need help with new prop 2003 5.0l with alpha 1

[tuttle593]

boat is a 2003 starcraft nextstar with a 5.0 alpha one either 1.61.1 gears ? has a 14 1/2" 19 pitch 3 blade prop on it now looking to go to a 4 blade stainless prop my rpms are between 4400 and 4800 max boat does 47mph gps at 4800 with full tank of gas and two people i dont haul tubes or anything looking to get more pull to plane faster and 5 mph on top or more if possible any ideas on a prop size?
thankss

 

[tuttle593]

Re: need help with new prop 2003 5.0l with alpha 1

boat is a 2003 starcraft nextstar with a 5.0 alpha one either 1.61.1 gears ? has a 14 1/2" 19 pitch 3 blade prop on it now looking to go to a 4 blade stainless prop my rpms are between 4400 and 4800 max boat does 47mph gps at 4800 with full tank of gas and two people i dont haul tubes or anything looking to get more pull to plane faster and 5 mph on top or more if possible any ideas on a prop size?
thankss

19' boat 2100 pounds 220hp no one has any ideas?

 

[tuttle593]

best prop? 2003 5.0l with alpha 1

best prop? 2003 5.0l with alpha 1

19' boat 2100 pounds 220hp no one has any ideas?

No one has any idea? Or similar set up 14 1/4 by 21p or 15 1/4 22 p? Maybe?

 

[tuttle593]

Re: best prop? 2003 5.0l with alpha 1

Re: best prop? 2003 5.0l with alpha 1

no one can help? looking to buy

 

[Philster]

Re: best prop? 2003 5.0l with alpha 1

Re: best prop? 2003 5.0l with alpha 1

Well... you can't get what you want.

You can get a 4 blade prop @18p. 4 blades=1 step down in pitch (sacrifices some MPH), and you get...

...better low- to mid-range response and about 2 MPH slower.

To go faster...

... you can get your current prop labbed so that it lets the engine spin up to high end of max RPM range, which nets 1 or 2 MPH, but doesn't help hole shot....

... or get more HP (about 60+) to realize the 5 MPH you want. In that case, you'd get the 5 MPH, but you want a 4B prop, so you'd earn about 2-3 MPH if you heaped on 60+ HP to your engine and went to a 4 blade 20p prop that you'd have the power to turn.





.

 

[Tail_Gunner]

Re: best prop? 2003 5.0l with alpha 1

Re: best prop? 2003 5.0l with alpha 1

Is this a MPI engine...2bl or 4bl..Lot going on here. OR could be

 

[Philster]

Re: best prop? 2003 5.0l with alpha 1

Re: best prop? 2003 5.0l with alpha 1

Well, it's 220 ponies.

I wasn't serious about adding HP; I was just trying to drive home a point.

A good 18p, 4-blade prop will help the low- and mid-range, but it trims some speed.

Guys drop 5-10 grand to get 5 MPH. Since the engine is working in the accepted RPM range, there is no prop that can get everything the OP wants.

 

[Tail_Gunner]

Re: best prop? 2003 5.0l with alpha 1

Re: best prop? 2003 5.0l with alpha 1

Well, it's 220 ponies.

I wasn't serious about adding HP; I was just trying to drive home a point.

A good 18p, 4-blade prop will help the low- and mid-range, but it trims some speed.

Guys drop 5-10 grand to get 5 MPH. Since the engine is working in the accepted RPM range, there is no prop that can get everything the OP wants.

Actually something is wrong...that boat should hit 53-55 with a 5.0 in a 2 barrel its light good hull and no load. ID be willing to bet its the tach speedo or engine tune..My wellcraft is a heavier deeper v and a 4.3..it was set up to run 50..just a prop change and plugs got it to 56

 

[90stingray]

Re: best prop? 2003 5.0l with alpha 1

Re: best prop? 2003 5.0l with alpha 1

That setup is calculating to 13% slip. As stated earlier the ss 4 blade will SLOW you down. Go with a stainless 3 blade 19p and you should gain some mph due to less flex (less slip). Should pull better on low end and gain on top end. Win-win! Look at a Solas they are affordable. And they are available right here on iboats.

http://boatpropellers.iboats.com/Me...9.00&chart=77&engine_id=765&*******=855977844

 

[Philster]

Re: best prop? 2003 5.0l with alpha 1

Re: best prop? 2003 5.0l with alpha 1

Actually something is wrong...that boat should hit 53-55 with a 5.0 in a 2 barrel its light good hull and no load. ID be willing to bet its the tach speedo or engine tune..My wellcraft is a heavier deeper v and a 4.3..it was set up to run 50..just a prop change and plugs got it to 56

It's only 220 HP at the crank. He's only a few MPH short of 50 with a full tank and two people. His engine is spinning up to 4400-4800 and I don't see much gains to be made. 90Stingray is right in that a good SS prop will help, if for no other reason than slightly cutting slip, but it'll be a 'meh' moment and doubt the slight gains will be very satisfactory, but I like shiny stuff so I agree w/ the SS prop.

