Technical Chevrolet 283 build for fuel economy

‘57 Chevy PU and fuel economy is a mismatch.
Write down your average use per day, miles, etc.

Figure your fuel bill getting 14 MPG and having some fun with the old girl, vs 17 MPG.
Maybe 1 less trip through the drive through for a #5 in a week.
get a clapped out import on the cheap for a commute car, enjoy the ‘57.

 

Comp XE250H cam. Find a T5 transmission to stick behind it. 3.42-3.73 rear gear.

 

During the first gas shortage, Hot Rod Magazine modified a Chevy station wagon for a mpg article in the mid 70s,
I think they claimed something like 20 mpg with their station wagon
So, did their modifications to my 307 ci sbc C-10 pickup and had a lot of fun, got really good results.
Been a while but this is what I remember,

A single plain intake manifold, with a Rochester 2 jet carburetor mounted forward on an adaptor plate to locate it at
same place the primary 4-barrel plates reside
I know this don't sound good; the theory was that at part throttle, partial open blades would dump the fuel in the center of the open plenum manifold giving all 8 cylinders equal opportunity.

Headers with an H pipe to dual exhaust

I also put a set of 283 heads on to increase compression, I remember about 18 mpg, it was a truck and was a stone in the wind

Maybe someone can find this issue, I'm sure I forgot some stuff

 

Nobody has mentioned the distributor. After you've done the things you decided to reap from all the previous suggestions, you need to do some distributor tuning. If you don't get the vacuum advance and mechanical advance curves right, you won't have the economy you are tying to achieve. The vacuum advance has a lot to do with fuel economy and takes some experimenting to get right.

 

Just my .02 cents instead of changing both rear end and transmission, put a 4L60 behind it. The 283 will be way more fun with the short gears and in O/D you're still at about a 3:1 effective top gear. Set up a Qjet. The old Edelbrock SP2P is a good torque/mileage intake. Like @rockable said, a good set up distributor pays big time. A Jacobs system or some kind of dealy like that works good. . Cam choice is whatever you want. I've had good luck with Schneider cams.

 

I drive my deuce pickup year round except during salt season. The motor is a 55 265 Chevy with a mild cam and performer manifold, 350 trans and a 3.00 9 inch rear. When I traded for it 12-13 was tops. After a lot of trial and error we finally got the distributor set right, took off the old Edelbrock and put on a new Edelbrock 500 cfm AVS2, bought the carb tuning kit. and after several adjustments we got up to between 20-22 depending how deep you plant your foot. If I keep it at about 70 on a good day I can squeeze 22 but I'd say 20 is closer. If I get on the freeway and run with traffic (80 ish) it'll drop to 17-18.

 

Use the 4 barrel but forget the Turbo 350 transmission if you want economy and torque. A 283 ain't going to provide a lot of torque. This is a situation where gearing is going to be the most important factor. Get a later version 88 and newer 700R4 (also 4L60 Not 4L60E) . The additional gear will give you a reasonable chance to get some torque and economy. First gear is lower than the T350 I believe, and 5th gear is an overdrive. Edit: (Should have said 4th gear)

Look at it this way........If you gear a 3 speed trans for torque, you have no cruising speed or economy.

If you gear it for economy, you have no low end torque.

You can't get both without gearing. My 2000 Chevy truck has a 4.8 liter which is about the same cu in as your 283. It has the later model 4L60E transmission. It has 3.73 rear gears.

When I get on the expressway, I can cruise at 80mph and about 2300 rpms. I also use a trailer I have quite a lot and its been loaded (over loaded) with some pretty heavy loads. Last year I hauled some large retaining wall stones over a hundred miles and it (the trailer) had all it wanted.......but my little 4.8 liter (288 cu in) purred right along. Thats a good combination to emulate in your 57 Chevy truck since you are starting out with the requirement to utilize such a small motor. When you go small, gearing is what will make it a good enjoyable driver and occasional hauler.

 

I have a chevy engine that was made 3 years only that was made for a thrifty engine, i have that is complete and ready to install if any is interested. Will sell at a bargain price. Also have a 283 that complete except sone of the accessories.

 

Use thinner/lo-tension rings in the build.
6sally6

 

First gear in a 700r4/4L60 is quite a bit lower than a TH350.
3.06 first gear ratio x 3.36 rear end ratio = 10.2816 overall ratio in low gear. This is right at the sweet spot for a street car. It will get up and boogie when you want it to, and will have lower highway cruising revs in overdrive than the TH350.
This will help fuel economy, and at the same time put a smile on your face...

@ekimneirbo , where are you getting 700r4's or 4L60's with a 5th gear...??? Let us in on the secret. I want one....

 

How much fuel does one have to go through before you get a pay off from all this additional expense to make it 'economical'?

I appreciate you're building a fresh motor here so you gotta buy stuff anyways, but all this additional stuff of transmissions and rear gears etc is really going to add up.

Personally, I'd build a nice solid mild motor, get it in the truck and enjoy it, life is too short to be mired in projects forever.
If you want to save money, go easy on the right foot and perhaps cut back on other small expenses in life and you'll be surprised.

My 2c

 

You won't save the planet with an at***ude like that......

 

I am also a big proponent of "drive it, dont make it an unnecessary project "

But, I also think overdrive transmissions, and adding extra gears is a great thing for old customs and hot rods. Sure, he is asking specifically about fuel economy, but a lot of that can be gained with making things efficient. Stuff like getting the quench right can really help gas mileage, but it also will make more power across the board, and help with drivability. Win win.
Having a automatic OD and the right rear gears are the same: the cost is balanced out between gas savings, and better performance and pleasant highway cruising sound (and engine wear) reduction.
So is the cost worth the MPG savings? Probably not. But having a truck with near modern power, range, and drivability? That starts spreading the "worth it" out.

