My Budget 250 build

chad":10pg80bq said:
can't that change?
Y not use something that can't: Ford HSC Tempo 2.3L/141ci, i4

I thought I was looking for these;

FORD/LINCOLN/MERCURY 153ci/2.5L 86-91 Connecting Rod : HSC/OHV

Is that not the case or are the 2.3L the same? Just want to make sure I would get the right thing if I go this route.

Thanks,
Mike
 
sorry, I listed the piston!
:oops:
 
I think the early .912" wrist pin 240 rods with custom pistons will be the easiest. Zero deck, 58cc chambers, .044" gasket and 18cc!! D shaped dish pistons with a .030" over bore would yield less than 9.3:1 static C/R. If I'm figgerin that right @ 6.795" rod length with a 3.91" stroke. And give you the future option of going to an aluminum head, .044" gasket @ over 9.6:1 SCR with 54cc chambers in the head.

In my mind it comes down to whether you want to save $3-600(or more depending on machine work, balancing, etc) and use stock parts and find a compromise or just go for it, find the right rods and get custom pistons made. If you can't or won't spend that extra dough, it's going to be a compromise. You're either going to keep a lot of the high comp height and lower the compression to compensate, put a huge cam in with loads of overlap that needs to get up to >2K before it starts making power(effectively lowering the compression), or you are going to build a motor that needs every bit and more of the 62cc chambers in the iron heads. And that leads me to another thing, if the heads are being made again, can we get them cast with bigger chambers? This is a huge problem for 250's and the aluminum head if you want to zero the deck.
 
Lots of numbers, too small a brain :roll: I am not the best number cruncher so forgive me if I am way off calculating this, but I looked at this, as one example;

Using these numbers I hope are close? With the following "off the shelf" parts, would this be good or bad?

Silvolite 3332H pistons .030 oversized, dish measure 2.843" did. .276" deep (equals 12.863cc) the Compression height = 1.530
FORD/LINCOLN/MERCURY 153ci/2.5L 86-91 Connecting Rod : HSC/OHV which is, I believe, 5.990 long
I will use a 62cc combustion chamber volume (this is yet to be determined)
Stroke should be 3.91"?
Compressed head gasket at .050" (calculated)
The stock engine currently measures .150" deck height.

Not sure I am right in my calculations totally but the stock 250 rods measure 5.880", replacing them with 2.5L HSC rods I would move the piston up the bore .110" that would leave me with .040" of deck height. Now if I replace the stock US 250 piston with a AUS 250 piston the difference in pin height .030" moving the top of the piston up the bore another .030" leaving me with .010" of deck height which could be milled off the block deck to bring me a zero deck block.

This is why I chose the 3332H piston over the 3328H piston to keep CR down a bit.

Using one of the online calculators I used; 3.711" bore, 3.91" stroke, 62cc head chamber, 12.86cc piston dish, 0 deck, .050 comp. gasket = 9.21:1 CR (I would guess this is Static Compression?)

Those numbers look right? Is the compression too high or low for pump gas? I believe my local station has 91 octane premium with no ethanol.

Thoughts? am I way off?

Thanks for the help everyone.

Mike
 
That will work. It's hard to believe the deck height is currently .150" though. How are you measuring that?

A 54cc chamber will push compression past 10:1. And in your scenario you will want to use the thinner gasket, .044", to get some quench effect. C/R would still be reasonable @ 9.34:1
 
Econoline":bkp840yo said:
That will work. It's hard to believe the deck height is currently .150" though. How are you measuring that?

Thanks Seth.

Just using the depth gauge on the digital calipers with the original parts so it is not totally accurate, any final measurement would need to be done at the machine shop with the new parts installed before doing any decking of the block. I am pretty sure this engine never experienced a machine shop after it left FoMoCo, it has, however had the head off at some point because it had an aftermarket head gasket, I don't have the head because it had a crack in it so I left it at the JY, in hindsight I wish I would have kept the head so I could cut it up and look at the insides. :p

Econoline":bkp840yo said:
And in your scenario you will want to use the thinner gasket, .044"

I just used the middle of the road head gasket according to the Falcon Performance Handbook.

