79 SN 351W Prop Selection

Hey all,

Just went through my first full year of running my rebuilt 79SN after having it out of commission for 2 years. (lucky I bought that searay a few years back so I wasn't high&dry for that long)

After all the tweaking and tuning, I have it running great! I put in a reman'd stock 351W from rapido marine and I am running with these specs:

Full tank gas, minimal gear, driver only
1:1 Trans
13x13 original bronze(I think it's bronze) Prop
4600 rpm WOT
45 MPH top-end on both speedos
0-40 MPH in about 6 seconds

Have really good hole-shot pulling power with skier/boarder/3 tubes w/ 4 riders or with nothing behind boat.

What I'm looking for is a prop that I could go with as an alternate prop when I want to swap out so I can just cruise and get some faster speed than the 45MPH top-end I have now with the 13x13.

From what I know, the higher the pitch#, the lower the RPM & higher the top-end speed. Not exactly sure what a 4-blade vs 3-blade will do for me. I know there's a limit to the pitch so it doesn't put undo stress on the drive-train, but not sure where that is.

Any suggestions?

seb,

On your question of rapido marine engines. I did an awful lot of research (they have a complete list of buyers on their website, which I liked, of what engine and when they bought), so I simply downloaded all the 351W buyers and fed the email addresses into a questionnaire I prepared to ask how they felt about rapido and the engine they bought. I got 30+ responses, some issues, but always rapido stood behind and most responses were very good. I know they don't just put happy buyers in the list, because my name appeared on the list the day they shipped the engine before I even received it.

I've put 50+ hrs on it this year and I am extremely happy with the power & performance of the engine. They were cheaper than other places I researched ($1,400 LH Long Block) and very responsive with everything I communicated with them about.

ALTHOUGH, I just put the finishing touches last night on the replacement engine for my '00 SeaRay, which I bought from usengine.com. I decided against going with rapido on the engine (I upgraded from a 305/220hp Merc to a 350/300hp Merc). The usengine website was much more detailed and had more options for these engines than rapido and in talking to both parties about my desires, I thought Mike @ usegine was much more knowledgeable than the folks @ rapido.

I'm going to drop this engine in the SeaRay tomorrow, so I won't know how it runs until I get some hrs on it. You can look at the 2 websites and compare $$$'s, but you'll find rapido was cheaper by $3-400 or more on all engines. usengine had several choices hp-wise for the 351W where rapido only had base stock and they don't even list hp rating for their engines.

Hope that helps.

Well, very good looking boat you got there, seb. Good luck on the rest of your rebuild.

Give me some info on that pylon pole, if you would please. I'd like to get one for mine. Does it replace the stock short pole or attach to it somehow?

Good weather just broke through, so I'm off to drop that 350 in the searay, so will check back tomorrow.

jfarc wrote: What I'm looking for is a prop that I could go with as an alternate prop when I want to swap out so I can just cruise and get some faster speed than the 45MPH top-end I have now with the 13x13. Any suggestions?

Sort of a conflicting question but here goes.

As is, your 13x13 3 blade is pushing the boat 45mph, that's respectable for dead stock.

You don't have too many options with your power, if you go up to a 13x14 3 blade you'll be able to "cruise" at a higher speed and lower rpm than with the 13x13 but you'll get no more top end and will drop about 400 rpm. Only advantage to this would be fuel savings but the boat will be slugish out of the hole.

Another option is an Acme 540 which is a 13x12 cnc prop. This one will give you a better hole shot than either of the first two props but will typically spin your motor about 400 rpms more than the 13x13 you are currectly running. It has given most who use it here a 2-3 mph increase but has a negative effect on your fuel consumption.

behindpropeller wrote: I like the 540 on our stock 351, made it like a new boat. Pulls up 4 barefooters deeping up. Tim

I would argue that the 540 is the best bolt on performance upgrade money can buy for your boat.