Building a Y block for reasonable gas mileage

My 55 Ford convertible is going to get a Y block again in a few years and since I drive my cars I would like to see if I can squeeze a little more gas mileage from a 272 or 292,right now I am collecting the parts and did find out about a complete drivetrain from a 55 with a manual trans that I am considering buying so if I get it I will have the parts for a automatic or stick. Is it possible to get about 20 miles to the gallon out of a Y block or am I just dreaming,I yanked the original motor before I ever drove it on a long distance trip so I do not know how they do on the road.

 

Dream on,,you want gas mileage buy a KIA. HRP

 

The answer is overdrive. My parents had a 59 Ford with the 3 speed overdrive. 292 2 barrel. 20 mpg on the road was normal. I had a 57 Fairlane with a 272 and auto. 14 was all I got with that.

 

the key is going to be, how you drive, how well it is tuned, and a manual overdrive transmission then maybe youll get 20 if all of the above criteria is met and it depends on how heavy your car is

 

OD was what I was thinking, our Country Squire w/292 stick no OD would do 12.5 cruising 75 accross the Oregon deserts back in the early 60's. Those old Y's got pretty good heads for normal driving needs, seems like those combustion chambers enhance the swirl of the intake charge and help atomize the mixture. I know my 56 Customline 292 stick 2dr post had excellent low end and was a really nice daily driver, however never paid attention to mileage, just filled it up when the gage got to 1/4 tank. I know it was a lot easier on gas than my 454 4sp Monte Carlo, a lot slower too.

 

If I can get one to get 18 to 20 on the road I would be happy and seriously thinking about a 3 speed o/d for the 55,when I am on a road trip I drive easy. I do not want a Kia but would like to squeeze as much mileage out of my old rides as I can since I was not born into a wealthy family.

 

In all seriousness,,look at a 5 speed manual transmission and a 300 rear gear and you should be able to get close to your target. HRP

 

Having owned Y-block Fords before, I laughed when I saw the ***le of this thread.
Good luck is all I can say.

 

There's your answer....

Use the later distributor and intake (post '56) with an even later Autolite carb, along with the OD transmission.

 

My 51 shoebox gets 11.5mpg around 55 mph cruising on 3 9's with progressives and a 4 speed manual.

I can get 13.5ish on a single center at the same speed.

With a OD transmission I bet 17-18 in a car of that weight and aero. But you will have to stay way the heck out of the loud pedal.

 

I thought about a 5 speed but want it to look close to original since its been in the family since new so I would go with the 3 speed o/d if I go with a manual trans,since it has a 351-W in it now I am going to install a AOD for now to help on the gas consumption and possibly adapt it to the Y block when the motor gets built. I am gathering info on modified valve bodies for those trans so I can lock out o/d and do normal up and down shifts through first to third.

 

I have a 62 292 and a 57 intake for it.

 

The wagon I built was originally purchased by my wife's grandmother and was a inline 6 and 3 on the tree,,the 302 and 5speed gets good mileage on the highway,,of course around town the mileage ****s because of a heavy right foot and rowing the gears! HRP

 

I do not expect good mileage around town but I do drive this car to Daytona for the Turkey run and worried if I do go back to a Y block I will make it worse than it does now. I spent about 500 on gas last year,I am still going to gather the parts to put it back to Y block power and possibly build another old car for the long road trips that will not break the bank to drive and just drive the 55 to events around a couple hundred miles from home.

 

Sorry to highjack a super old thread, but my 64 F100 with a bone stock 292 has bested 15mpg on road trips. Of course the later y-blocks were tuned down a little, mine is bone stock 2bbl still running points, T98 trans, and some pretty low gears. Key is I was cruise between 55 and 60 mpg.

 

Its getting a 55 272 with some good 57 and up parts and will see how it does,going to build another car for those long trips.

 

My first car was a 57 fairlane 292 3 peed overdrive 4.11 rear end. My dad could drive it and would get upper teens @ 60 mph. Me not so much. Super high gear does not mean mileage. A given speed with the least amount of throttle is where mileage is. hears an older thread https://www.jalopyjournal.com/forum/threads/y-block-gas-mileage-questions.254158/

 

With the five speed, ***uming the fifth gear is a over drive, I would have to to say a 3:00 to one ratio in the rear end would be a little high geared , for my tastes.








