I'm looking at a 350 chevy that produces 365 hp at the crankshaft. How much less hp do you think it produces through the propshaft of an alpha ss drive? thanks a ton!

Jim

I would guess a 30 hp loss to the outdrive. I am not sure about a ss alpha but I have read that a 30 hp drop is the avg on a B1
Dwight

A 454 Magnum has 365 at the crankshaft and 350 at the prop.

I talked to Mercury a year or so ago and they told me 11% HP drop thru the drive.

very cool , thanks everybody for their help!

I looked at this based on published data last year. Looks like 30HP is the average of 25-35HP range I found.

I know that I should know this but.... are the Mercury racing engines hp rated at the crank or prop?