All Small Six 250 pistons
- Thread starter comet6
- Start date
This relates to all small sixes
Yes they are a great way to go in the 200 Six since it brings the top of the piston up to a zero deck height or very close to it. It's a near perfect solution without needing to mill the short Block down as much to get to a Zero Deck Height, all of the spec's make it a Win Win. Good luck
Flat tops will bring CR in a 250 up to 11:1 or so, which is generally too high for regular fuel. The ring pack given in metric will be the same as the USA setup, they have metricated the dimensions. the latest of our unleaded 250s have a narrow low friction ring pack, but they do fail, pretty sure they were locally made ACLs. Flat tops work in 200s, and 221s (getting a bit high here). Can you get them?
It shows the pistons available, but rings are expensive. The cheapest rings are nearly as much as piston set. I am a little confused with compression ratio. The advertised cr 9:1 stock but I can't get those numbers when doing the math. If piston is .123 in the hole with 6.5 cc dish and .045 gasket, a 64cc head makes it around 8:1 ?
These same above pistons can be used in the USA 200 or 250 inch Six in our engines this pistons as I stated above would bring the Piston to deck height for a 200 Six right at a Zero deck height or very close to it this is excellent great for a 200 Six. This doesn't work out quite the same in our 250's though since their Block Deck is much higher than the 200 Six or the Australian 221 or 250's Sixes and the though the stock 250 Rods are longer they are not that much longer at 5.880 long to get anywhere close to a Zero Deck Height in a US 250 Block.
For example my un-moded was a very low mile and only 4 month's old when purchased 1977 Maverick 250 Six. It was built for the California Emissions market and had the Pistons setting way down the Bore at .180 below the block deck its stock compression I think was rated at about 8.5 to 1. True C.R. was under 7.00 I suspect that that block had an even a taller deck height than the 49 state spec models I am also amassed that it ran as good as it did before Moding it. The stock Ford 200 and 250 Pistons we have are a Compression Height of 1.511 with 2 different Dish Sizes majority are the smaller 6.5 CC dish size was used for the other 49 state specs as well as all the 200 Six's from 1963 1/2 up (except for the larger 13 CC Dish California Emissions only spec Pistons used from about 1969 up). These above Australian Pistons are only .019 higher of a Compression height Plus no Dish so a bit higher compression. Our stock Large Log Heads usually measure in at 62 or more CC's. All of the other current rebuilder replacement 200 and 250 Six Cast Pistons will have a 1.50 Compression Height (C.H.) making the Piston to set down at .030 below deck in the 200's and additional .011 lower on the 250's this is not helping them.
Thanks to the many other's that have worked on the USA 250 Six problems to name a few like Lavron, Xctasy, RockLord, and several others, their are a couple Fixes in the Ford parts bins to help the 250 Six Compression Ratio with out going to far. One of the better ones is to use the Ford 2.5L HSC/OHV “E63E-B1A” 4 cylinder Connecting Rods they are said to be 5.99 inches Long a nice .110 longer Rod over the stock 5.880 250 Rods. Pretty much a drop right in Mod as the Big end and and Small End Rod sizes are the same as the Stock 250 Rod. The Rod bearing are a little different than what a 250 uses on the bearing Tang Location you could just use the Taurus Rod Bearings and bolt it right together or maybe have the Rod's Big End Machined to accept the regular Ford 250 Bearings Tangs likely a fairly easy and inexpensive job. This is very minor to fix these Rods are only number 1 to 4 so you will need to renumber 2 of the 6 you find for cylinders 5 & 6. With this set of Rods in the 250 Six and the standard Replacement Cast Pistons (1.50 C.H. and 6.5 CC Dish) are now setting up at about .024 below the Block Deck plus a better Rod Ratio going from 1.504 to a 1.532, giving us a nice 9.39 to 1 Static Compression Ratio. With the above Pistons we would now have Pistons that are setting up proud at +.006 above the Block Deck on an average 9.469 250 Block centerline and a 10.52 C.R to 1. For my 77 250 block with a .020 over bore using the above Australian Pistons I would of had a the above pistons setting .029 below the deck and a C.R. at 10.01 to 1 with the right camshaft Choice should be workable. Correction note they have recently been found to be an accrual 6.045 Inches Long by site member Comet6 so its nor workable with a Stock type Ford 200 / 250 Six Piston and like the 300 Six Connecting Rods would require a Custom made Piston.
Another choice for a more Performance / Race build is the early Ford 300 Six Rods (1965 to 1969) they would still have the Same Small end size with bigger Rods Bolts on the big end. The 1970 to 1997 300 / 4.9 rods could also be used but they have a larger small end not any big deal with a Custom Piston being used however they do have the Oil spit holes that might make the Rods be . a little weaker. I haven't looked at any of the off the shelve type Pistons as most that do this Mod have always used a Custom Aftermarket Forged Piston to fit. These Rods are even Longer at 6.210 and you would need to also use the 300 Rod Bearings to bolt them right in. There are also some even stronger Custom aftermarket Rods being made in the 300 Six length too.
