Re: 302 Pistons
[QUOTE=dh302]Does anybody out there make a 1969 Z/28 302 piston that is a lower compression than the stock 11:1 pistons, or if this subject has already been discussed lead me to that posted discussion. If not, can the stock 11:1ís be milled down to a 9.5:1 or 10:1. If a lower compression piston is not available what octane rating would an 11:1, 302 with the 1969 Z/28 302 camshaft and 186 heads require? Thanks.
We've just finished one unit (1969 302" DZ), have one more going on now. We use Eagle H-Beam (6.250") connecting rods and a set Ross pistons and end up with 9.6:1/9.7:1 C.R. using the same 186's that belong on the DZ's. They run excellent on 93 with no issues. We end up with a bobweight around 1885 grams. We've put some kits (rods, pistons, and rings), into inventory due to the popularity of restoring these Camaros. Due to these units be high "revvers", don't use any cast (Hypereutectic) pistons under any circumstances. Thanks, Gary in N.Y.
P.S. The "long-rod" units work great. The original pistons were very heavy, had the pins too far down (1.805 C.H.), and put excess loads on the bores. The Ross's we use have a much higher pin location (1.250+ C.H.) and make the rod/stroke ratio come in at 2.080 instead of 1.900. The higher the number the lower the side loading and increased piston "dwell" time.