I've got a question for all you Y-Block gurus out there. I've got my eye on a 1957 Ford pick up that is for sale down here. The time has come for me to get another ride and I want to get something I can pretty much drive everyday and anywhere. I will travel long distances as well as in stop and go traffic. The truck has a 59 292 Y-block that has been bored 40-over and runs a 4bbl carb with a manual three speed tranny. My question is: Can anyone give me an idea what type of mileage I can expect and if it can be improved by going with a 2 bbl carb? I don't know how thick the cylider walls are on a Y-block, is 40 over too much that will cause frequent overheating? Thanks, TD
+I would imagine around 16 mpg. This is what my 61 fairlane gets with the 312... plus my old 69 el camino with a 396 and quad got the same.
My 54 F100 for 2 years and 7168 mi.ave 18.25 mpg with 312 Merc 4 bbl and 3.90 rear with 3 speed OD. Most of this was short trips of 20 mi. or so. will do better on a trip.
The age old answer is . . . . "DEPENDS". if you drive real sane and stoic, the wrong 2 bbl could get worse mileage than a 4 bbl that has small primaries. Actual mileage also depends on rear end, how tall the tires are, etc. The new 317" Y in my 56 Victoria was sonic tested before punching it .080" or same as a 312 .030" over. Haven't run it but a few hundred miles yet and it hasn't been hot. Still tweaking so no mileage numbers yet. I had a 331" Y that was built on a 292 w/ 312 crank and .155" over. It was too thin in the walls (cracked) and did get hotter than preferred but ran it almost 3 years. This rig coupled to a T-5 (.67:1 OD) and 3.73 rears would get 21 on the highway at 70 MPH (2,050 RPM). Sonic test and then let piston availability dictate what bore to use. Good luck TC
How heavy is your foot? My 292 gets low to mid teens, which is better than my 93 Wrangler 6 cylinder with fuel injection. I'm running a 2bbl on it, I can still chirp the tires, but I won't win any races. If you don't really put your foot into it, the other 2 barrels on the 4 bbl carb won't open. Also, a truck is lighter than my Fairlane, and dropping the tailgate will also help with the mileage. You also have to consider what type of exhaust it has also. Y-blocks are heavy engines with lots of material between the cylinder walls, .040 over isn't unheard of.
'57 272 Y block, motorcraft 2 bbl, 3 speed stick (non o/d), 3.55s, 205/75R15 all in a '57 Custom 300, used to yield around ~22 mpg highway, and 15 city. Not bad at all. Sometimes better, sometimes worse. You can overbore the beejesus out of a Y block and not risk overheating. I'm pretty sure some of them can be bored .125 over. .040 is safe for a 292
My '64 F100 gets roughly mid-teens with the 292 which has headers and electronic ignition. .40 over is small talk for these engines! The 4-barrel may do better for you, if it has smaller primaries than the 2bbl. Just be sure to keep your foot light on the pedal.
I get about 20 mpg with a 292 bored 30 over 3 holley 94s with progressive linkage so it runs on the center carb 80% of the time. its in a 57 wagon with a 3.00 gear and T5 overdrive so that probable accounts for a few more mpg on the long hauls.
my 58 ford with a fordomatic and a 308 rear anda truck 2 bll getws about 16 in city and 20 on highway
I agree with the small 4 bl for mileage. With the small primarys. At least 16 without high gears or anything special.
Thanks for the replies. That helps me with my decision. I gotta have it! That mileage doesn't seem too bad. I have to find out what gear ratio the rear end is. The rest of the truck seems to be all stock. Any you guys know the stock rear end gear ratio for one of these '57 pick ups?
A truck with no overdrive will get around 15 @ 65 from my experiences in years gone by. Faster you go the more it will use because of barn door aero
At 65mph, with no overdrive, my 292 has to spin at approx. 3500 RPM. It's no fun, especially when you see the fuel gauge begin to drop FAST. I BARELY can get 15mpg on regular 35-40mph roads. Get on the highway with stock gears, and your winding the snot out of the motor just to keep up.
Y block question from another post I can't find... Yep I used search, just can't get the right combo of words... There was a thread about gearing with a yblock and getting the right highway gears... anyone send me the link to the thread? Thanks...
Maybe its this one I posted a while ago? http://www.jalopyjournal.com/forum/showthread.php?t=284951 By the way I ended up going with 3.00 gears in the rear and it helped so much on the freeway...
Great info, but not the one I was looking for, someone went into all the gearing and all... but that inof is helpful...
'60 Starliner, stock 2-bbl 292, Cruisomatic, 3:00 rear. Avg between 15&16 mpg stop and go and 18 to 20 at a steady 60 mph on the hwy. Yes, I let that one get away...been know to do some dumbass things along the way!
Not the one I had in mind but still great info... think I can use these two and come up with what I need... I'm just building this F100 and want to be able to highway cruise it also... need to see what's in store for motor and go from there... Thanks for all the help guys...
i have a 58 with a stock 292,has a toploader 4 spd. out of a 67 stang,and 3.25 gears,255/70/15 rear tires,speedo doesn't work but i drove to fla. for the turkey rodrun and i averaged 15.69mpg. turning about 3500r.p.m.i am sure i could get better with a 3.00 gear and some more fine tuning,oh yeah,it has a stock holley 2bbl.good luck.i think alot of them had 3.70 gears from the factory.
'56 Customline, 272, 3:78 gear, 3 on da tree. Average last year = 14 mpg. Mostly short trips, not many over 10 miles. Going to Billitproof this weekend. Will see what it does there. Had a 2bbl and singles & vacuum distributor. Changed to Holley 390 4bbl, duals and electronic ignition. Mpg went up about 1 1/2 - 2 mpg same conditions.
should be a Ford 9in with 3:73 ratio.good or bad mileage i saw gas for 1.70 around the corner from my house .so im good.57 is the best year
my 292 gets probably 12-15 in town/light driving, and probably 18-20 highway, 3.31:1 gear with tri-power, EDB factory manifolds, backed by a ford-o-matic. I'll probably swap in an 8" with 3.0 or taller gear next winter. I run premium, by the way. It's probably overkill, but it was factory rated at 9.5:1. Also, as stated before, Y-blocks can be punched out alot.
The good thing is you have a 9" rear so getting rear gears in the ratio you need for mileage won't be a problem or expensive.
A well tuned Y block with 4BB carb and every thing right--IE gear-trans-duals ect should be in the 18-20 mpg without any problem. A lighter car or hot rod possibly a little better. There very dependable and ez to work on.
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