200 to 250 worth doing

[65-coupe]

I have the chance to buy a 1972 in good shape 250 for 100 dollars. Not sure if buying it and replacing my 200 in my 65 mustang is worth it. I will still be using my CI head and intake on it. I might get a bigger cam like the 274/274 or 280/280 instead of the 264/264 I have in the 200 right now. About how much power should I gain by switching. I realize it will take some work to get it to fit and have to buy some new parts to get it all to work. I would like other opinions on the switch being worth doing.

 

[rbohm]

i think the effort is worth it. better torque curve with the 250, and better power potential as well where it counts, low to mid rpm ranges. as for actual power gains, perhaps 20hp or so.

 

[First Fox]

...or you can gain another 75 horsepower by installing a big a$$ Chinese turbocharger on your 200.

 

[xctasy]

Turbo or supercharge, or 4.9 EFI the 200 you have. Keep the cam, and do it as a work in progress. Its a stock configuration, and its just easy to use what was there, stock.


The 200 verses 250 is just like comparing a 302 to a 351. The little 302 is reliable, and easy to mod, the 351 is always a cagy engine to modify successfully, and as you get greedier, the chances of you screwing something up, go up. Its the blocks mainly, with the bigger I6 and bigger V8's in the same block bore spacing always at more of a ragged edge. They should be more reliable, but they aren't, and that is one reason the 3.3 and 5.0 outlasted the bigger 4.1 and 5.8's by a few years.

The US 250 is another 25% capacity, but it takes an better gearbox, axle, and a cut down carb air horn and better engine mounts to fit under a 65 hood. Lot of extra work, and then you've got custom pistons, better rods and timing chain matters to contend with.

Then you have to offset the extra weight of the 250, and pretty soon, the 25% of extra capacity is only a 9% power boost, if everything is apples matching apples. On my Aussie based tall deck FAZER engines, the 25% extra capacity yields an 11% power increase. A turbo or supercharged 200 will make 380 hp, the 250 425 hp. A stock 3.3 port EFI using a very basic intake will make 168 hp, but as a 250, its only 188 hp. A Tuned Port Injection 200 will make 225 hp, and a 250 will make 250 hp with the same system.The bigger engine needs a more cam and air flow management to get a proportional power increase. 9% for the US 250 verse the US 200.

 

[FalconSedanDelivery]

Well I will vote for a 250 every time , yes its taller ( I ran a Teardrop Scoop ) The extra TORQUE is the Key , (very muck Like My Harley Sportster 883vs1200 only not much more HP , BUT Almost 50% more Torque ) add the Aluminum Head and its a Combo I would of loved to build , The Transmission Options alone make up for the Cost of a different hood / Scoop IMHO In a street driven combo CUBES always win

 

[65-coupe]

Thanks for all the replies not sure which way to go still. I like both engines but still hard to deiced. I welcome more opinions.

 

[65-coupe]

Turbo or supercharge, or 4.9 EFI the 200 you have. Keep the cam, and do it as a work in progress. Its a stock configuration, and its just easy to use what was there, stock.


The 200 verses 250 is just like comparing a 302 to a 351. The little 302 is reliable, and easy to mod, the 351 is always a cagy engine to modify successfully, and as you get greedier, the chances of you screwing something up, go up. Its the blocks mainly, with the bigger I6 and bigger V8's in the same block bore spacing always at more of a ragged edge. They should be more reliable, but they aren't, and that is one reason the 3.3 and 5.0 outlasted the bigger 4.1 and 5.8's by a few years.

The US 250 is another 25% capacity, but it takes an better gearbox, axle, and a cut down carb air horn and better engine mounts to fit under a 65 hood. Lot of extra work, and then you've got custom pistons, better rods and timing chain matters to contend with.

Then you have to offset the extra weight of the 250, and pretty soon, the 25% of extra capacity is only a 9% power boost, if everything is apples matching apples. On my Aussie based tall deck FAZER engines, the 25% extra capacity yields an 11% power increase. A turbo or supercharged 200 will make 380 hp, the 250 425 hp. A stock 3.3 port EFI using a very basic intake will make 168 hp, but as a 250, its only 188 hp. A Tuned Port Injection 200 will make 225 hp, and a 250 will make 250 hp with the same system.The bigger engine needs a more cam and air flow management to get a proportional power increase. 9% for the US 250 verse the US 200.

