tag234

hello everyone i have a 1994 271 with a stock 502. right now it has a 24p bravo 1 wot is 4200 rpms do i need to go up or down in pitch? ive heard with a 22p i cane see high 60's on this hull is this in reason?

1wide7

Down in pitch equals increase in rpms
I would think your 502 should be able to spin that prop faster though...

tag234

when i bought the boat it had a 21 mirage on it.

Blueabyss

That is for sure too much pitch. A 22 wil probably be perfect.. You will not see 60 though. 58-59 tops.

BBCLiberator

iTrader: (2)

I would think a 21 would be about right, maybe as low as a 20. 502's like to rev about 200-400rpm's higher than the 454's, they like the 5000-5200 range for the Gen V's depending on the particular model (newer MPI's were 5000max, 4600-5000rpm range). What was the stock prop on the boat?

My boat had a 20" Raker stock and would turn about 5200 rpm at about 62mph. Plug your information below. Prop slip of 10-12% is a good place to start as a guess.

http://www.rbbi.com/folders/prop/propcalc.htm

And no way you are seeing upper 60's unless that thing pretty built. twin 454's see mid-sixties, a friend who has twin 350/320's sees about 63 stock. I would agree, mid-to-upper 50's.