200 vs 250

When I started the build in my sig line, original idea was for a 250ci but was unable to find one at the time. Build is finished and contemplating another project, since I finally picked up a 250. What would I actually be gaining with it? Still need the low to midrange power band. Torque curve is more important than horsepower again. You all helped me so much with my last build, figured I'd ask again. Tickled to death with how the last one turned out. Got my V8 power and over 18mpg, life is good.

While I have no direct experience with the 250, my understanding is you gain low power torque from the extra cubes of the 250. However, I've heard the 250 doesn't rev as well as the 200 due to the longer stroke. But, for your application and intended use, that is probably of little concern.

Regards,

The 200 is known for its ability to rev but is limited in power by its miniscule connecting rods.

The 250 is a torque monster and since your most likely limited by a hydraulic cam and the huge crank throws the rpm limit is about 5500 anyways.

If I were building a 250 I would try to bump compression and run as long a connecting rod as I could, maybe around a 7.00" long rod with smaller Chevy inline six rod journals and bushed to use Ford .912" wrist pin.

A strong mid range cam say around 260deg duration and about .470" lift and 112deg lobe centers, ported CI head, 4bbl intake and a Autolite 4bbl with annular discharge around 460cfm.

Add a set of dual out long tube headers and I think that would be a pretty wicked street machine application with lots of stump pulling torque.

While I can't say this is a "budget" build, I've learned nothing is cheap building these engines. I don't really want to spend as much as I did on the 200. I was thinking more in the line of a direct mount 2V with some head work, cam, and header. The head is a 69. This vehicle will see very limited street use. Low gearing, probably 4:56's and 33" tires. Given this additional info, what would you advise as far as cam, carb, and compression level?

are you using parts from your current engine on the 250?

No, this will be an entirely new build. I'm just guessing here, but with most of you dealing with Mustangs, Mavericks and Falcon's, it seems like maybe what you would build for the 1/8 mile.

Explorer":19ubfiu4 said:

...... What would I actually be gaining with it? .....
.......... Torque curve is more important than horsepower again......

Click to expand...

I think you answered your own question; you gain the easiest 25% increase in torque you will ever find right off the get-go, anything you did to the 200 will give roughly the same percentage of improvement from there.
Go for it!

Even I can understand that. 25% free, then how much I want to spend. Thanks guy's.

Instant 25% increase in cubic inches

Here's some links:
viewtopic.php?f=1&t=60043
http://fordsix.com/250swap.php

The hardest thing is installing 255 pistons and coming up with enough money for an aluminum head. I'm going for the performance 2V conversion route. The only serious issue is the lack of double roller timing chain.