Marinette Boat Forum

I bought my 1987, 32 Sedan-Bridge "KOKOMO" last August. It was in the water when I took delivery. ( After the sea trial ) And it had a set of 3 blade props on it.. However, along with the boat came a brand new, never in the water, set of "bronze looking", 4 blade props for "spares".. I have twin Chrysler 360's, with electronic ignition, and two, 100 gal. fuel tanks ( side mounted )..
My question is this:
Which prop set is better, and why.?
What will I gain, and / or loose, if I put the four blade props on it.?
If I get better control in the marina, and in / or out of the slip control, with the four blade props, but give up a little top end, thats a trade I might benefit from.. But if the trade off is way more fuel burn for the same speed ( RPM/KPH ) then keeping the 3 Blades may be the best answer..
What do you all think.? What do you use, and why.? What has been your experience with 4 blade props..?
I splash next week, so any help is greatly appreciated...

Thank You..

It depends on the pitch. On my 32 footer with 360s I ran 15 pitch (4 blade) props that worked well. Top rpm was about 4,000, and she cruised nicely at 2,500 rpm making about 18 to 20 mph and burning 9.5 gph per engine. Gas mileage was much better than with the old 16 pitch, 3 blade props.

The only thing you might not like is that the boat moves too fast at dead idle! That takes a bit of getting used to.

Jeff

I switched to a 4 blade set in the spring of '19. Felt that there was significant improvement in performance and gas usage. I have a floscan system which gives me an accurate accounting of gas usage.

Bill

Thanks guys for the input, and answers..
I guess the best way to find out, for me, is going to be to try the new 4 blade props.. The worst that can happen is that I won't like them.! So much, that I have the boat hauled out early just to swap back to the old ones.. Being a slip owner, the haul-out is cheap, at $ 64.00 each way, so why not go for it..!
The P/O bought them, and never got to use them, so he had no information to offer.
I gave him an extra $500 for them, and being brand new, I figured I got them at half price.! So if nothing else, I can sell them if I don't like the way they work out for me, and I won't be out anything...
I finally got the paperwork done today. Registration and Insurance.. I'm getting the new transducers installed tomorrow, that go with the new electronics at both helms, so we can splash next week.. ( If I did everything right last fall.. )

Again, thanks for the in-put.
Be safe, and stay dry..

Richard

Don't put them on until you determine what pitch they are!

Wouldn't you be embarrassed if the boat would not plane off with them, or screamed like mad at cruising speed!

Jeff

PS: Mine were 17 x 15s.

My '88 32 Sedan has 318s that are 240hp.
What was the hp of the 360s?
4 Blade props would be nice, im sure i would have to play around with the size

Bryank97 wrote:My '88 32 Sedan has 318s that are 240hp.
What was the hp of the 360s?
4 Blade props would be nice, im sure i would have to play around with the size

Chrysler 360ci were 275hp.
Factory standard 3 blade 16x16 props.

I just switched from 16 x 17 3 blades to 18 x 15 Dyna Quads and love them. Just feels like much better control and better hole shot.

I would really like to try a set of 4 blades. It a shame because i have a spare set of stock 3 blades that match what is on the boat. They came with the boat. I really do not need a spare set for my spare set haha.

If 318 and 360 boats came with the same props (I believe my 318s 240hp came with 16X16 3 blades).... what was the performance difference? Top speed?

I think the 16x16 only came with the 360ci, 275hp. The 318ci, 240hp came with slightly less pitch?...I cant recall for sure, might be wrong about this.