My Budget 250 build

I have been scouring the forum looking for how folks have been dealing with 250 deck height issues and have a few questions.

First I want to reiterate what my end goal is and the means that I am attempting to get there - I want a dependable build that utilizes fairly commonly available parts, this would be, initially, the parts that are most prone to failure (starters, ignition, pumps, etc.) followed by major components that may need replaced in the future (brakes, clutch, etc) I am looking for a road car the can fairly dependably make a 1,500 mile trip with out too much concern, I would like a well performing car but not high performance (it will never see a drag strip or most likely any form of performance competition). I am attempting to get there on a low budget, mostly as a proof in concept that it can be done.

With that said I understand there are certain things that cause the budget to be higher like using the 250 when a SBF would have been way cheaper and easier, but these are personal preferences because they are what I want

With these things in mind I am currently looking at deck height issues, while I know I could leave well enough alone and go all stock Ford 250 rebuild parts, but I would like to make it a bit better in the performance arena if I can without causing much issue.

First off, I need to bore and deck the block anyway (engine has neither been bored or decked in the past) so I will be replacing pistons, I think a .020 overbore will work but may be a .030 - I have been looking at the Oz 250 pistons 3328H, Summit lists them for $150 a set (not sure this is the cheapest place) and RockAuto list stock 30 over pistons for $130 a set, this is pretty much a wash in price. So basically I could get the piston .030 higher up in the bore. I know about the 255-V8 pistons but they are over $200 a set and I can't find rings for them hardly (unless they use 200-250 rings?)

What is a safe number to deck the 250 Block, it seems .030 - .040 is fairly common?

I know I won't achieve the desired zero deck height but I can bring it down some, it this a help or just as well leaving it stock?

I also have the forged stocks rods for what it is worth :roll:

I know you guys have been on me to CC my head chambers and I will eventually get the stuff together and get it done, I just haven't had a chance yet.

Anyway I will start there on just those 2 things

See Ya,
Mike

The US 250 deck height was 9.469 vs 9.38" in the Australian 250.

US 250 shortfall to deck varies between 103 to sometimes 123 thou, but the Aussie to US difference is 89 thou.

This shortfall was the right move for the new plans to go to lower compression engines with higher weight compacts now becoming heavy intermediates, like the formely 2300 pound round body Falcon becoming a 3200 pound Torino unibody, then a 4200 pound perimeter frame intermediate Gran Torino, often in ever popluar Station Wagon form.

Teh 250 was a go to gap filler for when you couldn't get 351 Cleveland, 351M, 400 Ford, or Windsor 351's or 302 Windsors. A low cost, low compression ploddder, which could take all the V8 gearbox options.

It only had 95 to 99 hp net, but pulled around those behemouths.

Just like the old 3.8 and 4.2 V6's and the ill fated 255/4.2 V8, it was a typical "lets use other stuff in a plain wapper base to save costs"

It was HFII's master stroke to reduce costs and fill gaps in the market.








http://forums.vwvortex.com/showthread.p ... p=88171378

It allowed a no cost extra to use the same pistons 1.500 or 1.531 piston deck as the 200.

In Australia, the dish was 200 was the same as the US 200/250, the 221 8.425" deck, same as US 200/250, but the Aussie 250, was either 15.6 or 22.9 or 27.9 cc.

Soooo....

The stock aftermarket high performance 250 Piston in Australia was the US 200/250 piston in either was 5.5, or 8.5 cc, but with improved Hypereutectic construction, and a better skirt design so it wouldn't fly appart. We had access to 95 octane unleaded after 97 octane leaded was withdrawn, so the gas situation isn't the same as with 87 and 91 Octane unleaded you guys use.

The solution is 89 thou longer than the stock 5.885" conrods. An 1986 to 1992 domestic Taurus/Sable con rod cna be resized to become a 5.974" Rod, Before resizing, they were 6.000" blue printed 2.5 Liter HSC/HSO Taurus 4 cylinder.

Good luck finding six of those, but YRMV.

