pocket rocket Posted May 23, 2011 Report Share Posted May 23, 2011 This might be completely useless information, but in the spirit of sharing information, thought I would post this as it may help someone else. Over the weekend I cc'd a couple of cylinder heads. Mild ported L18 head, fitted with larger (44mm) Intake valves, welded chamber, milled surface, has been used for racing; Intake port - 108.2cc Exhaust port - 86.4cc Chamber - 30.8cc Valve sizes - In 44mm/Ex 35mm Intake Port Opening measures 35.5mm dia Std L20B head, removed from a early '80s Bluebird Intake port - 108.4cc Exhaust port - 83cc Chamber - 47cc Valve sizes - In 42.2mm/Ex 35.5mm Intake Port Opening measures 35.5mm dia 1 Quote Link to comment
ggzilla Posted May 23, 2011 Report Share Posted May 23, 2011 wow that's huge -- 47cc. Are all the L20B heads such large combustion chamber? Quote Link to comment
datzenmike Posted May 23, 2011 Report Share Posted May 23, 2011 Normally about 45cc unless the valves have sunk or a valve leaked slightly. 41cc for the closed chamber. Quote Link to comment
pocket rocket Posted May 23, 2011 Author Report Share Posted May 23, 2011 Pretty sure the valves have pulled down into the seat. The valve head is only just above the seat surface. This motor is still original and did a bunch of miles. Quote Link to comment
pocket rocket Posted May 23, 2011 Author Report Share Posted May 23, 2011 Anybody have the cc's of an L18 intake manifold vs an L20B intake manifold? Quote Link to comment
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