hi, then its okay, u just have the delivery little smaller than the suction pipe diameter eg(2"-1.75").

may be i have done mistakes while doing my project on engine run by a water , sorry about it.

pipe diameter is important to have a proper flow rate , if u use the delivery side for any pressure based application pipe diameter and its material is also very...

it is possible with a revolutionary engine ,but with conventional engines it can be done, but efficiency will be minimum.

iron will be less in cost and will give better stability and strength to the structure , but don't add too much metal, try to have a perfect design.