My hope is if I can put the bottom end together cheap enough I can spend a little more on head work and other extras :roll:

Thanks again,
Mike
 
I would expect that # to come down. If the head is off you can get or borrow a micrometer with a magnetic base. You want to measure near or on the pin axis on the face near the edge. Try both sides and both ends of the engine. You never know if one piston was replaced with a shorter pin hgt rplmnt piston. I actually helped a friend last year fix his 170 here and the only solution he could afford for his broken rings and ring lands on the #6 was just such a piston. When he showed up it was limping, we fixed it, had a valve job done while the head was off and when we fired it up, I checked the initial timing and it was off the scale by at least 15 degrees advanced, ie. 30 degrees or so of intial. Culprit. The two months before he was running all over the US fully loaded in a 65 econoline supervan, extended model with a 170! Mind blowing. It's still running today, in Amsterdam of all places lol. If you end up to high for the aussie pistons with the 2.5 rods, they used to make an oem usa smog piston with a 13cc chamber that would work, if you could find them. Or there's custom pistons, or Calspec will mill the cast dishes further out cheap. Imo, there's a reason why silvolite shows the sliced cast profile of the pistons in their catalog. If they aren't hypereutectic, iow if they are oem cast pistons, they're all the same and meat is meat. I'm not losing any sleep over having the 2.5 hsc pistons milled with 8cc dishes for my application. I just wish I would have had them milled further, like 10 or 13 cc's. But a different cam was involved in the get go.
 
Econoline":ar9gzk08 said:
they used to make an oem usa smog piston with a 13cc chamber that would work, if you could find them.

I have been looking for those in case of such a scenario but have not found any yet.

Econoline":ar9gzk08 said:
If the head is off you can get or borrow a micrometer with a magnetic base. You want to measure near or on the pin axis on the face near the edge.

The head and everything else is off the engine, it is just a bare block now, not that I couldn't reassemble but I figured with worn components it wouldn't be very accurate anyway.

Thanks,
Mike
 
The pistons I really like are the used stock size 3.736" 305 forged or 229 V6 forged pistons (Che#y).

Small block chevy 305 cui TRW L3028F

I can't quickly find the other two part numbers for the 305 and 229 older forged pistons, but they are around, and they are great pistons.

I have a 250 over bored 56 thou with 200 Australian Ford rods (300 Ford size but approx 6.275", or 65 thou longer than the the 6.2097 inch 300 rod, and with the stock pin taken out to 0.927")

The pistons came from a Valiant racer who used small block Chev 305 pistons in his 229.

The V6 has an offset inside the piston to suit the V6 crank, while the 305 forged has none.

Each is 11 to 13 cc with an approx 180 thou trench, and the stock compression height is 1.536 vs 1.531" For the Ford.

You can cut the piston down a massive 100 thou with ease. Chevy guys have used stroker cranks or longer 5.85" rods with these.

TRW made them in two part numbers for years, and the take up was good (ie a lot of people bought them for stock rebuilds, as forged pistons like a little more clearance, and if an old 305 or 229 has just been cruising, it won't need anthing more than a plateau hone to bring the taper and ovaliarity into cohee for a forged piston.

viewtopic.php?f=1&t=1579&p=11477#p11477
xctasy":1pze018h said:
My advice is to chat with a good piston specialist. When I talked to my local Ford engineer, he asked me if I knew more than the FoMoCo? The point is, if you want to dabble in the black art of piston swaps, you must ASBSOLUTELY know what your doing. I'm not there yet because my little project I6 build isn't on the road, and I don't have the cash to correct an expensive mess up. Heres what I found about the Chevy pistons:-

There are two types of 229V6/305V8 forged piston. Light duty, and heavy duty. Some will handle a cut of 60 thou or more without weakening, others will be compromised strength wise. Because my 229V6/305V8 Chevy pistons were going into an odd ball 250 block with Aussie 3.3/200 long rods and a Aussie/Argentina 3.6/221 crank, I had a situation where the normal 1.531 inch piston was 56 thou out of my cylinder block. OOOCH!

