Hi folks, I'm approaching retirement and looking for a project. I've got a hankering for a 50's era vehicle, with a slight leaning towards a truck. I currently have my eye on a 1957 Chevy long bed. My main concern is that I don't want to spend a lot of money and time on something that I would rarely drive because it uses too much fuel. I'm also not looking for a show truck. I want a practical hauler. And maybe I'm just not setting my goals correctly. Perhaps I should look elsewhere for my projects, since the concept of these old vehicles, and fuel efficiency, don't necessarily coincide. I'm wanting high teens, 20's if I can get it, for mpg. So, in the interest of greater fuel economy, what is feasible with vehicles like this? Smaller block diesel? If so, what works? Shaving weight? Besides a shorter bed, what works? I don't want to go with a completely fiberglas body because I want some metal around me. Fuel injection? I see TBI thrown about somewhat as an easy middle ground. Gearing? I'm not going to be pulling boats or RV's, so maybe tinkering with the rear-end, or getting a 5 or 6 speed tranny. If so, what works?
Diesel is good ! . There are kits available to put a Mercedes OM617 turbocharged 5 cylinder engine in , I'd want to retain the sturdy 4 speed automatic tranny too . Unless you want to drive 70 + MPH , 23 + MPGs will be easy , these are really simple , robust and economical engines as they come from the land of $7 / gallon fuel . Or , find a nice SBC with fuel injection and keep it stock , raise up the final drive ratio to 3.73 or higher for good fuel economy . Sadly , getting over 15 ~ 7 MPG's out of any of the original engines is very difficult .
Well, I like the sound of a diesel my son has a 1986 Dodge diesel, shortbead, it sonds like a UPS delivery every time he comes over. But to be able to drive my1959 truck and my atempt to save gas. I replaced my 235 and three speed with a 350 small block and a 200R4 overdrive trans, I think the rear gears are stock 3.93? (the option for 1959) needing more fuel efficent ratings. I think I reduce the weight by approximately 250 bs by removing the big 235. Keep in ming diesel cost 20% more the pump gas.
Look into A 4BT cummins with a NV4500 5 speed behind it. That should get you into the low 20's easy with more room to improve after that. Or if you want to tow a lot with it and over 10K lbs pretty often then you could just step up to a 6BT cummins. You should still be around 20mpg but it will pull whatever the truck can handle. Go to 4btswaps.com for more info, you'll probably even find some builds with similar trucks on there.
The best way to produce better fuel mileage is to cut rpm at any given speed, cut weight, cut drag, and make it more slippery. Everytime a piston goes down on an intake stroke it draws in a mixture of 15 parts air to 1 part fuel into the cylinder so the fewer times it cycles the less fuel required. Several ways to get there: fuel injection meters out exactly the correct ratio while a carb just dumps in a load and lets the cylinders fight over it; cut slippage from an automatic with a lockup converter, overdrive, something with massive torque in the same size or smaller engine (diesel and/or supercharging), shedding weight and making it more aerodynamic, radial tires, and eliminate any brake or bearing drag along with the lightest fluids, lube, and oil that will do the job. This lets one run gearing down into the 2's and still pull good. My 37 Buick which makes an old truck seem like a feather weight gets 19mpg at 70mph and this is with a carburetor. Has about the same aerodynamics (barn door). It's geared to pull 2000rpm at 70mph. Has a 263 straight 8, lockup 350 turbo trans, 2.73 rear gears, and 28.5" tall radial tires @ 40psi. If you're really serious about fuel mileage use an LS series Chevy V8. The ones in the Corvettes puts out in the 400hp range and get 26+ mpg with the double overdrive 6sp trans. Have one going in a 57 Chevy and a 70 442 Olds right now.