The 1988 to 2017 6.06" I6's rods.

The Aussie 4.0 liter EL2 or AU SOHC /Aussie 4.0 liter BA in line DOHC6.06" rods with either the thickest head gasket you can find would work with a 1.500" 200 or 250 pistons decked a little.

Or 89 thou taller than stock 1.531" pistions. Traget depth 1.620", custom made by Racetek pistons, and you'd use the good 5.885" forged steel 250 US conrods, not the later D8 1978 onwards cast iron rods.

mike1157 is in this same situation now. He got really low deck IIRC 1.455" Racetek Forged pistons made up to suit 5.885" cast iron D8 rods, and he's running them with 12 pounds boost and probably well over 400 hp net flywheel in his Turbo 250 Fairmont Glia Monster. He's planning to get custom con rods made. He always planned to "Do it Twice Mike", and a well machined cast iron conrod can survive, its not the best option, but his engine was always a work in progress. Most 250's have cast iron rods, just the last 3 years, 78, 79 and 80 didn't, and possibly some 76-77's might have had the down grade.

Ford Sedan Delivery just used the stock parts 3 carb Offy 250 Ford engine he sold to another board member here. It used a decked early Large runner C9 170 Maverick head 120 thou, which was just about the time Ford downgraded the casting thicknesses to 187 nominal.

Had the block decked 120 thou, and got his car into the low 14's with stock cast pistons.

You'll go over the options, and find a solution. My suggestions? Do what Mike1157 or FSD did. There is a risk when you take too much metal off, and there is a cost if you use Forged custom pistons. But if the engineering is good, you can do other stuff.

Econoline also uses stock cast 2.3 HSC or 2.5 HSO pistons, CNC shaved and milled to a 9 to 11 cc dish, and thats the dreaded 90 thou offset Silvolite piston that some have trouble with. Yet Does10's (Will and Kelly) did 10 second 1/4 miles with in in a 425 rear wheel hp Falcon.

I have been scouring the forum looking for how folks have been dealing with 250 deck height issues\

The vintage Clifford built 250 I've been driving for @ 10 years all over the NE ( including LV dragstrip occasionaly), has an overbore of .070 and uses stock STD bore AMC/Intl 258 pistons for a zero deck height with shot peened 250 rods opened up to the 258's (+.019 ) pin size.

... the pistons are TRW/SealedPower # 470NP's. The application is 79-89 AMC 4.2 (258).

Ford 250: bore = 3.68 / comp distance = 1.5 / dish volume = 13cc
AMC 258: bore = 3.75 / comp distance = 1.633 / D-Sump = .178(?)

This puts the bore at @ .070 over and raise the piston toward the deck .133 . The specs list the pin diameter of the ford at .9122 and the AMC's at .9310 which can easily be accommodated.

++++++++++++++++++++++++++++
For a 'budget build' with a different approach. here's an excerpt from my forum discussions with Dave Schjehldahl :

Wow!!! Thanks for sharing that discovery. I did a quick search on the Silvolite website and found a similiar piston. It is part #2227. They list the cc volume of the recess at 21ccs- which makes it ideal for this application. It lists the depth of the recess at .185".

With the .070" overbore the bore is 3.75", stroke of 3.91, a Felpro head gasket at .050", a zero deck height, chamber volume of 60ccs and a piston recess of 21 ccs, gives an ideal street compression ratio of 8.8:1!!!

And, the recess is not "D" shaped, but appears to more closely mirror the shape of the combustion chamber of a small ford six. The dish is more of a bathtub shape.

This piston has got to be more accessible to obtain than the 2.5 HSC rod route I've been pursuing.

