Posted By: 78asprin
which pistons for my 440 for 9.3-9.5:1 with 80cc heads? - 01/16/13 06:16 AM
I'm putting together a 76 440 with a steel crank (stock stroke) +.030 with a set of 440 source stealth heads. They advertise 80cc chambers. Can someone help me figure out a set of pistons/rings to use for a comp ratio between 9.2-9.5:1? The combo will be used with an xe274 cam, roller rockers,performer rpm intake,4160 750cfm carb, and headers.thanks!
Posted By: Cab_Burge
Re: which pistons for my 440 for 9.3-9.5:1 with 80cc heads? - 01/16/13 07:42 AM
With aluminum heads I would pump the compression up to 10.00 to 10.5. Try looking at KB Icon pistons or United Machine for the KB hypertutitec(SP?) pistons for that application
Posted By: JohnRR
Re: which pistons for my 440 for 9.3-9.5:1 with 80cc heads? - 01/16/13 04:06 PM
A flat top at zero deck with 5cc valve reliefs , .041 thick gasket and 80cc heads comes in at 10.46.
A 15cc dish/valve reliefs will bring it down to 9.5.
What is your reason for wanting 9.0 -9.5 ?
Posted By: 78asprin
Re: which pistons for my 440 for 9.3-9.5:1 with 80cc heads? - 01/17/13 01:08 AM
well its for a daily driven truck, running pump gas, didnt think i could go much more than that with pump fuel. id like to squeeze as much as i can without having to run any special fuel or anything.can i go higher than that because of the aluminum heads?
Posted By: 67Satty
Re: which pistons for my 440 for 9.3-9.5:1 with 80cc heads? - 01/17/13 02:53 AM
I'm running 9.5:1 compression with open-chambered iron heads with no quench and it is running fine on 91 octane pump gas with no pinging. I run it hard and race it on the 1/8 mile whenever I get a chance with no problems.
I plan on swapping on some Stealth heads when I get some more money and time and I think it will run fine with the smaller 80cc chambers and higher compression.
If you get some TRW 2355 pistons that will get you close to zero deck and give you a workable compression ratio with the Stealth heads. Lots of people are going to say these pistons are too heavy, maybe there's something else someone can recommend that is as reasonably priced that will get you close to zero deck and a good ballpark compression.
Posted By: 67Satty
Re: which pistons for my 440 for 9.3-9.5:1 with 80cc heads? - 01/17/13 05:38 PM
Yeah, that's what I'm doing.
Posted By: 78asprin
Re: which pistons for my 440 for 9.3-9.5:1 with 80cc heads? - 01/18/13 01:49 AM
so would i be ok with say 10-10.5:1 compression on pump fuel then? 440 source says these heads have a quench area in them. im looking at the ross 82008 pistons, they seem to be fairly light weight and the price is right. what do u guys think?
Posted By: BSB67
Re: which pistons for my 440 for 9.3-9.5:1 with 80cc heads? - 01/18/13 01:56 AM
10:1 yes.
10.5:1 maybe not.
Posted By: 78asprin
Re: which pistons for my 440 for 9.3-9.5:1 with 80cc heads? - 01/18/13 05:45 AM
Sweet deal! Damn that sounds like u have quite the setup!
Posted By: BSB67
Re: which pistons for my 440 for 9.3-9.5:1 with 80cc heads? - 01/18/13 12:19 PM
Cab, be careful on what you put out there as it sounds like the OP is kanda new to some of the technical aspects. I don't know if you meant it or not, but is sounds like your telling him he can run 10.8:1 CR because you can. Just not worth directing a guy to be potentially a couple of tenths to high vereses leaving a couple on the table.