I have been building this motor for a LONG time now- almost a year. It's a 292 bored out to .030" over 312, or 3.830" bore. I had a local shop offset grind a 312 crank to a 3.610" stroke. I had the journals turned down to utlize the Eagle Forged Feather-weight H beam connecting rods, 6.125" long. I also bought a set of custom forged aluminum flat topped pistons that John Mummert offers (Probe). I also chose a Mummert cam Y-284S, with 236 duration at .050", with 108 degrees separation. I'm running stock 312 rockers with a 1.54 ratio, and Comp Cams dual spring 985-17 (A little stiff for my application). I had a torque plate made up and for honing the block (Steve Flatt is my machinist). My combustion chamber is 66cc, and the piston comes out of the hole .006" for a quench of .038". Compression ratio is right at 10.2:1. I also followed Tim McMasters guidelines on pressurizing the rocker arms. With some instruction from John Mummert I also ported the heads, and they flowed surprisingly well, 225 on the intake and 165 on the exhaust. Dick York (Dickster) worked his mojo on my tri-power set up, and Frank Quinlin’s Dyno Shop in Nampa ID helped me break her in. HUGE THANKS to everyone I’ve bothered along the way, including John Mummert, Tim McMaster, Ted Eaton, and everyone else on the forum who has answered questions and offered parts/advice along the way. Enough said, here's the video and the dyno sheet.



Start Up Video at YouTube.com



Dyno Pull at YouTube.com










Heber City, UT (15 mins outside of Park City- basically it's in the mountains)

55 Effie