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Building a 440 with low compression pistons.. opinions. #153964 11/20/08 08:39 AM 11/20/08 08:39 AM
Joined: Jan 2003 Posts: 4,282 Danville, NH M Mopar_Mike OP master
Mopar_Mike OP master M Joined: Jan 2003 Posts: 4,282 Danville, NH	I am going to be building the numbers matching 440 for a 67 Coronet RT I have. I am not looking to go with anything wild, actually looking for a good "smooth" idling set up. I will be running the stock 2.08 1.74 915 heads, aluminum intake, 750 Holley, HP manifolds and electronic ignition. My question is, I have a new set of TRW L2388 forged pistons, but they sit way deep in the hole, like around .080-1.0. and will probably give me around 8.1 or so compression with the steel shim gasket. I don't want to build a Dog 440 but I would like to be around 400hp. What do you guys think about these pistons and/or set up? Thanks. RS23L7 4-Speed

Re: Building a 440 with low compression pistons.. opinions. [Re: Mopar_Mike] #153965 11/20/08 08:44 AM 11/20/08 08:44 AM
Joined: Jan 2008 Posts: 1,211 Minn S SportF pro stock
SportF pro stock S Joined: Jan 2008 Posts: 1,211 Minn	I have had a couple of motors like that for street cars, and you will probably top out at the high to mid 13's. That�s lots of fun for the street. If you ever really want to go faster I think you need more compression.

Re: Building a 440 with low compression pistons.. opini [Re: Mopar_Mike] #153966 11/20/08 08:49 AM 11/20/08 08:49 AM
Joined: Jan 2003 Posts: 74,978 U.S.S.A. JohnRR I Win
JohnRR I Win Joined: Jan 2003 Posts: 74,978 U.S.S.A.	edit ... i guess they are that deep , put then on ebay my thought , get a flat top and build it as a quench motor either wit ha 6 pk piston .020 in the hole with a steel shim gasket or zeo decked wit ha .039 felpro, you have the heads to do it with and the engine will be less detonation prone , building it will a piston .100 in the hole it's going to be a pig . Last edited by JohnRR; 11/20/08 08:53 AM.

Re: Building a 440 with low compression pistons.. opinions. [Re: Mopar_Mike] #153967 11/20/08 09:40 AM 11/20/08 09:40 AM
Joined: Jul 2008 Posts: 30,424 Florida STAYcation dOc ! The village idiot's idiot
dOc ! The village idiot's idiot Joined: Jul 2008 Posts: 30,424 Florida STAYcation	I say put a "zero-deck" piston in it(as suggested by others) and use a water-injection system.

Re: Building a 440 with low compression pistons.. opinions. [Re: Mopar_Mike] #153968 11/20/08 10:19 AM 11/20/08 10:19 AM
Joined: Oct 2005 Posts: 8,866 Ontario, Canada S Stanton Don't question me!
Stanton Don't question me! S Joined: Oct 2005 Posts: 8,866 Ontario, Canada	Didn't you bother to check what the compression ratio of the L2388's is before you bought them !?!?!?!?

Re: Building a 440 with low compression pistons.. opini [Re: Stanton] #153969 11/20/08 10:32 AM 11/20/08 10:32 AM
Joined: Jan 2003 Posts: 4,282 Danville, NH M Mopar_Mike OP master
Mopar_Mike OP master M Joined: Jan 2003 Posts: 4,282 Danville, NH	Quote: Didn't you bother to check what the compression ratio of the L2388's is before you bought them !?!?!?!? Thanks for helping to answer my question... but to answer your ignorant question, I bought an engine package a few years back and these came along.. RS23L7 4-Speed

Re: Building a 440 with low compression pistons.. opini [Re: Mopar_Mike] #153970 11/20/08 10:42 AM 11/20/08 10:42 AM
Joined: Jan 2003 Posts: 24,562 Brookeville, Md Mr.Yuck Not enough dumb comments...yet
Mr.Yuck Not enough dumb comments...yet Joined: Jan 2003 Posts: 24,562 Brookeville, Md	mill the heads .030 use the steel shim head gasket, it crushes to .019 Use a cam with no a ton of duration and a 112 centerline and you should be ok, boost would be a good option

Re: Building a 440 with low compression pistons.. opinions. [Re: Mopar_Mike] #153971 11/20/08 11:42 AM 11/20/08 11:42 AM
Joined: Nov 2003 Posts: 36,040 Lincoln Nebraska R RapidRobert Circle Track
RapidRobert Circle Track R Joined: Nov 2003 Posts: 36,040 Lincoln Nebraska	What JohnRR said, definitely do not use those pistons & get a set of kieth black hypers & adjust your deck height & with the right head gaskets to get your piston to head clearance(quench) at .035-.040 which will let you run a CR in the 10's. 93 octane will support this ONLY if you have .035-.040 quench. Squeeze is power & a high CR is the main parameter that makes it. live every 24 hour block of time like it's your last day on earth