I already have a 8" rear end and a T5 trans. The pistons for both the 200 and the 250 are the same price from Classic Inlines. I also have a low profile carb hat from spectra. Getting a bigger cam for the 250 is easy. I might get a custom grid too. I would have to get a new bell, flywheel and clutch.

 

[bubba22349]

Tough call the 200 is a great engine for its size and weight. X2 but Like FalconSedanDelivery I really like the torque of the 250. Good luck in your build

 

[xctasy]

Keep what you have, forget the 250.

A bird in the hand is better than two in the bush in this case.

As stated, lot of extra work. I don't want to insult your obvious smarts and devotion to the 250 cause, I've never had a problem with the Aussie 250 ever, but when you lean on the US 250, its not reliable as the 200. When you lean on either when they use stock rods, they can fail unless the rods are upgraded, and the 250 is disproportionally expensive to get right compared to the 200.


Despite the advise here, unless you risk decking the block 103 thou or leaving the huge ledge that stock US 250 has due to its piston shortfall,

1. You have to get custom pistons, CI doesn't have what you need to suit your application

2. You have to get better than stock rods

Then

3. there are timing chain matters to contend with.


Any US 200 or US 250 is an interference engine if the conrod bolts or rods go, look at the wreckage from Parkwood60's 24 hours at Lemons race engines.

I have loved my 250's, Ive got em by the barn load, but this is a case of an Aesop's fable where the dog looks to get the reflection of the extra bone in the water...https://www.youtube.com/watch?v=QpWKBBDyiqo

In my modest opinion, going to a 250 when you've got a 200 is pointless, and you won't get benefits unless you spend big.

A stock 7.803" low deck 1963-1965 narrow block 200 with an alloy head sits at about 337 pounds all up

A tall 9.469" 250/4.1 engine with an alloy head sits at about 481 pounds, so that extra 1.666" of engine deck height makes an extra 144 pounds heavier than the lightest possible 200 engine.

A tough 144 pounds of 250 engine block, puts the gearbox and axle under more stress, its torque that does it, not the less than 25% power increase, all of that extra over the front end, which is already unable to wield la 5 turns lock to lock steering gear. If you go to 4 turns lock to lock steering it will be heavy, and you may even need power steering to cover off the extra 144 pounds.

But its your ride, and everyone here know you'll make whatever choice you make work really well.

Good fortune!

 

[bmbm40]

A good 250 for a $100 I would definitely pick that up if you have room for it. They are a bit harder to find these days. I am a big fan of the 250 with the torque at low and midrange. That turbo option is sure attractive and several guys on here have done that so good resources to help along the way.

 

[Econoline]

What's wrong with the stock rods? Mine has forged rods('70), I've read some later ones aren't, not sure about '72, still pretty early.

 

[rbohm]

1. You have to get custom pistons, CI doesn't have what you need to suit your application

dont forget that the 255 ford V8 used 3.68" pistons, but had the taller ford 302 pin height, thus bringing the top of the piston much closer to the top of the block.

2. You have to get better than stock rods

that depends on what you want from the engine. stock rods do well in mild applications, but i agree that if you are going to lean on this engine, better rods are required.

3. there are timing chain matters to contend with.

yes this is an issue, but it can be dealt with easily enough. there are two different options for a full roller chain listed in this forum.

 

[xctasy]

1. You have to get custom pistons, CI doesn't have what you need to suit your application

dont forget that the 255 ford V8 used 3.68" pistons, but had the taller ford 302 pin height, thus bringing the top of the piston much closer to the top of the block.

2. You have to get better than stock rods

that depends on what you want from the engine. stock rods do well in mild applications, but i agree that if you are going to lean on this engine, better rods are required.

3. there are timing chain matters to contend with.

yes this is an issue, but it can be dealt with easily enough. there are two different options for a full roller chain listed in this forum.

Just to continue the healthy debate....

