Which SS Prop???????

[Tail_Gunner]

Re: Which SS Prop???????

There's a baypro doing its thing, that particular boat is a short and wide 19'x8'... the boat that does the porpising...notice the print it is only 24" wide on a 8'beam that's overall lift...with a nudge from the 4th blade. Now all 4 blades will not lift like that for the most part they are stern lifter's..now with the stern riding high the weight of the boat being in the stern it will...well dance on it's tail.

The 3 blade will more than probably do all thing's in one package it is a simple a elegant solution....Now we can muddy up the water's a bit and go along these line's..That baypro has very aggressive cupping allowing it to ride high in the water line higher that a 3 blade....So lift the engine less drag higher speed's...and still no cavitation.

So 17@ 5300
16@5500
lose 2 for ss 5300
lose 1 for the fourth 5200

Etc etc etc...If the stilleto's intrigue you pm me on the 4th blade model

A

 

[Tail_Gunner]

Re: Which SS Prop???????

I will be the first to admit i am a Stiletto fan they offer me top performance and very reasonable pricing and very uniform results. The baypro is my prop of choice it give's very strong midrange performance along with tremdendous grip and lift..four blades are smoother than three and my hull plane's at lower speed's with the baypro. There is so much midrange lift going on i can be a flat water doing 30 and if a wake come's my way i can punch it hard and literally almost jump over the wake.

Now the boat does have 300hp and is only 19' so that to comes into play but the 4 blade manage's it very effectivly. It does cost me 2-3 mph on the top end but i really dont like running up there to long thing's can get dicey quick.. i am older..I also mentioned the porpoising the boat does have built in lift tab's on the outer corner's so i am sure they assist in the lift or bouncing.. high lift prop tab's and some power could exagerate things a bit.....In short from launch to 60 it's cant be beat..But that just a opinion.

The t1 however is faster and has as much grip...a little less mdirange and at wot the lift is very close...The more i think about its the power to weight ratio the boat has and the midrange punch and lift the baypro has.

 

[WIMUSKY]

Re: Which SS Prop???????

Just ordered the vented TP, 17p. I couldn't get myself to buy a 4 blade. If we ever see soft water I'll report back on it's performance......

Turning Point Express Stainless Stainless Steel Boat Propeller #3143 1711 for Johnson 60 HP Outboard 1998 & Newer 4-Stroke

 

[QC]

Re: Which SS Prop???????

You shoulda got the Ice Cleaver model!

 

[Tail_Gunner]

Re: Which SS Prop???????

Good choice i really believe the stiletto would have had that flat bottom really bouncing....That three blade will have her skateing down the lake...Um skateing?????

 

[WIMUSKY]

Re: Which SS Prop???????

They actually consider the hull a deep-v with a reverse chine........

 

[WIMUSKY]

Re: Which SS Prop???????

I was researching deadrise. I didn't know the numbers to define the hull. I would say my hull is neither. It falls in the middle. But with the reverse chines, it's runs very well in rough water.

Low deadrise bottom? Sometimes called shallow-V bottoms, these running surfaces have a deadrise angle of 20 to 25 degrees amidships which reduces to 5 degrees or less at the transom. (Deadrise is the angle measure of the "V" in the bottom. It is generally greater at the bow, or "entry" of the boat, and shallower at the transom, or stern of the boat.) This provides a smoother ride, but it still retains the quick ability to plane of a flat-bottomed boat.

Deep-V bottom? This type of hull has a deadrise of 25 degrees amidships with reduces only slightly to 20 degrees at the transom. This shape allows high-speed operation in rough water.

This was a good article if anyone is interested:
All Aboard Boats: What's the Deal With Deadrise? | Boating Magazine

 

[WIMUSKY]

Holy cow is this thread old.... I'm finally going to splash the boat tomorrow and test that SS I bought in post #23. I hope I'm happy so I don't have to exchange it.... I'll post up the results.

 

[WIMUSKY]

What a nice day to splash the boat for the first time this year. Warm, sunny and a good breeze. Perfect! Put a bunch of miles on too.

Now for the prop. Epic fail! I soon as I hit it, it felt like I was dragging an anchor. Very doggy. The vents in the TP didn't seem to do a thing. I need to measure them, but they appear to be relatively small. No plugs. They are too close to the blades to plug anyway. Will take a pic. I lost 500 rpms which seemed to be excessive. I noticed it has more rake than my OEM AL. Holeshot was terrible. Top end MPH was the same as the OEM. When I put the AL back on it was night and day. rpms shot up quick and I had a little better hole shot, go figure..... So that was disappointing.......

2003 60 Johnson 4 stroke
Rated max WOT rpm 5300
Current max WOT rpm 5300 - perfect!
Top end around 30
Current prop - OEM 14x17 #177131 AL

Turning Point Express SS Vented 13 1/4x17
WOT 4800 rpm

Sorry, I still can't create paragraphs.....