Calcs were 6.275 inch rods, plus 3.46 stroke halved, all subtracted from a 9.48 inch deck register. That leaves only 1.475 inches of piston top to wrist pin space...less if the deck is 9.469 inches like most of your US 250's. I may have had to shave 67 thou off to get the piston level on that block. And remeber, that a six needs more room for rod and piston streatch at 4000 to 5000 rpm range most I6's max out at. 25 THOU BELOW THE BLOCK IS SAFE
. (I'm told the latest Gen iii Holden has a plus 6 thou piston/block protrusion with a semi cast piston, but the've spent millions getting the piston to dove tail in with the alloy heads on a stiff alloy block)

The solution for me was to mill 60 thou, which is likely to be too much on a cast piston. On a 200, a 30 thou mill would be fine, and would put a Chevy piston back in the block where it belongs. I can't rationalize it, 30 thou is not much to mill a cast piston, but 60 or 70 thou is a lot more and I'd be pretty scared lopping off that much. Could excecute a good piston!

The thing is, most cast and cheeper forged pistons are optimised designs which may have little margin for 60 though of shaving. After spending out on some left over Chevy pistons, which are rare and expensive down here, I wanted the security of a good forging. My pistons are old TRW forgings, can't remember the exact line number. Down here, theres a guy in Christchurch, South Island, who does custom machining of imported US Ross forged blanks, and he says some off the shelf forgings are not thick engough to get savage with a milling machine.

viewtopic.php?f=3&t=67792

xctasy":1pze018h said:
Back before I joined Ford Six, I had a special block made up. My 229 cubic inch X-flow Falcon engine runs a cold run welded cast iron XT Falcon 221 crank (the 1968 to 1970 221 ran 200 Falcon main bearings, but the post 1971 non cross flow and crossflow blocks were all a similar to US 250 bearing size, and also ran the small 200 Ford crank pilot, which was 3.4" diameter rather than 250/240/300/Small Block Ford 3.625" crank flange).

For pistons, some 12cc dish 3.736" 305 and 229 TRW forged pistons which have two different part numbers but are the same piston. Each has a lot of meat in it as a forged piston, with 110 thou depth and an irregular shaped trough of 3.1" diameter on its longest side. Enough to take 110 thou or more off in a lathe. The 1971-1993 3.3 Liter Aussie rods were all 6.27" and are fixed to the 0.927" Chevy rod after a 15 thou hone out from the nominal 0.912 wrist pin. Then the pistons were decked to suit the 9.387" deck register our Aussie ohv 200/250 sixes had from 1971-1993. I had to add a much taller 62 thou head gasket, as the pistons had to be shaved right down a massive 140 thou to 1.39". 1.39 compression height, 6.27" rod, 1.73" throw 3.46" stoke crank, perfect o deck, but the stock nice big Chevy small block dish was totally gone, and the stock alloy head X-flow chambers are 53 cc, so compression was 10.75:1 to suit propane. It solved the L/R ratio problem, but then I lost heart, and as I was looking at supercharging, there was no way to get the C/R down unless I added a 140 thou plate and found another set of TRW Forged pistons as I'd already cut them down. I'd used the first four from the right bank from the 305 forging and the two of the right bank from the 229. The pistons have a 62.5 thou thrust left to right, and the V6 ones were designed for the semi even fire 229, which was designed to run offset conrods. The dish is biased, so you can't just get six the same. Long story short, my combo only works for a high compression engine on NZ 98 octane, and its layed dormant in my basement because of that reason.
 
I ordered 6 of the Ford Tempo 2.5L HSC/OHV Connecting Rods today so I guess I am ready to see if this will work. :roll:

I am holding off on the pistons for now until I know what overbore is required, this will be a long term project BTW don't expect me to come back next week and tell how it worked, I just wanted to make sure I could acquire all the parts first :p

I may try and do a better measure on my bore to see generally what, if any, overbore needs to be done, if I can do a .020" I would rather.

