R27-OB Propeller Testing <-- RESULTS are IN!

Submariner

Channel Surfing
Joined
Feb 2, 2020
Messages
1,386
Location
Everett, WA
Website
www.letsgochannelsurfing.com
Fluid Motion Model
R-27 (Outboard)
Hull Identification Number
FMLT2702C021
Non-Fluid Motion Model
https://tinyurl.com/yrv84xdm
Vessel Name
Channel Surfing
MMSI Number
368187810
I wanted to start a new thread about propeller testing, specifically on the R27-OB, though I suspect similar results are possible on other outboard model boats in the Fluid Motion family.

In January I reached out to PowerTech for help. I had a very detailed objective in mind with what I needed out of a prop. I can't say enough good things about PowerTech. I worked directly with Steve Powers, the president of Power Tech and Marcus, the VP. They are fantastic to work with. This project included some patent-pending concepts so I wasn't able to publicly release pictures of the prop, which is comprised of two to three pieces. (Some assembly required). In addition, I have numbers on a Turning Point 16", 3-blade prop, and the Sharrow (on an R27-OB), for comparison purposes.

This first video is published. It covers the Sharrow, Turning Point, Yamaha 3-blade, PowerTech 4-blade, and 5-blade and some patented modifications.
We have a second video called "Prop Talk" coming out in another day or two with LaZina and I discussing more about our experience.

Which prop is Channel Surfing running?
 
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I just love it when I see a new Channel Surfing video pop up!!
Lots of great info here Martin with tons of utility. Thank you for doing these. I’m going to watch it a few more times
 
Great work and contribution! My computer rang a bell and flashed its lights when your new vid hit!!!!!
 
Excellent testing and analytics. I am updating (not sure if UPGRADING is accurate) my 2018 Ranger 27 OB Suzuki to the Sharrow. The first Sharrow prop was not a good fit. The Sharrow prop was 30-40% less efficient at almost all ranges except the top end. Above 5,000 RPM, it did well. I am looking for better MPG on plane and between 25-28 mph. I presented this information to Sharrow, who sent me another to test. Unfortunately, time to test got away from me this season and I only tested the OEM this year versus the second Sharrow. Georgia Girl is stored for the winter.

Generally speaking, the Suzuki gets better MPG than the Yamaha. I have experienced better MPG than the Yamaha engine with OEM prop. On a recent trip to the Broughton Islands with a friend, I compared the two on one of our legs. Same boat year, the same approx loads *mine was probably a little heavier, same seas, distance, speed.
I achieved 23.8372% better mileage. A friend put in 213 liters, and I put in 172 liters. This was not a one off, as I consistently needed less fuel per leg than my friend during this voyage.

I will test the Sharrow in March. Then, I am putting Georgia Girl up for sale! We got 2 footitis on the Broughton trip and placed an order for a 29 Luxury CB.
 
PowerTech is shipping the SCE5 Modified, Channel Surfing Edition prop's. I got my black anodized exhaust tube and flare today.
I know of at least 7 prop's that have already shipped to others (complete prop's).

I'll get mine upgraded from the Prototype to the finished prop this weekend and will publish a short video on how to put it together and what loctite to use.

I also posted all the info on our website.

IMG_5821.jpegIMG_3183.jpegIMG_3181.jpeg
 
I emailed PowerTech after I saw your video. Been working with Jared on the right prop for the R23 F200. After several discussions, the SCE5 is not available in a 12 pitch. He recommended the OFS4 with the modified exhaust hub extension. It's ordered, and he was talking with 8 other R23 owners to recommend the same prop. Looking forward to lower plane speeds.
 
I have R23-200 and would like to connect with Jared as well for new prop. Could you provide contact details for him?
 
I've been talking with Jared at Powertech as I get asked a lot about the R23. They've had success in the past with the F200 using the OFS 4-blade, in a 12 pitch. I know of several owners who ran that OFS4R12 on their R23 and were happy with it. The modification (extended exhaust tube) being added should improve mid-range and stern lift. A 5 blade I don't think would work well at all on the F200 as it's a 4 cylinder. The F200 and F250/300 are different motors (4 cylinder vs 6 cylinder).
 
Thanks, I will reach out to Jared and get a prop ordered. The 3-blade doesn't perform well for all the reasons talked about above.
 
I've got a pair on order to try on my Cutwater C302c, currently running OFS 5 bade 17s. Will report back once they arrive.
 
I've got a pair on order to try on my Cutwater C302c, currently running OFS 5 bade 17s. Will report back once they arrive.

Please let me know how they work out for you!
 
Please let me know how they work out for you!
I will definitely be sharing results, good, bad or indifferent. The OFS 5s helped out a lot with mid range, I just hope to get more than 5100 RPMs.

The standard orientation (SCE5 modified) props were available, but, the counterrotating left hand prop will take about 6 weeks to build.
 
To anyone who's worried about the modification falling off... I'm sure it's possible. It happened to me early on with testing. However, fast forward to 70 engine hours later, 6 months of time, and 1000 miles traveled, in saltwater, on that SCE5 Modified prop... I went to swap out the prototype exhaust tube which is just raw aluminum that you see in the photos. I couldn't get the screws out. Stainless screws into aluminum, with locite, in salt water, add time... dissimilar metals. I tried penetrating oil, I tried heat, I tried drilling them out. My final attempt, postage. My prototype arrived at PowerTech's machine shop Friday as I can't get the thing off.

Lemodrop's SCE5 Modified prop arrived last week. I picked it up yesterday to record an unboxing and assembly video on it as I wait for my prop to return.

I'll talk more In the video about why not just make the prop in one piece.
I'm now convinced that once the screws are in, and I'm done playing with it... stainless plus aluminum in salt water, add time... and it becomes permanent/solid.
 
How to install the PowerTech SCE5 Modified, Channel Surfing edition, on an R27-OB.

Why not cast the prop as one solid piece?
Am I worried about it falling off again?
How easy is it to get on and off the Yamaha?
Does it work on the R25-OB or the R23?

Video just released.
 
I spoke to Jared yesterday and I have the SCE5 - 15 inch , 5 blade on order for my R25! Thanks @Submariner !! I'm most worried about getting that cotter pin in. Not my favorite part of this process. Any tips are welcome.
 
@Submariner how do I get LemonDrop to give me docking lessons? I want flawless docking skills too.
 
My props arrived, I'm skiing in Tahoe and will install upon return home. 2x:
SPEC ORDER - SS Propeller - Semi-
Cleaver Style - 5 Blade - 14 x 15 -
Standard Rotation - CushionLok -
Machined for Extension Ring
CLYX-RODS

I'll post on a separate thread for Cutwater.
 
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