Thanks for the tip.
Adios, David

The 250 was built many years ago in the Clifford shop while Jack still ran it, and built for a Maverick application but mothballed in original crate and protectively sealed until I purchased for the original speed and modified parts. After bore-scoping and investigating internals with my machinist, it was installed and fired up. The Clifford built 250 in the '61 Comet has run like a Hybrid for over ten years - it burns both gas and rubber ...

have fun

Blueprinted D6DE Ford small block 250 Six; Shot Peened and Balanced Rods, Clifford 272H Cam, 1.88 intake valves/1.50 exh with- silicon springs and HD retainers, Ported and Polished chambers and relieved valve shrouds . Fisher custom Harmonic Balancer, Tri-Power / Offy , Modified Holley 1904 glass bowl carbs, Exhaust ¾ siamese port divider, Re-Curved distributor, HEI ignition, Indexed Champion plugs,s, Glyptal sealed block, Detroit gasket set,. SFI 157 neutral balance-lightened flywheel spinning Centerforce Clutch, T5-Z Cobra 5speed, Short throw Hurst shifter, 8”- 3.80:1 TracLoc Posi rear, Fab'd Caltrac clones, Shelby sway bars, Mustang front strut bars, Scarebird Disc front brakes, Shelby Drop UCA's and relocated LCA's, Fabricated subframe connectors / crossmembers, 8 Point roll cage, 5.0 alum. radiator, Perma-Cool fan, Holley fuel pump/pressure regulators, Hooker dual out longtube headers, Smithy silencers, Original tube radio, vacuum wipers and front fender Gunsights…

xctasy":11zkthq5 said:

Good luck finding six of those, but YRMV.

Click to expand...

What I am trying to avoid is rare hard to find parts, well mostly because that will translate to a higher price and my goal of finding off the shelf semi-common parts.

I am trying to look 10 years down the road when something possibly breaks and needs to be replaced (even though I do hope that is not a piston)

One of my other goals is to avoid custom machining parts, for one thing I am not in an area where there are local automotive machine shops, in the last several years all of them have closed down in our throw-away society.

Is it a good idea to move toward a smaller quench even though I cannot obtain the zero deck that is desired?

I just seems the 3328H would move me .030 closer and then decking .030 would trim the total of .060 off, I know it is a drop in the bucket when trying to overcome .150 of deck height but it seems that would be desirable to just rebuilding to stock, there is the 3327H as well but wasn't sure if a flattop would raise CR too much.

powerband":11zkthq5 said:

has an overbore of .070 and uses stock STD bore AMC/Intl 258 pistons for a zero deck height with shot peened 250 rods opened up to the 258's (+.019 ) pin size.

Click to expand...

I was a little concerned with the .070 overbore thinning my cylinder walls, but you are comfortable with that much overbore, or I guess I would say what are the downside to doing it this way? I mean I like the sound of it and this is not a daily driver but would like to be able to drive it on longish trips and don't want too many failures along the way. I am certain, at my age, the car will never see 50,000 miles on it before it becomes someone else's issue :roll:

Thanks,
Mike

powerband":3rjxlaib said:

... the pistons are TRW/SealedPower # 470NP's. The application is 79-89 AMC 4.2 (258).

Click to expand...

I do like the price

See Ya,
Mike

was a little concerned with the .070 overbore thinning my cylinder walls, but you are comfortable with that much overbore, or I guess I would say what are the downside to doing it this way? I mean I like the sound of it and this is not a daily driver but would like to be able to drive it on longish trips and don't want too many failures along the way.

I can drive anywhere with the 3.80 rear/ OD T5, including interstate back and forth to the dragstrip on occasion. After @ 10 years in the Comet, last fall I blew a head gasket btween #4-5 driving to local hardware store. Looked like the Cyl head relieving/porting was a little too aggressive on the head near the block gasket circumference. Typical @ OEM chambers @62cc's, 250's cyl chamber volume measured @ 59cc's with oversize valve shroud relief' . Installed a regular Fel-Pro (@.045) HG and back to cruising this year...

I have not found any other 250 engines built with the AMC 258 pistons and remain hopeful someone has the interest to attempt similar build for comparisons .

The old Clifford shop .070 over-bore 250 , is partially a mystery. My original investigation of its origin provided hint at an off-center torque plate or selected engine blocks. The harmonic balancer seems a unique item as well as machining of the Holley carb air cleaner necks to fit standard filters and other specially machined features. Literally built ( incrementally budget building ) the 61 Comet around it ... .


