[jim_howard_pdx]

Good point Andy, and I have said it a half dozen times today. Check your rule book for the bracket you want to run.

See if you can angle mill the head to reduce chamber volume, then take that material out around the valve pockets to make a little bit of a dish. I am not sure from your comments if the class stipulates flat top unmodified, or a maximum static ratio given the stock class you are running.

Man I wish I had a current rule book. Mine is way far old. I just street race and grunge race now, so everything is straight up on the tree. I just do not have the desire to bracket race this street rod. It is built to autocross, not knock the snot out of the thing....

If they allow angle milling, and they allow you any stock piston, then you can usually find a ford forged or hypereutectic piston with a dish. just make sure you also remove all the edges ridges etc as long as the rules allow smoothing contours. Most rule books allow this if the combustion volume remains stock. So the angle mill reduces the quench area significantly, and the dish is just to smooth the valve reliefs and nothing more.

USE ZERO GAPPED rings if they are allowed. I like child and alberts because it is a slider style and holds up to mild abuse pretty darn well. This will reduce the leak down on the rings from 31 cubic inches per rotation to just 16 cubic inches per rotation. That equals A LOT of cylinder pressure that could have been converted to torque. If you have to use stock rings. Take a file to fit set and do what child and albert does with their sliding overlap. We did this all the time on the Hemi's to keep the cylinder pressure high during the power stroke. High cylinder pressure made for a more efficient exhaust cycle and the additional scavanging would net us an additional 8-12 hp over a standard ring set on a static dyno run and almost 30 hp on a dynamic dyno run.

Someone asked how I got an extra point of static compression with coatings. I did the angle milling on the heads first to reduce the wedge volume, then added that volume back by evenly removing material across the entire face of the piston. The coating was a standard brand at the time, to which I added a high silicate ceramic substrate that my buddy at Northrup developed for heat shields on space craft. It was really cool of him to lend me some material to test at 1400 degrees.

So my coatings were especially thick, but legal because they were a single coat. Almost resembled "aluminizing" if any of you are old enough to remember that process. My buddy helped me glue together a persimmon golf driver too. That thing is still holding up 21 years later. Wish I could run out and buy epoxy that good.......