Re: which pistons for my 440 for 9.3-9.5:1 with 80cc heads?
[Re: 67Satty]
#1370614
01/17/13 08:56 AM
01/17/13 08:56 AM
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Joined: Jan 2003
Posts: 75,062 U.S.S.A.
JohnRR
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Quote:
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.
If you had quench, and depending on the cam , you could have gotten away running a lower octane fuel.
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Re: which pistons for my 440 for 9.3-9.5:1 with 80cc heads?
[Re: 6PakBee]
#1370615
01/17/13 08:58 AM
01/17/13 08:58 AM
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Joined: Jan 2003
Posts: 75,062 U.S.S.A.
JohnRR
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I Win
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Quote:
Quote:
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....
Have you tried 87 octane just to see how the engine responds?
It would be an interesting test , but I think he would have an issue without quench, unless he is at a higher altitude.
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Re: which pistons for my 440 for 9.3-9.5:1 with 80cc heads?
[Re: JohnRR]
#1370616
01/17/13 12:40 PM
01/17/13 12:40 PM
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Joined: Aug 2007
Posts: 1,271 Vista, California
67Satty
pro stock
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pro stock
Joined: Aug 2007
Posts: 1,271
Vista, California
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Quote:
Quote:
Quote:
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....
Have you tried 87 octane just to see how the engine responds?
It would be an interesting test , but I think he would have an issue without quench, unless he is at a higher altitude.
Where I drive around town is pretty close to sea level, or actual sea level when I drive to the beach. Where I race 1/8 mile is at 1700 feet.
I'll have a quench motor when I step up to some aluminum heads. Also going to change to a solid lifter cam but that's a different topic.
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Re: which pistons for my 440 for 9.3-9.5:1 with 80cc heads?
[Re: 78asprin]
#1370621
01/18/13 01:27 AM
01/18/13 01:27 AM
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Joined: Aug 2003
Posts: 43,230 Bend,OR USA
Cab_Burge
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Quote:
can i go higher than that because of the aluminum heads?
Yes you can with aluminum(they suck more heat out of the combustion chambers than iron heads do ), usually by 1 full point My pump gas stroker has 10.78 to 1, I run Oregon 91 octane, non ethanol, pump gas, 9.97 ET at 134.6 MPH at 3450 lbs through the muffs with the air cleaner on motor only I have a wideban on my car, I run it a little lean on the air fuel ratio, 13.3 to 13.5 at WOT and I have no signs of detoonation on the spark plugs or in the motor I've raced it at sea level, even with the D.A. 800 ft. below sea level and it runs fine on the local pump swill with that compression ratio IHTHs
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
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Re: which pistons for my 440 for 9.3-9.5:1 with 80cc heads?
[Re: Cab_Burge]
#1370623
01/18/13 08:19 AM
01/18/13 08:19 AM
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Joined: Feb 2005
Posts: 4,318 Prospect, PA
BSB67
master
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master
Joined: Feb 2005
Posts: 4,318
Prospect, PA
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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.
Last edited by BSB67; 01/18/13 08:20 AM.
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Re: which pistons for my 440 for 9.3-9.5:1 with 80cc heads?
[Re: BSB67]
#1370624
01/18/13 11:04 AM
01/18/13 11:04 AM
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Joined: Jan 2003
Posts: 75,062 U.S.S.A.
JohnRR
I Win
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I Win
Joined: Jan 2003
Posts: 75,062
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Quote:
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.
OP shoot for 10 for your application and you will be safe and not disappointed.
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