Hello N Board Forum,
I've a 1941 Ford Model 9N S/N 9N57720 and the engine has a noticeable CLACK when running at all rpms. When the engine is pulling the clack diminishes or goes away altogether, however, when the engine is running with no load, the clack is pretty loud. Oil pressure starts out at 40 on the gauge when cold, however, goes down to around 10-20 when at operating temperature. I'm thinking a valve or two may need to be adjusted, however, have learned the early N engines didn't have easily adjustable valves and this was changed at some point during 9N production.
Does anyone know the serial number of the engine when Ford went from non-adjustable valves to easily adjustable valves and/or the rotating exhaust valves?
If the valves are easily adjustable I can accomplish this by removing the intake and exhaust manifolds and if they are not adjustable I understand I'll need to remove the head and replace all of the existing valve assemblies with adjustable valve assemblies i.e., a much bigger job. Thank You!