I have a 1937 Cadillac Coupe with a tired Flathead. I’d like to use it for highway cruising and towing. I’m considering converting it to Diesel power. Is there a simple approach to this that would allow me to retain the charm of the old caddy with the benefits of a ***mings or other Diesel. Are there any companies that specialize in putting diesels in cl***ic cars?
Dave. I’m replying because I don’t know how to PM you on this format. My Caddie is in really good shape with only 50k original miles. It drives great. I don’t want to change steering, brakes or anything to loose the old car feel. It’s built like a truck and I feel a diesel would be appropriate. I don’t want computers or any complicated electronics. I saw an old packard that had a transplanted diesel. How hard would it be? My transmission is three on the floor. I guess it’s got to go but I’d like to keep it. What engine/ transmission would suit me?
Found this a few threads down: https://www.jalopyjournal.com/forum/threads/331-caddy-motor-and-tranmission.1327275/
Thanks for the suggestion. I know 49 caddies came with stick shift option but I don’t know how modern I can go with my 1937 transmission any idea?
Runs and drives currently? I’d leave it Diesel? Its your ride. I’m doing a 12 valve now in a c30. You really don’t know what to do until you stab it in. Has to push the center of the firewall back. Accommodating the inner cooler will get tricky on an early car. Using a factory inner cooler will be tough. Custom will cost a couple coins. the one I’m installing has an Allison auto, a lot bigger than the Dodge truck trans. Had to modify the floor. Probably will for any auto for that old of a ride. Older trans are small compared to new one. The diesel will operate at lower RPMs than a gas so gear ratios become important. But the 12v can turn up a few more revs than most other diesels. A later OHV caddy would be cool the current 12v swap I’m doing included custom engine and trans mounts, custom radiator mounts, modifying the core support and inner fenders to use an inner cooler, relocating the master cyl, cutting the firewall and floor, rear end swap and a custom driveshaft.
Core support mods 12v was out of a bus so a truck manifold was used to relocate the turbo away from the firewall (school bus manifold shown)
Caddy trans info https://www.jalopyjournal.com/forum...c-to-37-lasalle-trans-can-it-be-done.1071944/ https://www.jalopyjournal.com/forum/threads/1955-331-cadillac-manual-trans-ideas.1266822/
Or the Japanese equivalent Isuzu 4BD1-T 3.9l or 6BD1-T 5.8l A diesel with it's high torque off idle will wipe out your transmission. The Isuzu Diesel in some USA delivery trucks were mated to a GM TH400 trans I've done a few diesel swaps. You need a firewall mounted fuel filter and a return fuel line. The diesel engine usually needs 1 wire to connect [which goes to a fuel cut off/on solenoid] You'll need to figure out a glow plug timer [or do what I did and connect a push ****on to a Ford starter relay that controlled the glow plugs and count the pulses on the dash clock] If it has a Bosch rotary pump , you don't even need a lift pump Isuzu Diesels have a vacuum pump on the back of the alternator for brakes etc SO you could still retain your vacuum wipers [they'd be more reliable] The 6 cylinder diesel engine is heavy at 1200lbs [probably similar to the old Caddy boat anchor] And they can pull hard AND never stop in bad weather etc
A 49/54ish caddy had an extended bellhousing/block. A L***ale trans is supposed to bolt up until 54 Maybe. Don’t quote me. If you asked on the main board (not the off topic one) if a early 331 will work with a 37 trans you will probably get the correct answer. There should be an old school adapter to work with both early and 55- whenever caddy engines. just don’t mention diesel on the main board
might find that the diesel has about 5 times the torque of the old Caddy flathead 8, and will be tough on the driveline. And the rearend gearing won't be appropriate for the relatively low RPM the diesel will like. Did you notice that when Chevy started installing powerful diesels and Allisons in 3/4 ton pickups, that the trucks got really tall and real heavy duty frames? there might be a correlation. The Caddy flathead V8 is a real dog, though, so you have my empathy.
