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Increase compression ratio a little?

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Old Dec 15, 2011 | 06:34 PM
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RIKIL's Avatar
RIKIL
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Increase compression ratio a little?

How dramatic will a 0.5 increase in my compression ratio make? Is that enough to notice anything?

I ask because I can get one head gasket vs. another and it would make my compression ration increase from 9.27:1 to 9.55:1, OK, so a difference of 0.28.

It's a performance engine and will eventually be supercharged. Vortech told me I should try and stay close to the stock compression ratio, 9.0:1. So I am not sure if my increase to 9.55:1 will do me more damage?

Thanks.
 
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Old Dec 15, 2011 | 09:22 PM
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Freightrain
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Seat of the pants you won't really notice anything.

Yes, when you supercharge it helps to keep static compression down.
 
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Old Dec 16, 2011 | 01:19 PM
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Assuming you're running a centrifugal SC (since you mentioned Vortech), and assuming you went with a forged rotating assembly, I would go the 9.55:1 route. Centrifugal SC's and turbochargers generally tolerate higher CR's than PD blowers, and the higher CR's keep them from being total slouches when you're cruising along out of boost.
 
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Old Dec 16, 2011 | 01:40 PM
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blkfordsedan
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Originally Posted by White Max
Assuming you're running a centrifugal SC (since you mentioned Vortech), and assuming you went with a forged rotating assembly, I would go the 9.55:1 route. Centrifugal SC's and turbochargers generally tolerate higher CR's than PD blowers, and the higher CR's keep them from being total slouches when you're cruising along out of boost.
^^^^This...

It will also depend on your heads. Will you have factory iron or aftermarket aluminum heads? What is the chamber design? What form of spark & fuel management will you have, what camshaft profile, how much boost, . Either way, .28 points is not a huge difference, so I would probably just look at the head gasket design itself and go with the one that will be the most durable under boost and let the compression chips fall where they may.....it can be tuned accordingly.
 
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Old Dec 16, 2011 | 03:40 PM
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Slip ford man
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From: Calverton
Originally Posted by RIKIL
How dramatic will a 0.5 increase in my compression ratio make? Is that enough to notice anything?

I ask because I can get one head gasket vs. another and it would make my compression ration increase from 9.27:1 to 9.55:1, OK, so a difference of 0.28.

It's a performance engine and will eventually be supercharged. Vortech told me I should try and stay close to the stock compression ratio, 9.0:1. So I am not sure if my increase to 9.55:1 will do me more damage?

Thanks.

Were you able to determine if the bearing's got wet?
 
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Old Dec 16, 2011 | 03:42 PM
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Originally Posted by Slip ford man
Were you able to determine if the bearing's got wet?
They did, I mean the coolant was all mixed in the oil so I am replacing all bearings, piston rings, etc. Should have it ready to go by early Jan.
 
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