340 Block Bored to 4.160????? Help

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rumblefish360 said:
Not so;

X blocks are NOT limited to standard production block limitations.

Current-ish, are they even around anymore?!?!?!
LOL! NOT!
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actually, they arent extinct, have been a few pop up recently on evilbay. There's also a gentleman in West Virginia that I buy some of my engines from, he has a never ran, fully assembled 355 Nascar engine thats in a crate that is an X block as well. its for sale btw, last he quoted me was 14,000 cash
 
Dartswinger70 said:
Oh, ok. I still think its a 361 B block though :)
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How did he get X heads on a 361 block to overheat it? The 340 bore spacing is 4.460 and with that overbore, you end up with .300 between the cylinder for a fire ring of .150 for each cylinder? Does that jive? Show us a pic of the shared cylinder wall with a dime on it.
 
Dartswinger70 said:
Okee,Okee,, I go home now.. my 340 runs and doesn't overheat...
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So does my 340, and it's .060" for a bore of 4.1". I've seen plenty of Mopar small blocks go more than .030" without any issues at all. To say .030" is the "max" is just silly. I mean, I don't doubt that there are core shifted blocks out there that can only go .030" safely. Heck there may even be ones that won't go .030", there are some pretty badly core shifted examples running around. But .030" over as a max safe bore for all of them? Hogwash.

As for sleeves, perfectly fine, they work great. It's just an extra expense. If it's the original engine on a valuable car, it totally makes sense. If it's just some small block, find another one. The 340's aren't getting any easier to find though, so if you really want to keep the 340 it could be worth it. Some of the prices for 340 blocks I've seen lately would more than pay for sleeving all 8 holes in a block you already had.
 
72bluNblu said:
So does my 340, and it's .060" for a bore of 4.1". I've seen plenty of Mopar small blocks go more than .030" without any issues at all. To say .030" is the "max" is just silly. I mean, I don't doubt that there are core shifted blocks out there that can only go .030" safely. Heck there may even be ones that won't go .030", there are some pretty badly core shifted examples running around. But .030" over as a max safe bore for all of them? Hogwash.

As for sleeves, perfectly fine, they work great. It's just an extra expense. If it's the original engine on a valuable car, it totally makes sense. If it's just some small block, find another one. The 340's aren't getting any easier to find though, so if you really want to keep the 340 it could be worth it. Some of the prices for 340 blocks I've seen lately would more than pay for sleeving all 8 holes in a block you already had.
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I aint arguing with you man, when I said my 340 runs and doesn't overheat, I was effectively signing off and saying "do what you want, I really don't give a **** as long as my car runs" the information is out there, do some research and make your own decisions.
 
Dartswinger70 said:
I aint arguing with you man, when I said my 340 runs and doesn't overheat, I was effectively signing off and saying "do what you want, I really don't give a **** as long as my car runs" the information is out there, do some research and make your owners n decisions.
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Been there, done that. That's why I had no qualms about buying a used 340 block that was already .030" over and then punching it out .060" over for a rebuild. Can you do that with every 340? Probably not. Can you do it with a lot of the 340's out there? Yup.
 
greymouser7 said:
Does this mean a block could be over bored extensively and just sleeved to what you want it to be?
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Sure, as long as the block itself, water passages, etc weren't compromised. You just have to be able to find sleeves that are the right size. Obviously there are limits depending on the design of the block. But yeah, for example my 340 is already .060" over. So, if it needs a rebuild at some point more than likely it won't clean up with enough wall thickness left. But I could just have 8 sleeves installed and bore it back to standard. Then I'd have another couple of rebuilds left again. Of course since my 340 isn't matching or even correct for my car I'd probably just find a 360 block because that would far cheaper. At least at the moment.

It's pretty common with rare makes and models, stuff you can't just find another block for. You could bore and sleeve and re-bore and re-sleeve just about as many times as you wanted as long as the block is sound. It's just an extra cost, if it's done properly it shouldn't effect performance at all.

Lots of engines have sleeves normally, any of your aluminum blocks, pretty much all motorcycle engines, lots of diesels, etc all use sleeves straight from the factory.
 
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greymouser7 said:
Does this mean a block could be over bored extensively and just sleeved to what you want it to be?
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Yes. PAW used to sell std bore 340s that had 8 sleeves. They may have been better than new as the sleeves were uniform and perhaps of better metallurgy. IDK what the sleeve thickness was but they do sell 4.000 and 4.040 sleeves.
 
So here is a thought, question, could you take a standard 340 and re-sleeve it to be taken out to a 4.22 bore?
 
Piston selection beyond standard overbores (& strokes) and common engines sizes are I st simply expensive but available. There just listed in/with the common sizes normally listed/seen with the common high performance houses.

