What compression ratio - 383
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From: stop the fun suckers
What compression ratio - 383
I have a choice between 10.3:1 or 10.7:1 compression pistons for my 383 rebuild.... thats assumming stock 58cc heads..
car will have stock heads, stock exhaust, A4, stock stall and no gears.. with a mild cam
see cam choice here.. : http://forums.corvetteforum.com/zerothread?id=584612
so what have you done/or think?
car will have stock heads, stock exhaust, A4, stock stall and no gears.. with a mild cam
see cam choice here.. : http://forums.corvetteforum.com/zerothread?id=584612
so what have you done/or think?
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From: stop the fun suckers
Re: What compression ratio - 383 (BluByU)
oh.. an i'd like to go with the 10.7:1 and just run super fuel always..
i know the LT1's have 10.4:1 stock and the LT4's 10.8:1 so im hoping that means I can get away with 10:7
i know the LT1's have 10.4:1 stock and the LT4's 10.8:1 so im hoping that means I can get away with 10:7
Burning Brakes
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From: Marietta, South Carolina, USA
Re: What compression ratio - 383 (BluByU)
I would go with the 10.3:1 because if you have to clean the block or heads you will make it more like 10.5:1 and if you want to make your compression more then just go with a different head gasket I think they use Inpala head gaskit to make it more I think it is 0.029 and that would bring it up a little.
Jay
Jay
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From: Sachse Texas
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Re: What compression ratio - 383 (MrJay)
Go with the 10.7. I have run a 396 with 11.5:1 and now run a 398 with 11:1. never had any problems running premium octane fuel.
Running the Impala head gasket will raise it around another .3 compression points over the .043 compressed thickness Felpro.
Running the Impala head gasket will raise it around another .3 compression points over the .043 compressed thickness Felpro.
Burning Brakes
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From: Lewisville Texas
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Re: What compression ratio - 383 (BluByU)
An important question is do you ever plan on running Nitrous or supercharging it? If not I would go with the higher compression.
Le Mans Master
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From: Little Elm TX
Re: What compression ratio - 383 (BluByU)
If those are you're choices, I'd go with the 10.7:1 as well. If I remember correctly, mine is around 10.8:1 and I'm having no problems running premium unleaded.
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From: stop the fun suckers
Re: What compression ratio - 383 (R94 LT 1)
If those are you're choices, I'd go with the 10.7:1 as well. If I remember correctly, mine is around 10.8:1 and I'm having no problems running premium unleaded.
what kind of numbers did you pull?
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From: Little Elm TX
Re: What compression ratio - 383 (BluByU)
If those are you're choices, I'd go with the 10.7:1 as well. If I remember correctly, mine is around 10.8:1 and I'm having no problems running premium unleaded.
what kind of numbers did you pull?
what kind of numbers did you pull?
[Modified by R94 LT 1, 8:45 PM 6/18/2003]
Thread Starter
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From: stop the fun suckers
Re: What compression ratio - 383 (R94 LT 1)
was the fuel pump the reason your car was falling flat on its face on your dyno sheets? I think i remeber you posting you were trying to track down that problem..
Melting Slicks
Joined: Oct 2000
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From: Freehold, NJ
Re: What compression ratio - 383 (BluByU)
I have a choice between 10.3:1 or 10.7:1 compression pistons for my 383 rebuild.... thats assumming stock 58cc heads..
Also on my Mustang, I am running 10.8:1 with IRON heads on 93 octane with no problems...
Le Mans Master
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From: Little Elm TX
Re: What compression ratio - 383 (BluByU)
was the fuel pump the reason your car was falling flat on its face on your dyno sheets? I think i remeber you posting you were trying to track down that problem..
Thread Starter
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From: stop the fun suckers
Re: What compression ratio - 383 (jmr302)
glockLT4 did a 11.5:1 piston in his last rebuild and had continious problems with detonation... his was a 383 rebuild however..
Burning Brakes
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From: Lewisville Texas
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Re: What compression ratio - 383 (BluByU)
12:1 :crazy: I don't know if anyone has done it but personally I would not go any higher than 11:1, especially down in this Texas heat.
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From: stop the fun suckers
Re: What compression ratio - 383 (BluByU)
I did a search awhile back and see to recall someone here is running 12:1 in an LT1... but the motor is insane and runs crazy fuel or somehting..
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Re: What compression ratio - 383 (BluByU)
Cam duration can play a part in being able to run high compression, although you should not have a problem with either CR with 218/224 @ .050". Victor Rienz makes a .027 thickness gasket also that's available at NAPA. If you're really gonna use that CC 218/224, I have one I pulled after just 300 miles I would have just about given to you. I didn't like it, I boiled the tires down low but didn't have the top end power, the LPE 219 is much better for power up top. In any case, you may want to use at least a 1.52 rocker like CC Pro Mag, 10.7:1 sounds good with aluminum heads.
JMOH
JMOH
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From: stop the fun suckers
Re: What compression ratio - 383 (Mark84_L383)
Cam duration can play a part in being able to run high compression, although you should not have a problem with either CR with 218/224 @ .050". Victor Rienz makes a .027 thickness gasket also that's available at NAPA. If you're really gonna use that CC 218/224, I have one I pulled after just 300 miles I would have just about given to you. I didn't like it, I boiled the tires down low but didn't have the top end power, the LPE 219 is much better for power up top. In any case, you may want to use at least a 1.52 rocker like CC Pro Mag, 10.7:1 sounds good with aluminum heads.
JMOH
JMOH
mark,
the only difference is i'm using stock exhaust.. which wont really be able to utilize any power about 5500 rpm... which is why i picked a cam with such a low operating range... all of us have heard time and time again.. its all about matching componeants.. since you've run that cam do you think it'll run good with stock heads, rear gears (2.59), stock converter, stock rockers.e.tc..etc..?
I only wanted to go a step or two about stock... do you think this cam fits the bill? i'm thinking the LPE 219 is a bit much for a application i used to run earronds and go to work with..
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Re: What compression ratio - 383 (BluByU)
It's your choice, not trying to dis your decision, I guess we're just performance nuts and want to see you make the most of your setup. I understand the low budget, you'll be fine for what you want out of it. Good luck with it!