 

[spdracr39]

Re: best prop? 2003 5.0l with alpha 1

Re: best prop? 2003 5.0l with alpha 1

but I like shiny stuff so I agree w/ the SS prop.

This is the most important factor for me too

 

[Tail_Gunner]

Re: best prop? 2003 5.0l with alpha 1

Re: best prop? 2003 5.0l with alpha 1

It's only 220 HP at the crank. He's only a few MPH short of 50 with a full tank and two people. His engine is spinning up to 4400-4800 and I don't see much gains to be made. 90Stingray is right in that a good SS prop will help, if for no other reason than slightly cutting slip, but it'll be a 'meh' moment and doubt the slight gains will be very satisfactory, but I like shiny stuff so I agree w/ the SS prop.

No Phil its at the prop if it's a 2 barrel 220 or 4 barrler or mpi it could be 250..Starcraft is a expensive boat dont take to much for granted..Even a 2 barrel v8 should outrun a 4.3

 

[Philster]

Re: best prop? 2003 5.0l with alpha 1

Re: best prop? 2003 5.0l with alpha 1

I am under the impression the I/O hp is measured at the crank, and O/B's are at the prop.

Regardless, he operates in max RPM range, so... I think he needs to say whether it's 4800 or 4400 RPM. It's a big difference.

 

[tuttle593]

Re: best prop? 2003 5.0l with alpha 1

Re: best prop? 2003 5.0l with alpha 1

That setup is calculating to 13% slip. As stated earlier the ss 4 blade will SLOW you down. Go with a stainless 3 blade 19p and you should gain some mph due to less flex (less slip). Should pull better on low end and gain on top end. Win-win! Look at a Solas they are affordable. And they are available right here on iboats.

http://boatpropellers.iboats.com/Me...9.00&chart=77&engine_id=765&*******=855977844

if i were to go with the 3 blade ss what size? would be best to gain a little more on top i dont really care about out of the hole but it be nice to gain all around, the boat has a 14 1/2 19p on it now but is not ss, also its at the shop seeing why im only getting around 45mph out of it when its plained out any ideas? what about the best ss 3 blade prop for my set up its running 4800 when wide open now

 

[tuttle593]

Re: best prop? 2003 5.0l with alpha 1

Re: best prop? 2003 5.0l with alpha 1

I am under the impression the I/O hp is measured at the crank, and O/B's are at the prop.

Regardless, he operates in max RPM range, so... I think he needs to say whether it's 4800 or 4400 RPM. It's a big difference.

its a inboard , 5.0l 4800 when i get to 47 mph thats what its turning

 

[90stingray]

Re: best prop? 2003 5.0l with alpha 1

Re: best prop? 2003 5.0l with alpha 1

In my earlier post i gave a link to the 19p props from iboats. I would go ss since it will flex less and provide less slip. I bet you will get 50mph and a few less rpms with the ss.

 

[tuttle593]

Re: best prop? 2003 5.0l with alpha 1

Re: best prop? 2003 5.0l with alpha 1

Actually something is wrong...that boat should hit 53-55 with a 5.0 in a 2 barrel its light good hull and no load. ID be willing to bet its the tach speedo or engine tune..My wellcraft is a heavier deeper v and a 4.3..it was set up to run 50..just a prop change and plugs got it to 56

true my question is they make a 14/14 '' or a 15'' or a 15 1/4 all 19p all 3 blade looking to stay with that instead of a 4 blade in stainless but not a 14 1/2 3 blade like i have now or should i go to a 20p?ss

 

[Philster]

Re: best prop? 2003 5.0l with alpha 1

Re: best prop? 2003 5.0l with alpha 1

Go with the smallest diameter you listed @ 19p in stainless steel.

You shouldn't take the RPM hit and go to a 20p. The stainless props have a little more design to them, the material is stiffer, too, so the engine has to overcome this little extra resistance, which it can. Your RPMs are good, so stick with 19p.

You should get less prop slip.

Basically, you are sticking with what you posted because the specs for your boat/prop are good; you're just getting a better prop and of better material which should transfer a wee bit more power to the water.

 

[Tail_Gunner]

Re: best prop? 2003 5.0l with alpha 1

Re: best prop? 2003 5.0l with alpha 1

true my question is they make a 14/14 '' or a 15'' or a 15 1/4 all 19p all 3 blade looking to stay with that instead of a 4 blade in stainless but not a 14 1/2 3 blade like i have now or should i go to a 20p?ss

Diameter is meaning less here..what is important is this a mpi motor carbed..two or 4 barrel

 

[tuttle593]

Re: best prop? 2003 5.0l with alpha 1

Re: best prop? 2003 5.0l with alpha 1

Just did some test runs with a digital tack today the boats tacking 5000 not 4800 like the guage reads its on rev limit .. it has a 2 barrell carb on it now looking to go to a 4 barrel what would u guys think for a prop with the 4 burrell now that I know where my rpms are?