For example my un-moded was a very low mile and only 4 month's old when purchased 1977 Maverick 250 Six. It was built for the California Emissions market and had the Pistons setting way down the Bore at .180 below the block deck its stock compression I think was rated at about 8.5 to 1. True C.R. was under 7.00 I suspect that that block had an even a taller deck height than the 49 state spec models I am also amassed that it ran as good as it did before Moding it. The stock Ford 200 and 250 Pistons we have are a Compression Height of 1.511 with 2 different Dish Sizes majority are the smaller 6.5 CC dish size was used for the other 49 state specs as well as all the 200 Six's from 1963 1/2 up (except for the larger 13 CC Dish California Emissions only spec Pistons used from about 1969 up). These above Australian Pistons are only .019 higher of a Compression height Plus no Dish so a bit higher compression. Our stock Large Log Heads usually measure in at 62 or more CC's. All of the other current rebuilder replacement 200 and 250 Six Cast Pistons will have a 1.50 Compression Height (C.H.) making the Piston to set down at .030 below deck in the 200's and additional .011 lower on the 250's this is not helping them.
Thanks to the many other's that have worked on the USA 250 Six problems to name a few like Lavron, Xctasy, RockLord, and several others, their are a couple Fixes in the Ford parts bins to help the 250 Six Compression Ratio with out going to far. One of the better ones is to use the Ford 2.5L HSC/OHV “E63E-B1A” 4 cylinder Connecting Rods they are said to be 5.99 inches Long a nice .110 longer Rod over the stock 5.880 250 Rods. Pretty much a drop right in Mod as the Big end and and Small End Rod sizes are the same as the Stock 250 Rod. The Rod bearing are a little different than what a 250 uses on the bearing Tang Location you could just use the Taurus Rod Bearings and bolt it right together or maybe have the Rod's Big End Machined to accept the regular Ford 250 Bearings Tangs likely a fairly easy and inexpensive job. This is very minor to fix these Rods are only number 1 to 4 so you will need to renumber 2 of the 6 you find for cylinders 5 & 6. With this set of Rods in the 250 Six and the standard Replacement Cast Pistons (1.50 C.H. and 6.5 CC Dish) are now setting up at about .024 below the Block Deck plus a better Rod Ratio going from 1.504 to a 1.532, giving us a nice 9.39 to 1 Static Compression Ratio. With the above Pistons we would now have Pistons that are setting up proud at +.006 above the Block Deck on an average 9.469 250 Block centerline and a 10.52 C.R to 1. For my 77 250 block with a .020 over bore using the above Australian Pistons I would of had a the above pistons setting .029 below the deck and a C.R. at 10.01 to 1 with the right camshaft Choice should be workable. Correction note they have recently been found to be an accrual 6.045 Inches Long by site member Comet6 so its nor workable with a Stock type Ford 200 / 250 Six Piston and like the 300 Six Connecting Rods would require a Custom made Piston.
Another choice for a more Performance / Race build is the early Ford 300 Six Rods (1965 to 1969) they would still have the Same Small end size with bigger Rods Bolts on the big end. The 1970 to 1997 300 / 4.9 rods could also be used but they have a larger small end not any big deal with a Custom Piston being used however they do have the Oil spit holes that might make the Rods be . a little weaker. I haven't looked at any of the off the shelve type Pistons as most that do this Mod have always used a Custom Aftermarket Forged Piston to fit. These Rods are even Longer at 6.210 and you would need to also use the 300 Rod Bearings to bolt them right in. There are also some even stronger Custom aftermarket Rods being made in the 300 Six length too.
Yes and it can be even less of a C.R. see my example of my California spec 77 Maverick 250 Six with a 13 CC Dish Piston and .180 down the hole it was under 7.0 to 1.
That is correct
You can find out all about those Rods and much more in my friend Lavron's 250 Build near the top of this forum it's Called "My Budget 250 Build here is the link. https://fordsix.com/threads/my-budget-250-build.77057/
fast64ranchero
Well-known member
The only problem I ran into when I used them was rings. to be specific, the ring lands are cut swallow and the only shelf rings I could fild in the US was just a standard cast ring. I had Childs & Albert back grind a standard set of Moly coated rings. I think the set was around $220. As for the pistons they also make a set with a small Dish. I think the # is 3328H
I have abandoned the 3327 3328 idea after I came to the same conclusion on rings. I'm probably going the longer rod stock piston route.
Plan is daily driver maverick. 3.55 rear with t5 transmission. I will probably start with stock large log head and just a little cam. I will be running ac too. Goal is to optimize efficiency. Contemplating edis ignition. I have it on 460 bbf and vastly improved idle stability etc. Having 2 ignition maps with a flip of a switch allows you to safely manage available octane level .