.


2006








have fun



.

One thing to keep in mind is that if you ever foresee putting on one of the aluminum heads w/o reworking the short block you will need to build an engine that can use 54cc chambers or less. And with the long stroke of the 250, that is tough without having custom forged pistons made with huge dishes. Unless you can get the deck to zero I would recommend keeping the C/R below 9.3, DC/R @ 8 or below.

When you say 'dependable', does that mean daily driver? Or just rock solid? What is the use and what are your expectations for the car? Big cam high rev machine or ? Where do you want/need the powerband? Smooth idle or lumpy? Manual or automatic trans?

X doesn't have alot of faith in my milled 2.5 HSC pistons. So far so good. It's a low revving engine. Starts and drives daily. I've got about 2000 miles on it now. Been running cool with temp switch cycled electric fan in the doghouse, which is amazing. It will light up the 9" rear end on command The Econo aft end is light though and there are 3.7's in the rear. But with 9.6:1 C/R the engine requires high octane and still needed the vac advance limited to 10 deg and the mechanical pushed out further than what would be ideal. With the initial set to 12 deg.

Econoline":3v8e0fjk said:

When you say 'dependable', does that mean daily driver? Or just rock solid? What is the use and what are your expectations for the car? Big cam high rev machine or ? Where do you want/need the powerband? Smooth idle or lumpy? Manual or automatic trans?

Click to expand...

lavron":3v8e0fjk said:

First I want to reiterate what my end goal is and the means that I am attempting to get there - I want a dependable build that utilizes fairly commonly available parts, this would be, initially, the parts that are most prone to failure (starters, ignition, pumps, etc.) followed by major components that may need replaced in the future (brakes, clutch, etc) I am looking for a road car the can fairly dependably make a 1,500 mile trip with out too much concern, I would like a well performing car but not high performance (it will never see a drag strip or most likely any form of performance competition). I am attempting to get there on a low budget, mostly as a proof in concept that it can be done.

Click to expand...

To add to that; Not a DD, I have another post on cam choices I have not made that decision yet, but not a big cam or a high rev motor, I figure on mostly open road driving, I have a dual out PaceSetter header (that I hope will clear the starter), and finally the engine will have dual 2 barrel Motorcraft 5740s semi-direct mounted to a '72 flat log 200 head that may get '78+ intake valves installed in it, the transmission is a '98 Mustang V6 T5, and it will have a 8.8LSD 3.73 from a '98 Explorer and not that it makes a bit difference to the motor it will have air ride

The only "options" I am looking to do is to add one of the AC systems like Classic Air.

Seth I did read your build and learned, hopefully, something from your experiences, I don't know if you have done so already but it would be nice to see a little follow up (on your build thread) on things you have learned since driving it, it seems to me to end abruptly :roll: at least last time I looked at it.

Thanks guys for any information and if I ever get this build rolling along I will share what I learn.

powerband":3v8e0fjk said:

I have not found any other 250 engines built with the AMC 258 pistons and remain hopeful someone has the interest to attempt similar build for comparisons .

Click to expand...

You are working toward convincing me to give it a try So far the only added expense I see is reaming the rod holes out, not sure what that would cost but I can't think very much. Plus I can get a set of pistons for under $90 that has great appeal to me :roll:

See Ya,
Mike

Have the block decked 103 thou then. Use the Aussie destined, American made piston with the right dish for your desired compression ratio.

Becarefull with the stud to front water pump impellor intersection point...cut down an ARP stud after a trial fit at the new 9.366" deck.

This is since all haskets will be 41 thou or more.

Choice is yours. Cost of potential resleaving exists with all late 1969 small six blocks. powerbands engine is a C8, an early 250, IIRC.

Not worth running 70 thou pistons on post 1969 model year 250's, they are shell moulded castings at the pistons.

Mike1157 resleaved the block on his 78 Maverick engine.


