JAP 1100cc Model 8/80 JTOR Racing Engine -modified for petrol and road use. The famous JAP methanol-burning Racing Engine was introduced in 1936 with production continuing into the post war era, it was successfully used in speedway sidecars, Cooper JAP racing cars and other sprint specials etc. This project engine has been modified and detuned to operate on petrol for use in a petrol burning road going special and is 98% finished with only minor work required for completion. To make the suitable for running on the road the following modifications were undertaken: • Modern forged lower compression pistons fitted to reduce the compression ratio to both enable the engine to run without detonation and to reduce the heat generated by the use of petrol fuel • New more generously finned aluminium cylinders were manufactured to better dissipate the extra heat generated from the use of petrol as a fuel in place of cooling methanol • New replica road going JAP crankcases were used, cast from stronger, durable aluminium to replace the original engine’s thin and corrosion prone magnesium crankcase castings used by the factory • Addition of a recirculating oil pump to replace the total loss oiling system to enable the engine to be used on the road • Provision of two sets of points suitable for coil and battery ignition for more reliable starting • Auto advance-retard mechanism fitted to enable the engine to idle and pull smoothly away from low speed Other details • New crank assembly built to suit new S&S Extra Heavy Duty Harley style conrods and big end bearing • Bore and stroke of 89mm x 89mm give a capacity of 1100cc • Generous plain bush timing side bearing employed, perfectly adequate and suitable for such a stiff and narrow crank and moderate revving engine such as this. • New forged JE pistons as used in Harley Davidson 1340cc EVO engines supplied • Timing side main bearing is a high load rating durable bronze bush to suit the stiff crank assembly • Drive side mainshaft bearing is ball and roller This engine as supplied is 98% complete and loosely assembled. Remaining tasks that can be readily completed by a competent enthusiast is: • Add a breather to the timing chest • Cut pushrods to length from new chrome-moly tubing supplied • Purchase and press fit new 500cc speedway JAP pushrod ends to pushrod tubes. Pushrod ends are readily available from Speedway Services in the UK • Hone new cylinder liners to suit new JE pistons supplied • Fix oil pump cover supplied to timing chest
