200 or 250

Im thinking about building a drag car, we have a local track and Im looking for a new hobby. My SIL would do the driving.

Im funding this with the sale of my 64 F100, so 10-13k is the budget.

Ive got my eye on a 61 Comet, 170/3spd.

Which is the better engine for a drag car, the 200 or 250? Is the extra weight offset by the extra cubes? How high can I rev either engine??

I would stay with a 3 speed. log head, single 2v or tri-power, and as much cam, compression, gears as I can get away with.

This would be a winter project.

I'm not the expert on building drag cars, but here are some dyno runs done by multiple other members.

https://fordsix.com/archive/www.classicinlines.com/dynoroom.html
It could be a good place to start getting ideas. One thing to note on the 250, your weak link is going to be the timing chain. We don't have a COTS solution in the US for a double roller. Others have made it work though Does10s and Mike1157 have managed to make it work. A significant amount of engineering went into Mike1157 build. Check it out here:

https://fordsix.com/viewtopic.php?f=22&t=75514
https://fordsix.com/viewtopic.php?f=1&t=70927&hilit=gila#p543942

Alot of the pictures have disappeared from the second link there. You might have to go to the FourEyedPride forum to find them. I know he was posting alot of his build progress there as well.

Good luck and let us know what you pick!

Howdy bmcgc1960:

Either engine will do fine so long as either is built appropriately. THe big difference in the two is the length of the stroke. Neither has an ideal rod to stroke ratio, 1.5 for both. IIRC the weight difference is not huge, about 50 lbs. An advantage for the 250 is the ability to adapt to a variety of transmissions more easily than a 200. The 200 is likely a quicker rever due to its shorter stroke while the 250 will be torquer because of its longer stroke and additional cubes.

What class are you planning to build to?

There are several members here that have been racing either engine for years. Check them out.

Good luck and keep us posted.

Adios, David

Hi David, I ma building the 250 log head modified for sportsman racing 12 second index, only, no street use, turbo charged on e-85. Concerning the timing chain I have read the modifications that Will has done , he is running a mid 10 second car with the aluminum head and turbo charged. Is there a point where the double roller chain is mandatory? I plan on a 6000 to 6200 rpm redline. I have so much to learn yet. Much thanks Randy

In most performance builds in this day and time, its pretty easy to achieve 1 HP per cubic inch, so with a 250, you're at a 50 HP advantage right off the bat, plus a definite increase in torque because of the 250's longer stroke as has been pointed out. Also, because one engine may be able to rev higher than another one doesn't mean its going to outperform the other. Most of the time it just means it will make more noise, giving the impression it is going faster. I for one think you'll be ahead of the game by choosing a 250, plus as has been mentioned already, you will have better tranny selections.

Then there R plenty of 300 / 4.9s being raced.
We have a forum for 'race" I think it's called 1320… look at the index page.
Also "Nitros, super & turbo charged" forums.
This IS of course the best forum :nono: but THERE ARE others , may B more to your purpose…

as the saying goes in drag racing,

"there is no replacement for displacement, except rectangular dollars"

i would build a 250 considering the success that deoes10s has with his. the longer stroke combined with a bit stiffer rear gear pays dividends on the starting line, and that is where most races are won or lost.

next i would dump the three speed manual in favor of either a four or five speed manual, or a three speed automatic. if you plan on driving the car on the street as well as the track, go for the five speed.

as for how high these engines rev, in MOST cases the 200 can rev to 7000rpm when properly built, and i would limit the 250 to about 6000-6500rpm. in most drag classes that is plenty.