I just got around to checking the gas milage on my F-7. It still has the original 337 flathead. It turns out that I am getting a whopping 6.16 MPG!!!!!
John
NNY

 

6.1, Cool! I'm still wondering whay my 239 in the F-5 will get

 

I am wondering the same thing. Its got to be better than that though, I don't think its possible to pour that much gas through a holley 94 two barrel. Hey john please tell me thats loaded with like 20,000 lbs pullin a trailer!!!! seriously, how fast were you traveling and about what kind of RPMs were you pushing? By the way, an awsome, really good looking truck!!!

 

Not bad mileage! My f600 with the 390 gets 7.....Empty.

 

Those old engines were not very efficient they have a pretty low compression ratio.

 

My engine is still at the machine shop. They tell me that it will have about 9.5 to 1 comp ratio. I'm hoping that it'll get somewhat decent mileage. IF I can find a good OD trans I expect it will wit the 2 speed rear.

I guess we'll see!


REgards,

Rick

 

thats great mileage! my 239 8ba get 8mpg driving in the burbs on flat ground-pulling nothing

 

Snipa, your mileage makes me feel a little better about my 239 8BA. I'm getting just over 11 mpg with it and thought it was way too low. I used to get around 14 or 15 with a stock motor on my F1 but after this upgrade (3/4 cam, Offy 400 heads, and 390 4bbl Holley) I lost some.

 

6 eh? Make sure that you guys figure out all of the tree huggers IP's and block em from this sight mmkay?

 

There is a guy here with a 239 in a car and he claims to get like almost 20 mpg. Is he full of crap?

 

Hey Scott,
my 8-9mpg is on STOCK!! wait till next spring when I put my 2 holley's on

hopefully I can knock the mileage down to 6mpg (i gave up trying to get my mileage any better this summer---new power valve,new jets, new plugs , new plug wires, 26 degree dwell at 475rpm---still CRAPPPP)

 

That's just not right. Have you got good compression, 180 deg. thermostats, and the timing/vacuum advance working correctly? It should get 14 easily. Usual problems are the Holley/Ford 94, 160 deg thermostats, and Loadamatic distributors.

 

I'm hoping for more. The other thing that kills mileage is RPM. If you're turing 3000 RPM on the freeway you're gonna "suck the gas" as it were!!

Higher compression, higher coolant temps, correct jets, and high gears are the recipe for better mileage.


Regards,

Rick

 

Ross,
I have not tried testing the timing/vacuum advance-whats the best way for that?

I also have not checked compression-i do suspect that it is not so good (when it first starts up it's a little smokey, black sooty water-like stuff on floor under both exhaust

the other areas you mentioned i have checked, and are good

thanks!

 

According to my 54/55 shop manual those years OHV 239's had 7.2/7.5 to 1 compression ratios respectively.

It's about as good as it gets. Compression ratio is DIRECTLY related to efficiency....(MPG for those of you in Rio Linda!)

The newer 292's for example had about a 9.5 or so to 1 comp ratio. You can still run regular but that's about the upper limit for it and if you get the timing advanced a bit too much it'll "ping". Timing will also affect mpg. (Too retarded will lower efficiency)

If you have smoky-sooty exhaust, install smaller jets in your carb. or check the float level...it may be way too high. Also change your air cleaner(if it's plugged)


All this stuff is pretty standard stuff. comp ratio is fixed though. you cannot change it unless you rebuild the engine.

Go down to the local autoparts store and get yourself an advance type timing light. You can actually measure your timing at different RPMs. This way you can determine if your distributor is advancing at the correct rpms stc.


Regards,

Rick