The resurgence of Cleveland-style heads on deep-breathing Windsors has prompted one manufacturer to do something about it.      

 At first blush, Diamond’s press release for their new line of Cleveland stroker pistons makes you wonder if the calendar wasn’t turned back to 1974. “Who builds a Cleveland anymore?” one might rightfully ask. If you work in this office, you’d know that the top competitors in the Jeg’s Engine Masters Challenge like Cleveland-headed monsters for their deadly power levels.

The back story goes something like this. A few years ago, CHI out of Australia started making their 3V canted-valve head modeled ostensibly after the Cleveland, but since few people bother to build Clevelands any more, they sold mostly to folks wanting to put a Cleveland-style head on a Windsor block. That makes sense, because the canted-valve design of the CHI head (and other Cleveland-derived variants) flow much better than traditional Windsor heads, for a whole bunch of reasons we won't go into here.

Of course, the flow limitations of existing Windsor heads weren’t really that big a deal, until big cranks, stronger blocks, and stroker kits started overtaking small-block Chevy hardware in popularity. If you dig about 15 years back in Ford history at look at the unrelenting surge of the 5.0 Mustang and Mustang racing in general, and you’ll see where that need came from.

So now we find ourselves with big inches in a tall-deck Windsor package, lots of hungry Ford customers with a hankerin’ for horsepower, and the traditional Windsor cylinder head architecture incapable of delivering on the goods. That's when CHI, Edelbrock, Blue Thunder, and Air Flow Dynamics stepped up with their canted Cleveland heads to fill the void.

Suddenly, Cleveland-style pistons are in fashion again, because to get the most combustion efficiency and power out of those cavernous Cleveland heads, you need a piston dish under them that matches the contours of the cylinder head, and the reliefs for those big, canted valves.

So now we’ve come full circle to Diamond, and their Cleveland pistons. They don't sound so old fashioned any more, do they? After getting inundated with custom orders for pistons that were obsolete just a few years before, Diamond figured out what was going on, and got ahead of the curve before everybody else. These forged pistons come in two principle configurations designed to work with the following stroke and rod types: Ford OEM connecting rods (5.596 inches with a .912 inch wrist pin), or Chevy 6.000-inch connecting rods with .927 wrist pins. Bore sizes begin at 4.000 inches (standard bore), and extend in small increments to 4.060-inches. Diamond developed these for use with pump fuel, with compression ratios of around 9.5:1 to 10.5:1. That makes them ideally suited for weekend warriors and budget bracket racers running older Mustangs and Torinos. Diamond’s stroker Cleveland pistons are supplied with a conventional ring stack (1/16-inch, 1/16-inch, and 3/16-inch). 

So now you know the rest of the story. For more information, contact Diamond Pistons at 877-552-2112, or email them at RBeaubien@Diamondracing.net.