How Much Compression with Blower?
08-20-2005, 05:52 AM
#1
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How Much Compression with Blower?
I'm thinking about getting a blower, and I was wondering if I will need to lower my compression? I running 289 hypo heads, which raise the compression about 1 point over 302 heads. So I think I'm at about 9.5 to 1. I'm also running an E303 cam. Will that be ok with a blower? I was told that I was probably boarder-line, but using the right pulley size I should be ok.
08-20-2005, 03:31 PM
#6
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RE: How Much Compression with Blower?
My machine shop told me that the stock compresson on a 5.0 was 8.5 to 1, and by using the hypo heads it would raise it to 9.5 to 1. This is because of the tiny heart-shaped combustion chambers on these heads. This shop is pretty reputable. They sponsor and build engines for Dwayne Barbaree in the Pro 5.0 class. He placed 2nd last year or the year before, I don't remember. I thought they told me stock was 8.5. Maybe I missunderstood.
08-20-2005, 05:16 PM
#7
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RE: How Much Compression with Blower?
depends on which 302 you have, or did you say 5.0HO. sorry i dont know what kinda car you got, the 86-93s are all 9.0:1-9.2:1, so it would be around 10.0:1. and this is kinda high for anything over 5-6psi, unless its a drag car and youre using straight racing fuel around 113octane or higher.
08-21-2005, 12:54 AM
#9
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RE: How Much Compression with Blower?
9 to 1 is perfect for boost, most factory FI cars have around 9 to 1 compression, tuning will be more important than anything to achive the right af ratio. depending on E303 overlap specs would depend if its boost friendly. u want a cam that has high lift, short duration.
08-21-2005, 01:45 AM
#10
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RE: How Much Compression with Blower?
you want a cam that will match the powerband of the blower. a cam with to high of a lift isnt going to be that benefical as a cam with a lower lift.. reason why the stock cam is a good cam for boost
e cam is 221/221 it think[otoh]498/498 112. with its produced powerband its a nice cam to be used in a JYTT setup that uses SVO turbos. power is dead around 5200. now a supercharger may not like it but it may also. all depends on the power band of the blower
e cam is 221/221 it think[otoh]498/498 112. with its produced powerband its a nice cam to be used in a JYTT setup that uses SVO turbos. power is dead around 5200. now a supercharger may not like it but it may also. all depends on the power band of the blower