200 to 250 worth doing

[First Fox]

Would the extra Tq be worth switching to the 250?

Dollar for dollar, using what you have and installing a hairdryer will yield the most torque per dollar spent, i don't think anyone can argue that. And as Xctacy was pointing out, the 200 lacks a few design flaws that are inherent in the 250 and are only corrected at a considerable cost. The 200 is the way to go from a dollar per horsepower standpoint and you are already set up for it.

If you were starting with nothing and money was not an issue and you wanted to build a small six to make the most torque and horsepower, then yes the 250 would be the way to go. For those who have to stretch their play money out and still want power, there is indeed a substitute for cubic inches... Positive manifold pressure.

 

[62Ranchero200]

Would the extra Tq be worth switching to the 250?

Dollar for dollar, using what you have and installing a hairdryer will yield the most torque per dollar spent, i don't think anyone can argue that. And as Xctacy was pointing out, the 200 lacks a few design flaws that are inherent in the 250 and are only corrected at a considerable cost. The 200 is the way to go from a dollar per horsepower standpoint and you are already set up for it.

If you were starting with nothing and money was not an issue and you wanted to build a small six to make the most torque and horsepower, then yes the 250 would be the way to go. For those who have to stretch their play money out and still want power, there is indeed a substitute for cubic inches... Positive manifold pressure.

Off topic ... this thread makes me wonder what a 250 with an aluminum head and positive manifold pressure could do.

Thanks
Bob

 

[First Fox]

No need to wonder, Will and Kelly have already figured out what what a boosted 250 will do. High 10s at 130 MPH.

Although its not really a street car and they probably have more time and money invested in that falcon than I have in all my cars combined, it still is a shining example of what can be done given the enough time, money, knowledge, tuning and perseverance.

 

[xctasy]

First, the extra cubes and simplicity of the 250 are outlined by mike1157.

......
First, the 200:
The 200 has 80k miles on it and it looks pretty good inside. The engine is the one that came in the car, (so, it fits w/o any modifications) and already has all of the accessories I want in place. It is complete,..and up until today, ran.


The problem I have w/the 200 is the lack of a bell mating surface to accommodate a full size 4 speed auto trans (i.e. 4r70W) I found a company in Colorado that makes an adapter to allow a 2.3 engine to mate to a SBF pattern trans, and I'm pretty sure that I can order the thing "undrilled" for the 2.3 engine, and transpose the 200 bell pattern onto it. It sells for a reasonable 185.00.

As I said earlier, plans are to T/C the combo, and fuel inject it. The problem w/that is that the injection is a mega squirt,.... and has no run time on it. Starting a new engine w/a brand flat tapped cam requires a break in process that I'm not willing to risk to a untried fuel injection system. I do have the old stock 200 cam shaft and old lifters that I could install for a short time until I get the injection "dialed in",..but obviously that requires I tear it back down at some point to do the cam swap for the turbo.
The rub comes from the temptation to completely rebuild the 200, including a new set of forged pistons. this engine looks like I should be able to get away w/a minimal .020 over bore to get it to clean up.

The 250:
The reasons for the 250 are obvious,..50 more cubes, a longer stroke, more tq as a result. It has the SBF bell.
The cons.....it don't fit w/o oil pan mods, the accessories are not as neatly bundled. The block is worn out, and the cylinders are beyond boring,...I'd have to sleeve all 6 cylinders (which aside from cost, would add back some structural integrity, and allow me to return the bores back to standard. (a plus considering the turbocharging I intend to add))

The iron head: I copied another member here and cut the cast log intake and exhaust completely off. I will make a tubular intake w/a log style plenum w/ a throttle body on one end. From what I've read, cutting this head for a bigger exhaust valve (1.5) runs the risk of breaking into water, and after the amount of work already invested, I'd hate to have to ship the heavy pig off somewhere to have it welded. I'd have to modify the valves and ports to make the targeted power(400/500), additionally I'd have to swap the cams, but not after getting the injection right.

The xflow:
I know what's involved w/ making this head work on either engine. I contacted Crow cams, and the quote for the cam shipped to me was not unreasonable. (330.00) The problem again is installing a flat tapped cam (this one all the way from Australia) in a new engine that has an untried fuel injection system. So,..again I would have to modify the block to allow for the head swap, unscrew the blocked passages to allow a cast iron log head to run, use the raggedy stock cam currently in my 200 until I'm sure the injection is right, then tear it back down, plug the passages that are not required, install the xflow head and install the turbo cam and run the thing for the required break in period. The look of the xflow alone is justification for me to use it, the aesthetics of having an intake on one side, and the exhaust on the other just makes sense to me. The huge weight savings is just a perk.