Re: Building a 440 with low compression pistons.. opini [Re: RapidRobert] #153972 11/20/08 11:45 AM 11/20/08 11:45 AM
Joined: Jan 2003 Posts: 74,978 U.S.S.A. JohnRR I Win
JohnRR I Win Joined: Jan 2003 Posts: 74,978 U.S.S.A.	Quote: What JohnRR said, definitely do not use those pistons & get a set of kieth black hypers & adjust your deck height & with the right head gaskets to get your piston to head clearance(quench) at .035-.040 which will let you run a CR in the 10's. 93 octane will support this ONLY if you have .035-.040 quench. Squeeze is power & a high CR is the main parameter that makes it. he is using closed chamber heads so there is no reason to buy a step head piston unless you are a glutton for punishment

Re: Building a 440 with low compression pistons.. opini [Re: JohnRR] #153973 11/20/08 11:50 AM 11/20/08 11:50 AM
Joined: Nov 2003 Posts: 36,040 Lincoln Nebraska R RapidRobert Circle Track
RapidRobert Circle Track R Joined: Nov 2003 Posts: 36,040 Lincoln Nebraska	I dont know about a step head piston but one of KB's offerings that would give him quench with the closed chambers & ending up with a CR in the 10's would suit his purposes perfectly. live every 24 hour block of time like it's your last day on earth

Re: Building a 440 with low compression pistons.. opini [Re: RapidRobert] #153974 11/20/08 12:43 PM 11/20/08 12:43 PM
Joined: Jan 2003 Posts: 74,978 U.S.S.A. JohnRR I Win
JohnRR I Win Joined: Jan 2003 Posts: 74,978 U.S.S.A.	sorry , whenever i see KB hyper I automaticlly think the step head , there are many forged flattops available for a decent price , why subject yourself to the hassles of the hyper ??? don't answer that , it was a rhetorical question .

Re: Building a 440 with low compression pistons.. opinions. [Re: Mopar_Mike] #153975 11/20/08 12:53 PM 11/20/08 12:53 PM
Joined: Jul 2006 Posts: 6 HI D Dodgebrother member
Dodgebrother member D Joined: Jul 2006 Posts: 6 HI	Don't know what would happen at 8 to 1 but I'm right at 8.5 to 8.6 to 1 with my sig 6bbl car and have about 155-160 lbs cranking cylinder pressure. Been together long enough I can't remember how far down the piston was but, it was a ways. W/a hughes 1523 cam & headers (through full exhaust) my 4100# car runs 13.1-13.2 @ 107 at 2,000 elevation. I did clean up the bowls/ports a little. Pretty much a slug but still fun to drive & idles smooth @ 800 rpm. Oh, all on 87 octane, too! Oops, no sig picture. Forgot I was on the kids computer, too early here! This car Last edited by Dodgebrother; 11/20/08 01:10 PM.

Re: Building a 440 with low compression pistons.. opinions. [Re: Dodgebrother] #153976 11/20/08 01:07 PM 11/20/08 01:07 PM
Joined: Nov 2003 Posts: 36,040 Lincoln Nebraska R RapidRobert Circle Track
RapidRobert Circle Track R Joined: Nov 2003 Posts: 36,040 Lincoln Nebraska	I've used Kieth Black hypers & havent had a problem with them but they have a CHEAP look about them that's always bothered me & I have been thinking the same thing that for a little bit more money I could end up with something much better with forged ones. live every 24 hour block of time like it's your last day on earth

Re: Building a 440 with low compression pistons.. opinions. [Re: Mopar_Mike] #153977 11/20/08 02:01 PM 11/20/08 02:01 PM
A Anonymous Unregistered
Anonymous Unregistered A	Or find a stroker crank for $400, spend $100 to trim .1 off the tops of the pistons you have and have even more fun for just slightly more than new pistons. Sheldon

Re: Building a 440 with low compression pistons.. opinions. [Re: Mopar_Mike] #153978 11/20/08 03:44 PM 11/20/08 03:44 PM
Joined: Feb 2003 Posts: 21,318 Manitoba, Canada DaytonaTurbo Too Many Posts
DaytonaTurbo Too Many Posts Joined: Feb 2003 Posts: 21,318 Manitoba, Canada	If those pistons sit .08-.1 in the hole, with closed chambered 915 heads(~80cc chamber), and a steel shim gasket my #'s show you should end up with around 9.5 compression. Which is about the max you would want to run on an iron headed non-quench pump gas 440. I think some people replying are mistaking those pistons for the ultra low compression pistons of the later 70's that sit about .17 in the hole. Now those would kill your compression down to the 7.5-8:1 range. You don't have what's considered the idea combo these days, but what you have is very usable for a 400hp+ engine.

