I'm in the process of modifying a standard Vans IO-360 cowl to a James style cowl using some new inlet rings I had made by a metal spinner.
To get a reasonable transition to the new inlets they protrude about 3/4 in forward of the spinner ring. Minimum clearance to the aft edge of the prop blade is about 1-1/2 in (coarse) to 2-1/8 in (fine). Prop clearance on the original cowl was about 3 to 3-1/2 in.
Does anybody know of any research, theory, opinion or just wild speculation about optimum/ minimum clearance between prop & cowl?
A/C is RV-8A with supercharged Subaru/ 3 blade MT prop.
thanks
John Moody
Melbourne
To get a reasonable transition to the new inlets they protrude about 3/4 in forward of the spinner ring. Minimum clearance to the aft edge of the prop blade is about 1-1/2 in (coarse) to 2-1/8 in (fine). Prop clearance on the original cowl was about 3 to 3-1/2 in.
Does anybody know of any research, theory, opinion or just wild speculation about optimum/ minimum clearance between prop & cowl?
A/C is RV-8A with supercharged Subaru/ 3 blade MT prop.
thanks
John Moody
Melbourne