So the dilemma......which engine, which head would you choose...........provided you're still with me.

Off topic ... this thread makes me wonder what a 250 with an aluminum head and positive manifold pressure could do.

Thanks
Bob

My Answer to 62Ranchero200 and mike1157 was the same...250 iron log heads make 445 hp rwhp without even trying, despite way inferior cylinder head flow rates. That's because the cam specs and intake define power more than port shape and flow.

Under a little more boost (18 vs 16 pounds) , and a little more weight (2900 verses 2835 pounds), the iron sawzall log head, turboed Fox 250 has bested the most power of any US 250 ohv turbo engine. fast64ranch did similar mph as Does10's but with more dynoed power in a street car. Mph figures are close to being right down the line. The Idahoers Idaho potato verses Arizonian Good Oak having a Little Spring, yeah!



See http://classicinlines.com/dynoroom.asp#D5

viewtopic.php?f=1&t=62208&p=543513#p543513

Has anyone ever flowed a log head that has had the log cut off?

Yes. But you'll be disappointed
The gain is no better than worked 2V and inferior to any alloy Classic In-lines on ported on intake. Power wise, the gains aren't really what you'd expect, although when turboed, they show a stellar gain on the early Classic In-lines turbo configuration, that's only because Kelly's car was in its infancy when dynoed.


Like my old preacher said, Miss a Read, Miss a Feed....

viewtopic.php?f=3&t=70720&p=542156#p542156


JGTurbo from Portland, Oregon.viewtopic.php?f=22&t=54242

http://i484.photobucket.com/albums/rr20 ... 9/Flow.jpg



and fast64ranchero from Boise ID, viewtopic.php?f=22&t=52695

1975 250 head, 1.75 and 1.5 valves, mill'd head with my own hand made intake, and exh 168cfm @ .5 intake 128 cfm @ .5 exh. flow numbers

This compares with the 2V intake 1.649 to 1.75 and 2v exhaust 1.388 to 1.50 upgrades which with a general port cleanup give a flow gain of 170 cfm to 190 cfm on the intake side and from 110 cfm to 135 cfm on the exhaust side. Aussie 2V's have large valve guides and aren't that fantastic for exhaust flow.


Read more: http://www.mustangandfords.com/techarti ... z2goSyvR9Y


Check also 73greenmachine, send him a PM, and do some chatting. He has had 200's, 250's, logs, modified logs and now a Classic Inlines 250. The whole time, he's used a flow bench to help him out.

 

[xctasy]

Mind you, the equivalent of about 308 flywheel hp should be enough to make most 200 turbo owners happy.

Looks like Matts 66 Mustang could be added as Dyno #10 on the Classic Inlines site

http://classicinlines.com/dynoroom.asp#D10

viewtopic.php?f=22&t=70797&p=543103#p543103

Hey guys, been a while!!!

Matt

 

[xctasy]

The 250 weighs MAYBE 20lbs More , I leaned on The 250 I built , it was fine , would I turn it to 6000 No ( the LOG head would never support that anyway ) but 5500 with the Aluminum Head easy!! My 250 walked away from almost EVERY N/A Combo on here , based on ET , and My home track is easy .25 slow compared to most , still sticking to the 250 , but its my opinion Race / a class car HP per Cube , the 200 would probably win , on the street / strip , I vote 250

Hey there. I did the research, and your right. Although I did see 450 listed in Popular mechanics 1972 I6 family car test, it might have included a/c or perhaps p/s or air pump

I did some follow up work, and found that your indeed right on the 250, our Aussie engine which was a little bit shallower was 410 net.

Problem was, our Aussie iron head and alloy head 9.38" tall 200/250 engines were rated as 481 alloy head, and 532 iron head, dressed.

200 were listed as 365 until the wide block update, which made them 385 pounds.

In 1971, the tall deck came out, 410 pounds as a tall 200 or 250.

That's 25 pounds more right there.

The cross flow, due to its head and block width, was way heavier, and weigh's in more than a stock 302, which is 470 as an early carb engine.

 

[xctasy]

You'll also notice that when listed as net hp, the 25% bigger short 5.88" rod, 3.91 stroke 250 yields only 10% more power than the long 6.275", 3.126 stroke 200. Both Aussie engines, unlike the USA 200 and 250, ran the same camshaft timings. As gross power, the bigger 250 is only 19% more powerful for a 25% increase in capacity.

But torque wise, its 25%.


The point being that at either 93 net or 130 gross, the long rod 200 is over 17% up in power over the same US 200 engines. The Big Aussie 250 is the same as the pre emissions US 250.

 

[CNC-Dude]

At the bare minimum if done correctly you should always be able to gain 1HP for every cubic inch you add, so yes it's always worth doing.