But there most likely under the custom catogory and price tag. An example would be MP 's create engines with the big bore. AMA 440 small block with the 4.185 size bore.
 
rumblefish360 said:
So here is a thought, question, could you take a standard 340 and re-sleeve it to be taken out to a 4.22 bore?
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Interesting.... With a 4.46 bore-center-to-bore-center distance, that would leave .240 inches or less for sleeve walls and coolant gap. That would take out the cast bore walls for all practical purposes; they would be gone, or what might be left would just crumble and break out, and leave the sleeves supported at top and bottom only. I would imagine they would have to be welded top & bottom to seal off the water jacket, and/or have the cooling jacket filled. And with a max wall thickness of under .120" each.....not counting any interference with the valley or outside block surfaces. Sounds like a challenging proposition....but knowing hot-rodders, it may well have been done!
 
FWIW.... there are .062 and .093 sleeves around. But regardless, the cast bores won't take any of them to this range of ID.
 
I think it would be all 4 sleeves together like the MP block states. Siamese
 
I still think the OP is doing something wrong
A 4.160 bore without custom pistons and only running a 262 cam ? Don't add up
 
273 said:
I still think the OP is doing something wrong
A 4.160 bore without custom pistons and only running a 262 cam ? Don't add up
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I agree something may be wrong, but to me it sorta does make sense,or could, cuz
1) we don't yet know the stroke, and
2) maybe the PO knew he was pushing it with the overbore, and the 262 was his way of trying to beat the odds...
3) but the block must have been of great value to the PO, to have gone to this much cost and trouble.
4) the OP says he triple checked it. To me that means he zeroed the micrometer against the standard, so I have to believe that if he measured something 3 times and it came out the same to 3 decimal places, that he did it right. And didn't he say that they're all the same? So that's at least another 7, to maybe 14 more times.
5) wouldn't it be interesting if the stroke wasn't 3.31. I mean this combo already maths-out to 360 cubes. What if there's a 3.79crank in there? That would calculate to 411 cubes. And guys put [email protected] cams in there 408s all the time.Well maybe not all the time,lol. And those 223s can be 268 advertised as normal,or maybe 262s as fast-rates, or 292s as thumpers. And so,I can imagine a 411 cuber with a 262 fast rate being quite the stump-puller.
I mean check this out; With an ICA of 57*
Static compression ratio of 9.3:1.
Effective stroke is 3.14 inches.
Your dynamic compression ratio is 7.88:1 .
Your dynamic cranking pressure is 156.77 PSI.
V/P (Volume to Pressure Index) is 161..............................................161

Look at that; burns skunk-pee, has very modest cylinder pressure,has a go-anywhere cam, and a huge VP! That's a torque-monster.
So it kindof makes sense to me. Or at least it might with a 3.79crank.........

Or what if it had a 3.265 crank in it. That would make it a 355 and a screamer,still with the 57* ICA
Static compression ratio of 9.6:1.
Effective stroke is 2.68 inches.
Your dynamic compression ratio is 8.06:1 .
Your dynamic cranking pressure is 161.44 PSI.
V/P (Volume to Pressure Index) is 141............................................141

You know; I had a [email protected] in my 367 once. I loved that cam. It wasn't that fast a rate, as it was a 270/110. But, on the street, it pulled and pulled and pulled; I used to shift that one at 7000 all the time, with a 4gear.That combo went 12.9@106 first and only time out, at about 3700 pounds, and on 245street tires with 3.55s. And you gotta think 7000 is way too high a shift-rpm.
So,bottom line is; that 223cam is no slouch.
That 367 looked like this, with an ICA of 61*
Static compression ratio of 10.9:1.
Effective stroke is 2.86 inches.
Your dynamic compression ratio is 8.91:1 .(Eddies)
Your dynamic cranking pressure is 183.76 PSI.
V/P (Volume to Pressure Index) is 162...........................................161

Yes, it was a torque monster. It took 295s to kindof tame it.



6)but you're right;..... right now something "don't add up", lol...................
 
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My guess is he checked one more time and realized he was reading his caliper or mic wrong.
 
Robin House said:
Hi guys, I picked up a 73 Dart Sport last year with a 340 in it. I opened it up and just did a top end refresh and tossed on set of x-heads. I had over heating issues all summer, tossed in a new 3 core rad, new fans and multiple thermostats. Still had issues. I just pulled this engine apart and found that he rings were cooked. before ordering new rings I wanted to double check the piston size and found that they were at 4.160..... IS THIS MY OVER HEATING ISSUES???? CAN THS ENGINE OPPERATE AS A DRIVER BORED THIS MUCH??????
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Did You run/have the overheating before You tossed the X heads on? Cooked rings are not the cause of overheating, they would be the result.
 
You would also need to run a Fel-Pro 1008 gasket w/a 4.180 bore if indeed that is the bore.............dumb question, but You didn't install the head gaskets reversed &
block the cooling passages did You ?...........................
 
Killer6 said:
You would also need to run a Fel-Pro 1008 gasket w/a 4.180 bore if indeed that is the bore.............dumb question, but You didn't install the head gaskets reversed &
block the cooling passages did You ?...........................
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As far as I know;The head gaskets only fit one way, unless you either pull the line-up pins or make new holes.
 
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