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here is my situation in building a motor and have been collecting parts for some time I currently have a set of humps with 2.02 1.60 valves and 58cc heads fresh rebuilt with hard seats brand new everything ported and polished I would like to use these. Here is where its gets weird I'm running 2eaton m90 superchargers through a intercooler blown through a quickfuel 750my head gasket is4.150 bore and compressed height of .040 my Cr is like 12:1 I need to drop it to 9:1 at a min I at the point where I'm buying my rotating assembly and would like to keep it under a grand what do you all recommended
any help would be great
 

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Wrench Turner
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Is this a 350,400,383 ??? How did you figure a CR w/o knowing what parts you are using yet.You'll need to add volume thru a piston w/ a lot of dish.Need a lot more info to be able to help. Bore size,deck hgt,cam specs,stroke,etc.
 

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Discussion Starter #3
sorry I did the valuations using stock pistons no valve reliefs its a 350 bored .030 over I have a comp cams big mutha thumper but my swap it out for a roller and a blower cam
 

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here is my situation in building a motor and have been collecting parts for some time I currently have a set of humps with 2.02 1.60 valves and 58cc heads fresh rebuilt with hard seats brand new everything ported and polished I would like to use these. Here is where its gets weird I'm running 2eaton m90 superchargers through a intercooler blown through a quickfuel 750my head gasket is4.150 bore and compressed height of .040 my Cr is like 12:1 I need to drop it to 9:1 at a min I at the point where I'm buying my rotating assembly and would like to keep it under a grand what do you all recommended
any help would be great
Supercharged engines run better with a different ratio between the exhaust and intake valve, in this case a larger exhaust is needed even at the expense of the intake diameter.

The needed compression of say 6 pounds or more of boost will be something closer to mid sevens to low eights. This is a place where the stronger 2618 alloy forging should be used, unless you're building a show car that doesn't really use the twin blowers they're just there as technical eye candy. If this is a driver/racer than you've got to design around how fast detonation can destroy a huffed motor.

You should replace the cam with a blower cam, these add timing and lift to the exhaust which is always a problem getting enough flow with a blown or nitrous engine up on the top end again if you're going to use it like that.


Bogie
 
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