First Mate Marine
Quality Control

Heads: After cylinder heads are repaired and before final assembly of valves-they are sealed off and pressurized with 50 psi and submerged under water to check for leaks-obviously if any are present - the head is rejected.

Assembled long blocks: After the longblock has been assembled, the engine, as a whole, is again sealed off and the water jacket pressurized with 50 psi and measured for loss.  The engine must hold 50 psi, and not  lose more than 5 lbs for a period of 5 minutes.

Other QC measures: There are several other QC checks that measure head/block surfaces, crank journals, valves, bolt torque specs, etc.

Sim Testing: As the final part of our Quality Control Procedures, we do sim test each engine that leaves our facility.  This allows us to verify the engine is performing properly.  Oil pressure and flows are recorded while we monitor oiling to the top end of the engines.  The oil itself has a fluorescent added to it-as we then "black light" the engine to verify there are no oil leaks from cam/soft plugs, tin ware, etc.  We also test and verify compression on every cylinder, in every engine that is tested.