I understand budgets and desires. You'll need 62.5, 100 or 125 thou shorter pushrods. Its all easy to do.

Econoline":x9awklmo said:

.....

X doesn't have alot of faith in my milled 2.5 HSC pistons. So far so good. It's a low revving engine. Starts and drives daily. I've got about 2000 miles on it now. Been running cool with temp switch cycled electric fan in the doghouse, which is amazing. It will light up the 9" rear end on command The Econo aft end is light though and there are 3.7's in the rear. But with 9.6:1 C/R the engine requires high octane and still needed the vac advance limited to 10 deg and the mechanical pushed out further than what would be ideal. With the initial set to 12 deg.

Click to expand...

I love the idea of HSC's and HSO cast pistons, they should work fine if clearance is right, but they do have a greater gugeon pin offset. Just I've been here 15 years, and seen four engines junked with those pistons. Mustangaroo had issues, his son Jason, technically Does10s although he's on record for sayin it was a frozen wrist pin and it was okay at 20 psi boost, and there was Parkwood60. There were some others, can't remember the names and applications.

255 pistons I like too, but you know, YRMV.

My Block is definitely not a C8 block



Is there a way to check the thickness of the deck? And taking .103" won't thin the deck too much?

With my measurements on all the old parts in the engine, I do not think (near positive) the deck has ever been cut, I was getting .150" deck height and my bores were all measuring standard.

Am I correct :roll: that there is 3 different Aussie Pistons and the difference is recess size (or the lack there of) ? The 3328H, 3332H and the flat top 3327H.

And I guess I will ask this because you mentioned it, are the ARP Studs the way to go, I was considering them?

Thanks for the info guys keep the suggestions coming they do really help me.

See Ya,
Mike

they stress need of using the APR rod bolts around here...

chad":pel4y8te said:

they stress need of using the APR rod bolts around here...

Click to expand...

yeah the stock ones are the weakest point in the engine...

Yes I intended to replace the rod bolts.

See Ya,
Mike

powerband":3me5pbwr said:

......





have fun

Click to expand...

Ah D7 BE block. That's why you could go 70 thou, PB.....
Thicker wall construction than the Cleveland plant engines after 1969.

lavron":hgbmz7fb said:

My Block is definitely not a C8 block

Is there a way to check the thickness of the deck? And taking .103" won't thin the deck too much?

With my measurements on all the old parts in the engine, I do not think (near positive) the deck has ever been cut, I was getting .150" deck height and my bores were all measuring standard.

Am I correct :roll: that there is 3 different Aussie Pistons and the difference is recess size (or the lack there of) ? The 3328H, 3332H and the flat top 3327H.

And I guess I will ask this because you mentioned it, are the ARP Studs the way to go, I was considering them?

Thanks for the info guys keep the suggestions coming they do really help me.

See Ya,
Mike

Click to expand...

A cover meter or sonar depth gauge will do everything with a great chance of success. You can hard fill the block with cement grout if you get nervous.

viewtopic.php?f=1&t=76986

xctasy":hgbmz7fb said:

According to Ak Miller and the details on the new shell moulding processes at the Cleveland plant, after 1969, Ford started downgrading the iron thickness. For early heads, 90 thou is the practical limit, but you can go to 120 thou like FalconSedanDelivery did on both his head casting, and the block deck. Rocker geometry then has to be checked and adjusted.

After 1969, the average casting droped to 187 thou bluenprint at the Cleveland foundary, and for cylinder bores, they shell moulded down to 130 thou. Great if your making them, not so good if your reconditioning. Compared to a Chevy 283 or early small journal 327, the heads measure 242 thou everywhere,




with no less than 180 thou in the working face of the cylinder bore. Ford used to make engines like that, Y blocks, I blocks, FE's. Lima MEL 430 and 462's.....it wasn't a cost cutting measure made until Ford won LeMans, and then it came time to pay the rent. Less iron less cost. Its not an issue unless you really need a lot of compression.


