Prop,load,speed ?

[tendollar]

I am new to the prop, always ran OB jets and need a little guidance. Been reading alot on this site about prop's so i'm ready to go at ice out. Bought this rig fall of 09' so I have a little water time with it and some knowledge of its performance.

1. Would like opinions on current setup and performance. Recomendations for better holeshot/top end?

2. PROP MANUF = OMC SSTII > 3-blade stainless

3.PROP DIA/PITCH = 14 1/2 X 19

4. WOT rpm = 5400 > SPEED = 47.6mph (GPS)

5. ENGINE/GEAR RATIO = johnson 1.86:1 > J150ELECD > 1998 > 150HP

6. BOAT > crestliner > phantom 196SST > 1993 > 1670lbs

 

[steelespike]

Re: Prop,load,speed ?

Sure appears to me your damn close to right on.Speed seems good, rpm good
Prop size good. What do you think of your hole shot and top end?
Is the antivent plate just above the prop about even or slightly above the bottom?
Do you have trim tabs?

 

[tendollar]

Re: Prop,load,speed ?

steelespike thanks for the reply! Hole shot doesnt have a "seat of the pants" feel to it but there is almost no bow rise and comes on plane very quick, boat length or close to it. A/V plate is 1 1/2" + - above bottom of boat. No trim tabs. Top end is smooth and quiet, it takes full trim out and a loooong time to hit 47 but it gets there. I am in need of a spare prop (part of reason for this post) If there is room for improvement with a diff. prop I will upgrade and use the SST as spare.

Thanks, Tom

 

[steelespike]

Re: Prop,load,speed ?

Indeed looking for a spare is an oportunity for prop improvement.
It sounds like your holeshot is close to instant.Improving holeshot and top end usually don't go together.If there is a prop with more bow lift it might give you a little top end at a sacrifice to your hole shot.Then you could add trim tabs to get some hole shot back.Not saying that makes sense just a thought.
If you can find a dealer that will let you try some props on an exchange basis
Thats the safest way to play with prop selection.Usually requires a deposit with the understanding your buying a prop from them.I don't know what happens if you don't find a prop you feel gives you enough boost.Perhaps at worst you'll just end up with
the same prop as a spare.?? Just had a thought as a spare you might consider the Turning Point Hustler an agressive Aluminum prop that delivers close to ss performance at al. prices. Run your numbers at the Turning point site.Might make sense as a more reasonable spare.Of course when changing material results are even more unpredictable.Hopefully someone with more expertise will be along with some suggestions.

 

[tendollar]

Re: Prop,load,speed ?

ok, everything you suggested makes alot of sense. Say i wanted to go for 2-3mph more on my top end how much do you sacrifice on your bottom end with a deep vee hull? I suppose one would have to get alot of bow lift on a deep vee to get there? Unfortunatly I dont have a dealer around my area who offers the loaner props.

 

[smokeonthewater]

Re: Prop,load,speed ?

2-3 mph? on top of 47?.... sheesh.... new spark plugs, another degree or two of spark advance and higher grade of gas.... amsoil or other premium synthetic oil..... take some junk out of the boat...... clean and wax the bottom.....lean forward and whip it a bit

 

[tendollar]

Re: Prop,load,speed ?

2-3 mph? on top of 47?.... sheesh.... new spark plugs, another degree or two of spark advance and higher grade of gas.... amsoil or other premium synthetic oil..... take some junk out of the boat...... clean and wax the bottom.....lean forward and whip it a bit

Im sorry, i cant seem to find any information here that has anything to do with my original post.

 

[steelespike]

Re: Prop,load,speed ?

ok, everything you suggested makes alot of sense. Say i wanted to go for 2-3mph more on my top end how much do you sacrifice on your bottom end with a deep vee hull? I suppose one would have to get alot of bow lift on a deep vee to get there? Unfortunatly I dont have a dealer around my area who offers the loaner props.

Unfortunately I'm not the guy to help you with specifics on a prop selection for your setup.
2 to 3 mph when your allready approaching the 50 mph range will probably be a tough assignment.See if you can raise hwiii he can do calculations and recomendations regarding slip etc.based on your setup.But based on what I see options may be limited.I really think he will find your setup to be close.Even the real experts won't be able to be specific on what you will lose on hole shot when looking for more top end about as close as you could come is you will likely lose some hole shot.If you go to some prop sites and possibly right here and run your numbers in the prop picker. You will no doubt get a number of solutions But the results will give you an idea where your actually at.

 

[smokeonthewater]

Re: Prop,load,speed ?

Im sorry, i cant seem to find any information here that has anything to do with my original post.

That's because you can't read between the lines.... point it that you are propped correctly and you have a speed prop now..... your rpm's are spot on and your holeshot is good..... You could switch to a 4 blade prop for better holeshot and lose 2-3 on the top but changing to a 2 blade for top end isn't practical.... If you are looking for speed there are better places to look than the prop..... You might gain 1 or 2 mph and you might lose 1 or 2 mph with a change.....

a clean and waxed hull on the other hand can make a big difference

It isn't the answer you asked for but it's the best one I have..... with any luck someone else will know of a magic prop that will give you what you want but I don't so I offered the best info I had.....