Merc 470 - 16ft Boat Prop Choice/Query

[pcmpete]

New boat to me, came with no prop so I have no baseline to work with. But need to know what prop to get/try first.

Details:
Reinell T180
Length 16'8"
Beam 87"
Dry Weight 2028 pound
Motor/Outdrive Mercruiser 470 (170hp) with MC1 with ratio 1.84
Tank size 18gals
Normal loading will be two adults and two teenagers

Boat with be used for both cruising and watersports. So looking for a good all round good performance.

Thanking you in advance to anyone that can help.

 

[Rocky_Road]

Re: Merc 470 - 16ft Boat Prop Choice/Query

I'd be trying a 19" pitch...I have a 18.5' and 17', and they both like that pitch in S.S.

The 19" on the 17' can over-rev with a light load, but I need it with more weight. I just watch the tach!

Happy boating!

P.S. The 19" on my 470 is available (S.S.)...I have a blown head gasket, and might never get around to fixing it!

 

[pcmpete]

Re: Merc 470 - 16ft Boat Prop Choice/Query

I am thinking a 23" should be ok with my setup,

 

[Rocky_Road]

Re: Merc 470 - 16ft Boat Prop Choice/Query

I am thinking a 23" should be ok with my setup,

The only positive way to know what you need (or like) is to try it. The key is to find what allows you to reach max RPM...or slightly above, as I prefer.

You might have a local prop dealer that is willing to let you test drive various pitches...or you might have a buddy that can lend you a prop to try. Just remember that a aluminum prop will feel different than a stainless steel one, especially in the 'hole shot'. This is for several reasons: the aluminum will 'flex', and the stainless steel are usually more progressive pitched (this is very good).

A 19" stainless steel Quicksilver Stiletto is really a 17" to 21" prop...depending on the load demands. In short...the progressive pitched prop will perform across the widest demand range, and will be the closest to a 'one size fits all' solution!

Happy boating!

 

[heathk2003]

Re: Merc 470 - 16ft Boat Prop Choice/Query

My last boat and the boat that my dad now has is a 1980 silverline 16' open bow with a mercruiser 470. I was running a 23 pitch aluminum prop @ 4400 rpm's. I also had a 23 pitch apollo ss prop that would turn 4100-4200 rpms.
I also had a 21 pitch aluminum that had great holeshot but would over rev pretty bad if you tried to open her up. Hope this helps.

 

[pcmpete]

Re: Merc 470 - 16ft Boat Prop Choice/Query

My last boat and the boat that my dad now has is a 1980 silverline 16' open bow with a mercruiser 470. I was running a 23 pitch aluminum prop @ 4400 rpm's. I also had a 23 pitch apollo ss prop that would turn 4100-4200 rpms.
I also had a 21 pitch aluminum that had great holeshot but would over rev pretty bad if you tried to open her up. Hope this helps.

What speed would you get from the 23" prop?

 

[heathk2003]

Re: Merc 470 - 16ft Boat Prop Choice/Query

What speed would you get from the 23" prop?

Depending on the load anywhere from 46-50 mph on the gps. Paddle wheel speedo on the fishfinder showed as much as 67 mph ( i sure was dissapointed when i brought the gps out ) The best things i did with that engine was the pertronix electronic ignition, alternator conversion and upgraded the heat exchanger from the 3 inch to the 4 inch.

http://www.youtube.com/watch?v=3Uu7yj1PAzU

http://www.flickr.com/photos/12442332@N05/sets/72157601809762228/

 

[pcmpete]

Re: Merc 470 - 16ft Boat Prop Choice/Query

46-50 mph is about the speed I would be comfortable with. Thanks for your input and video link.

Depending on the load anywhere from 46-50 mph on the gps. Paddle wheel speedo on the fishfinder showed as much as 67 mph ( i sure was dissapointed when i brought the gps out ) The best things i did with that engine was the pertronix electronic ignition, alternator conversion and upgraded the heat exchanger from the 3 inch to the 4 inch.

http://www.youtube.com/watch?v=3Uu7yj1PAzU

http://www.flickr.com/photos/12442332@N05/sets/72157601809762228/

 

[heathk2003]

Re: Merc 470 - 16ft Boat Prop Choice/Query

let us know how she performs after you get her propped and going !!