60 thou for head planing for C9 heads to E1 heads, and 30 thou for overboring blocks. The 250 always had a lot of deck height, you can cut em down 120 thou, but block cracks around the head studs can occur unless some stress reliving is done.

Click to expand...

xctasy":9yk06tb9 said:

You can hard fill the block with cement grout if you get nervous.

Click to expand...

Guess I don't know what that is, you will have to excuse me for being ignorant on this.

xctasy":9yk06tb9 said:

but block cracks around the head studs can occur unless some stress reliving is done.

Click to expand...

What is the stress relieving process?

Sorry if I am asking dumb questions.

See Ya,
Mike

So if one had 6 2.7 HSC rods what piston do you use, the stock 250 piston?

See Ya,
Mike

lavron":h0udegs8 said:

xctasy":h0udegs8 said:

You can hard fill the block with cement grout if you get nervous.

Click to expand...

Guess I don't know what that is, you will have to excuse me for being ignorant on this.


Its called Hard Filling the cylinder block. Mike1157 did it to his 250. You mix up standard aftermarket cememt grout called HardFill,which has a 25 MPa rating or greater, and pour it into your block to add strenth into the bottom of the cylinder walls. A normal 250 has perhaps a 10 quart water capacity, adding HardFill might fill up 1/3 to even half of the water cooling capacity in the block. The metal that comes off during the milling process is replaced with cement. In your case, you'd pop in some plastic hole gromets or water proof ProMerseal, and turn the block upside down, and grout the underside of the head gasket face to add strenght to the decked block to head face.

Cement and steel have exactly the same co-efficient of expansion, so when heated up, the two dis-similar materails have a constant affinity for one another.

xctasy":h0udegs8 said:

but block cracks around the head studs can occur unless some stress reliving is done.

Click to expand...

What is the stress relieving process?

Sorry if I am asking dumb questions.

See Ya,
Mike

Click to expand...

Point 1 stress relieving process

viewtopic.php?f=2&t=74583&p=573513#p573513

old jupiter":h0udegs8 said:

From the late great Joe Mondello:

http://mondello.com/page23.html

We've all heard the stories about how Packard and other top-end carmakers of the Thirties used to leave their raw castings out in the weather for a year to get some thermal cycling and stress relief before machining. And long service in a vehicle is supposed to do this as well. One thing I found surprising (and evidently Joe did as well) was the amount of stress-relieving and "moving around" that he found even in block and head castings that had been seasoned by years of thermal-cycling and vibration in passenger vehicles before being stripped and re-machined for hot-rodding and racing use. Since he built fixtures to hold crankshafts for shaking (and freezing), apparently those parts also come out of street machines still having some locked-in stresses. (As always, how much are you willing to spend?).

There's a conversation in another place on whether 300 EFI heads are particularly prone to cracking. Seems to me that if you find a used EFI head that passes pressure-testing, et al, once you do a little hand-detailing to chamfer sharp edges, this is one part that maybe should take a ride on the shaker table (and then get re-tested) before you do final re-machining, valve-grind, porting, etc.. Again, this costs money, but might be worth some piece of mind for any part that seems to have a marginal reputation. What do you smart guys think? Flyer?

Here, read this one too. The owner of the machine shop I've been using for decades has been saying how crappy all the parts have become recently.

http://mondello.com/page24.html

Click to expand...

lavron":h0udegs8 said:

So if one had 6 2.7 HSC rods what piston do you use, the stock 250 piston?

See Ya,
Mike

Click to expand...

Point 2. Forged steel 6" 2.5 Ford ohv I4, NOT the 2.5 OHC Ranger truck engine.


HSO 2.5 pistons, the port EFI 4 cylinder Sable/ Taurus base engine. Stock 250 or HSO or 255 or 200 pistons.

Thanks for the clarification X.

So is a casting number E63E-B1A the correct 2.5L HSC rod? Or does anyone know the correct number?

See Ya,
Mike

can't that change?
Y not use something that can't: Ford HSC Tempo 2.3L/141ci, i4
(? SilvolLite-KB 1185, lighter? Sealed Power 489P)