Cylinder head question

Rusty_S85 wrote

Thats why me personally I am not splitting hairs over my quench as I am looking at 0.052" quench at the absolute most and 0.011" deck clearance.  From what I could find a stock 302 had a piston compression height from Ford of 1.61" which puts OE deck clearance as 0.006" and OE head gaskets as far as I know were 0.040" which makes a factory 302 in the neighborhood of 0.046" quench from the factory.  Mine at 0.052" inch is a decent 0.006" difference.  But still I dont know what my deck height will actually be.

Interesting, cause the closest deck clearance I've been able to calculate with an OE deck height has been 0.025". After supper last night I went and looked up the part number on the gaskets I have and they compress to 0.047" for a quench of 0.072". Even if I bought another set of gaskets that compress to 0.039", I'm still just shy of the "minimum" at 0.064".
It just seems odd to me, because even looking strictly at "stock replacement" pistons, there is enough variability in compression height that I could end up with as much as 0.125" of quench using the gaskets I have on an OE spec block. I never did measure how far down the holes the existing pistons sat before they went to the machine shop, but I doubt they had the ~0.013" deck clearance they'd need for a minimum quench. But then again, maybe I'm wrong. I'll have to call the machine shop today to get an actual deck height from my block.

Lucas

Lima Delta wrote

Rusty_S85 wrote

Thats why me personally I am not splitting hairs over my quench as I am looking at 0.052" quench at the absolute most and 0.011" deck clearance.  From what I could find a stock 302 had a piston compression height from Ford of 1.61" which puts OE deck clearance as 0.006" and OE head gaskets as far as I know were 0.040" which makes a factory 302 in the neighborhood of 0.046" quench from the factory.  Mine at 0.052" inch is a decent 0.006" difference.  But still I dont know what my deck height will actually be.

Interesting, cause the closest deck clearance I've been able to calculate with an OE deck height has been 0.025". After supper last night I went and looked up the part number on the gaskets I have and they compress to 0.047" for a quench of 0.072". Even if I bought another set of gaskets that compress to 0.039", I'm still just shy of the "minimum" at 0.064".
It just seems odd to me, because even looking strictly at "stock replacement" pistons, there is enough variability in compression height that I could end up with as much as 0.125" of quench using the gaskets I have on an OE spec block. I never did measure how far down the holes the existing pistons sat before they went to the machine shop, but I doubt they had the ~0.013" deck clearance they'd need for a minimum quench. But then again, maybe I'm wrong. I'll have to call the machine shop today to get an actual deck height from my block.

Lucas

For my quench numbers I am using for a 302 with the shorter deck height as thats what I am building currently.  I gave up trying to piece together a performance build on my 351W as the quench was excessively high every time.  From the factory the excessive quench might not be as big a problem as these engines were 8.0:1 compression from the factory for the most part.  When you start getting into higher compression you do want to tighten the quench up to help.