77 Century OMC 190 302 V8 prop?

[Icicle]

Need a new prop, it has a 12 inch prop on it, not even sure of the pitch, but it's low by looking at it. I hit about 35 MPH and get nothing but more RPM and it will rev way too high.

My WOT preferred is about 4200. Boat weight about 3300 with fuel and gear, open bow runabout, 19 foot.

Suggestions would be very welcome. I was thinking 14 x 22 or so?

 

[steelespike]

Re: 77 Century OMC 190 302 V8 prop?

delete

 

[Icicle]

Re: 77 Century OMC 190 302 V8 prop?

Funny you mention that, I just grabbed a GPS app for my iPhone. I'm pretty sure it doesn't have a spun hub, but I will look into that, I let the RPM go to 6k last time on the lake, it was at WOT and right at 6k, and it scared the crap out of me, so I didn't open it up again.

I'll try and find some numbers on gear ratio and prop size that are concrete.

 

[steelespike]

Re: 77 Century OMC 190 302 V8 prop?

May have a spun hub. Put a waterproof line across the hub and body and do a test run.
What is the rpm at 35?
Look carefully near the base of the blades and on both ends of the hub for numbers.
Do you know your gear ratio.It may be on the outdrive.
You should be able to rev momentarily long enough to obtain a wot rpm and gps speed.
Some cells have a gps app.Just off the top op of my head I think 22 is too much.
Is 4200 what you prefer or what OMC suggests?
Are you saying the speed was still 35 at 6000?

 

[Icicle]

Re: 77 Century OMC 190 302 V8 prop?

Update: I was out last weekend with GPS in hand: I remember specifically that at about 4400 RPM I was only 24.9 MPH. I pushed it to 5k and got pretty close to 28 (don't remember this one exactly) I didn't want to open it up anymore.

I've still not found ANYTHING stamped on the prop. I did the mark test and it was fine, so not a spun hub?

Boat plane time was very fast, it pops right out of the water, and gets to the mentioned 25 mph very quickly. I'd say it planed in 3 to 4 seconds.