Project 1977 F100 - New radiator + electric fan!

[bobo333]

ah ok, im not sure where it was built, i will probably recondition the heads later anyway and check the seats then as well as look into upping the compression. Thats still a fair way off though until i get one of my other cars back on the road to drive while its apart

[ron]

the compression may help but the older 66 I think it was has a smaller cu in engine and smaller wheel base (lighter) so more mileage is possible.

[bobo333]

Ah ok that makes sense.

Ive put the thermostat back in and bled the coolant to make sure there are no bubbles and the vaporizer hasn't frozen up yet, so far so good! hopefully its ok now and my mileage returns to normal with the operating temps back up.

[johnunit]

Very interesting build!

A couple notes from a ford guy:

The silicone only on the t-stat is quite normal. It's hard to find a good gasket for the 351W. I personally run only silicone around my T-stat in my 351W.

The 66 is significantly lighter. Even at the same wheel base, drivetrain, etc. it's a couple hundred pounds lighter.

4000RPM is really, really spinning it. How fast are you moving to rev that fast? Few 351W's redlined from the factory over 5000RPM, though that was as much a restriction issue as wear/strength.

I know Australia had different dates and magnitudes in terms of 1970s compression ratio loss, but a big +1 for increasing compression ratio and seeing what's going on there. At least a leakdown test is worthwhile.

If you haven't already, go through the rear brakes carefully. Aside from the drag issue, you might be astounded at how much dust and rust and crap there is behind the drums.

IMO, if you're not 99% confident in the carb's condition any mileage considerations are pretty useless. It could well be dumping raw fuel at random. Mileage few carbs ever polluted less because they were ailing.

As much as I like a 351W's torque, if you aren't towing something the size of the truck or more regularly, I'd strongly consider some sort of 302 swap. Less internal drag (short stroke, smaller bearings), slightly easier to find parts, and of course just less cubes of air and fuel per revolution.


I can't recommend a 5spd swap strongly enough for this application. You're basically buying 2 more gears. You get the more practical use of first because you can probably use a higher (numerically lower) rear end ratio, and the overdrive 5th. Plus most 5 speeds are probably a more modern (read lower drag) design. If you haven't already, use an internet gear ratio calculator to get a better grasp on what different tire sizes, rear ends, and transmissions will allow for cruising RPM. Very useful tools.

[bobo333]

Thanks for all the tips!

The t-stat gasket ive got seems to be holding fine for now, il keep an eye on it though

sits on around 4000rpm at 100kmh (65mph?) my tacho is a bit dodgy and waves between 3500 and 4500 so im not 100% sure on the RPM but it sounds like its doing pretty close to 4k

Rear brakes are a bit dodgy, they didnt work at all when i got it as it was low on fluid, after filling it up and bleeding them they now lock up real easy if theres nothing in the tray, i will pull them apart and check them over soon

the carb is definitely shot, leaks fuel like a sieve so i use the LPG all the time at the moment, im getting the carb rebuilt soon though

5 speed of some kind and a lower (number) diff are top of my priorities at the moment, one of my mates has a 73 ambulance with a 5speed but all of the numbers on the gearbox and diff are worn off or covered with dirt/oil so i dont know what either of them are, any ideas what combo/s they would have come out with?

with the gearbox i have now i need around 3.0-3.2 rear end to get it to cruise nicely in 4th around 1500rpm, obviously that will change with a different gearbox though.

[Sporty Modder]

Have you figured what rear end you have in the truck now? Easy way to do it is, jack the rear end up put the truck in n and spin the rear tire (mark the driveshaft first) if you have a open diff in back lift only one tire. Count the number of times the driveshaft spins per 1 tire rotation. That is your rear end ratio.

For work trucks in the Us 3.55 rear w a 5 spd or od is considered high gearing,

[bobo333]

Its 4.11, mine has the tag on it that has the ratio, my friends ambulance doesn't though so i will have to jack his up and count the rotations, only problem is its been sitting there for so long its grown into some bushes and is sunk into the dirt a bit

[hotrodfeguy]

4.11's are the killer almost anything is better than that. I swapped from 3.25 to 2.75's in my 77 with a 351M and it was alot better. I think by looking at your engine there you have a 351C or a 351M either way the MPG is in the rear gears right now. I would even leave the trans alone for now. Go with anything but the 4.11's good GOD mate !!!

[bobo333]

Hi guys,

Been a while since an update, havnt done any ecomods lately as i have been busy getting the interior and audio system finished for national Sound Quality competition finals next week...

Carpeted fiberglass dash and kick panel pods:


New door trims:


Custom drivers seat, lower, further back, and closer to the center of the car than before, much more supportive that the couch that was in there before lol:


and a quick walk around video (sorry about the terrible audio, my camera sucks)

http://www.youtube.com/watch?v=0Wh8j...ature=youtu.be

Anyways onto stuff that you guys might be interested in!

I got a new personal best tank again last tank, the new radiator and electric fans has made a decent improvement now that i have it all working properly, 8.16mpg or a 0.23 increase on my previous best

I have also started an airdam with some aluminium U section that i have screwed onto the bottom of the front bumper. I will use this to secure some plastic or rubber strip down the the level of the lowest hanging suspension components

It is also going into a mechanic on Tuesday to get the carby rebuilt and the engine tuned up so i can run it on petrol again if i need to.

Thanks for looking

[Beau]

What drivers are you running in the dash? Passive or active?