has anyone ever researched a detroit 8v-71 swap?

[Lothar]

I'm thinking about buying a new trailer (a big heavy one) and a change of career may allow me to spend lots of time pulling on the open road. I love my truck but dont think my 6.2 will pull a 40ft triple slide toy hauler with all my tools and toys all over this country. So just for fun i've been thinking about swapping for a detroit 8v-71 (2 stroke supercharged) which produces a little over 800 ftlbs of torque. has anyone else ever thought of such a thing or done it?

[NH2112]

Eeek! Considering the weight of the 8V71 I think you'd get a lot more power for less weight by going Cummins, Cat, or maybe Navistar. The Cummins will probably get you the most for the least (money, weight, trouble, etc.)

[CleviteKid]

8V-71T, weight = 2,496 pounds.

I think you would need a second FRONT axle :eek: .

Dr. Lee :cool:

[dieseldummy]

If you want to go the Detroit root, which I think would be cool, I think that a 6V-71 would be more suited. It would be short enought to fit in the alloted space a lot better, and wouldn't weight nearly as much. I think with a turbo added to the supercharger you could fairly easily get 300 hp out of it as well. Good luck if you decide to go this root.
Justin

[CleviteKid]

6V-71T weight = 2080 Lbs.

6V-92T weight = 2005 Lbs.
(bigger holes for bigger pistons)
So in this dream lets use the more powerful 6V-92T, with ratings up to 550 horsepower.


Now we are down to less than three times the weight of a 6.2L diesel. Maybe just dualies on a single front axle :confused:

Dr. Lee :cool:

[dieselhumvee]

What about the 6v53T with aluminum block? like the ones this guy drag races www.teamdiesel.com? (http://www.teamdiesel.com?) Does anyone know how much they weigh? twin turbocharged, supercharged, 2 stroke diesel would be great in my hummer

[Diesel Dan]

I seen a old '77 or so 1 ton crewcab chevy with a 6V-53 in it. Took up alot of space under the hood. It was a 4wd model with one heck of a stack of leaf springs. I would recommend upgrading to a dana 70 front for the heavier GFAWR. It ran some sort of a clark 5speed and divored case I believe.

I have a spare 12V cummins if your are really looking into a swap. Setup for a NV4500, has the P7100 pump.

[Diesel Dan]

dieselhumvee,

Gotcha beat on the gearing.
My unimog has a top speed of about 37mph at 3500rpm. Tires are 37+" with either 8.2 or 8.8:1 axles :eek: . Definitely no room for anything much bigger than its 4cyl mercedes diesel.

[dieseldummy]

Is the pickup a 2 or 4 wheel drive? If it is a two wheeler, then the front axle situation can be taken care of by scavenging one off of an older farm truck. They were generally rated high enough to support the weight of this motor, plus the weight of the trailer. If it is 4x4 it is still possible to get an axle from a 4x4 fire truck type application. I have seen several old 1600 International 4x4's with big diesels in them I'm sure with enough ingenuity it can be done. While your at it make the hood and fenders fold forward all as one piece, just like a truck...
Justin

[a5150nut]

Back in th 70's there was a couple guys out of Bakerfield Ca. that used 1 ton Internationals and used 4/53 Detroits out of reafer rail cars. They would climb a telephone pole if you could get traction! 22mpg with a stick an 18mpg with an Allison. Empty or loaded, didn't make much differance.....

[NH2112]

Rockwell 2 1/2-ton truck axles can be had pretty cheaply from www.boyceequipment.com. (http://www.boyceequipment.com.) These are top-loaders with 6.17:1 gear ratios. These will definitely hold up to the weight of a Detroit if you don't mind the closed-knuckle setup and a limited selection of wheels, and I think Boyce sells disc brake kits as well. I believe stock tire size is 9.00-20 for dual rear tires, or 11.00-20 "super singles" but you'd need tall tires for that gearing anyway. IMO the best thing about a Detroit swap is that ultra-cool Detroit sound! I love heading out in the woods here and hearing those old skidders just growling their way along the logging roads.

[Diesel Dan]

The truck I saw with the 6v-53 had the stock dana 60 in it. It had been converted by a farmer many years ago. The front held the weight of the motor, don't know what it had left for cargo capacity however. Definitely would not want to put a plow on it without an axle upgrade. This is where a Dana70 would help, basically a bolt-in swap, lots of gear ratios available. The axle shafts are about the same strength as a D60 but the housing is much stronger.

[Craig M]

Have seen some 4-53 in our trucks but since you are looking for power the 4-71T would be a good compromise for weight and power. This has 71 cubic inches per cylinder and the turbo. The V6's would probably fit in there, have not seen that done though (again a 6V-71T would have max power, but now you are getting heavy). Local guy with a F250 put an 6-71, inline 6 cylinder in his ride. Got the engine cheap so decided to install it. Had to severly modify the firewall to get it in. Had to use electric fans on the radiator also. Had that nice Detroit 2 stroke sound. Could hear him coming from a block away.

