Web Forum for Singer Cars

Hello to all. I have a 1952 AD roadster. I have an oil pressure issue. At cold start the engine provided 60+lbs of pressure. Once the engine has warmed up and is setting at idle it produces 15-30 lbs pressure. Once driven short distances (at 45 mph) the gauge drops to almost nothing. The gauge was sent out for restoration and calibration. The engines starts at the snap of a finger, doesn't smoke and idles like a champ. As soon as the engine gets hot, there goes the pressure. Any ideas? Any suggestions? Are there any oversized lower end bearing available. Has anyone mastered this issue? I'm also looking for a set of top bows; does anyone have a set they would sell. Would anyone be willing to do a dimensional drawing and send so that I could have a set fabricated? Does anyone have an original tire pump for sale?
Thanks in advance!
Duane Ellis / 1952 4AD roadster

what weight oil are you using and also how old is the oil ?
My 4AD always ran 20-50, its not a modern car where you can run 5-20 or even 0-20. Also as oil gets old, multi-viscosity oil looses its viscosity.