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Discussion Starter #1
is 11:4:1 to high a compression ratio for a stroker?
 
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Discussion Starter #2
Originally posted by murphies_finest:
is 11:4:1 to high a compression ratio for a stroker? will eventualy be adding a twin turbo set up?
No way would I run 11.4:1 CR with a turbo.....but that's just me
.

That CR is not too high for a stroker......you are talking about a LT1/LT4 engine
......correct
?

I run 11:1 CR with no issues. I know of several others with quite a bit more CR.

With proper tuning....you'd be fine!

I'd repost your question about the turbo on the Forced Induction page where some of the turbo gurus would see it.

Good luck!!!!!!

KW
 
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Discussion Starter #3
KW I think he's talking about a GEN 1 SBC, L03/L05.
 
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Discussion Starter #4
Originally posted by mass9c1:
KW I think he's talking about a GEN 1 SBC, L03/L05.
If that's the case....then 11.4:1 CR is definately in the category of a 'specialty' engine
!

KW
 
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Discussion Starter #5
KW why is that?

The L03/L05 can't handle that much compression, any specifics??
 
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Discussion Starter #6
The reverse flow cooling in the LT1/LT4 engines allows it to get away with higher compression than a gen 1 SBC. On a LO3/LO5, I would go 10.5:1 with AL heads, or 10:1 with iron heads max, and either will require premium gas. Of course how much static compression you can get away with depends on lots of things, expecially the cam. Generally though, 11.4:1 will reguire higer octane racing fuel.

For a turbo motor, I would run about 8.5:1, but performance will suck terrably until you get the turbo on it.
 
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Discussion Starter #7
Originally posted by Bugman:
The reverse flow cooling in the LT1/LT4 engines allows it to get away with higher compression than a gen 1 SBC..........On a LO3/LO5, I would go 10.5:1 with AL heads, or 10:1 with iron heads max.........Generally though, 11.4:1 will reguire higer octane racing fuel......
^^^^^^^What 'Bug' said^^^^^^^

KW
 
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Discussion Starter #8
Originally posted by murphies_finest:
is 11:4:1 to high a compression ratio for a stroker? will eventualy be adding a twin turbo set up?
11.4:1 cr is way too high for a power adder unless you plan on running race gas.

As far as n/a performance goes, you missed a very important variable, the cam. The compression ratio would be too high if you plan to run a small (227/845 cam) in a stroker. It would be too low if the cam has a 250+ duration @ 0.050" lift. This assumes you are using aluminum heads and the quench height is not too big.

You need to provide more information.
 
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Discussion Starter #9
Originally posted by mass9c1:
The L03/L05 can't handle that much compression, any specifics??
Reverse cooling is one reason why an LTx engine can have higher compression ratios than a regular SBC. A more efficient combustion chamber is the other. Just look at LSx engines. Their compression ratios uproach LTx ratios without reverse cooling.

The maximum streetable dynamic compression ratio is a matter of head material (iron/aluminum), combustion chamber, quench height, gasket bore, rod length, cam specs, piston shape, valve shrouding, etc and tuning.
 
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Discussion Starter #10
the block is gonna be a motown lite with e tec 200 heads and the edelbroc MPFI set up comp cams recomended to me 8-306-8 not building until next year after iraq and my tuning will be done by wild jim at ccstuning in san antonio all forged internals H beam rods with flattop pistons yeah I notice my turbo question is out of place gone see if i can edit my original post
 
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Discussion Starter #11
LSX motors also use a whole new design cooling system in the block and herads not as readily comparable as the gen1 and LTX motors are.

Personally I would probably aim higher than 8.5 and well below 11.4 for use in a TBI turbo car. Maybe more like 9.0 with iron heads 9.5 with aluminum paying close attention to quench with either.
 
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Discussion Starter #12
all right is quench the space between TDC and the top of the Combustion chamber?
 
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Discussion Starter #13
It's the distance between the top of the piston and the head surface, aka piston-head clearance.
 
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Discussion Starter #14
Thanxxx guys for your input and the comments to come
 
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Discussion Starter #15
wuh do the ratios stand for??i seen a 95 bubble wit 10:5:1???
 
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Discussion Starter #16
Originally posted by Bugman:
....I would run about 8.5:1, but performance will suck terrably until you get the turbo on it.
I resemble that remark! :( I'l gett forced induction someday :(
 
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Discussion Starter #17
chevyman85,
Dictionary.com
compression ratio
n.
In an internal combustion engine, the ratio of the maximum to the minimum volume within the cylinder, between the piston and cylinder head.
Chevyman85, another thing the L99/LT1 can handle much higher compression ratios and still be very streetable as it has reverse flow cooling. i.e. the reverse flow cooling helps prevent detonation at higher compression ratios, by cooling off the combustion chambers first.
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DeanstuD, you have a low compression L03 or L05 and get good performance?
 
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Discussion Starter #18
Originally posted by mass9c1:

DeanstuD, you have a low compression L03 or L05 and get good performance?
I have POOR performance...

I have 8.5:1 (I thought 9.5:1 but my friend says it is 8.5) in my SS 383 LT1 Au heads port polish LT4 hot roller blah blah blah....

SUX w/o a blower. LOL I guess it does LITERALLY!

Best it has done is 13.9, but I have since gotten 3.73 and a new transmission.
 
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Discussion Starter #19
Dean Is it safe to assume you're waiting for that supercharger or turbo kit??
 
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