Stingray 220DR Prop Question

[BGraz180]

I have a 2008 Stingray 220DR with the Volvo 5.0 MPI 270 HP SX. The prop on the boat right now is a Turning Point LE-1417, 14-1/4" x 17 aluminum 3-blade.

The prop is pretty chewed up and corroded, and I'm looking to replace it with a stainless prop. I've tried to do my best to research what I need, and I've had friends tell me I should go to a 4 blade 19 pitch.

I've been satisfied with the performance of my boat and am not looking to do anything radical. I don't pull skiers, so hole shot isn't a huge issue. WOT is around 5100rmp putting me around 42mph or so.

Before I just go out and buy an identical SS replacement, can someone give me some input? Should I consider 4 blade and/or a higher pitch prop?

Thank you in advance...

 

[alldodge]

I have a 2008 Stingray 220DR with the Volvo 5.0 MPI 270 HP SX. The prop on the boat right now is a Turning Point LE-1417, 14-1/4" x 17 aluminum 3-blade.

The prop is pretty chewed up and corroded,

I've been satisfied with the performance of my boat . WOT is around 5100rmp putting me around 42mph or so.

Before I just go out and buy an identical SS replacement, can someone give me some input? Should I consider 4 blade and/or a higher pitch prop?...

If we assume you have a 1.5 ratio drive, plugging in your other info tells us your prop slip is around 23% which is high. The slip being high with a damaged prop is expected. What isn't expected is having a damaged prop and not being able to over rev the motor. If your prop slip was at 10% you should be able to run 49mph.

If your speed is being read off the boats speedometer then it probably is not correct, if it is GPS speed then you have a bad tachometer or something else is wrong.

If your tach is correct, going to a higher pitch prop would only hurt the performance.

 

[jbcurt00]

Isnt the jump from a 17p 3blade to a 21p 4blade a huge jump? Bigger then the 4in pitch increase suggests?

 

[BGraz180]

If we assume you have a 1.5 ratio drive, plugging in your other info tells us your prop slip is around 23% which is high. The slip being high with a damaged prop is expected. What isn't expected is having a damaged prop and not being able to over rev the motor. If your prop slip was at 10% you should be able to run 49mph.

If your speed is being read off the boats speedometer then it probably is not correct, if it is GPS speed then you have a bad tachometer or something else is wrong.

If your tach is correct, going to a higher pitch prop would only hurt the performance.

The drive is the SX-A single prop drive. It's ratio is 1.66:1, according to the VolvoPenta website.

The speed WAS being read from the boat's speedometer and not a GPS, so it's safe to assume it is wrong.

I have no reason to doubt the tach readings, but I have no way of knowing how accurate they are, either.

According to the original window sticker, the original prop was a 19 pitch. Given this one is a 17, I have to assume there is a good reason why the original owner made a change.

 

[alldodge]

A 1.66 ratio puts your slip at 15% which is still bad for a boat your size, but may be doing more speed. So lets say your going faster then 42mph, this is good but the damaged prop should increase the slip which would increase the rpm, and your maxing out at 4100 rpm.

Suggest doing a GPS run if you can find one, or do a compression test to check health of engine

 

[Scott Danforth]

AD, the OP's RPM at WOT is 5100, not 4100

BGraz180, you need to verify RPMs with a shop tach and speed with a GPS, true gauges on the dash cost the boat maker about $5 each

 

[BGraz180]

BGraz180, you need to verify RPMs with a shop tach and speed with a GPS, true gauges on the dash cost the boat maker about $5 each

I can have my local shop verify the RPMs when I take it in for annual maintenance. I can't really measure the true speed at this point. I'm reluctant to put my old prop back on, and the boat is on the trailer for the winter, so it'll be at least April or May before I can run the speed test anyway.

Back to my original question, as the prop needs to be replaced before I put the boat back in the water. Should I just stick with a 17 pitch, since the boat's performance was fine with that one, or should I go to a 19? Is there enough information to make that decision? Should I steal the prop off my brother's boat and plead ignorance??

