3081 or 3087 G23 with H6 stock ballast

[Whitetail15]

What is the final debate on these props. I would like to reduce some engine noice at surf speeds and cruising speeds. Usually only use stock ballast with 400lbs lead.

[Tallredrider]

I get a little confused about the prop numbers and do better with prop size and pitch.
Regardless, it will depend on your elevation, so make sure to include that information.

[Whitetail15]

always less than 2800 feet.

[Kmayotte]

What is the final debate on these props. I would like to reduce some engine noice at surf speeds and cruising speeds. Usually only use stock ballast with 400lbs lead.

I too would like to reduce engine noise. Haven't considered changing the prop but I wonder if anyone has tried lining the engine compartment with dynomat?

[Team230]

I'm interested in this discussion. I will be buying a second prop soon so I always have a spare.


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[Whitetail15]

I have lined my entire engine compartment with dynomat. About 375.00 dollars worth. I did not notice a difference at surf speeds. Just idle.

[greggmck]

What is the final debate on these props. I would like to reduce some engine noice at surf speeds and cruising speeds. Usually only use stock ballast with 400lbs lead.

I spent a few days last week speaking to Jim at ACME. He was pretty certain that the 17.5X17.5 (3087) was the best prop for a moderately loaded G23 H6DI if I was interested in improving noise and fuel performance for surfing. We surf exclusively (sea level). We have an additional 900lbs of lead ballast and 3-5 people in the boat. With the stock prop we achieve 3450 RPM at 11.5mph. Our fuel burn is 6.7gal/hr over the past 25 hours.

I received the 8087 prop today. I will install it this weekend and report the RPM we achieve while surfing under identical conditions as the stock 17"x17". It will take me a few weeks to record an accurate fuel burn. I also plan to use a sound pressure meter to record engine noise before and after the prop switch.

The good thing about going straight to ACME is that they offer a 30 day trial on the prop. If this one doesn't work out I can swap it out for a different pitch/diameter to achieve the performance I am after.

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[nyryan2001]

I’ll help you jump straight to the results:

17x17 will burn more fuel and run higher Rpms than the 17.5x17.5

if your goal was to burn less fuel (lower rpms) and run quieter, you’re not going to do it going that route

[greggmck]

I’ll help you jump straight to the results:

17x17 will burn more fuel and run higher Rpms than the 17.5x17.5

if your goal was to burn less fuel (lower rpms) and run quieter, you’re not going to do it going that route

I think you misread my post. I currently have the 17x17 prop. I am changing to the NEW 17.5 x 17.5. The new prop has a HIGHER pitch and GREATER diameter. It will turn lower RPM than the stock prop. When an internal combustion engine produces lower RPM to achieve the same speed it burns less fuel. Yet you say that wont happen?

[GMLIII]

I think you misread my post. I currently have the 17x17 prop. I am changing to the NEW 17.5 x 17.5. The new prop has a HIGHER pitch and GREATER diameter. It will turn lower RPM than the stock prop. When an internal combustion engine produces lower RPM to achieve the same speed it burns less fuel. Yet you say that wont happen?

Looking forward to what you discover since I primarily surf as well and I'm carrying around 750 lbs of steel shot bags

[nyryan2001]

Ok, gotcha, I thought you were going the other direction.

you’ll see a 2-300rpm reduction difference for the same activity and weight going to the .5” larger and .5” more pitch’d prop. Good luck

[greggmck]

Ok, gotcha, I thought you were going the other direction.

you�ll see a 2-300rpm reduction difference for the same activity and weight going to the .5� larger and .5� more pitch�d prop. Good luck

Agree. That is the expectation. I am interested in measuring the relative reduction in engine noise, fuel burn improvement and the affect on the list angle of the boat while surfing. The greater diameter prop should translate increased rotational moment on the hull impacting the surf wave, perhaps increasing the starboard side wave at the expense of the port side. My hope is this is not significant as we primarily surf the regular (port) side. I will use a tilt gauge to measure any increased list of the hull while surfing that the new prop may induce.

[GMLIII]

Agree. That is the expectation. I am interested in measuring the relative reduction in engine noise, fuel burn improvement and the affect on the list angle of the boat while surfing. The greater diameter prop should translate increased rotational moment on the hull impacting the surf wave, perhaps increasing the starboard side wave at the expense of the port side. My hope is this is not significant as we primarily surf the regular (port) side. I will use a tilt gauge to measure any increased list of the hull while surfing that the new prop may induce.

I hope that is not the case. Seems like the portside always gets the short end of the stick in regards to surfing when the majority of folks surf on the portside vs starboard.

[greggmck]

I hope that is not the case. Seems like the portside always gets the short end of the stick in regards to surfing when the majority of folks surf on the portside vs starboard.

Agree. My number one request to Nautique each year is to develop an engine that rotates in the opposite direction so the majority of surfers who are on the regular side would get the "better" side wave.

[Tallredrider]

Agree. That is the expectation. I am interested in measuring the relative reduction in engine noise, fuel burn improvement and the affect on the list angle of the boat while surfing. The greater diameter prop should translate increased rotational moment on the hull impacting the surf wave, perhaps increasing the starboard side wave at the expense of the port side. My hope is this is not significant as we primarily surf the regular (port) side. I will use a tilt gauge to measure any increased list of the hull while surfing that the new prop may induce.

At some point increasing the lugging of the engine is going to increase fuel burn. I might consider that switch if I thought my engine could handle it. I do some boating at 3600 feet and getting to plane at wakeboard speeds is a noticeable effort. I am anxious to hear your results, and hope they are good!

I am surprised anyone is complaining about noise. Compared to every other boat I have been in, the G is the quietest of them all.

If you get some problems with increased listing, it could be pretty easily offset with a ballast adjustment. With your presets available, you would only have to do it once.