[JeepSJ]

I saw a Ford dually with a Cummins 8BT. The engine was a little long, but he got it in. Had it tweaked to put out about 1200ft/lbs (or so he claimed). That wouldn't sound as cool as a 2 stroke Detroit though.

EDIT: Oops, that should have been a 6C series 8.3.

[ 04-14-2004, 01:00 PM: Message edited by: JeepSJ ]

[Craig M]

A couple of people have put the Cat 3208 and 3208T into the GM trucks. They have similar torque to what you are talking about. Reasonable mileage and great torque. A bit of fabrication work to get them into the truck, but a doable project. Can go with an Allison transmission if you like automatics, or various manual transmissions if you like choosing your gear.

[CleviteKid]

CAT 3208TA, 425 horsepower ( GOOD :D )
2080 pounds ( bulky :mad: )


Dr. Lee :cool:

[britannic]

Cummins 5.9L (with mods) or 8.3 I6 with the P7100 inline pump: 400HP/850tq plus, only 1000-1200lbs in weight - yummy :D .

[CleviteKid]

Hey Brit,

Did I do a good job setting this up for you, or what? OF COURSE the 6 cylinder B engine is an obvious choice.

I see your signature has changed to show the Cummins and the CUCV together now - does this mean you have the new engine bolted in place, and if so, is it running, and if so, does it exceed your expectations :D ?

Dr. Lee :cool:

[britannic]

No, the 5.9L and NV4500 are currently sitting by the side of the M1028 as I prep the engine bay and upgrade the Cummins fuel system for more power. I'm just waiting on the South Bend 1200ft/lb clutch, inj. pump delivery valves and #10 torque plate.

I have the engine mounts ready to go, they bolt up to the existing Chevy mount pads on the frame and use the 1st gen. Dodge isolators. I just need to cut a 1/8 moon into the front cross member and cut the intercooler ports out of the core support and I can drop the engine in.

I'll take pictures for posterity before everything goes in.

[Polar Diesel]

I have an oliver tractor model 1950, with the 4-53 detroit. I wouldn't recommend this engine for the long haul. the screaming will drive you crazy. also there is no low end torque. maybe turbo models are better, but you get to a certain rpm and it just drops.

[Lothar]

Sounds like everyone thinks it would be cool to go the detroit 2 stroke way, but not likley possible?? Well i think the inline 6 cyl's might be too long, and in either case i would probably have to remove the entire front body work and refabricate it to make it fit. Its a 2 wheel drive truck so i will be adding a new front axle. Dana 70 the best route?? i am looking for some high gearing like 3.73 or higher for highway cruising. I just think that for the long haul on the highway at 75-80 mph pulling a 41 foot 20,000 pound plus trailer on some 2000 mile or longer trip every month of the year i'm better off looking into doing a detroit or cat mod. (I'd rather avoid the cummins) and GM owns Detroit right? (or at least used to) getting something like the 8v-71 (not the Turbo version, much bigger because of the turbo location) which produces 350 hp or so and 817 torque STOCK is a good route..add propane and other goodies and who knows.. Putting in a heavily modified 5.9 cummins to get the same power as a stock detroit seemes to me to not be as dependable of a choice. the other option is i remember reading an article here on the dieselpage about a rebuilt 300+hp 6.2 from the diesel depot (non turbo) I like the V8, the 2 stroke is cool, and i need serious towing power..i have no problems putting in a new front axel (I was going to do a custom 5 link air bag suspension on the front and a 3 link airbag on the rear to carry the weight) But is the power to weight ratio going to be a negative versus a smaller lighter but not as powerfull motor?

[Craig M]

If one is to go the 2 stroke route, and that is a fun route, I still think the V-8 is to big. The 6V-92T Can give you similar power and in a smaller easier to install package. 6V-71 or 6V-71T is also not a bad choice. Weights are similar, the 6V-92T will give max power.

[NH2112]

The biggest problem with Detroit 2-strokes is they run best when set right to the redline and held there. They don't take very kindly to the up and down, up and down use they'll see while driving on the road. Ask any army motor sergeant about the 6V53s in M113-series armored personnel carriers - the standing joke is you get 1500 hours out of the engine, and no more. It's not very far from the truth, either! The 8V92Ts in the 10-ton HEMTT trucks don't have much better of a record. If you blow that Detroit, you'll be looking at about $1000/hole to rebuild it, plus experienced Detroit techs are getting harder and harder to find nowadays. There's a reason Detroit stopped making 2-strokes, and that's because they just couldn't compete any longer - and haven't been able to since the late 60s or so. You can get just as much power for a lot less money and a lot less weight out of a dime-a-dozen 5.9L Cummins. I'm sure Britannic can rattle off some actual figures, but there are guys on the TurboDiesel Register site who are reliably making over 500HP in their daily drivers, and that's from an engine that has only about 60% the displacement of an 8V71.

