[John Rush]

I have been doing a little bit of research over the past weekend on what prop would be best fitted for my 96' Z210 5.7L EFI Bravo 1.

Currently it has a 4 blade mercury offshore prop. 19P. (Came with boat) The 19P seems to be a little small.. my 3/4 throttle is a 4800rpm which i know it the max, and should never see that for long.

I do not do a whole lot of water sports, mainly just cruse around and hang out at local party spots.

Would i be better off purchasing a 3 blade 21P? A little extra top end speed out be greatly excepted

Any preferences or comments are most defiantly appreciated.

John.

[mikeyt]

hi John,

If you go to a 21" you should expect approximately a 400 rpm increase at WOT. That doesn't always result in an increase in top end but with your boat/motor/drive combo it should give you an extra 2-3 mph. You will notice a bit of reduced performance out of the hole though but it shouldn't be anything significant. Keep the 19" as a spare in the event you plan on spending some time doing a few watersports.

[John Rush]

fantastic!

Just so i understand this correctly.. When you go up in pitch you are also increasing RPM of the motor?

Would it be worth the money to invest in a 3blade 21p?

[ColoradoDiablo]

Pitch goes up - RPM goes down
Pitch goes down - RPM goes up
But as mikey said , the 3 blade 21 outta work out good for you
Aluminum 3 blade isn't bad priced at all. If you go to stainless steel at least double the cost.

[mikeyt]

Originally Posted by John Rush

fantastic!

Just so i understand this correctly.. When you go up in pitch you are also increasing RPM of the motor?

Would it be worth the money to invest in a 3blade 21p?

D'OH!!! I must had a brain cramp when i wrote that. Lower the pitch means the higher the RPM and vice-versa. At least i got the '400' correct.

[Motoxxx43]

Hey John, here is something that is kinda interesting to play around with.
Prop Selector | Mercury Marine

As a general rule of thumb going from a 4 blade to a 3 and staying in the same pitch you might notice a 200 RPM increase. I can say I have noticed that on a boat of mine.

I was looking for this cool video on youtube but cant seem to find it. It shows how much the aluminum flexes under power. As in the blades flatten out. It may have been on a prop website or Mercruiser. Pretty cool to see. The stainless props wont do that- as much. BUT the stainless have a disadvantage in that they wont give if you hit something like a rock or stump or etc... That is how the drive shaft ends up getting tweaked.
I have been watching the Mirage 3 blade props in the 21p for a while. I have found used ones going for around 300 that look great. One ended at 195 and no one bid it...
21P Mercury Mirage Plus Stainless Prop Gently Used | eBay

[John Rush]

Thanks Guy's,

That looks to answer all my questions. While on Ebay I came across a company named Hustler Props..any good? they seemed to have decent reviews on Iboats.com

MOTO- That link was a great help, really appreciate it!!

[Motoxxx43]

Can't say I have heard of them. The big reason I am partial to the Mercury props is the local shop has them an I have been able to test them. I've heard good things about Michigan props too.
I forgot to mention that earlier. It kinda one if those pro/con things. If you buy from a shop they will usually let you exchange props till you get one you like. Buying off line won't let you do that...
So yesterday I ran a "re pitched" prop that went from a 23 to a 21. It did not work well. Currently with a 19p mirage I can get about 46mph @4600rpm. With that supposed 21p I was going the same speed but it took a long time to get there @4100rpm- the motor did not like it! (Maybe it was not re pitched after all).
Anyway, just putting that out there because I was testing it out prior to buying one.

Sent from my DROID RAZR HD using Tapatalk 2

[mikeyt]

Originally Posted by John Rush

Thanks Guy's,

That looks to answer all my questions. While on Ebay I came across a company named Hustler Props..any good? they seemed to have decent reviews on Iboats.com

MOTO- That link was a great help, really appreciate it!!

Turning Point - Hustler props seem to work well in some applications and are downright awful in others. With our boats they tend to be smaller in diameter than comparable props and cavitate under load possibly due to their aggressive cupping. A couple of our members have tried them w/out success in the past but if a local shop will allow you to try one then its worth installing it and seeing what happens. Personally i would stick with Merc/Michigan Wheel/Solas brands and stay away from the gimicky & composite props unless you are simply buying one as a spare.