LT1-LT4 Modifications 1993-97 Gen II Small Block V8

Compression question

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Old Apr 8, 2019 | 08:36 AM
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Default Compression question

A guy is ******* with me...
Saying my car is too high for boost on pump gas ...

Heres what i have

396

Zero decked
6.0 h beam
3.875 crank
-34cc piston
Supervictor intake
80 pound injectors
Camshaft 231 247 581/600 114 lsa plus 1.65 rocker
56cc afr 227

Too my knowledge its 9.25 compression so why wouldn't this beable to run pump gas with boost


Please correct me if im wrong.
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Old Apr 8, 2019 | 09:47 AM
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Even if you had a zero thickness HG, you still are below 10:1 scr

Seems like you are good to go but, IDK how to get your DCR, that could be an issue
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Old Apr 8, 2019 | 09:50 PM
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Originally Posted by Lsp Przy
A guy is ******* with me.....
So what? Tell him to kiss your *** and mind his business.

Get a competent tuner, don't get crazy with your boost....and enjoy!

KW
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Old Apr 8, 2019 | 09:54 PM
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That's about the compression I aim for with standard cooling. It's more than safe with reverse cooling.
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Old Apr 8, 2019 | 10:02 PM
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Depends on how much boost you plan on running. After a certain point you'll need to spray it or run better fuel.
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Old Apr 9, 2019 | 04:16 PM
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if your rings are properly gapped, then you are good to go, I run 9:4:1 compression.
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Old Apr 10, 2019 | 10:15 PM
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Originally Posted by moehorsepower
if your rings are properly gapped, then you are good to go, I run 9:4:1 compression.
Speaking of good tuners...…. ;-)

KW
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Old Apr 10, 2019 | 10:33 PM
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Default Moe...

I need you retune my computer

You did tune on the computer not to long ago

Send me your addresss so we can fix it before i blow it up

Compression is 9.35 i just got it from lloyd
And tune was set at 9.25 and 77 pound injectors... i have the ford 80 pounders
Now
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Old Apr 11, 2019 | 11:31 AM
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Originally Posted by Lsp Przy
I need you retune my computer

You did tune on the computer not to long ago

Send me your addresss so we can fix it before i blow it up

Compression is 9.35 i just got it from lloyd
And tune was set at 9.25 and 77 pound injectors... i have the ford 80 pounders
Now
9787 ALexa PL
San Antonio, Tx 78251
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Old Apr 11, 2019 | 12:22 PM
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Originally Posted by Lsp Przy
A guy is ******* with me...
Saying my car is too high for boost on pump gas ...

Heres what i have

396

Zero decked
6.0 h beam
3.875 crank
-34cc piston
Supervictor intake
80 pound injectors
Camshaft 231 247 581/600 114 lsa plus 1.65 rocker
56cc afr 227

Too my knowledge its 9.25 compression so why wouldn't this beable to run pump gas with boost


Please correct me if im wrong.

Curious as to what this guys automotive background is that he can make a blind statement like that. Everything looks good, and with a competent tuner I don't see what the problem is. As previously stated don't go to crazy with the boost and have fun. I know someone who had a stock bottom end low mileage LT1 running 7psi of boost and a good tune last something like 12 years. And he only rebuilt it because he got bored and went a different route with his build.


EDIT: I'd like to note that his car was a seasonal car only and he only drove it like 3-4 times a week weather permitting.
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Old Apr 13, 2019 | 01:06 AM
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Default This guy...

He claims hes a prototype engineer
Calls him himself mathematical engineer
Says that numbers on my build are 15 static
I confirmed with like with diamond, lloyd , calies everyone told me around 9.2 and 9.35
I thought guy was bullshitting but hes dead serious, says he uses math every day... and has built 4 race spec motor even calculated 3 angle vavle jobs on how it will affect compression.. guy is either a meth head or a ******* genius.. i cant wrap my head around it
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Old Apr 13, 2019 | 02:52 AM
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Originally Posted by Lsp Przy
He claims hes a prototype engineer
Calls him himself mathematical engineer
Says that numbers on my build are 15 static
I confirmed with like with diamond, lloyd , calies everyone told me around 9.2 and 9.35
I thought guy was bullshitting but hes dead serious, says he uses math every day... and has built 4 race spec motor even calculated 3 angle vavle jobs on how it will affect compression.. guy is either a meth head or a ******* genius.. i cant wrap my head around it
He's not a mathematical engineer. He's an idiot and a liar. Your compression is around 9.3 by my figures.
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Old Apr 13, 2019 | 03:20 AM
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Default Lol yea i figured that

I found this calculator

https://www.rbracing-rsr.com/comprAdvHD.htm

But i dont know the ab what ever that was so i cant be accurate
.i just put 50 as the number and my dynamic sits a 7.0
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Old Apr 13, 2019 | 08:45 AM
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Are you sure he's not talking about effective compression ratio at a certain boost level?
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Old Apr 14, 2019 | 01:06 AM
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Default Nope

He mentioned static

Originally Posted by LLLosingit
Are you sure he's not talking about effective compression ratio at a certain boost level?
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Old Apr 14, 2019 | 01:14 AM
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Default See , not sure if hes using 2+2 =5 math or what


Last edited by Lsp Przy; Apr 14, 2019 at 01:16 AM. Reason: Cause
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Old Apr 14, 2019 | 12:32 PM
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I made some assumptions like you are using the typical Felpro blower gasket and I got 9.22 with zero deck height. To find dynamic you need to find the specs on your cam. Not sure what this guy is on about but some people have no lives and like to waste time arguing on the internet.
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Old Apr 14, 2019 | 12:37 PM
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After reading the post in the picture it sounds like agreed with the 9.25 but he's saying the numbers you gave him added up to 15.1 after all he did say get your numbers right.
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Old Apr 15, 2019 | 09:10 AM
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IVC would be -.050" - 47*.006" - 73*Thats what loyd told me ..How do i calculate that in the calculator i posted.anyone know
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Old Apr 15, 2019 | 09:17 AM
  #20  
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Default Lol

I agree thats why i posted this, i had double check my build
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