Performance-wise, I think you'd be disappointed with the Detroit, and that the Cummins, a DT466, an eBay/salvage yard Duramax, or even an Isuzu 6BD like a DP member put in his truck, would be a much better choice in the long run.

[britannic]

Although the Cummins is long, it'll fit in the engine compartment with only minor adjustments:

Remove enough of top of the front crossmember (has the brake lines mounted to it) to clear the Cummins' harmonic balancer. The other modification is fitting the intercooler, but some choose to rework the actual 2nd gen. Dodge i/c and rotate and reweld the inlet and outlet so that the original Chevy diesel radiator will fit between them.

The seam that projects downward at the firewall end of the transmission tunnel will require several sawcuts and then hammer it back to give a bit more clearance (unless you have a 1" plus body lift).

It all depends on time, money and the will to do it.

A Dmax would be equally sweet, albeit costly, but More Power is leading the way and you can read all about over in The Duramax Diesel Power Project (http://forum.thedieselpage.com/ubb/ultimatebb.php?ubb=forum;f=11).


Originally posted by Lothar:
Sounds like everyone thinks it would be cool to go the detroit 2 stroke way, but not likley possible?? Well i think the inline 6 cyl's might be too long, and in either case i would probably have to remove the entire front body work and refabricate it to make it fit. Its a 2 wheel drive truck so i will be adding a new front axle. Dana 70 the best route?? i am looking for some high gearing like 3.73 or higher for highway cruising. I just think that for the long haul on the highway at 75-80 mph pulling a 41 foot 20,000 pound plus trailer on some 2000 mile or longer trip every month of the year i'm better off looking into doing a detroit or cat mod. (I'd rather avoid the cummins) and GM owns Detroit right? (or at least used to) getting something like the 8v-71 (not the Turbo version, much bigger because of the turbo location) which produces 350 hp or so and 817 torque STOCK is a good route..add propane and other goodies and who knows.. Putting in a heavily modified 5.9 cummins to get the same power as a stock detroit seemes to me to not be as dependable of a choice. the other option is i remember reading an article here on the dieselpage about a rebuilt 300+hp 6.2 from the diesel depot (non turbo) I like the V8, the 2 stroke is cool, and i need serious towing power..i have no problems putting in a new front axel (I was going to do a custom 5 link air bag suspension on the front and a 3 link airbag on the rear to carry the weight) But is the power to weight ratio going to be a negative versus a smaller lighter but not as powerfull motor?

[Craig M]

I do not have the bad experiences that NH2112 refers to. Never in the Military. Have been around trucking and construction. Lots of busses, trucks and cranes have run with the Detroit 2 strokes. While they have the reputation as being oil burners (rightly deserved), they seem to last fine in trucks and busses when properly cared for. Still lots of mechanics around that have worked on them. To me one of the best things is they can be had for pretty cheap. Used motors for $400 to $1500 all over the place. While the Duramax and Cummins are definitely nice engines, $5000 to $8000 is a lot of dough. I have seen over a dozen of these 2 stroke conversions into small pickups. The 2 strokes have good torque and can make a good hauler. You have to be prepared to do the fabrication to make it right, but all that I have talked to after tha fact have been happy.

[britannic]

Depending on the mileage you can get a decent Cummins 6BT for $1800-3500, $5000+ for new surplus. The wet weight is 970lbs and like the GM engines, parts are plentiful and reasonably priced. Another plus is the amount of aftermarket tuning knowledge that's available for the 6.2/6.5L in these forums and many other sites for the Cummins.

I weighed up the pros and cons and finally decided on the 5.9L for the reasons above.

If you really want to drop in a Detroit, go for it :D !! There's a guy with a 316 v6 detroit putting over 1600ft/lb torque, 1/4 mile is in the 9 second range and he can get from the pits, do the run and back again with less than 5 quarts of #2.

Boost is a leisurely 68lbs or more and it is an absolute animal - yummy!!!

[Diesel Dan]

Originally posted by Craig M:
While the Duramax and Cummins are definitely nice engines, $5000 to $8000 is a lot of dough. :confused: , $2500 will get you my extra cummins(100K) with a brand new clutch for a NV4500. Also 1st & 2nd gen motor mounts and a used 2nd gen intercooler.

I can seem to find used CTDs cheaper than 6.5TDs.

[britannic]

DieselDan, which clutch do you have - stock or something a little more tasty?

[Diesel Dan]

Standard replacement, bought it from a clutch shop in TX. Also included are the bellhousing and flywheel. The motor is a 180HP auto calibration and I aquired all the parts short of the trans for a NV4500.