Again thanks for suggestions and advice on this and I am sure I will have more questions as I progress along (if I can get some progression in there)

See Ya,
Mike
 
chad":3gmkpnv0 said:
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)

Circumstances alter cases.

5.45" tall if 2.3 OHV, 3.30" stroke, 3.68" bore Four with 140.4 cubic inch engine with 250 cam postion, but 8.66" tall block
6.00" tall if 2.5 OHV. 3.585" stroke, 3.68" bore Four with 152.5 cubic inch engine with 250 cam position, but 9.36" tall block (Australian 250 block height, 89 thou shallower than 250)

OHC EOA 2 LITER "Pinto 2.0", 4.96-5.00" (good for 200 with Chrylser 3.3 OHV piston of 1.26" compression height )
OHC Lima 2.3, "Pinto/Fox/Ranger2.3" 5.20"
 
I got 6 of these today, Ford 2.5L HSC/OHV Connecting Rods, now I have to figure out how to make 2 of them say 5 & 6 :p :roll:

21ae165c848aacf857ca192f4dc26601.jpg


See Ya,
Mike
 
lavron":3pxymonp said:
I got 6 of these today, Ford 2.5L HSC/OHV Connecting Rods, now I have to figure out how to make 2 of them say 5 & 6 :p :roll:

21ae165c848aacf857ca192f4dc26601.jpg


See Ya,
Mike


The tough as goats knees E63E-B1A.

Nice pick up, solves all the problems. (y) :nod: :wow:
 
Anyone know if the rod bolts are the same as the 250 on the 2.5L HSC rod? Would they use the same ARP bolts?

See Ya,
Mike
 
I believe that they would use the same ARP Rod Bolt, but you might do some quick measuring just to be sure? If you happen to have a 250 Rod handy would you take a picture or two with them side by side. Good luck :nod:
 
bubba22349":3erutbmu said:
If you happen to have a 250 Rod handy would you take a picture or two with them side by side.

I could do that but the pistons are still attached to the 250 rods, I will post a pict if I can press the pin out easy but I don't want to damage the original rods, someone might be looking for some forged 250 rods down the road :roll:

See Ya,
Mike
 
the ARP rod bolts are one of the few upgrades some here recommend for a standard to mid level build.
Have U cked the Tech Archive here (C above 2nd blue horrizontal bar) or the "Handbook" ?
 
See if the bottom of the 2.5L connecting rod will fit on the 250 rod, and vice versa.

The openings on big ends of the rods should be the same diameter.

Or just measure the diameter of the bolts on the 2.5L and 250 rod to see if they are the same.
 
chad":1e2kbiu4 said:
Have U cked the Tech Archive here (C above 2nd blue horrizontal bar) or the "Handbook" ?

The Handbook is like my 6 cylinder bible (I have like the first or second edition and the newest edition), and I have read several of the tech articles.

See Ya,
Mike
 
I was messing with comparing the rods today and pulled one of the rod bearings out, pretty sure they are the original.

274994029fc8eb103e29688c1f170ec5.jpg


And I know this is a crude way to show the difference in length but I don't have a way to press the wrist pin out, so the "precision" ruler is sitting against the pin and then you can see on the other one I was measuring from edge to edge on the holes.

13fee310c10817916755f92d0b68280e.jpg


A bit of difference in length, hopefully I have solved my quench issues if I can keep from getting the CR too high.

I also was checking to see if the rod bolts were the same because I am wanting to have ARP bolts installed and I wasn't sure what to order, looks like regular SBF bolts will work, have to see if I can find a 6cyl set so I don't have to buy the 4 extra, expensive bolts - I think we know why that is :roll: I switched the rod caps and nuts as suggested here to see if they were a match, I was pretty confident they would but better safe than sorry.

e265145cffa2b35bc873df7cd144ba76.jpg


Everything looks good for ignition!

0d82212e3c534d344d1ae44fbe188521.jpg


I really need to order pistons soon so I think I need to do some more measuring.

See Ya,
Mike
 
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