I don't post here as often as I should, but I thought I would provide some information on my latest trip in my 69 F100.

I usually only use it around town, but this weekend I went on a 432 mile "jaunt" to Atlanta. Except for a broken oil cooler… having to cut braided stainless steel lines off with a set of wire cutters... taking a bath in hot oil... and getting caught in a traffic jam.... everything went "relatively" well...

Here's the mileage:

14893.80 (Starting mileage)
15056.85 13.192 (12.36 mpg)
15193.90 14.245 (9.62 mpg)
15326.50 11.065 (11.98 mpg)

432.7 miles and 38.502 gallons of premium. That averages out to 11.32 mpg.

With the exception of the 9.62 mpg area, the rest was cruising on the interstate at a fairly even 70 mph which is 3000 rpm. The 9.62 mpg is due to the traffic jam in Atlanta and driving around town trying to find an address.

Anyway, here’s the vehicle configuration:

Engine:
472 cu in (460 bored .060 over)
D2VE Heads w/SCJ Ports w/351C 4V valves (2.19/171)
1.73 roller rocker arms
Flat top hypereutectic pistons
Small cam (I can’t remember the specs off hand, but something in the area of .518 lift and 272 deg. advertised duration … I think)(Yes, I know a bigger cam would REALLY help! )
Weiand Stealth SCJ intake
Holley 750 vacuum secondary
E-250 Van exhaust manifolds (2.5 outlets) feeding dual 3” exhaust with three chamber Flowmasters.

Drivetrain:
C-6 w/low gear set and “R” Servo
3.50:1 traction lock, 28 spline, 9” differential
31 x 10.5 x 15 tires

I’m pretty sure I could nurse a couple more miles per gallon if I could get the rpms down some… say with an overdrive unit (I’ve had 2.75’s in it and just didn’t like them…) or driving slower. But any slower and I would be taking my life into my own hands!! Especially in Atlanta… GEEZ!!! Crazy drivers!!!

I just thought I would post those numbers for everyone’s information for comparison with other setups that people may have out there.

 

11.31 with that built 460 at 70mph sounds like good mileage to me.

 

I owned a '67 F-100 from 1977 - 1981 it had the stock 352 2-bbl. and it never got over 11 mpg. Most of the time commuting to work I got about 8. Wouldn't you love to buy gas at todays prices to feed that MONSTER.

proud to b hear,
Great Parts

 

from nc to wv , pulling a trailor (empty ) 390 , 3 on the tree, 3.25 gears , 70/ 75 mph @ruffly 3000 rpm . headers . duel 2 1/2 exhust 8.5 mpg ...... want to go with a new carb , cam and intake package from elderbrock but hate to see my millage then lol

69 f100 wht didnt you like about the 2.75 im thinking going to 3.0 to drop my rpms im thinking going to a t5 tranny but i hate the idea of loosing my 3 on the tree.. just love that old time feel .. i really dont do that much high way time with it but really want to drop the rpm's down at least 500

 

I have and highly recommend a stock Borg-Warner T-85N Overdrive transmission if you want better mileage, are thinking of swapping trannys, and want to retain the good, vintage feel of the 3 on the tree. I don't know how hard these are to find these days because I was told I was lucky to have found my original Overdrive truck. Not sure why the great luck, but I do know the transmission does a great job.

A much easier way to gain fuel mileage is to eliminate the belt driven cooling fan and go to an electric unit. Much less engine drag.....

 

I had a 1972 F250 2wd all stock, 360 4spd 4.10 dana 60, 4wheel drum brakes no PS, 235/85/r16 all seasons, 112 miles round trip commute mostly highway mostly between 60and 70 mph average 19.1 mpg. thats a Canadian gallon 4.54 litres . US gallon 3.78 litres.
These numbers were for a 10 month period in 1989 on 87 octane fuel, truck started with 68,000 original miles. Truck was a handfull to drive in traffic, always needed to have an escape route! Can you say BRAKE FADE?
I still have some of the parts off it stashed away.

 

19 mpg !!!!!! id kill for that with 4/10 gears lol

 

I would love to convert to a manual overdrive transmission from the current C-6, but with the low end torque of the 472 and using a clutch would be too much "fun". I'm probably going to go with a Gear Vendor O/D unit that is the stand alone type. I'll just replace the carrier bearing with the GV unit and shorten the driveshafts as needed. But boy have they gotten pricey! OUCH!!

