i got a set of cast windsor heads and im looking to get like 10:1 out of it but i was told no good with the cast heads have to be alluminum. can someone explain?

 

The type of material really has nothing to do with the compression ratio?. The piston and combustion chamber dictate the compression ratio. Yes you can achive a high compression ratio with an iron head.

 

.........huh????


stock cr. ratio's used to be like 10.5:1 with iron heads....

 

... yea that makes no sense... just make sure you have the appropriate piston (forged)

 

you don't need a forged piston to run high compression nor an aluminum head to do such,what you will need is high octane gas, the reason people may be telling you no good is what'll be the issue is spark knock/detonation which will be more prevalant with a cast iron head coupled with high compression and the lower octane gas now a days dictates lower compression engines, you should be able to run about 10 to 1 on high test and a little octane boost without having any issues but the use of an aluminum head can allow upwards of 11 to 1 on pump gas due to aluminums characteristics of being able to disapate heat more evenly and quickly

 

I have heavily ported 69 heads that yield 11.25 to 1 compression. Mine runs fine with 93 octane and a bottle of 104.

 

im going with a 66 mustang head off a 289 block and that should bump me to 10.5 to 1. and those of course, are cast as well.

 

'66 289 heads with ~52cc chambers user here (~10.3:1 CR). Was my DD for ~14 yrs.