Thank you. Interesting that the ratios are quite different. Any idea why?fredrosse wrote: ↑Sat Dec 14, 2019 12:26 amA most popular model compound engine bt Stuart "Compound Launch Engine" HP=3/4 inch (19mm) LP=1-1/4 inch (31.75mm) diameters x 7/8 inch (22.25mm) stroke, gives a volume ratio of 2.78
A Stuart 6A, large enough to power a real launch: Stuart "Compound 6A Engine" HP=2-1/2 inch (63.5mm) LP=4 inch (101.6mm) diameters x 3 inch (76.2mm) stroke, gives a volume ratio of 2.56
Long existing Stuart dimensions
I have also found the Stuart triple expansion model engine data:
HP----------MP----------LP
19.05------31.75-------44.45 bore mm
25.40------25.40-------25.40 stroke mm
Wich gives the following ratios:
HP/MP of 2.78 (just as the model "Compound Launch")
MP/LP of 1.96