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Compression ratios influence on power outputs?

Dan355

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Just wondering how much of a difference the compression ratio makes to the power output of your motor. I have a stroker on 9.1 comp which makes 198rwkw. Just wondering what it would make with a 10.5 comp?
Cheers
 

immortality

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increasing the compression ratio will increase the output ofthe engine, however to much and it'll start pinging on pump gas and then you'll ruin your engine. would need to knwo more about the engine combo, especially the cam as this usually governs the compression required to make the cam work. it's best to consult the cam supplier as they will know what compression is required for cam they supplied you
 

Dan355

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Its just a general interest question. My comp is stayin where it is for some psi. How does compression affect the way the cam works? Doesnt the cam just control the timing and hight of the valves?
 

xcop5l

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the cam has a major part in the compresson it controlls the duration that the valve is open as well as the lift and the timing
thats how most proformance cams work they keep the stock timing (unless its a race cam) and the make the lobe of the cam taller and fatter there fore giving it a longer duration and a higher valve lift

so if you put a bigger cam in with longer duration and lift the valve will be open for longer allowing for more air fuel mix into the cylinder
 

Dan355

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Ah ok. Cheers for the info. Looks like il be changing my cam shortly anyway for good and bad reasons. Thanks people
 

SweetWagon

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Higher compression is only good on a N/A engine, for example ferrari's and the like run 12:1 compressions, however if the motor has forced induction, you would need to drop the compression depending upon how much boost is being put in. for low boost say 5psi you should be fine but upwards of 10psi you will be replacing head gaskets every week with a high compression compression, but yours should be fine.
 

AirStrike

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Higher compression is only good on a N/A engine, for example ferrari's and the like run 12:1 compressions, however if the motor has forced induction, you would need to drop the compression depending upon how much boost is being put in. for low boost say 5psi you should be fine but upwards of 10psi you will be replacing head gaskets every week with a high compression compression, but yours should be fine.
What does this have to do with the topic what so ever? No one mentioned boosted applications at all:supersad:
AirStrike :air:
 

Dan355

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Thanks guys. I do know how a cam works i just wasnt to sure how compression influenced the grind of cam. I guess the higher the comp the less duration? lower the comp longer duration? Basically giving more or less time for gasses to enter/exit each cylinder depending on the amount of time each valve is open for and how far open each valve is? Does this sound right?
The motor was built for a blower but the previous owner left as is with a big cam. So yer i was just wondering how much of a difference compression would make to my power output.
Thanks
 
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