Re: 20' SeaCraft - better w/ or w/o a bracket ???
 

Transom angle on all the 20' SeaCrafts is 14 degrees.

Re: 20' SeaCraft - better w/ or w/o a bracket ???
 

This is on the take off . . . if I punch it with the motor trimmed down. The boat rockets up on a plane and the bow will stay down. The sternlift from the mirage plus helps quite a bit.

http://www.wellcraftv20.com/gallery/...308_Medium.jpg
http://www.wellcraftv20.com/gallery/...309_Medium.jpg

Re: 20' SeaCraft - better w/ or w/o a bracket ???
 

Does that prop hold well enough to trim the motor up and lift the boat for max speed also. Thats supposed the be about the best prop for these boats. I run a Michigan Apollo which picks up the stern but really doesn' t give a whole lot of bow lift when necessary.

Re: 20' SeaCraft - better w/ or w/o a bracket ???
 

It holds the water like a screw moving through wood on the take off. I need to raise the motor on my boat up a hole or two, but I love mirage plus for these boats.

Re: 20' SeaCraft - better w/ or w/o a bracket ???
 

Hey Big Shrimpin and Fr Frank,

Thanks for the previous advice.
I was up in Stuart Fri at the 50% off sale and got a very nice 17p mirage plus at a nice price. Can`t wait to try it. :cool: Anyone want a michigan wheel? 14 1/2 x 17p
GFS

Re: 20' SeaCraft - better w/ or w/o a bracket ???
 

Good to know. That Michigan prop breaks loose and makes the boat porpoise at about 30% trim.

Re: 20' SeaCraft - better w/ or w/o a bracket ???
 

Ben, those numbers seem a bit low. I have a 20' Seafari, with a remanufactured Merc 150, probably putting out about 190-200 hp. I also have SlicKote bottom paint. With a new, stock lower unit, I can run about 42 mph on the GPS at WOT, loaded with 4 adults, full fuel, and the Bimini up. With the top down, just myself, and full fuel I can run about 47-48.

With my old lower unit, Bob's nose-cone w/ low water pick-up I could touch 53 mph under the right weather conditions: cold air, high humidity, 10-15 knot winds, light to moderate wind chop and running downwind. At 50+ mph, a Seafari positively dances across the chop like a ballerina :) It feels like it's almost airborne, just touching the tops of the waves; very light and nimble, like it could chine-walk, but simply has too much class and manners to behave in such an unseemly fashion.

It's truly exhilarating. Just one of the reasons I love the Seafari.

Re: 20' SeaCraft - better w/ or w/o a bracket ???
 

Ben,

I'm running a Power Tech Prop, 3 blade SS, and if I remember correctly, it's 15X16 (I'm not near my boat right now, so I can't confirm). Anyway, I know I'm alittle under proped, but I wanted to get good low end performance out of the 4-stroke (running Sebastian inlet, low end punch is a must) At 4500rpm I cruise 23kts(26mph), and WOT, 6100rpm and 36kts(41mph). These numbers are running light, with 30 gal livewell, a few more guys, and the rest of the stuff, I lose 2-3kts. I know I'm not setting any speed records, but the hole shot is descent for a 4-stroke. The first prop I tried was a 20 pitch, my boat would do almost 50mph @ 5500rpm, but the hole shot was terrible. Then I tried a 18 pitch, light load conditions it was fine, but with the livewell full and 3 guys, it was a bit slow out of the hole. So I went with the 16, and gave up some top end speed. I would like to try the mirage plus and see how it works.

I hope this info helps. Good Luck

Lloyd

Re: 20' SeaCraft - better w/ or w/o a bracket ???
 

BTW, I also run a PowerTech prop, although mine's a custom 15X16.5 pitch, behind a 1.64 gear ratio.

Calculated slip ratio, properly trimmed, is about 11% with this prop, an excellent, very low slip ratio. My experience is that most props, even high-performance props show effective or "apparent" slip ratios between 15% and 20%, depending on the application.

The weight of the load, depth of the prop, angle of attack, all obviously make a huge difference, as well. Having a prop with excessive pitch that will not turn up into the powerband of the motor can give you slip ratios approaching 30%

For instance, a very well set up high-performance bass boat might show an apparent slip of only 8% to 9%. A 23' SeaCraft will be doing very well indeed to get below 18%

At any rate, my max RPM behind the new lower unit gearcase now is about 5900. (Old case w/ nosecone was 6100, with slip of 10.5%) I also went with the lower pitch prop for loaded holeshot and acceleration under adverse sea conditions. The motor also doesn't strain as hard at cruise rpm of 3900 - 4000, about 32-33 mph.

Re: 20' SeaCraft - better w/ or w/o a bracket ???
 

Fr. Frank,

Thanks for the great info, I like the numbers you're getting. My gear ratio is 2.59:1 on my Suzuki 140 4-stroke, and I know we're comparing apples and oranges with your boat/motor setup and my boat/motor setup, but my question is do you think I may gain some overall performance with a 4 blade prop? I know we'll getting into "mystery science" with all the variables involved, but I'm curious about any experience with 3 blade vs. 4 blade.

Thanks again!

Lloyd