360 gettin 7.5 mpg!!

[Ford428CJ]

Originally Posted by TheTinian Ok, well I already have a set of long tube header (dont know what brand though), with straits and dual 40's. Also have 4.10's with 37's. It dont do bad RPM wise i can run between 65-70 at about 2000. I know im not gonna be able to push to much out of it, just 7.5 mpg is kinda harsh at 3.10 a gal. I really dont have the money to upgrade everything to make it a 390 right now. But i guess well see.... Your math doesn't add up here! 4.10 gears with 37" tires and doing 65MPH is 2,425RPMs So if you where doing 2,000RPM's then your speed is 53.717. I think slowing down will help. 65 to 70 is a little fast. Here is a web site to figure your speed and rpms http://users.erols.com/srweiss/calcmph.htm

[adamraaron]

I think i'm getting around 13mpg in my full ton truck after I did all my conversions. It has a 390...

[NumberDummy]

You can upgrade the engine to a 390, you can swap dizzies, you can add headers, different cams, carbs, yadda yadda yadda.

You will spend mega bucks doing all a this, but...you'll be lucky if you get more than a 2 city MPG gain, and the money spent, will buy a heck of a lotta gasoline.

Prior to 1975, regular grade leaded gasoline was less than 30 cents a gallon nationwide. These trucks have the aerodynamics of a brick. NO one back them gave a hoot about gas mileage.

1960's thru today's Ford F100/150 average gas mileage: 8-12 city / 13-18 highway.

Purchased new in 1965: 1965 F100 8' styleside, 352 2V w/ Borg-Warner T-85N Overdrive, 3.70-1 rear end ratio.

Now: 1965 F100 390 4V (built from the original 352), balanced and blueprinted, w/ C6OZ 390 GT cam, dual exhausts, Cobra Le Mans ovate air cleaner, Borg-Warner T-85N Overdrive, 3.00-1 axle ratio. City mileage: 8-10 MPG / Highway...best was 28.7, but that was averaging 45 MPH on a Route 66 Rod Run. Usual hwy average is around 20.

[Freightrain]

RPM is everything, but once you start trying to push these things fast(over 55) you'll kill the mileage no matter what you try. Wind resistance will be the worse thing you have to deal with.

Try this, put a vacuum gauge on it, drive it at varying speeds up to 65 mph and see what kind of vacuum drop you get for keeping it at certain speeds. I'd bet that keeping it up to 65 is pretty bad.

Just some thoughts.

[Ford428CJ]

Originally Posted by NumberDummy

You can upgrade the engine to a 390, you can swap dizzies, you can add headers, different cams, carbs, yadda yadda yadda.

You will spend mega bucks doing all a this, but...you'll be lucky if you get more than a 2 city MPG gain, and the money spent, will buy a heck of a lotta gasoline.

Prior to 1975, regular grade leaded gasoline was less than 30 cents a gallon nationwide. These trucks have the aerodynamics of a brick. NO one back them gave a hoot about gas mileage.

1960's thru today's Ford F100/150 average gas mileage: 8-12 city / 13-18 highway.

Purchased new in 1965: 1965 F100 8' styleside, 352 2V w/ Borg-Warner T-85N Overdrive, 3.70-1 rear end ratio.

Now: 1965 F100 390 4V (built from the original 352), balanced and blueprinted, w/ C6OZ 390 GT cam, dual exhausts, Cobra Le Mans ovate air cleaner, Borg-Warner T-85N Overdrive, 3.00-1 axle ratio. City mileage: 8-10 MPG / Highway...best was 28.7, but that was averaging 45 MPH on a Route 66 Rod Run. Usual hwy average is around 20.

I dont disagree with ya on what you are saying. Why run a old school cam??? The new camshafts are a lot better in design then the old stuff is. Better power and better for fuel mileage.

If he plains on fixing up the truck, he will have a killer runner and a good looker. If it comes down to a money thing then buy a Honda or a Toyota. LOL Most people are into the old Fords because they love them! Not for the money LOL

I got my little 390 with nothing special. Headers, Ignition, Performer intake and my 750DP at the time. All in my lifted 76 F150 with 35's for tires and 3.50 gears, 4" lift, 3" body and got 16mpg out of it! Keep the speed down to 55 but no more then 60mph.