I think the 1.585" tall Silvolite # 1176255 4.2 pistons are still marginal, and with a 49 thou short fall and close to 4.5 cc relief from the four eyebrow cuts, its unable to lower the compression below 10.5:1 enough with the cam timing that makes proportionally larger power. Its constrained by that factor.


But the pistons with deeper dishes allow the most indestructible rods per dollar, the 6.21" 300 Ford items, but you then have to either sleeve it and bush it to accommodate cheap cast Aussie turbo pistons, or do something even more expensive. There are heaps of options, 288 bucks for ones that won't work well, and 590 to 690 for ones that will, all expensive.


Then you can't easily degree the cam, and then you have to custom build a timing gear set from SBF 302 parts to get it degreed right. Stock replacement chain sets aren't the ideal.

http://www.summitracing.com/int/parts/u ... /make/ford

 

[65-coupe]

xctasy thanks for all your info and everybody else on here too. That is why I posted this so that I could other people that know more then me about the 250. If I did go with the 250 I would try to get the stroker kit that Mike has on his. Not sure if it is still available. Most likely keep the 200 and either turbo or go with EFI and raise the C/R when I rebuild the bottom end. I still will go look at the engine and might still buy it. I think I will just stick with the 200. I have a buddy that might want the head and power by Ford valve cover. Hopefully they will let me pull the head off to look at the block.

 

[my way]

For 100$ I would put that 250 in my inventory
You need to know plain silvolite (if not hyperutectic) and sealed power cast pistons are called replacement and do not actually have the regular comp height the originals do. Most are .020 shorter to accommodate machining during regular rebuilding (block decking)
Currently have a 250 rebuild project. Going to use sb gm 6 in rods. Have both silvolite #1185 and Sealed Power 489p pistons cataloged as 1.5 comp height--NOT SO They both have 1.480 comp height.
Measuring the original piston height in the block before disassembly things would have come out with 1.5 pistons and 6 in rods with pistons about .005 out of the block. Have been buying every head gasket I came across, so have plenty of thickness options to arrive at a desirable quench even with a light block decking. Anyway all out the window as calculated because of these short pistons. SOOO as the crank needs .030 to get 2.1 gm rods to work, the plan is to offset grind the crank as much of the .030 as is practical and still have a clean journal, and deck the block the remainder to get the piston above the deck .005-.007 .
Point is check for actual comp height rather than cataloged height!!
My way

 

[FalconSedanDelivery]

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

 

[xctasy]

I've gotten 8 years out of one of my 250's, so I'm not anti 250 at all. But I've gotten 4 years out of my 200, and love it even more.

Then again Parkwood60 has blown up a heap of 200's.

I remember what Falcon Sedan Delivery said. Get a Durapark II. But his advice made your DUI work brilliantly for you. Then he said Put a 600 4-bbl Edlebrock on it. But then the 2100 Autolite and 390 cfm worked to give over 123 hp (155 flywheel hp), up form 78 to 80 rwhp (111-113 flywheel hp) with the 32/36, a 36% boost in power.

Remember that with just 450 cfm of triple carbs, he made his 250 run low 14's.

For straight line power, go cubic inches.

So I'd have to say that if you just follow Falcon Sedan Delivery's advice, you'll probably avoid the costs most would incur doing a 250 swap.


I guess what I'm saying is that if your able to network, you can make a 250 really work well, and it will be fun, and you'll maybe make budget. That's why we talk, so we get the right answers to problems.

The Silvolite #1185 and Sealed Power 489p pistons are a solution to a problem. Stroking, 6" rods and using ones brain to make everything fit is also good.

Your 4cylinder T5 won't like the awesome power a 250 can make if its done right, nor will your 8". Our Alloy head 250 weighes in at 481 pounds dressed, without power steering and a/c, 144 up on the alloy head US 200 which is 337 pounds dressed, so your US 250 must have a lot of metal taken out of it. You might not like extra pounds over the front end. But I keep looking at FSDs old triple carbed Mustang and how it made 220 hp with just three stock Autolite and Holley carbs and I know anythings possible.

And he did it all with the stock defective 250 timing gear on a ballistic compression ratio http://fordsix.com/forum/viewtopic.php? ... ng#p447439

And known problems with what happens with triple 1-bbl carbs under acceleration.

