Ref: Model Engineer August 15th 1986 page 204 (drawing) and 205 (build text)
Before I blindly follow the drawings, I have a question about chambering of the boiler feed water pump of which there are 2 on this model. The drawing shows a 7/32” diameter reamed cylinder which is relieved to ¼” diameter. The remaining bearing length is .812”. The build text says such chambering can be omitted because of the potential air locks and the author, Mr Bertinat, then says he has reduced chambering to a minimum. I assume chambering, with some air trapped, provides some damping from hydraulic shock in the boiler feed system? What would be wrong in reducing to the counterbore depth to where I have put the red line? Or even a little higher at 11/16’’ deep? That would give 1 1/8’’ of bearing surface or 38% more than as designed. I appreciate your guidance
Thanks, Mike