Bones

 

I have owned several Y blocks over the years. The only way I know to get great mileage out of one, is the hidden hook option. That's a retractable hook under the front end that can be extended out to hook onto the rear of a Semi. Then kick it out of gear and let him tow you to where you want to.

 

Swap in a newer fuel injected six with overdrive and you can get good fuel economy. And it will run circles out of the Y block. My wife has a injected 2 wheel drive 6 cyl Jeep Grand Cherokee. Auto overdrive trans. normal driving get better than 20 MPH. and its a solid 14 second 1/4 mile car at about 105 MPH. As fast as a mid 60,s GTO with a 4 speed and 430 gears,

 

What is the stock compression on the Y blocks.
Many times compression holds the key to mileage,,,and cam profile.

Tommy

 

Peaked in '57, detuned and 8-1 by '64. At least they aren't too picky about octane.

 

The 312 in my 57 4door with a T5 gets 17-18 MPG. It has 15" tires . It has a John Murmet aluminum 4 barrel intake . It was a 3speed car .

 

The 272 I got is a 2 bbl that as 7.6 so I picked up a set of 55 292 heads that should bump the compression up to 8.5,its going to get 57 intake and exhaust manifolds and a set of the better ratio rocker arms and a 62 distributor. Not sure of the trans right now but was thinking about a FOM/FMX hybrid,could go with a C-4 which would be the better way and trying to avoid the FOM since I would have to put the 55 rear end back in with the 3.30 gears and would like to keep the present 3.00 gears.

 

So you’re building another entire car to save a few hundred bucks a year in fuel?

 

Compression, Compression, and more Compression. Seriously as much as you can get away with and still run the fuel you desire. Nothing has a greater effect on fuel mileage more than compression. The right cam to take full advantage of it, and an overdrive will go a long ways.

Turbo's and Intercoolers, although not always HAMB friendly, are also another great way to boost mileage if utilized properly. As Mr. Banks would say, it is all about air density.....

 

I once used the front pump & torque converter from a Green dot crusomatic on a 69 FMX. It worked perfectly. I had a 59 merc 312. automatic it did not have the finned torque conveter like a 56 did. it had a steel flywheel with the ring gear on the flywheel.

 

Stick for sure, later four barrel manifold and electronic F I like Edelbrock, Holley, Fuel Tech, etc. Port would be better but harder to do.
The engine is just an air pump. I think 25 is attainable with 10.1 comp ratio.

 

Your 55 292 heads will lose 1/2 point on a 272 I would mill the heads .060 and cut the intake side .084 so the intake will fit. I have never had a problem if you don't mill past the area where the G is in this picture. https://images.search.yahoo.com/sea...t/items/images/34/143334/002.jpg&action=click

 

All kinds of jiggery-pokery may have been done to these motors over the decades, take the time to check everything out and bounce the numbers you get off the specs in the book or generally accepted rebuild practices. I paid to have a Y-block rebuilt some years ago, but that isn't exactly what happened.

So I had the opportunity to pay twice for it (and then some) and the privilege of learning all the fine points of a Tune-Up. If you do your homework and measure (don't guess) versus deploying the parts cannon, it will go a lot faster. All that **** in the Shop Manual, MoToRs, Tune-Up is good stuff, they sussed it out a long, long time ago. Even manuals written in the 1920s diagnostics - 100 years ago - is still exactly the same principles. Like someone said, it's just a big air pump.

Compression, ignition, valve timing or camshaft phasing makes a big difference too. And then when all that is straight carburetor calibration. There's no good reason to spew pollution and waste fuel, it just trashes the rings and fouls plugs, contaminate crankcase oil etc with no performance benefit.

The Y-block did have some particular attention paid to combustion chamber turbulence in the design phase as an aid to equal cylinder fuel charge, I did notice it will run well with lean cruise air fuel mixtures without misfire or surge and tolerates lots of vacuum advance. I have it set around 54° BTDC on flat ground.