Any experience with Hering 6 blade #6 props?
I'm looking at prop selections and would like to hear what differences will I see in a 5 blade vs. 6 blade hering prop vs. mercury cnc prop, thanks
|
We need more info on the boat to answer this question for you. We need your performance data WOT RPM and WOT MPH with your current set up including gear ratio, propeller diameter, rake, blade count and pitch as well as the year of your hull.
Julie |
Julie, 6400rpm, 143mph, 16.5x38 5 blade cnc merc 18 rake , 40 skater, 1000hp/side, 1.35 gear
|
Originally Posted by buttonhead40
(Post 2669008)
Julie, 6400rpm, 143mph, 16.5x38 5 blade cnc merc 18 rake , 40 skater, 1000hp/side, 1.35 gear
|
I have calculated 16% slip which is NOT good for a cat with a normal range of 6-8%. The good news is there is room for improvement. There is more speed in your boat ...you just need to do some dial in work to find it! We have recently dialed in a few Race Skaters and the percentage of slip with our props and the has been low. Efficient propellers equals greater top end.
Julie Julie |
Originally Posted by buttonhead40
(Post 2669008)
Julie, 6400rpm, 143mph, 16.5x38 5 blade cnc merc 18 rake , 40 skater, 1000hp/side, 1.35 gear
|
Julie, yes pitch is 36, not 38, how do your new props compare to the other 2. what is your experience with the 40 skaters, we have a 5.5" x dimension with 16" ext boxes on wet sump 6's
|
Originally Posted by buttonhead40
(Post 2669106)
Julie, yes pitch is 36, not 38, how do your new props compare to the other 2. what is your experience with the 40 skaters, we have a 5.5" x dimension with 16" ext boxes on wet sump 6's
|
Julie, your right slip is in the 14% range, how do you account for number of blades in your formula, a 6 blade will have less slip then a 5 blade correct? also how do you correct for merc and hering prop pitch being 2 * by the number but same actual pitch? can we expect to get to a 6-8% slip on the 40 skater, how can we get there and what speed increase will we see between say 14% and 8%, thanks Jim
|
When adding a blade we usually expect the slip to decrease, but not always. There are many varibles to take into account.
All the CNC props, Merc, Hering and ours are all very close to the marked pitch. The previous generation, non CNC, of Mercury props were about 1.5" taller in pitch than marked. If you were to run a straight edge along the bottom of the hull infront of the drive how high above the bottom are the center of your prop shafts? What is the thickness of your Merc CNC props? It should be stamped on the prop, something like "850HP, 1200HP, etc"? Are you shooting a rooster tail when the boat is running at top speed? Do you have to go into negative trim to attain top speed? |
All times are GMT -5. The time now is 10:25 AM. |
Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.