Fuel economy
 

Thought I'd share this with the group.
I just returned from a trip to Chester, CA., where a nice car show is held.
I started from my home in Brownsville, CA with a full tank of gas. The total round trip distance was 298 miles going from an elevation of about 2200 ft down to sea level, then up to an altitude of 4500 ft.
The car is a 32 Tudor sedan with an 288 CI flathead, Potvin 425 cam, 2 4bbl carbs, etc. Rear axle ratio is 4.11, but I have an overdrive that reduces the final drive to 3.21 (not used too much on the climb up, but used when possible).
Mileage on the way up was 16.9 mpg, with an overall of 18.1 mpg
Flatheads can be real good, I think
Thought I'd share
Jim

Re: Fuel economy
 

Let me get this right ! you have " 2 4bbl carbs ?? and you'regetting 18.1 mpg ??

Re: Fuel economy
 

I did a double take on the 2 4bbl carbs regardless of the mpg!

Re: Fuel economy
 

Don't sound like a regret.

Re: Fuel economy
 

Yes, (2) four barrels, NO regrets

Re: Fuel economy
 

Me too! Don't recollect ever seeing a manifold for that....

Re: Fuel economy
 

Please post a picture of your flathead.

Re: Fuel economy
 

That the one with two 4bbl teapots on him?
Martin.

Re: Fuel economy
 

Unless it doesn't have secondary's they are really only two 2 bbl.'s probably 99% of the time.:)

Re: Fuel economy
 

I've talked to Jim, he has a beautifull set up there. I am running 276 with four 97's straight linkage T5 with 3:50 gears. Don't know what that finally ratio is in OD but at 60MPH with a GPS I'm turning 2000RPM. On secondary roads I get 18mpg. Walt

Re: Fuel economy
 

Two weeks ago, scroll to post no. 36-

http://www.fordbarn.com/forum/showth...118#post933118

The only set up like it in existence.

Re: Fuel economy
 

Having been working on improving the fues mileage of our flatheads, I've found that yo must start in the combustion chamber it's self. One reason you shouls try and keep the piston to head clearance very tight. Next the AF in cruise in the hi 14's low 15's, mid 13's in WOT. Followed by a good ignition curve, you need a fair amt of adv to burn a lean mixture. Last but not least is the basic design of the intake system allows the AF mixture to better vaporize before the plug fires. I like to run these engines in the 180 plus range. This is something that takes time and effort. However most people like to tell fish stories, it's the nature of the breed.

Re: Fuel economy
 

I think about 18 MPG is the best I expect with my car.(276 and single 4 brl.) I have checked it several times. The 40 sedan, with Mitchell O.D. is heavy, with my load(3700), and it is not good from the aero viewpoint. However, there is much to be said about the driver when MPG is the focus. I am not a good MPG driver. I installed the MSD adjustable timing device and mounted the dial on my radio grille so I can adjust timing while driving. The crab distributor has limited capabilities when searching for a better "cruise" timing setting. Unfortunately I have not taken the car on extended road trips since installing the toy so cannot report on an improvements.

Re: Fuel economy
 

JWL and everyone:
I expected far less than what I got.
I'm now thinking that on a regular road (not so hilly) that the
car will do 20, maybe more.
On the trip I described, speeds were 65 max, 45-55 normally.
Oh, not really hammering it, so no secondaries were used that I remember.
Yes, 51 merc is correct. It's just like running 2 Stromberg 48's until you
punch it

Re: Fuel economy
 

I'd say that's an excellent result and you obviously have the engine set up very well. Especially so considering the one off manifold and carb setup.

Mart.

Re: Fuel economy
 

Kahuna, I talked to Willie and he pulled the old VW trick on you where he snuck in 5 gallons of petrol in your tank at a stop on the way. Next part of the trick is to siphon off 5 gallons from your tank during your next day trip.:p

Re: Fuel economy
 

My Dad had a 65 Tbird and a guy asked him in sarcasm what he got for gas millage, his answer was "anything I want"! That being said I just got back from Lake George 506 round trip from Ri and got 18.2 mpg with a 276 in a 37 sdn. I have a Mitchel OD with final drive of 2.82. Engine built by who else but Ol'Ron.
Don

Re: Fuel economy
 

Good one, Lou
Don, you did great.
Flatheads are pretty good on gas

Re: Fuel economy
 

37don, what carburetor are you using, and what are the specs? if you please.
thanx, tom

Re: Fuel economy
 

my 51 merc is stock 3spd od and i only get 18 i thought that was really good. guess i was wrong.

Re: Fuel economy
 

I am running 2 new english 97's on a vintage Wiend regular manifold. Carbs have 43 mains and 69 power valves. The plugs are a nice light tan and are champion lawnmower plugs. Engine has 30000 mi on rebuild.

Re: Fuel economy
 

Sooo??:confused:

Re: Fuel economy
 

I have 3.3 rear end stock OD trans, 276ci Flatty with Holly 390. I can get 18/19 mpg mix of highway/light in town traffic. I know the stock engine got best mpg at 30 mph. The drag on a 50 ford is .62 (about double my 2009 Hyundai modern 4 cyl of similar weight and probably similar hp). The drag goes up exponentially with speed so cruising at 65 on the highway won't help like a modern car.

Re: Fuel economy
 

Agree .... these flatties can be good on gas if well tuned. Have a 59AB in 47 coupe that gets 20 mpg on open road at average of 60 mph with overdrive .... single 2 barrel stock except electronic ignition.

Re: Fuel economy
 

When I am behaving myself and keeping between 55 and 60, my stock motored '40 stake gets around 16 or so. The authorities frown upon that speed going through town, however.

I'm running 3.78's, and gained a little mechanical advantage by running 31.7" tires.

Re: Fuel economy
 

I guess I'm in the minority here. Last time I checked, I was getting about 14 mpg with my stock '51 club coupe. That may be because of the type of driving I do; mainly short trips with lots of "stop-n-go" (I have four stop signs before I even get out of resort proper). My shop is another two miles, I have to stop at the intersection it's on and again at the security gate. It's another 3 miles to town with it's intersections and short streets, so I guess it's not to unreasonable. IIRC, that's about what I got with the '51 I had in high school back in '58. I drove that one a little harder, though.

Re: Fuel economy
 

Tubman, I was referring to my highway mileage. Around town is considerably less, as I tend to drive to the exhaust note.

Re: Fuel economy
 

It's a good day in an F-1 when you break 15 mpg. If you think a shoebox is bad aerodynamically, the trucks are like pushing a barn door thru the air, especially if not lowered and with west coast mirrors. But I managed to record 16+ on a trip going from 5300' up to 8000', with lots of up and downhill sections in between, averaging about 55 mph. My air/fuel meter was showing mid-13's by the time I got to the highest country, no better without going downhill. Since then I have made some changes to the Rochester and am hopeful I can improve on that. I'm running a 3.50 9" axle.