Then I dumped in a 11to1 Solid roller cam 428 and got 12mpg (highway)out of that. But you had to be real easy on the gas LOL. Not bad for what it was....JMHO

[TheTinian]

[quote=Ford428CJ]Your math doesn't add up here! 4.10 gears with 37" tires and doing 65MPH is 2,425RPMs So if you where doing 2,000RPM's then your speed is 53.717. I think slowing down will help. 65 to 70 is a little fast.

Here is a web site to figure your speed and rpms

http://users.erols.com/srweiss/calcmph.htm[/QUOTE]

Ok well maybe its 55-60 my speedo is way off and that was a rough estimate. Anyways its not like im constantly running that fast, just on occasions.

[GunMuse]

I know this is an old topic but it has so much random crap by people relaying information.

470cfm Your carb is too big.

Its a big block 3,000 rpm is running it hard. Speed of the air through the carb will effect atomization. Bigger carbs means slower air and less atomization. Your not drag racing so stop listening to guys who dream of big cars with big carbs.

Add a Rear-mounted turbo or find one of the 330cfm 2 barrels that were fairly common.

EdelBrock makes a 500cfm carb that when tuned properly can jump your FE to 12-14mpg

Shaving the heads. Actually solid advice the 360's were low compression engines so shaving the heads or add some boost in the form of supercharge or turbo.

YOUR FUEL has been turned "green" it doesn't vaporize worth a damn.

Now this is going to sound a bit crazy but Improve your cooling system to handle a bit more load then start some leaning methods that are illegal for racing but fine for the road.

I.e. SPARK super hot spark can and will jump your HP and MPG but it will make the head run hotter and Melt points or even the aftermarket Solid state point replacement systems. So you need to spend some money here to do it right. Remember we updated our cooling system as part of our UPDATED thinking on these engines.

SPACERS are your friend on a FE Further more take 3 layers of stainless door screen and make a screen that breaks up the air stream and put it under the spacer not under the carb. This combo will increase your throttle response and is illegal in circle track racing because the increased response tears up the corners on the tracks when racers accelerate out of them.

Gear ratio. This took me a while to get over myself but taller is not Greener. Your mind wants to tell you that less rpms = less gas. Less Load = Less HP required So a balance has to be struck between rpms and what the AIR is doing going through the carb remember as you lower RPMS you reduce the effiency of a carb to do its job.

390 vs 360(or 352) MORE VOLUME of air means higher air speed with all other factors the same. Soooo yes a 390 ends up being more effiencent but not because its a 390 only because people are using the same parts on all size of engines.

600cfms vs the 470 Modern 600's are more likely to give you a 300 cfm without bleed by the secondaries like older carbs had. so swapping those out does improve mpg but not because bigger is better.

The Old tri-power engines ran triple 200's and ran most of the rpm range on only a single 200cfm carb with 600hp to 800hp depending on engine manufacture.

Do not let Race track marketing override your decision making USE MATH and set up the engine as best you can.

I think most shade tree mechanics looking for MPG needs to lean on Edel and Holly to reproduce a low cfm carb for daily drivers.

330 cfm 2 barrel tend to be outstanding setups on these engines with more intake volume, spark and cam that lets the engine open up a bit.

[MeanGene427]

One thing about a 360, the compression is so low, that installing a cam with any kind of duration increase just compounds the problem, just flogging a dead horse. They might have put in a stock replacement timing set for a 360 during the rebuild, though, which is the retarded smogger set, so a straight-up set would help some, and not too expensive- maybe even advance it a couple degrees. An Autolite 4100 or 4300 makes a great mileage carb, and the Pertonix kit helps too, 6AL box if you can afford it, they will work with your future engine too. Spending a lot on peripherals for a 360 is the old lipstick on a pig thing- it's only gonna look so good, no matter how much you spend. I'd look at the timing set thing, carb, & ignition, tune it to a gnat's ass, and start looking for a good core car 390, instead of pouring money into the lipstick fund