Cntl PA

6BT's aren't expensive if you know where to look But they got hundreds of thousands of miles on them..............Other than maybe rolling in bearings, they don't need much. I'd still take a 12V with 350K on it over a new 6.2 or 6.5 GM..........

Amen to that!!!!!!!!!!!!!

[special-K]

No doubt the Cummins in-line diesels are the "best" motor out there for light trucks.I`d like to know your secret on how to get them cheap
In my area diesel is not more expensive.And,I do buy diesels to run at least 300,000 miles and haul,that`s what they`re made for,right?Anything else is "p"-ing into the wind.Like I said,I don`t single out the cost of the diesel option,I figure the total cost of the vehicle.We pay for 5-6 thousand dollars for comfort and convenience items and for an automatic that drops mileage.The total cost of trucks is ridiculous.So,to me,what I pay extra for that diesel motor option every month is insignificant compared to what I save in fuel.I`d still like to know how much extra that guzzler 8.1 cost to attempt to have the pulling power of the DuraMax.
I`m not getting offended or trying to offend.It`s hard to show feelings in print.I assure you,There`s no "ruffle" in my feathers.This is truck discussion and nothing more.I guess it`s like statistics,you can focus on any one aspect to bring out the desired result.This is just the way I figure my savings on fuel vs cost of truck,total cost.I went from driving 67/72 trucks to diesels for work and the money I saved on fuel every month was equal to my payment.That`s another way I figure it.

[ChevLoRay]

My part-time driver has a Cummins 5.9/Allison 5-speed automatic. It gets around 6-7MPG.....hauling school kids!!

Back when I was driving a Gamma Goat (USArmy amphibious vehicle!?!), I wanted to get hold of a 3-53 Detroit and an SM-465 to replace the tired 283 in my '65 C-10. I loved the sound of that engine in the 'goat, even though we were required to wear hearing protection to drive one of 'em.

What I miss, though, is my low-mile (140K) '82 'Yota LWB Diesel....30-40MPG...no problemo.

[TP from Cntl PA]

Originally Posted by special-K

No doubt the Cummins in-line diesels are the "best" motor out there for light trucks.I`d like to know your secret on how to get them cheap.

Ummm, all I can say is find the right scrap yard.............I can get them cheap because that are SUPPOSED to be scrapped with the vehicle, but usually they cut the front end off(Right infront of the drivers seat) while they are shearing up the vehicle with a trackhoe and they remove the engine.............If it is a GM powered one they cut the whole thing up, but any with a Cummins they save the power plant.

ChevLoray, Eventually that is what I am going to put in my K-20.........4-53 Detroit I was going to buy a 5.9 and stuff it in there, but until I got done farting around moving half the drivetrain around, and getting the engine bought, I'd be farther ahead buying a pre-'93 Dodge like I always wanted and not have to put alot of hours in working one it. I want one with a Detroit..........Always have, I really like them. Not to mention the sound, but a real jacobs engine brake from a 6-71 can be bolted on them and since I am going to pull a trailer alot with it, that will be really appreciated! Not to mention coming to a light in town with the engine just cackling without a load on