Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines

Update:

I Just remembered something that makes my last report misleading! I AM running stock springs on the low PSI....HOWEVER...during my tinkering I did install (1) ink pen spring between the 2 stock springs (just lucky it fits nicely) this counter force has the effect of slightly reduce the pressures of stock springs! One of my goals for all this fine tuning is to be able to leave the stock springs installed and have the engine run so well that I can run it on Steam OR Aquarium pump Without having to swap springs out for low/high pressure.
  The D12 has now been "running in" for over 1 hour and RPM has come up running on aquarium pump, so I know my seal is improving...however I just removed the ink pen counter spring and it almost...but... not quite run on Full stock spring pressure....I have high hopes tomorrow's improvements will get me there!
  I felt it was important to correct this data error in case someone reading my thread would like to duplicate some of this tuning.

Photo: this image shows the counter spring fitted between the 2 stock springs. I will report back when I get it running without this "helper" on 2.32 PSI

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