 

[WIMUSKY]

Here's a couple of pix of the vent hole. It's 5/16, but very close to the blade. Not sure how big, or, if the hole could be drilled out anymore. I couldn't feel/hear it vent. I know Laser prop vents aren't that close to the blade. Maybe these are in the wrong location. I'm going to trade it in for a 15P and at least get my rpms back closer to max WOT. If it still doesn't perform very well I may try and drill the holes out more and/or sell it and stick with the AL.

 

[MikDee]

Wimusky, Sorry to hear the prop did not work out. From the reviews on the forum here, I thought it surely would?

I have a link that might help, check this out:
http://www.marinemechanic.com/site/page76.html

 

[achris]

Hi Wimusky,

Sorry I'm a bit late into this thread, but I see what you're trying to achieve. Using the same size prop as you were originally happy with, but vented would certainly help with holeshot. The 'problem' with vented props is that they are vented all the time (up to about 3000rpm) , so if you want to go cruising you need to change back to the unvented, or put the vent plugs back in. One of the nice features of Mercs' prop range is that they make them usable on any brand engine with a change of hub (see 'Flo-torque II'), so one of their props might help. One of the better ones is the High-Five, although vented even with the vent plugs in it still is the choice prop for skiers... Excellent holeshot and good overall performance...

HTH,

Chris........

 

[WIMUSKY]

Thanks for the link Mik.

Thanks for the info achris. My cruising rpm is 4400 @22 mph. Maybe 4 strokes were meant to run with the OE prop that is supplied with the motor...

 

[achris]

Nope... A prop is a prop. As long as it performs and the engine is able to reach the right operating range, it'll do the job. The engine manufacturers will try to tell you that you MUST use their prop, but that's only a 'keep the profits in-house' reason. In the Johnson V8 outboard era we were getting the best results on those engines with a modified Quicksilver (Mercs' accessories brand) props. Modified because the interchangeable hubs weren't around back then.... You can use whatever prop fits on the shaft and is right for the housing diameter...

BTW, the fact that it's a 4 stoke is almost irrelevant. What it is, is a power plant producing 60hp @5300rpm... As long as the prop can allow the revs, everything else is equal. Also, going from Al to SS shouldn't change the revs much (a little, but not significant), It might allow the engine run a little QUICKER (maybe 50 rpm), due to the thinner blade section, less drag.

Chris.......

 

[MikDee]

No problem Wimusky, By the way that website home page has a lot of good boating info there. So,have you tried running the prop with the holes plugged? I'm curious how that would work?

 

[WIMUSKY]

One issue I believe is the SS has more rake which will increase bow lift and make it more difficult coming out of the hole(which is compounded because I'm tail heavy to begin with, and there's nothing I can do about it other than adding weight in the bow. It's a design flaw). Bow was way up. Tends to plow more. Not enough rpms to push it up on plane quick enough. Once it got up it wanted to go, but I was still 500rpms under WOT/AL prop rpms. That's excessive. The only difference at WOT between the props should be weight and rake. You could tell the motor was working harder with the SS. It felt like I was dragging an anchor, especially out of the hole.....

I didn't plug the vent holes because the holes should help the holeshot by ramping up the r's quicker. There's no plugs for it anyway. I purposely bought that prop for the venting.

 

[Tail_Gunner]

Turning point's have been known to have varying result's and pretty aggressive cupping....as to the vents.. 4 strokes are not known to do as well as two strokes's simply due to the lack of exhaust pressure. Drilling larger relief's would or should cause more cavitation and faster prop spin up and aid your launch. You may still have some option's however..motor height spefically is your cavitation plate 1 or 2 inch's above the keel, raising your engine height may improve your results.

 

[WIMUSKY]

That's the thing TG, as we all know, on a good day 4 strokes don't ramp up like a 2 stroke. And, it's rated for a 90. I really should have at least a 75. So a 60 is down on power and add a 4 stroke, well........... But, I still really like that motor except for the holeshot. Top end is in the low 30s and I usually only run around 22 anyway...... Cav plate is at the most 1" above the keel. I still have 3 holes to play with. I wouldn't mind raising the motor with the current prop except for taking the chance of getting a ding. I don't want to alter this prop because if it still doesn't work I'm stuck with it. If I put a scratch or ding in the prop forget the exchange. I figure exchange for the 15P, then if I have to, drill out the vents more and/or raise the motor some and try to achieve a better holeshot. May lose some top end, but, unless I'm trying to outrun a storm I don't go WOT. Not sure if that's a good plan or not?

 

[Tail_Gunner]

Well using your number's your alum had 7% slip the SS did 6% if your numbers are accurate its not going to get much better than that regardless of prop material. The only thing i can think of is changing the hull drive dynamic's...lifting the motor to the point of cavitation less drag..... and then adding tabs to assist lift out of the hole.Being underpowered if you are those two move's should help.

 

[achris]

As you're above the keel (with the engine), maybe a wing on the engine will help with the holeshot....