Building an FA20 Race Engine for Michele Abbate: Part 1

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For head gaskets, we went with heavy duty MLS gaskets from Cosworth. MLS stands for multi-layered steel. With forced induction, high compression and long duty cycles, we needed a serious gasket and Cosworth delivers just that.

Cosworth gaskets are made from multiple layers die cut stainless steel stock with a tolerance of plus or minus 0.001″. The stainless layers are coated with a 0.25-micron thick layer of nitrile synthetic rubber to ensure a good seal between mating surfaces and within the gasket itself. For the FA20 application, the gasket is 0.78mm thick, which is great for maintaining proper function of the squish pads in the combustion chamber.

 

You can see the multiple steel layers and the nitrile rubber coating here.

The most important feature of the Cosworth head gasket is that it has a folded stopper layer. This is an additional ring around the cylinder bore, which provides a much-improved combustion seal. It also greatly increases blowout resistance due to an increase of clamp load around the cylinder.

 

Since we built our last FA20 engine, camshafts are now available. We got a set of Piper Stage One cams from their North American Distributor, Piper Cams USA.

The cams have 262 degrees of intake duration and 266 degrees of exhaust duration with 11.35mm intake lift and 11.30mm exhaust lift. These specs will give improved midrange and top end without sacrificing bottom end with the right tuning of the variable cam timing.

Piper cams are CNC-ground on the latest Landis cam grinding machines. If you know cam manufacturing, you already know that the Landis is the state of the art cam grinding machine capable of undercut flanks and supreme dimensional accuracy. The cams are ground on OEM quality new chilled iron billets with the proper metallurgy to assure a long and reliable service life and proper base circle dimensions.

 

Although the Piper Stage One cams will work with stock valve springs, we decided to run their dual valve spring kit to give us some more headspace before valve float.

We wanted to rev the engine higher and were planning to raise the rev limit to 8000 RPM. For extra overrev headspace, we opted to use Piper’s double spring kit. Although Piper also has a spring kit for this engine, the double spring kit has a seat pressure of 248 lbs vs the single kits 197 lbs. This might cost us a little power, but we want more valvetrain stability in case of accidental overrevving from downshifts, etc.

 

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