I have a '65 F350 with a dump bed. The engine in the truck is a 240 ci and is original to the truck. It is very tired and has a lot of blowby (so bad that the PCV valve pops off). I like the truck and would like to rebuilt / replace the engine. My questions is 240 or 300. If I am going with the 240 then I will rebuild it. And if I go with the 300 then I will by a rebuilt long block. I mainly use the truck to haul brush and gravel. Thanks in advance for your input.

 

300 is just a stroked 240. 3.98 is the stroke on the 300 3.50 is the stroke on the 240.
If you feel the truck was underpowered when she was still young, Then I would opt for the 300. You will pull alot more with a 300 though it wont wrap as quick due to the bigger stroke. Grab a low miles carbed engine out of a junkyard for a few hundred bucks. A decent stock rebuild should cost about a grand for either of these engines. That is with machining and parts. Your intake, carb, radiator, exhaust,wiring, and distributor should all match up between the engines.

Use your judgement. The 300 is rated about 20 ponies and 40 ft-lbs higher then the 240. Do you need it?

 

My vote would be for the 300. The 300 started production in 1965, and lasted until 1996. It is one of the best engines, most versatile engines Ford ever built. I have a 240, and I plan to drive it until I have issues, and then I will replace it with a 300 long block. I know a 300 will not rev as fast, but you can't argue with history. No other engine survived as long with as few changes.

 

The 289/302/5.0 has about the same life line as the 240/300 did and there are a heck of a lot more of them sold over the 300.

It was good for a time, and a tuff engine, but peeps wanted more than the 300 could deliver. Ford stopped making them because folks stopped buying them. AFAIK, Ford doesn't offer an I-6 at all today.



John

 

Thanks for the input.

Broomfieldbum, you describe my current situation. I have driven the 240 until it has significant issues.

Flipklos, thank for the suggestion of searching the junk yards for a low mile 300. I had not considered that option. What I did not know was the hp and torques differences between the 240 and 300. At this point I am not so sure that the 20 extra hp and 40 pounds of torque will amount to much for me.

Again thanks for the input.

 

It darn sure will on a big truck, you need all of the power that you can get.

Anything late model will be a 300. Bill can check, but I would say there weren't many 240s installed after 1970.




John

 

Go for the 300 longblock use the 240 for your core. Everything should bolt right together. The only issue you may run into is the exhaust down pipe will be 1/2" short due to increased deck hight.

 

Take this oportunity to switch to a V-8. The v-8 will have a ton more power, and not get any worse mileage, in fact depending on your choice it might do better. The 8 wont have to work as hard. I switched from a 300 6 on a 1980 truck I had to a 351w and the power went up significantly and the milage went up about 4mpg. The swap wont be difficult if you choose the right engine all the parts are made to do the swap, so no fabricating. Just my .02

 

Lot more involved with the V8 swap. I would recomend the 300 or using the 240 as a core on a rebuilt.
The deck hight is the same on a 240 as a 300. Externaly the engines are 100% identical.

 

I think I am going to look for a low mile 300 or buy a rebuilt 300 and use my 240 as a core. Thanks for all the input.

 

You know what would be really cool is a 4.9 (300) swap out of a late eighties-96 with multi-port injection. I had a full size '87 Bronco with that motor and it had plenty of power. The wiring would be the tough part.

 

The EFI engines were a lot more snappy. The carbed engines were alot better at the low RPM slugfest that a working truck does. In a 65 F350 the carbed engine is going to show its strengths. Throw a 252 or 260 cam in her and a pertronix ignitor with a flamethrower and you will be able to tug a load at 600 rpm in third. The mild horsepower gain of a stock 300 is going to throw that old worn 240 to the wind. A 240 with 120000 hard miles on a truck that probobly has 4.88 gears has to have an actual output of about 90hp a fresh 160hp 300 is going to be like a rocket ship plus that downlow torque will realy make a load move nice.

I got a carbed 300 in my 85. 252 cam, pertronix in a points dizzy, 3.55 gears. Once she is warm I can feather her out from a 450 idle in third! My 96 couldent do that in second at a 550 idle. I got a 2bbl 265 CFM on a shaved manifold and EFI exhaust goin on in may. I cannot wait to see waht she'll do with that old 190cfm YFA in the junk pile.

 

1965/74 F100/350: The standard equipment engine was the 240 I-6, the 300 I-6, all the V8's were optional.

Little known fact: 1965/72 LTD/Galaxie, the 240 was the standard equipment engine, ALL the V8's were optional.

No 300's in passenger cars. No I-6's in Galaxie/LTD's after 1972.

The 240 was canceled after 1974, so the standard engine became the 300.

I wouldn't spend a cent rebuilding a 240. The early engines (1965/66) were crap, blowby was common, they burned oil like a diesel.

Like most of the members of this forum, I'm a V8 guy. Unlike most of the members of this forum, I'm a loooong time collector of things Ford made.

I've owned 80 FoMoCo vehicles, one was a V12, two were I-6's, one is a 4 banger, the others were/are all V8's.

But...if I was in this situation, I'd pass on installing a V8, and go with the 300 instead. After all, this is a work truck, it's prolly not gonna be an over-restored show truck.

The 300 is a direct swap. Everything bolts right up. The whole tamale of installing a 300 engine will take a coupla hours.

Regardless of what V8 one chooses, changes will have to made in wiring, engine/trans mounts, exhaust and etc. How long will that take? It depends...

1965 F100/350 240 I-6 specs: B&S: 4.00" x 3.18" / 150 Gross HP @ 4,000 RPM / Torque: 234 ft. lbs. @ 2200 RPM.

1965 F100/350 300 I-6 specs: B&S: 4.00" x 3.98" / 170 Gross HP @ 4,000 RPM / Torque: 283 ft. lbs. @ 1400-2400 RPM.

How exactly can one determine how many miles a junkyard engine has? If it's in a truck or Econoline, you certainly cannot go by what the odometer sez!

1965/79: The odometers of these vehicles read to 99,999.9 then return to ZERO!

For decades, used/new car dealers rolled odometers back, which of course was illegal.

So...how many miles do junkyard engines have? Why are all the vehicles there in the first place if not involved in a collision?

Unless you have X-ray vision, are psychic, have the luck of the Irish, and the best karma to come down the pike since grandma was a gal...there's no way to know.

Would you trust what someone in a junkyard told you? Hell, they have zero history with the engine, so how would they know?

 

Bill,

What changes were made to the 65/66 240's to eliminate the blowby and oil burn issues?

Tim

 

It's been awhile so I cannot remember all the "fixes."

I do know that Ford changed the design of the rings at least once, the pistons several times.