I have just bought a 65 F100 with the original 352. I plan to rebuild the motor as part of the project.

I want to use the 352 because I would like to restore the truck to original condition as much as possible. I have read alot of things on the forums regarding the 352 ( some good, some not as good). However, I want the original motor in the truck more than I want additional power, torque, etc, from other engines or serious 352 modifications.

As I want to use this truck as a summer time daily driver, I am aware of the apparent poor gas mileage of the 352. Is there anything I can do as part of the engine rebuild to improve mileage?

I would consider sacrificing some of the originality for improved driveability, if I needed to.

 

I replaced the carb on my 66 with a 352 and my mileage went from 10 to 15 MPG and acceleration was much improved. It a stock 2bbl Motorcraft that was rebuild by Holley. I got mine at O'Reillys for about $160.00.

 

Since you are not opposed to some changes and since a Fe352/390 from the outside looks the same, you might want to seriously consider changing it into a 390. You will get more power better mileage and no one but you will visually
know the differance, Put a 352 sticker on the air cleaner and let all marvel at
how much power you get out of that 352 by your expert tuneing.

 

10 to 15 mpg...the old carb must have had a leak.

For MPG from a 352.... tighten up the carb with respect to no leaks, proper float level, experiment with one down jet size, make sure the choke works correctly and the power valve is correct.

Rebuilding? 9.0 compression, esp if you are in the low 8s or high 7s will make a diff.

Ignition timing, as much as it will take.

Dual exhaust with a crossover tube.

Low restriction aircleaner.

Accessories in good condition.

Don't expect miracles.

 

I Hope you do not mind my asking a question. What is meant by the timing statement above? Is 12 degrees better then 8 or 10?

Thanks!

 

Gernerally speaking, yes. Seems like most all my Fords like 12° BTDC...BTW, we are talking initial timing only.

 

I plan on driving the truck for many years, so I am going to have the motor completly rebuilt. What is required to turn the 352 into a 390. I suspect that since I plan on going to this level of work, the cost may not not be more than the 352 costs.

 

Requires a 4.05 cyl bore, 390 crank and the short FE rods. This can be done economically as 390 cranks, rods can be found fairly cheap. The 352 block stock is 4.00" bore and will easily take 4.05". New pistons won't break the back either for a desireable CR.

 

I have a 352 in my current 67 F250 and I like it just fine. Years ago I had a 67 F100 with a 352 and I liked it. What is wrong with the 352 now. If it runs and doesn't burn oil etc I would just clean it up and run it. No since in rebuilding it unless it needs it. What tranny do you have. If you have the NP 435 look at the diff gear ratio. !st gear in the 435 is useless unless you are really loaded. My 250 has 4.10 and I am trying to figure out what the highest ratio that will make 1st act like it should and then 4th will seem like I have an overdrive for much improved mileage (I hope).

 

I have thought about that too 60F100. You could probably get away with running a gear ratio around 2.75 I am guessing. Your 1st gear would be fine but that jump to second could be a killer. I would be interested if anyone has tried it. Bueller? Bueller?

 

If you build it into a 390, you may build it to be a relatively economical 390, but it will eat more gas than the 352 if the 352 is built with the higher compression etc. You want fuel economy, build it for economy and put a 330/332 crank in it...

 

What kind of Compression Ratio do you get with stock (translated: Cheap and readily available) pistons? Go to your local library and look in the old manuals for these years. The 352 has a respectable Compression Ratio among truck engines.

I'm not busting out the manual tonight, but the granny low in the NP 435 is too steep, and it's not synchronized. Stick with the 2-3-4 shift and play with the gearing.

 

I have run a 2.75 behind my 352 C6. It will run the truck OK but is a dog when towing. I currently run a 3.00 and it is a better all round ratio for me. The 2.75 will sip gas better.


John

 

A respectable truck engine CR is too low for economy. (7 & 8 to 1)

Things are cheap and readily available for a reason. The OP said he wanted to build for economy. That requires a higher CR than the stock truck engine.

Now it's gotten into building a 390. Economy or performance, the OP has to decide.

 

What Kind of mileage do you see with the 352/c6/3.00 setup Jowilker? What size tires are you running?