 

Brain fart + Hand/Eye co-ordination. I wanted to tell him to use a 5 speed manual trans and that was lurking in the back of my mind. Good Catch . I'll go highlight it and put the correct info in. Thanks, as I really try to post accurate info.

 

@Clydesdale Not having to Know or find the next gas station before that needle falls,
can make for a happier ride.

 

Years ago I had a 455 in a Pontiac LeMans. Q-jet, recurved HEI, MSD, mild cam, headers, SP TH400, and a Ford 9" with a 2.75 ge****t. I was able to get 19 mpg on the highway out of it.

 

Exactly, anyone who has rode a motorcycle with a small tank understands this, continuously stopping for gas is a pain in the ***. Plus this is a hot rod site, so being logical or making financial sense goes out the window as soon as you walk through the door.
Dan

 

Not sure what prices are like for parts in Scotland, but in the US a used/rebuilt Turbo 350 and a 700R4 can be had for about the same cost. I think the 56 Trucks mostly came with 3:35 and 3:55 ratios, so that should be a reasonable starting point. With the 283 though I would be concerned about the overdrive maybe not being optimal for the engines available torque.

You are right about enjoying the vehicle instead of always being in project mode. He could try it with the original gears and if its not working well, upgrade the rear gears later. Like I mentioned above, my 2000 truck has a 4L60 (E) which is similar to a 700R4 and has 3:73 gears from the factory, and it works well driving or towing. Gas prices being somewhat variable these days, it doesn't take long to pay for a couple upgrades.

I lean more toward bigger engines with lower compression (9:1 /10:1) these days and run regular gas.

 

Bigger fuel tank. Done

 

A lot of talk about overdrive set ups behind this 283. You need to be careful with that. An economy built 283 will not overcome steep gearing and tall tires. It will need to turn about 2200 - 2400 rpm at the desired speed so it is not lugging. My father had a 67 Chevy pickup he bought new. 283, 4:10 rear with overdrive. He did a run of 200 miles, 3 times a week. He put the tallest 15" tires on it he could find for gas mileage. He only did one trip like that. It got about half the mileage and had no power compared to previous trips.

 

Just rolled into the garage after about 250 road miles today with the 32 pickup. Took 2 lane 90% of the time, checked it twice and was getting about 19-20. Also quite windy. I'm happy.

 

I’ll have to check the red 56 to be sure. 283 TH350 3:08 rear. Pretty sure it’s 18-20 range.

 

A th350c sounds like a fun choice.
700r? If you have one laying around.
I’m a run what ya got person
You can buy a lot of gas to build something you don’t have.

 

How about a streetmaster intake with a 500 cfm Edelbrock carb or if it's spread bore intake (they come either or) and a quadrajet or spread bore holley, wth this cam
Summit Racing SUM-K1101 Summit Racing™ Cl***ic Cam and Lifter Kits | Summit Racing https://share.google/nprQsOdupmdd19SDd
Of course some headers and dual exhaust.
Let's see a photo of the truck, I'm currently doing a 57 pickup myself.

Edit, I believe this was a streetmaster I had on my t-bucket at first, with a 650 dp spreadbore, thing had the best "kick it in the guts" out of all the intake carb combos on it.

 

What are the specifics of this engine?

 

Only cost $50-70 more to build my 283.

same hp as a 350? Nope
Cheaper? Yes,overall. I had a freebie 283.

And I didn’t want a 350.
It’s not rocket surgery. Just a simple stock rebuild Maybe a very mild cam.
Enjoy

 

The TH350 was on the garage floor. 3:08’s were already in the car when we got it. The 283 replaced the 235:

 

A number of members have mentioned that a 283 is NOT a torque-monster, and actually do better at somewhat higher RPM.

Some have mentioned that an overdrive manual transmission would be better on fuel economy than the automatic.

As far as carburetor selection is concerned, consider the following facts:

In 1957, the Rochester 2-barrel used on the 283 was rated at 278 CFM.

In 1957, Chevrolet offered a 283 in the Corvette with a "special race cam". This engine came with a special Carter WCFB four-barrel number 2493s that was rated 380 CFM.

In 1957, Carter offered production 4 barrel carburetors from 295 CFM to 675 CFM. Chevrolet thought the 380 CFM was sufficient for the racing engine.

So given the above for a racing engine, what about an economy build?

How about rebuilding the original 2-barrel, which I am ***uming you have, and use the original Chevrolet intake manifold, which I am ***uming you have ?

I personally believe there is more fuel economy available in the choice of transmissions, and, when needed, a set of radial tires, than is available in any carburetor / intake manifold swap.

And rebuilding what you have is certainly going to be less expensive than the purchase of any different carb or intake. Sometimes it is best to admit the factory engineers knew what they were doing !

Jon

 

Don’t over think it
Use what you have. That 283 was born with everything you need to enjoy it.
Stock rams horns, intake, distributor and carbs
pick out a stock or mild cam. just buy quality lifters.
use whatever trans you have
Emjoy

 

I ***ume he is talking about a 262 V8.
Used in Monza's.
3.1 stroke x 3.761 bore.
Always thought the crank put into a 400 block would make a fun short stroke/big bore 336 cube combo.