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Discussion Starter #1
Hi all, new member.

I have a 1942 Ford 1 ton. I am considering a 4BT swap. I know it will not be a fast truck. I live on an island with a top speed of 55mph. I want to keep the stock look as much as I can. It will raise the horsepower about 15hp and torque by about 100ftlbs.

I plan to use:
4BT one wire
Dodge G56 or NV5600 transmission.
Double reservoir master cylinder with booster
Shear plate in drive shaft so I don't blow my differential
Possible secondary overdrive

Wondering if this sounds reasonable.

Thanks Bob
 

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If 55 MPH will be your top speed, you probably don't need any power increase. To raise the torque by 100 lb ft you'll need about a 40 HP increase on the engine. Good rule of thumb is torque is 2.5 times HP on the Cummins. '42 is kind of a rare bird. Don't see too many of the war year trucks. Might do some measuring in the engine bay. Length probably isn't an issue but width might have some problems. The stock radiator should do OK with a 4bt. They run cool. If you do any power increase you'll need to think on an intercooler. Whether you use a NV5600 or G56 is your call. Might read up on pluses and minuses of each one. If you should happen to get a 4bt with the Ford adapter plate and flywheel, might consider using a Ford ZF transmission. Not sure what differential your truck has now. If it's the original it may be strong enough for a base 4bt. On the brakes, if you go vacuum assist you'll need a vacuum pump. A option would be hydroboost. Do you plan of power steering or stay with the manual?
 

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Discussion Starter #3
Thanks for the response Char 1355,

I guess I was not clear. The original 6 cylinder is 90hp and 175ftlbs torque. My research shows 4BT at 105hp 265ftlbs torque. A gain of 15hp and 90ftlbs torque. I do not plan any mods to the 4BT.
The 1942 civilian models are very rare. This one is a 1 ton dually panel making it even more rare. I have only seen 2 of these and heard of a third. That is why I really don't want to damage it any more than I have to.
I will keep the Ford ZF in mind. My research showed the 4BT bolts right to the Dodge transmissions. I am trying to keep it simple.
My 41 Chevrolet dump truck has the stock manual brakes and they work very well. My 42 1 1/2 ton G506 has throw you through the windshield hydro boost. I mainly want to upgrade the master cylinder. If I go with power brakes or hydro boost there are some good electric vacuum pumps or I can get one off a newer diesel pickup. I am currently putting a 7.3 IDI into my 90 Bronco so I am aware of vacuum issues. Thanks for mentioning it. That can easily be over looked.
As for steering, these old trucks have pretty large steering wheels so unless you are dead stopped they steer pretty easy. I really don't need power steering right now. Maybe in a few years.

Thanks again for the informed response.
 

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Hi, I am currently putting a John Deere diesel into my 1942 Ford 1 ton.
I have mated the stock T8 to the engine. I'm keeping the manuel brakes and steering for now. My biggest hurdle thus far and one to maybe consider is the oil pan to front axle clearance due to the extra depth of the diesel. I was going to drop a 4bt into mine as I had one sitting there but upon investigation decided to use the smaller JD engine. The length on the 4 will probably require some massaging here and there but it is doable.
Good luck!
 

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It's a 4219 JD. Not a real common engine but it runs very smooth with little vibration. It's 66 hp and I'm not sure on the torque. But I'm guessing it's similar to the flat 6 that came out. It fits in very nicely. The only mods I had to do was remove the original engine mount pieces that go from the frame rail to the front cross member. Guessing the 4bt will need those removed too
 

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You've done some good research. Yes, the Dodge transmissions will basically bolt up as long as you have the matching adapter plate, flywheel, and clutch assembly. You'd have to work out the hydraulic clutch which will occur with just about any other transmission. The most common one we see used is the NV4500. We don't see a lot of the 6 speeds you mentioned but they can be done. If your 4bt happened to have the Ford adapter plate and flywheel, then a SB Ford ZF S5-42 would be a bolt on. The 6 speed ZF's can be done but will require a custom adapter plate and related clutch and flywheel that costs in the $1500-2000 range. Does this truck have a drive shaft mounted park brake? If so, there was one for the Ford ZF units that came on the F Superduty. Not a cheap item by any stretch, but you can sometimes find used ones that are reasonable. It requires a 4wd transmission to mount it. If you wanted to add a little more power, then a few simple mods to the injection pump and a better turbo would take you to the 150 HP area. Even 200 HP can be readily done with stock injectors. Injectors need to be tested to be sure they are in good shape. When you start adding power you will need an intercooler. More power creates more heat which you don't want. The 105 HP was the most Cummins offered without some kind of aftercooler or intercooler.
 

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Discussion Starter #9
Thanks for the info.
At this time I don't plan on increasing HP until I see where I am at.
I thought because of the 6bt in Dodge trucks there would be a lot of parts available. I am currently putting a 7.3 IDI in my 90 Bronco. (I don't like computers.) I bought an F250 4X4 diesel a tree fell on so I would have all the parts I needed. Thought I could do the same with a Dodge with a blown engine or wrecked. I am not afraid to buy a whole truck or two to get parts cheaper and then sell everything off at the end. I am looking into what equipment the 4bts came in to see of I can get an old piece of equipment cheap.
I do have the driveshaft E brake. I am seeing a lot of 4bts with Ford small block transmissions.
 

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I agree with you on the computer stuff. I drive a '90 F250 4x4 with the 7.3 IDI. No computers anywhere that I know of. Just replaced my second water pump in 320,000 miles. This one lasted 17 years and had a lifetime warranty. If the new one lasts that long I may quit driving by then.
 

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Discussion Starter #11
Hiltybilt,

That JD would not be enough power for me. We have 12% grades on the island. Thanks for fitment info. Every little bit Helps.
 
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