Original P40 Engines?

Hey guys, I need some more of your expertise.

I have these two engines in my collection and I believe that they both originally came out of Cox P40 control line planes. I hope that you can confirm or deny this!

Both engines have "Thimble Drome" stamped on their 5cc tanks.  The red spinner engine has a "1" stamped under one exhaust port. The tan spinner engine has "P40" stamped under both of its exhaust ports.

Thanks in advance for any information and insight that you can shed on these engines!

John



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If original, the engine with the P-40 stamping is most certainly from a Cox P-40 model, assuming it has all the correct parts.  The inverted engine, as shown, was the earlier version and indeed did have a tan spinner. Known as a Super Bee.
It is possible that the engine with the #1 stamping may also be an original.  The porting of the #1 & P-40 cylinders, I believe, was the same.  The later model had the engine upright, and did indeed use a red spinner.
It may be best to check this site for confirmation.  http://www.mh-aerotools.de/airfoils/cox_frameset.htm. If you go to "Model Data Base" you can confirm the years of manufacture.

Rod.