We won't I'm just trying to provide some insight on compression ignition engines. The fuel is optional
I have a 1986 Ford F150 with a 4bt and a 5 speed overdrive manual transmission (1997 Ford M5R2). It has survived about 12 years and was driven in 37 states. This afternoon, I taught two 15 year old kids how to use a clutch on this truck. Cut some tracks in the back acre, but did not destroy the transmission. The 4bt (when you can find a good one) will be more expensive than a 6bt. Also, there are 4bt's out of generators and other equipment that do not make good road engines. My build thread is here: https://www.4btswaps.com/threads/1986-ford-f150-shortbed-with-4bt.21506/?post_id=171354#post-171354 Russ
Isuzu is the Japanese ***mins Isuzu 4BD1 ***mins 4BT1 Isuzu 6BD1 ***mins 6BT1 The engines found on generators can be converted to road use by swapping the injector pump [or ****ing with the governors inside if that doesn't scare you] I've never been inside a "P" pump but the Bosch rotary pumps are simple. Both are very reliable engines, but the Isuzu can usually be bought for a steal.[and is GM] I doubt if the 88 year old Cad trans would survive a diesel engine.
I swapped a GM 6.2 into my J10 pick up 30 years ago and it's still running good, they only make around 135 HP but the truck now gets 26 mpg and cruses at highway speeds with 3:73 gears. . they fit in the same place as a SBC and they are cheap to buy .
If you’re serious about using a later caddy v8. Look up adapters The last link I posted had old part numbers for early cad OHVs So something it out there
I´ve heard the vintage Landcruiser and Landrover crowd do a lot of BMW M57D30 swaps. They are very reliable, respond great to upgrades and are a dime a dozen , at least around here. Any e39 530d parts car will have anything you need and they are going for around 5-700€ running and driving. I´ve thought about swapping one into a AD Chevy truck, but couldn´t bring myself to molest this old truck , so I sold the truck and the parts car. Our bad weather, daily driver/ tow vehicle is a 2000 530d touring, the best 2000 bucks I´ve spent on a winter beater yet. It´s got 221k miles on it, first turbo, first injectors, first transmission, does not leak and runs like a champ. I replaced the glow plugs when I bought it 6 years and 90 k miles ago. It gets 33 mpg cruising and 23 towing an overloaded trailer...
Another diesel to seriously consider is the Mercedes 5cyl, also avail w/turbo. 1965-1985. 200D, 220D, 240D, 300D, 300CD, 300TD, 300SD. Good book on tuning/fixing/modding is; Performance Tuning & Repair from Mercedessource.com . Old style diesels, cheap to maintain & run. Most engine parts are rather cheap. Good engines. Smaller mills were/are gutless, so go for the bigger(set) mill you can find. I'd look for a turbo 300, the Merc it was in was no featherweight, so's it'd probably be a nice powerplant subs***ute. I'd look for a rotted Merc, n use the trans, & the small bits. Not much in engine-required electrical, no electronics. Check your gearing vs tire heights vs rpm. & since it's old-style, iffen you wanted to, you could set it up for WasteVegetableOil or WasteEngineOil useage. But those need real good filtering, & heating, to run correctly. They will tow, but only a fairly small amount, about what the merc could. The BMW turbo diesel is another nice one, abit more electronics iirc(?), but hard to find in the States, at least around here. Marcus... Edit: Either of these 2 diesels will make a very nice *driver* w/very good fuel economy. The bmw will return better mpgs, but is more complex. *If* you want a driver, not a hotrod diesel - which is very possible... Marcus...
Not trying to throw a spanner at the works but you're in the US with an almost unlimited supply of LSs and cheap gas - why the diesel? Seems to me the usual LS/GM 700R4 auto combo would be the easiest conversion - and still return good fuel consumption. Me I'm in the EU so a diesel would make sense but only if one intends to cover stupid mileage with the car.
Since its a Caddy, you would like a 472/500 Cad and a Turbo 400 behind it. They came with the 400, so can probably find one with a trans attached ......usually about $500. It will cruise nicely and as long as you don't abuse it, last forever. If you abuse it, the rearend will become toast. Best combo is adapting an overdrive trans to it but hard to find one that will take a Caddy's torque without going to an electronic 4L80E which is basically an electronic Turbo 400 with overdrive. It'll make your Cad a sweet driver and having a Cad in a Cad sweetens the deal.. The 500 is also pretty light for its size and only weighs about 50 lbs more than a SBC. That should help keep the stock steering happy.
Find a 2 ton diesel truck, set the body on the 2 ton ch***is and drive it . Replace the duels with super singles . You did ask your question on the off topic thread
4bt , with late turbo , 3.54 gearing and , OD trans will easily power you to 80 mph and net 25 miles per gallon . I would look for a frame cut , you get every piece needed . Google Quick Draw diesel products . Chad will be your friend delivering every piece you need to complete the swap . It will be way way more costly than a late g***ser swap .
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