For 250 quarter mile figures despite all the problems a 250 has, see FalconSedanDelivery's old beast.

http://fordsix.com/forum/viewtopic.php? ... 31#p502631

FSD set up is very creditable 200-225 flywheel hp, and most likely the most powerful triple 1-bbl around. He ran a unison linkage, high initial advance of 16 to 18 degrees, total timing to 30 degrees its all in at 2350, decked block 100 thou and head 120 thou for huge 12.3:1 C/R, and the worlds neatest tri power intake ever seen. His best was 14.39 @ 91.76 mph one hot June 2011, and was shifted at 5000 and 4300 at the traps, earlier runs were 5200 and 4700 rpm. He ran with 3.5:1 gears for the 14.39. Best 60 foot time 1.915 secs in a 2600+ pound car with a an estimated 165 at the rear wheels. That's a minimum of 220 hp with a C4, probably more




But then I look at other great engine builders, and see that even the better components still fail

 

[62Ranchero200]

Just to add my 2 cents to the discussion:

I had a 200 in my '62 Ranchero, and over the course of the last year and a half, swapped in a 250. The 200 was reasonably "built" - heavier valve springs, CI 264/264/110 cam, Autolite 2100 2 BBL (1.02/245 CFM), Pacemaker headers, DSII ignition. It's mid-range performance was its best attribute, and made it pull strongly from stoplight to stoplight.

The 250 is heavily modified, including "early" 300 rods, custom pistons, and the CI aluminum head.

It's nowhere near an "apples to apples" comparison, because the aluminum head changes the character of the 250 completely. Nevertheless, I'd still say that the 250 is a significantly better performer across all RPM ranges: off-idle, midrange, and top end. With some upgrades to the bottom end - ARP main studs, ARP rod bolts, 300 rods, dynamic balancing - I'm certain that the 250 is good for 6,000 RPM (Gene Fiore has been spinning his 250 that high on a regular basis for years). For a street-driven car (even if it's street/strip), your engine will spend most of it's time in the low to mid-range anyway, so the 7,000 RPM potential of the 200 is something you won't use that often. Yes, a $600 set of very short custom pistons was needed to use the 300 rods - but if you're already planning on using an aluminum head, another $600 should not be a show stopper. In return for that cost, this combo yields near zero deck height, excellent "squish", and a very low tendency to detonate. You can tune the size of the piston dish according to how much static compression you want, depending on whether you're willing to pay for racing fuel or to limit yourself to available pump gas.

The 250 also allows you to use any BH, TC and starter compatible with SBF.

I'm certainly not "anti-200", but I do believe that the 250, with it's lower RPM range, will definitely make more usable torque in a street-driven vehicle. For drag racing, I think a really "built" 250 can certainly give a 200 "a run for its money".

Thanks
Bob the Builder

 

[xctasy]

The point is just that, it costs to make a 250 work well. FSD says the trans pattern and torque make the 250 the deal breaker. For me, the US piston short fall and timing gear make it a liability. But you guys have given 600 dollars of free advice, and at the end of the day, the money is saved if the right parts are used...you won't have to do the rebuild twice.


I worry about the thin wall casting of the block, the lack of depth in the head bolts, and there isn't any way I'd ever use stock 255 V8, HSC or 2.5 pistons on stock rods.

I'd sleeve it down with GM 4200 sleeves, keep the deck stock, and use better Aussie DOHC 4.0 deep dish turbo 3.632" pistons, and am quite happy to use later model EF Falcon OHC crank and some Nissan 240sx rods as well. All of that will allow for absolute abuse. But then I'd be looking at taller valves to carry more lift, a roller cam, and then it would start to get a lot more expensive...fast.

 

[65-coupe]

There is alot of info to really think about which way to car. I will still buy it and deiced later on which to rebuild the bottom end. I will be spending my time and money on paint and body starting in jan. Lots of sanding for me what fun. But I guess I have alot to still learn about both engines and really way out what will give me the best street engine and bang for the buck. I guess I need to add up the parts list for each bottom end and go from there. Would the extra Tq be worth switching to the 250?