Re: Building a 440 with low compression pistons.. opinions. [Re: Mopar_Mike] #153979 11/21/08 05:27 PM 11/21/08 05:27 PM
Joined: Jan 2003 Posts: 1,263 Southwestern Ontario Canada racealittle pro stock
racealittle pro stock Joined: Jan 2003 Posts: 1,263 Southwestern Ontario Canada	I have been beating on a short block that has .030 2266F pistons in it for going on 27 years. The pistons are down .089 in the hole. I tried various cams, intakes, gear ratios, converters etc. I had a spare set of ootb eddy rpms and rpm intake that I put on with 2" TTI headers. The same cam, a MP.474 has been in it for at least 10 years with a factory stock 2400 converter from a 360 727 (weights deleted). At 3925 lbs. it ran a best of 12.2 at 111.9 mph after driving it to the track, (1 1/2 hour trip at highway speeds). The combination is not really sorted because I don't really care. It's just a 87 octane driver. A tune might put it in the 11's, a little NOS would put it to the limit without a roll cage. I'm sure others have gone faster or slower. Low compression inadequate quench motors can make power if you are so inclined. My car is a joy to drive on the street and has enough power (torque) to surprise most who experience a ride in it. I built the short block when I didn't know any better, and it has been a dependable, frugal piece. Too many cars, too many parts, too little coin, too little space to work in, too little time left to make it all happen! Update: down to one ride, still too many parts, a little more jingle in the pocket, gaining space, and it's going to happen this year!

Re: Building a 440 with low compression pistons.. opinions. [Re: racealittle] #153980 11/21/08 08:02 PM 11/21/08 08:02 PM
Joined: Nov 2006 Posts: 1,456 oklahoma F forphorty pro stock
forphorty pro stock F Joined: Nov 2006 Posts: 1,456 oklahoma	i also have a 440 with the 2266 pistons and also at the time didnt know any better.they were the pistons that PAW sold at the time, so thats what i got.little did i know that i would only have about 8.5 comp. even so it has ran well (12.35) for a cheap 906 head hydraulic cam engine. on the other hand...im not sure about the 2388. i think that is a 72-78 replacement piston but forged. i would think it would be more like .110+ down in the hole unless the block was decked a bunch.seems like that might put compression down in the 7s even with the smaller chamber.

Re: Building a 440 with low compression pistons.. opinions. [Re: forphorty] #153981 11/21/08 09:25 PM 11/21/08 09:25 PM
Joined: Feb 2003 Posts: 21,318 Manitoba, Canada DaytonaTurbo Too Many Posts
DaytonaTurbo Too Many Posts Joined: Feb 2003 Posts: 21,318 Manitoba, Canada	Quote: i also have a 440 with the 2266 pistons and also at the time didnt know any better.they were the pistons that PAW sold at the time, so thats what i got.little did i know that i would only have about 8.5 comp. even so it has ran well (12.35) for a cheap 906 head hydraulic cam engine. on the other hand...im not sure about the 2388. i think that is a 72-78 replacement piston but forged. i would think it would be more like .110+ down in the hole unless the block was decked a bunch.seems like that might put compression down in the 7s even with the smaller chamber. I've been told the 2388's are just an older version of the 2266 - 1.991 compression height, no valve reliefs. Should sit .08-.1 in the hole.

Re: Building a 440 with low compression pistons.. opinions. [Re: DaytonaTurbo] #153982 11/21/08 11:17 PM 11/21/08 11:17 PM
Joined: Nov 2006 Posts: 1,456 oklahoma F forphorty pro stock
forphorty pro stock F Joined: Nov 2006 Posts: 1,456 oklahoma	i wasnt sure so i went looking. found some info in the archives. dwayne porter lists the 2388 compression height at 1.926. http://www.moparts.org/Tech/Archive/bb/59.html

Re: Building a 440 with low compression pistons.. opinions. [Re: Mopar_Mike] #153983 11/22/08 08:34 AM 11/22/08 08:34 AM
Joined: Feb 2005 Posts: 4,311 Prospect, PA BSB67 master
BSB67 master Joined: Feb 2005 Posts: 4,311 Prospect, PA	Mike, If you want to maximize your combination, now is the time to put the right pistons in it. Anything else will be a performance compromise. It becomes a personal balance between budget, time, and performance goals. If you use a flat top with with a tight quench on the 915s the CR will be too high for pump gas with a docile cam. You'll need a dish style piston. Let us know what you decide.

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