In 2016, with the help of Aaron Kelley of Tulsa, OK, Zekert Racing started a development program for a newer Datsun A-series racing engine. The goal was to win another SCCA GTLite National Championship (another Runoffs win). The last serious Datsun A-series development was in 2000, with camshafts from Dema Elgin, so development was long overdue. Before Dema Elgin's cam development, previous top camshafts were from Electramotive; Isky; and Sunbelt. This new camshaft has a "banana" shape on the intake ramp, and a traditional straight ramp on the exit.
Aaron and I developed both an A14 (77mm x 77mm bore and stroke) and an A13 (75mm x 77mm). The first A14 is currently being raced by Brad Lewis of St. John MO. The A13 is in my car, and made it's debut appearance at Indianapolis Motor Speedway for the year ending 2017 SCCA Runoffs. In qualifying we had some tire isses, but managed to qualify 3rd in a competitive field.
Using 45 Weber DCOE and Dellorto 45 DHLA carbs on the dyno, the A13 made peak Hp of 191 hp. To keep the engine alive, we dialed that back to 183 hp. The A13 engine made 70 dyno runs, (yes, that many runs) and then did 5 on-track test days; plus 4 twenty minute qualifying sessions; and finally a 50 minute race. After the race was over, the engine's hot leakdown rate was a maximum of 2%.
The engine uses Wiseco forged aluminum pistons, a billet crank, a custom assymetric camshaft, and a custom ported and polished GX cylinder head. The valves are titanium, and use 7mm valve stems. The valve springs are beehive (smaller diameter at the top) and use a smaller valve retainer.
