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Author Topic:   9 to 1 motor wet sump thank you in advance for your help.
posted December 22, 2003 10:27 AM
i would like to attempt to build my own motor this winter and would like to ask a few questions please.
I'm building a 9 to 1 motor for a 358 class modifed dirt car. is their a formula that tells you how to get the 9 to 1 ratio?
also this is a wet sump system, do i plug the oil dipstick or leave it?
thank you in advance.

posted December 22, 2003 11:25 AM
Most piston manufacturers publish their compression ratios with different stroke, bore combinations. Just look up in the catalog for your application and find a suitable part number. In a 358 depending on the size of your chambers on the heads you are prob going to be limited to a flat top piston to get that 9:1 number.
You can either plug the dipstick holeor youcan leave the dipstick in and use it to check oil leve. If you plug it make sure you always keep enough oil in it or have a check plug in the pan.

posted December 22, 2003 05:11 PM
dirt is right dipsticks are drivers preference doen't hurt to be able to check it but is not totally necicary as for your compression 95% of your flat top pistons are going to get you right in the 8.5- 9-1 range with a 76 cc chambered head so as long as you have a flat top and don't get crazy with decking the block and shaving the heads you should be pretty safe

posted December 22, 2003 08:50 PM
thank you for your help and information.
patrick moyer

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