And I agree about the fan. I already have dual electric fans on the Lincoln radiator. In 100 degree weather it still runs hot while cruising at 70/75 mph, but with the addition of an oil cooler (which is what broke on the way to Atlanta and I had to bypass it), it runs a little cooler. Once I stop, the fans pull the temp down fine, so it looks like I have a "capacity" issue with the Lincoln radiator that I need to research/rectify.

Thanks for all the comments. Before the trip I washed and waxed it... the first time ever since it was painted 15 years ago (crappy paint job so I didn't see any need to waste the time and effort to wax this behemoth!!). I'll see about posting some photos in a day or two.

 

69 f

460 60 over think anything you do youll have a hard time keeping it cool lol ... will deleating the fan reduce that much drag??? what didnt you like with the 2.75 gears would have thought with a c 6 and a hot 460 you would have had the best of both worlds .. i got 3.25's and want to go 3.0 or 2.75 to get my r's down at least 500 or so .. i turn just a tad under 3 grand at 70/75 mph just seems to be screeming to me .... would love to see 18 19 mpg right now would be happy with 15 witch is ahummmmmm 1/2 of what my ahummmmmmmmm import gives me ...... lol russ

 

I'm not really sure about deleting the fan as far as freeing up power since from the "get go" I installed electric fans. There was just no way to get the Lincoln radiator and shroud to line up with the engine.

I had the 2.75's while I was having this problem:
https://www.ford-trucks.com/forums/s...d.php?t=360892

So now that I have that fixed, it might be a lot better. But even with the 2.75's, I was still turning around 2300 - 2400 rpm (I think...it's been a while) and was getting about 10 mpg. I would love to shoot for 2000 to 2100 rpm at 75 mpg. But I have to admit... flooring it at 70 mph and 3000 rpm really "pulls".

 

69, Something isn't right with your setup. At 70 mph, there should be enough air flowing through the radiator that no fan at all is required. If it is still runing hot you might want to do some digging to see what might be wrong.

Properly installed electric fans work better than the old stock blades because they route the air better. A few years ago I sat in my Taurus for an hour and a half ideling with the AC running and it 96º out. The temp guage never moved from it's normal operating range. On the other hand you can't look in there and see the radiator either.

What you have described should not happen. I run the stock app with my FE and as long as it is moving a little the temp guage stays where it should, but it will not idle more than a few minutes without the temp guage moving up in hot weather. I need to install a shroud, that will help funnel the air better.

my 2

John

 

69, what kind of water pump do you have ? Some replacement water pumps are better than others. The genuine Ford pumps usually do well. Some of the replacements just don't move as much water. With a stock engine, one might never notice the differance. But with a warmed over one...the the differance can show. What pulleys are on the pump ? It seeems to be a normal hotrodder thing to slow the water pump, power steering and alternator for more rear wheel power, but charging difficulties and hot running can result. Finally, how are your hoses ? a good pump can suck a bottom hose without a coil inside flat rather easily....and not much water moves through as a result. DF, @ work on lunch

 

The pump is just the basic AutoZone remanufacuted pump. The new engine I'm building for it has a pump that I have installed the anti-cavitation plate on it. The pulleys are OEM 76 Lincoln town car (IIRC), as is the radiator which has been recored last year.

I agree, that this thing should not be running hot. It doesn't over heat, it just runs a little warmer that I would like when I'm cruising, but only when the outside air is 95 to 100!. Everything is new and or been flushed and my flow appears to be good. When I added the oil cooler it really helped a lot, but I have also only driven in 80 deg weather so far. When it hits 100, I'll have to see. (But the B&M cooler broke on my trip to atlanta so I got pissed and will be replaceing it with this: http://www.fluidyne.com/pl_theoc.htm...18,%20DB-30816 (DB-30816) )

I need to install an O2 sensor so I can double check my mixure, but according to reading the plugs, it is dead on. They look brand new after about 5000 miles. My timing is set to where it runs great on premium, but pings on 87 octane, so that shouldn't be an issue. And the vacuum advance is hooked up. I have a 160 degree thermostat and it stays right there as long as the ambient temp stays in the 80's or below.

IMHO, there are two ways to cool an engine... water in the jacket, or cool oil throughout the internals. I'll eventually get it to where it stays where it should no matter what. I just hope I don't have to drop the coin for an aluminum radiator!!!

Thanks for the info and I'm always open to different thoughts! Hey, 2,000,000 heads are better than one!!