The bad part of the Carburated I-6's was the cracking and breaking of the exhaust manifold. I haven't seen anything new on that in years.
The stated MPG of the last Six was 11 Mpg.
The newer 90's Six was 15 Mpg.
My 97 5.4 get's 15 Mpg.

I'd like to have my 77 back on the Road again if nothing newer gets any better Mpg.

 

Yeah, lol, that's why I went with the newer FI manifolds, and pretty soon going to a header. When they went to the TFI distributor and feedback carburetor, that was the worst running 300s of all-time; and a reason why I went to an older carb and Duraspark II with a GM HEI brain. Runs better now, at 427,XXX, than it did when I got it with 8X,XXX miles on it.

 

Whatever Ign I have on the 77, and all my Six's in AK, it all worked good. Great in fact.
We welded and brazed the manifolds. They still cracked.
What worked best was a metal 'sock' or 'heat shield' we wrapped around that exhaust manifold beneath the Intake and a Cover over the upper ends to keep the Cool and real cold air off that manifold.
When I started doing that, I had two Six's with cracked manifolds. It worked pretty well but I still don't know if my 'invention' would have worked with a new manifold.

 

For those with a MPG fetish, read this: FORDSIX PERFORMANCE • View topic - Ekonokrate update....

 

Thanks for the info.

 

I pulled my mixed mpg # today..

17.66 mpg, city/rural driving....A/C on Max, and 1/2 of a TTB in the bed...

 

You guys come up with some interesting stuff.
Thanks for the link to the other Documented gas mileage.

I sure hope I get my shot at another six before I get too old to take advantage of the opportunity.

 

I've owned several and I did get 20 from a couple back in the early 80s. Gas was a lot different then and the speed limit was 55. Both of those would drop to 17 if you drove much over 60. On stock 90s efi engines, I found the 302 actually did just as good or better when driving 75.

 

I think my dream of a 300/Auto trans is finally gone. I've advertised around here and ask anybody driving an older Ford Pickup where I might find some older Fords.

I found a 94-95~ Delivery Van with the Six, all the Electronics and the 4 Speed auto.
Just what I wanted.
Only he wanted $1900! :-( That was cruel!
So my Pasture baby sits till my health get's better or something....

 

Thudpucker,

I tried to PM you, but it will not go through...

I know someone who has a 1978 F100 long wheelbase which was repainted a very few years ago. It has C6 automatic and 300 with A/C and was very nice the last time I saw it. It is in NW Alabama [~70 miles from you]. I am sure it would be greater than $1900, though. Let me know if you are interested and I will get his number for you and you could talk with him.

Give me your email address, since your PM is closed, so this thread will not be hijacked.

 

Many thanks Buddy. Don't know why my PM is closed? I'll see if I can change that.

I can't afford anything right now. We are broke.
If it aint Free, I don't get a shot at it.

But I do appreciate the Tip. You get an Attaboy for that one!

 

Filled up tonight..17.70mpg...

Only difference in the last trip, is that was SLIGHTLY lighter on the skinny pedal and I removed the TTB stuff outta the bed...

Gettin closer to that magic 18!

 

I used to have an '81 F150 4x4 short bed reg cab with a junky 3sp w/OD that the best hwy I got was 22mpg. I miss that old truck.

 

My best mpg's so far are 18.8 in my 92, and 17.4 in my 93. Same engines, trans, and diff ratios, but the 92 has 215/75 r15 car tires, and the 93 has 235/75 r15 GY MT-R's.

 

You can't braze a manifold with any expectation of success. I have arc welded several over the years and they all held, even on our stock car. Just having efi manifolds doesn't mean they won't crack. I bought a used set from a junkyard and the back one was cracked. I went back and both of the other sets he had were the same, plus a set I had off a parts engine at home had a cracked rear. So I welded one and put it on. Even the gurus at the welding/machine shop said you couldn't do it. wouldn't hold. That was 4 years and about 30,000 miles ago. I have a pretty simple process if anyone's interested.