What pitch????
 

Okay so far all my questions on my new to me boat have been answered on this forum but now I have a prop question.
Boat is a 87 formula f23sr and it has a 454 with alpha drive, its sporting an aluminum 19 pitch and I'd like to go stainless. The boat will be used for some cruising and a litle play, but also for towing my daughter and maybe another person in tubes. What pitch can anyone recomend for overall performance. I dont want to over pitch. Thanks guys, I will say this site is incredble, glad I found it.

what RPM are you turning now ?

I dont know yet, I'm taking the boat out Monday for the first time since purchase. I'm sorry I sound so stupid about this stuff but I've been away from it for ten years and I'm just figuring things out again but I love gaining knowledge. Now for the stupid question-what RPM is the max you would push a 454? I dont need to launch an engine being uneducated about this. The boat has GPS so I'll get a fairly true speed and I'll make notes of speed vs RPMs and report back on here. Thanks again.

If it is the 454 Mag you need to run from 4600-5000 RPM.
If it si the 454 non-mag then 4200-4600 RPM.

Safe Testing!

Julie

Okay guys I ran her today and heres the deal boat is 23 ft formula LS with a alpha and 454 mag. Prop is an aluminum 19 pitch. Boat ran 40 mph @ 4,600 RPMs speed was checked on my gps. Any recomendations on what pitch to go to? I dont want to overpitch or under pitch.
I will say I havent had a boat in 11 years and being widowed with a 9 yr old daughter this was the best thing I ever did and the fever is back !!! This boat is great and I feel I got got some life back. Thanks guys for any pitch advice.

Prosno, i had the same combo on a Pachanga many years ago. The layman's place to start is a stainless of the same pitch... you won't get the prop flexing under power that occurs with aluminum. You also have a 3blade prop, not 4, consider something like a Mercury Mirage... again, this is the laymans starting point.
...consider any recomendations from Julie at Throttles Up to be gospel.

I believe that you should start with a 17P Mirage Plus or possibly a 17P Vengence for starters. Both of these props will get your RPM up and speeds may come with it.

Julie

Julie my thought was this, I can get more RPMs no problem but I dont feel comfortable pushing a big block too high on the rpm scale. I was thinking and again I'm new to this. a 21 pitch so I could get more top end and better fuel economy. Cruising at 40 turning 4,600 rpms seemed like running 5.88 gears in a car-real low. So now I look at a 17 pitch and it seems to be going backwards or am I missing something?
And question two, is there that much of a difference from alum to stainless? Thanks again

I find it hard to believe the boat only ran 40. I would think at least upper 40's but more like low 50's..

Dave

Well Dave unless somethings wrong with gps or tach thats what I have, 4,500 - 4,600 rpms and grs says 40.
I know nothing about this model boat so I dont even know what its capable of. I'm not looking for total top end cause I'll be pulling my kid on a tube at times and cruising around the rest of the time. But in my opinion 40 at that many rpms is not good for all around.