Moparts

No inexpensive 10:1 std bore 440 pistons?

Posted By: feets

No inexpensive 10:1 std bore 440 pistons? - 04/17/17 03:23 AM

I've been running through all the online catalogs I can find and nobody seems to make an inexpensive 10:1 piston for a standard bore 440.

My block cleaned up nicely at 4.322" and I don't want to punch it without good reason.

I can find them up to 9.5:1 then it jumps to the 10.8:1 KB363 at $640 a set.

I'm running stock rods and Eddy 88cc heads. The cam shows zero overlap on the card and I'm trying to build it into a high torque cruiser for the Imperial.

I get the feeling that even with the aluminum heads the 10.8:1 is going to be too high for most pump gas.

Any suggestions? It's been many years since I've shopped for pistons.
Posted By: amxautox

Re: No inexpensive 10:1 std bore 440 pistons? - 04/17/17 03:35 AM

Machine some big valve reliefs in the piston tops. grin
Posted By: EchoSixMike

Re: No inexpensive 10:1 std bore 440 pistons? - 04/17/17 03:40 AM

Run it at 9.5 and burn crap gas. Chasing half a point of compression on a street cruiser seems like the juice not being worth the squeeze. Or deck the heads .020.

Have you looked at the Icon IC9953? S/F....Ken M
Posted By: Jeremiah

Re: No inexpensive 10:1 std bore 440 pistons? - 04/17/17 04:23 AM

9.5:1 CR with open chambers is perfect for pump gas, Texas heat and a 47,000 lbs. curb weight. It might be a good idea to have the exhaust manifolds coated to keep underhood temps down. Pump gas percolates so easily this is more of a concern than ever, especially with 36 sq. ft. of underhood insulation lol.

Decking the block/heads to get it close to ten might be an option?

You might have the only set of open chamber Edelbrock Mopar heads ever sold?
Posted By: topside

Re: No inexpensive 10:1 std bore 440 pistons? - 04/17/17 04:33 AM

Did you try 440 Source? Cast, hyper or forged?
I'll assume that 9.5 advertised is for 88cc chambers & close to zero deck, and that those heads are stuff you already have. In which case given the weight & likely gearing & small cam, sounds OK. Might get you into mid-grade fuel instead of premium, or allow more timing.
You might need to deck the block & the heads anyway just to get true surfaces.
But...zero overlap?
Posted By: krautrock

Re: No inexpensive 10:1 std bore 440 pistons? - 04/17/17 04:51 AM

yeah, if you're combustion chamber isn't going to give you a tight quench then 9.5:1 is probably right where you want to be....especially with a little cam.
Posted By: RapidRobert

Re: No inexpensive 10:1 std bore 440 pistons? - 04/17/17 04:51 AM

eBay may have something.
Posted By: Twostick

Re: No inexpensive 10:1 std bore 440 pistons? - 04/17/17 05:56 AM

Advertised CR when it comes to pistons is a crapshoot unless you already know your measured deck height, chamber volume etc.

I'd steer clear of cast/hypereutectic unless I was going .030 over. They run tight piston to wall with those and I suspect that all went out the window with the cleaned up at 4.322 bore.

Summit has the forged L2266F Speed Pro's on for $328.99 in 4.320" with a 1.991 CH.

Don't know how that compares to the stock piston for CH or weight. Do you have balancing in the budget?

How about a set of stock used 440 Magnum pistons cleaned up with new rings?

If you can score a set of those you can check off cheap, bump in CR and no need to balance if you can live with the OEM tolerance.

Kevin
Posted By: calrobb2000

Re: No inexpensive 10:1 std bore 440 pistons? - 04/17/17 06:50 AM

hi
4.322 is not enough wear to be conserned about for evenstd bore pistons .

running in that heavy car will generate more heat and pistons
ons will swell a little more .

2355 trw will get app .020 deck heigth .

