Has anyone successfully transplanted a Detroit diesel in their 1940-46 truck? I was thinking about using a gama goat engine which is a Detroit 3-53 and sm420. While I have the measurements of the engine I’m not sure if it will fit. Length = 33, width =27, and height 39. Seems like a lot but checking the engine bay it looks like o could easily move the radiator forward a few inches and the width of 27 wouldn’t fit between the frame rails, but the max width on a 3-53 isn’t down low, it’s mid block where the blower is.
Anywho, if anyone had swapped in a Detroit already, I’d love to see pics of it!!
With an approximate usable RPM range of 1750-2150, you're going to need a lot more gears than that SM 420 has. Better add a 3 speed Brownie to give you 12 forward speeds, and do a lot of dumbbell curls with your right arm- - - - -you'll be "rowing it with the shift levers"! Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
Also the engine I’m talking about is the 3-53 from a. Gama goat. The gama goat came with an sm420 trans and it’s max speed rating was 56 mph with a 5.57 gear ratio on 9x20 tires.
My plan would be 5.43 gears and a ranger torque splitter overdrive (28%), with 8.25x20 tires.
The 3-53 was rated at 101 HP. new. I drove a 1970 3/4 ton GMC with a 3-73 and a SM420 in it. One of the most underpowered, slow trucks I have ever driven. It needed 6 inches of body lift to close the hood. Be prepared to do A LOT of work to make it fit. The detroit "power band" is fairly small, they don't "lug down " well. If you are looking for "slow and loud" then go for it.
At least look for a T engine, since you plan on 20" tires, do you have a 1.5 ton truck you plan on using. Will be pretty gutless on Hills. A 4-53T is too big for your engine compartment.
Ed
'37 GMC T-18 w/ DD 4-53T, RTO-610, 6231 aux., '95 GMC running gear, full disc brakes, power steering, 22.5 wheels and tires. '47 GMC 1 ton w/ 302, NP-540, 4wd, full width Blazer front axle. '54 GMC 630 w/ 503 gasser, 5 speed, ex fire truck, shortened WB 4', install 8' bed. '55 GMC 370 w/270, 420 4 speed, grain, dump bed truck from ND. Works OK.
That’s what I was thinking. Doing the measurement and comparing to Kline measurements, it looks like only the 3-53 will fit and just barely. It’s hard to find a 3-53T, so I’ll probably do a 3-53N and just add the turbo parts later as I find them.
Grigg on here did a 4-53T conversation in A-D 2-ton Truck. Others have done it. Search these forums. Also there are some YouTube videos of diesel conversions in old GM trucks. Maybe that will be useful.
Detroit may not be the most powerful, efficient, or easy..... but in my opinion they are the coolest of that generation diesel engine. They will definitely put in work and that sound is just amazing. My good friend just restored a 1968 gmc dump with a 6-71 and I am in love with how it drives and sounds. No other sound like it from a bygone era.
