Valve relief cc, deck height SpeedPro/TRW L2291F30

Any one measured it?

My calculations based upon some standard deck heights and gasket thicknesses using speed pros stated compression ratios put the valve reliefs at about 11CC, that sound any where near right?

If you install these pistons out of the box in a stock 390 do you get a -.015 deck height measurement?

I know I need to actually measure it, but I'm trying to get an accurate picture on paper before I start ordering any more parts.

 

Duck, I never measured the volume of the trw valve cuts, but my L2291F 060s were 1.760 tall before I cut the tops by .100 to make stroker pistons. DF

 

You have to take into account, block machining..Has your block been decked ? some came from the factory that way because, of casting flaws..Its not a problem to run a 0 deck height. If you do use Felpro or equivealent perma torque heas gaskets,as they are .025 thicker than the steel shim gaskets. You will need to assemble your block and physically check it...As far as valve reliefs..If you have any clearance doubts clay the pistons and take an true measurement...Your usually safe with .080 on the intake and .125 on the exhast....D44HD

 

If you want the actual cc set the piston flat and level fill the reliefs with water and use a sirrenge marked in cc's to suck up the water this will give you actual cc's.

 

Thanks guys.

I do not have the pistons or I would CC them myself. As far as I know, the block has not been decked.

I am just trying to come up with an accurate idea of what the compression ratio will actually be, but as I said, it will all be checked when I build.

It may be a mute point, as I might have a line on a 428