 

[Scott Danforth]

No, there is not enough information

we need accurate speed and accurate RPM

from the sticky http://forums.iboats.com/forum/gene...p-questions-and-topics/295058-read-this-first

ESSENTIAL DATA REQUIRED
When posting a question about propellers, you cannot get a reasonable answer unless you provide the following information in your post: Items 1-4 are essential for meaningful response to most questions.
1) Performance issue you are trying to correct.
2) Current prop manufacturer, model, aluminum or stainless as a minimum.
3) Current prop diameter and pitch (required).
4) Wide open throttle RPM and speed with an average load (very helpful)
5) Engine/drive make, model, year, and HP
6) Boat make model, year, length and weight

 

[alldodge]

AD, the OP's RPM at WOT is 5100, not 4100

No kidding, sorry for hitting the wrong key, I hit the right one in my first post

Back to my original question, as the prop needs to be replaced before I put the boat back in the water. Should I just stick with a 17 pitch, since the boat's performance was fine with that one, or should I go to a 19? Is there enough information to make that decision? Should I steal the prop off my brother's boat and plead ignorance??

Without further testing yes stick with the 17. My guess is your tach is probably close enough, and your probably going faster then the speedometer is showing.

 

[roffey]

The speed and RPM seem wrong to me, keep in mind I don't really know what I'm talking about.

My boat is a 198 Stingray with a 190hp 4.3 alpha one turning a 23 inch prop at 4900 RPM I hit 53 mph (on the GPS with an aluminum prop). I would think a 17 inch prop for a 5.0 is way to low, I would think a 19 at the least?

 

[BGraz180]

No, there is not enough information

we need accurate speed and accurate RPM

from the sticky http://forums.iboats.com/forum/gene...p-questions-and-topics/295058-read-this-first

ESSENTIAL DATA REQUIRED
When posting a question about propellers, you cannot get a reasonable answer unless you provide the following information in your post: Items 1-4 are essential for meaningful response to most questions.
1) Performance issue you are trying to correct.
2) Current prop manufacturer, model, aluminum or stainless as a minimum.
3) Current prop diameter and pitch (required).
4) Wide open throttle RPM and speed with an average load (very helpful)
5) Engine/drive make, model, year, and HP
6) Boat make model, year, length and weight

Except for the length and weight of my boat in item #6, I included every item on this list in my original post.
(The length is 22', and the weight with basic gear, no passengers is somewhere around 3900 lbs.)

We've concluded that my speed at WOT may not be accurate due to my use of the boat's speedometer rather than GPS, and I'm in a spot now where I can't put the water for several months, and am reluctant to run it at all with its current prop. So now I need to put a new prop on it in order to determine what new prop to put on it.

I understand there are a lot of variables that must be considered, and I appreciate everyone's help in trying to understand what those variables are.

 

[travelon1979]

A little late to the convo but for what its worth:

​I have a 2010 Stingray 220DR / 5.7 300 HP / SX Single prop drive / 1.66 ratio

​With a brand new OEM Volvo 19P aluminum prop I turn 4800 RPM at 53 MPH (GPS) 54 (boat speedo) My engine RPM range is 4600-5000. I believe your engine has the same range. Your RPM is likely correct but your speed seems way to slow as others have said.

​My holeshot is ok and overall performance is great for a boat this size turning a 19P Volvo Aluminum prop. I believe Stingray shipped the 19P standard with all boats. The 21P will likely keep you in your RPM range but in my opinion will be a slug out of the hole which is not much fun.

We do a lot of 3000 rpm ( ~30 MPH) cruising and wakeboarding/tubing so I am looking for more holeshot and mid-range performance. I'm not so concerned with top end so I am moving to a 17P SS 4 Blade. This should keep my RPM at 4800 if not more but should not exceed 5000 rpm. Likely going to go with the Rubex HR4. They are reasonably priced and good reviews for overall performance. It should be a big improvement over the 3-blade. ​I could pay a lot more for something I'm not so sure I'll be able to tell a difference under normal cruising conditions.

I realize we have different engine set ups but in my opinion moving to a 19P 4-Blade would not be an ideal combo on my boat. You have a little less horsepower so thinking it would have even more of a negative effect on your rig. I can only speak for my boat but wouldn't put anything bigger than 18P in a 4 Blade. I am going with 17P. If you stick with a 3 Blade I wouldn't exceed 20P. I'll look for the reviews I've found in the past but most tested with a OEM Volvo 19P SS prop and could hit 52 mph or so with your engine set up. in one review my boat with a OEM Volvo 19P ss hit 55 MPH with a radar gun. Again topspeed is not my concern just pointing out if you want mid-range cruising performance your best bet will be a 4-Blade at 17P or 18P. Just my opinion based on my experience with my 220DR.

​For what its worth I absolutely love the layout of our boats. I was in the market for a brand new Regal or Cobalt deck boat when I found the 220DR used. The layout is one of the best I've seen in a boat at this price point. Deck boat space with performance to boot.