Toffen
12-26-2005, 11:22 AM
Hi!
I have bought two Merc 2.5 EFI engines (SVS and PCU) with 15 inch midsections. The engines will be mounted 18,5-19 inches senter to senter.
I have been reccommended by some to mount the engines with the propshaft 1 inch below the bottom, and by others to mount them even - 1 inch above the bottom. Merc Hi Performance reccommends 0,25 below the bottom with the Sportmaster lower unit at 90 mph.
With the 15 inch midsection the propshaft will be approx. 0,5 inch below the bottom with the engines mounted all way down.
If it proves to be a little high (expecially at cruise), is it possible to compensate with larger diameter props?
I plan to use Bravo 1 props 28 inch for cruise and Chopper II 28 inch props for wot. I will also try Mercury ET props for wot.
Boat rigging starts in 4 weeks! Can't believe it soon spring again.
Enclosed a picture of a twin Merc 2.5 rigged Phantom 25 with 6 inch setback. I will only use 1 inch setback due to overall balance.
Cheeers, Toffen G :rolleyes:
I have bought two Merc 2.5 EFI engines (SVS and PCU) with 15 inch midsections. The engines will be mounted 18,5-19 inches senter to senter.
I have been reccommended by some to mount the engines with the propshaft 1 inch below the bottom, and by others to mount them even - 1 inch above the bottom. Merc Hi Performance reccommends 0,25 below the bottom with the Sportmaster lower unit at 90 mph.
With the 15 inch midsection the propshaft will be approx. 0,5 inch below the bottom with the engines mounted all way down.
If it proves to be a little high (expecially at cruise), is it possible to compensate with larger diameter props?
I plan to use Bravo 1 props 28 inch for cruise and Chopper II 28 inch props for wot. I will also try Mercury ET props for wot.
Boat rigging starts in 4 weeks! Can't believe it soon spring again.
Enclosed a picture of a twin Merc 2.5 rigged Phantom 25 with 6 inch setback. I will only use 1 inch setback due to overall balance.
Cheeers, Toffen G :rolleyes: