Don's Elan S4


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Camshafts reground to Dave Bean #112 specs; 0.385" lift and 300° duration seat-to-seat.

Intake Ports smoothed, Exhaust Ports reshaped, Combustion Chambers polished and CC'd.

Special Shims are needed for reground Cams. A surface grinder is needed to adjust the thickness.

The special Shims also need to be shortened to fit on the Valve Stem without touching the Keeper.

Setting up the Degree Wheel. An extension was needed to move the wheel away from the Water Pump.

Calibrating Top Dead Center.

Setting the Lobe Centers. The Exhaust Cam needed a 2° offset dowel and the Intake a 1° offset dowel with a 0.040" thick Head Gasket. A 0.027" Head Gasket needed a 1° and a zero.

Clay is used to check the Piston-to-Valve clearance. Measuring the cross section of the squished clay gives the clearance.

The Chassis Dyno will give the final verdict, but this should be a good start.

A Sun 506 Distributor machine was used to produce "Don's Elan" curve. The Big Valve Dellorto and Stromberg (Domestic) curves are from Miles Wilkins' book (pages 168 & 169).

Even though the Distributor is marked "12°" it required a bushing to limit it to 12 (24° crankshaft). Without the bushing it nearly had 20° of advance (40° crankshaft) !

Is YOUR Lotus ready for driving?
If not, call Don - 302-559-9374


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