High 5 Prop with tower?

[Noobguy]

Going to invest in a couple new props since the one my boat came with is pretty chopped up. Performance is ok, but aesthetically is gross. Keeping as a backup.

I'm in a 2006 Bayliner 185 220 hp (heh, at crank, tricksy marketing) merc 4.3l tks. Gonna go 21" 3 blade for cruising, unless you guys disagree? Might have fun with a 23" for top end. My current 21" gets me 48mph at 4600 rpm; SCARY in chop... but I'd love to break 50 mph on glass.

Main question is: I'm stern heavy with the 4.3. Bow jumps up in hole shot where I have to stand up to see the water (transom still way above water, but it's still unnerving) but it still planes out in a couple seconds. I'm going to add trim tabs, and dump my chubby folks in the bow, but I've heard good things about the high five for towing with the wakeboard tower. Think a 17" pitch 5 blade would be an improvement over 19" 3 or 18" 4? I also have a spare hustler 17" 3 blade, but I'm scurred of over-rev. Thoughts?

 

[rallyart]

If you are at 4600 rpm with the 21" on it when you are topped out you will probably go slower with a 23" on it. The reason is that you will be out of the power range of the engine. You are right in the ideal rpm for that engine. Is your 21" Stainless steel or aluminum. If it's aluminum you will get the most out of a SS prop. At 48mph the aero load makes a difference too. Don't have the tower or a bimini up and you'll hit 50.

On the High-5, I've always found a good SS 4 blade to work better but my brother and many others really like their High-5s. It's a good idea to have two props but almost everybody I know just leaves one on all the time and never makes the effort to change. If you are going to go with two props and plan to change, it might be best to have a significant difference in pitch. Otherwise, keep the current prop and find a good compromise for your normal use prop.

 

[Noobguy]

Well, I dig the new style breakaway flowtorque hubs, at least for the speed of a swap, and I suppose shaft protection. Literally 5 minute install I can do it the water, so long as I'm not too cold and I'm careful with the prop nut (I've learned to keep a spare everything, lol).

The current prop is stainless, but it's pretty thrashed. I could get it machined, but some of the bent gouges go in 3/4". I thought keeping at a new 21" would be my best bet. I know for sure that I'd be swapping props out for towing, but I'm not sure what to get.

Does stainless have higher performance due to tensile strength, or is it just a durability improvement? I like having a light aluminum prop bit if the acceleration performance gains are significant, especially in the mid range rpms (say 2000 to 2800) I'd upgrade.

 

[rallyart]

The SS props are thinner so the water flow past them is more efficient. Being heavier gives them more flywheel effect so the acceleration is fractionally slower but the engine feels smoother. I had a higher top speed with a new 4 blade 21" than I did with an old 3 blade 21", and a better hole shot. That's the affect of the larger diameter of the unrepaired and better shaped new prop. Normally a 3 blade should be more efficient and faster.
Good luck. It sounds like you are figuring it out.

 

[Noobguy]

Only because you guys got me there. Prop shop gave me two recommendations to try out. 4 and 5 blades sound fun, but testing the possible benefit over my existing 17" doesn't seem worth the water time just yet since I know it works alright in a towing role. Still watch my rpms but my riders never need more than 3/4 wot,so far. I'd like to hear em say the boat does all the lifting work eventually, but I'm still experimenting with trim and the tower; there's just so many variables to play with. Kinda fun in its own right.

Selecting the right cruise prop is my real goal. Have a 21" alum, 19" ss, and one other prop the previous owner hid under a couple preservers I haven't even looked at closely. I think I'll keep busy . Thank you!