Topic: 221 flathead fuel mileage


sharpshooter35    -- 06-13-2021 @ 7:47 PM
  I have a 1935 ford truck with what I believe is a 1936 221 flathead V8 with two speedway 97 carbs on an offenhauser intake. Also Fenton cast iron headers duel straight exhaust electronic ing. 12 volt and a4:11 rear with a s10 5 speed trans. I'm getting 10 mpg. Shouldn't I be getting more like 17 to 20 mpg??? Also it has electric fuel pump.

This message was edited by sharpshooter35 on 6-13-21 @ 7:52 PM


carcrazy    -- 06-13-2021 @ 10:09 PM
  What kind of driving results in your 10 MPG fuel economy? Are you sure that your speedometer is properly calibrated for the rear axle and rear tire size that you are using? Ten MPG in the city may be about right. Your fuel economy should be better on the highway at a speed of 55 MPH. Take a look at the spark plugs to see if they are black with carbon indicating a rich mixture. You may be able to reduce the sizes of the main metering jets to improve the fuel economy without making the engine run too lean. Is your spark advance optimized? You can try advancing the ignition by a coupe of degrees to see if the fuel economy improves.


trjford8    -- 06-14-2021 @ 5:58 PM
  If you are running only the electric pump it may be putting too much pressure(fuel) to the carbs. You might want to add a pressure regulator.


ford38v8    -- 06-14-2021 @ 10:38 PM
  A very conservative driver who never goes faster than 45 mph, with a well tuned engine, with 35 lbs air in tires, never idles in the driveway, and doesn't drive in city traffic or freeway bumper to bumper, MAY get up to 20 mpg, but that man never has any fun.

Alan


TomO    -- 06-15-2021 @ 8:56 AM
  Alan, I agree with you, but the OP has dual carbs, so even if he drove with a raw egg between his foot and the accelerator pedal, he would never reach 20mpg.

The truck is like a big sail crosswise to the wind. The faster you go, more fuel is used to fight the resistance of the air in front of the truck. If you are driving the truck at 55 MPH, 10 mpg seems very reasonable to me. If you are driving on rural roads at 35 MPH, 14 mpg seems reasonable. 10 mpg seems like a reasonable mileage for normal driving on today's roads.

My 53 Lincoln has a bigger engine and weighs more than my 40 Merc, but both of them get 15-17 mpg when driving on the highways at 50-55 MPH. My 2007 Buick weighs the same as my Lincoln and has about the same size engine with FI and better aerodynamics gets 28-30 mpg when driving on the highway at 55 MPH. The FI probably makes more of a difference than the aerodynamics as less fuel is wasted.

Tom


srg    -- 06-15-2021 @ 1:52 PM
  I have the exact same setup as you in my 37 sedan, with a 59AB engine. I get 9 miles to the gallon. Flathead V-8's don't get good mileage. Stock 37 transmission.

This message was edited by srg on 6-15-21 @ 2:02 PM


alanwoodieman    -- 06-15-2021 @ 2:23 PM
  we drove our 40 wagon 160 miles to a woodie club meet, it has a 3:78 rear gear, 221 engine, drove at 45/50. I had filled the tank when we left and refilled when we returned--8 gallons you do the math


1934 Ford    -- 06-16-2021 @ 4:37 PM
  Unless we're on a Glidden type tour, we don't drive far enough to keep track of mileage. At home here in the Smoky Mountains, we going up or down hill all the time and mileage doesn't matter. Saturday is Drive your V8 Day and yesterday we laid out our tour, photo site and restaurant. I now can dirve the antique cars by lifting my leg onto the clutch when necessary. Two new knees still don't work worth a shi*. Drove the 34 Fordor today and am regretting the truck clutch. Maybe I should take the 35 Pickup for the V8 Drive on Drive Your V8 day, it has the softest cluch I've ever had. All my v8's still have the 411 differnetial and high speeds are limited to short runs with bad mileage. Got the Fordor up to 65 today and the neighbor kid was impressed. I think the only 80 I'll ever see is age 80.

1934 Ford's since 1972


FordFreak    -- 06-17-2021 @ 5:53 AM
  My '37 gets about 10 mpg, on a day when the air is good.

1937 Ford Coupe
1952 Ford F1 Pickup
1965 Falcon Sprint


CaliforniaBorn36    -- 06-18-2021 @ 12:42 PM
  1936 Ford Fordor Touring Sedan, 21 Stud, 4:11 (as far as I know) and I average about 10 MPG


Grant    -- 06-19-2021 @ 4:28 AM
  Our '36 roadster with a stock engine gets about 17 miles per gallon at 55 to 65 mph with the Columbia rear end in HI gear.

Around town and in traffic, much less. Don't know for sure, but it might be less than 10 miles per gallon.


EFV-8 Club Forum : https://www.earlyfordv8.org/forum
Topic: https://www.earlyfordv8.org/forum/viewmessages.cfm?Forum=18&Topic=14918