2266 will be not less than .080 in the hole !


my block was decked .012 and my 2266 pistons are .080 down !
Posted By: feets

Re: No inexpensive 10:1 std bore 440 pistons? - 04/17/17 04:01 PM

Yeah, these are really early Eddy heads.

I've been doing the math, not going by catalogs.

The ICON 9953 gives me 9.37:1.
Speed Pro 2266 gives me 8.49:1 (what I ran in the TT440).
Speed Pro 2355 gives me 9.16:1.
Posted By: Neil

Re: No inexpensive 10:1 std bore 440 pistons? - 04/17/17 08:13 PM

Sell those heads and then get the ones that will get you where you need to be without custom pistons???

If a manufacture has a piston you want, but it's .030, can you try asking if they will make the same piston in the stock diameter? Seems like it wouldn't be that much effort.

What brands have you looked at? Arias, Wiseco, JE, Ross, Mahle???
Posted By: Supercuda

Re: No inexpensive 10:1 std bore 440 pistons? - 04/17/17 08:58 PM

Originally Posted By Neil

What brands have you looked at? Arias, Wiseco, JE, Ross, Mahle???


I believe he said INEXPENSIVE.

Feets you have a lathe.

Too tall a CH can be addressed.
Posted By: Hugh Jorgan

Re: No inexpensive 10:1 std bore 440 pistons? - 04/17/17 09:01 PM

Machine the domes off?

https://houston.craigslist.org/pts/6040600291.html
Posted By: Supercuda

Re: No inexpensive 10:1 std bore 440 pistons? - 04/17/17 09:20 PM

KB237 looks like it might be the ticket and STD is supposed to be available.
Posted By: EchoSixMike

Re: No inexpensive 10:1 std bore 440 pistons? - 04/17/17 09:22 PM

Originally Posted By feets
Yeah, these are really early Eddy heads.

I've been doing the math, not going by catalogs.

The ICON 9953 gives me 9.37:1.
Speed Pro 2266 gives me 8.49:1 (what I ran in the TT440).
Speed Pro 2355 gives me 9.16:1.


Run the ICON 9953 and be happy when you get that batch of crappy fuel. Deck the heads to get more compression, if you want.

For a street car, this is chasing Elvis. You're talking about circa 2.5% power difference in a point of compression. If it's that important, call Diamond and get the bore and CH you need from a 52001 or 52002 shelf piston. Going to be $800+/set. It's your money, your decision. S/F....Ken M
Posted By: Challenger 1

Re: No inexpensive 10:1 std bore 440 pistons? - 04/17/17 10:19 PM

I use the 2355 with eddie heads in my 446. Runs great now for 10 years. Makes my 340 10-1 challenger feel like a slant 6. I came up with 10.2-1 with 2355 and eddie heads on my 440.

No way I would run the LO Po 80 in the hole pistons. When I got my short block that is what was in there. I swapped them out for a set of 2355 when I built my 440 and it runs fine on 91 octane.
Posted By: feets

Re: No inexpensive 10:1 std bore 440 pistons? - 04/17/17 10:20 PM

Originally Posted By Hugh Jorgan



I was looking at the 2295 and it showed 10.8:1 with this setup. Milling the tops seems viable.
Posted By: fourgearsavoy

Re: No inexpensive 10:1 std bore 440 pistons? - 04/18/17 05:05 AM

Have you looked into Wiseco Pro-Tru pistons? They are the best low dollar pistons on the market IMHO twocents

Gus beer
Posted By: A39Coronet

Re: No inexpensive 10:1 std bore 440 pistons? - 04/18/17 01:44 PM

Most piston manufacturers will give you one free dimensional change. I had to get a custom diameter set for my 400 and Diamond did it without additional charges.
Posted By: feets

Re: No inexpensive 10:1 std bore 440 pistons? - 04/18/17 11:48 PM

I picked up a small piece of polycarbonate and a large medicine syringe from the pet store last night.

As soon as I get the chance (maybe tonight) I'll measure the heads and find the actual combustion chamber volume.
© 2024 Moparts Forums