Propeller purchasing - comments on...

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bcassedy
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Propeller purchasing - comments on...

Postby bcassedy » Sat Mar 11, 2017 4:15 pm

My 32' 88' FB Sedan, 1 to 1.5 velvet trannies, 240HP 318 Cu In Chryslers is in need of replacement props. Last fall, during our yearly trip downriver, we clipped a submerged log. When I pulled out for the season, I found the starboard prop has a slightly bent blade. Ok, need to repair. I also had the original props that came with the boat in the garage. I'd changed those out with the idea of having them reconditioned. One of those things that just didn't get done. Well, I took both sets to my prop shop here in town (Delta Propeller, North Bend, Oh). The replacement set I had just taken off are bronze, size 15x15 1.25". The original set at Nibral's, size 16x15 1.25". The guy at the prop shop said bronze set can be reconditioned. The Nibral set are too far gone. Edges are chewed up pretty bad - "nothing that can be done to fix/recondition them".

He quoted me a cost on new Nibrals 16x15 at 950.00 each. That's more than I'd like to spend. I've done some searching online and have found a number of possibilities:
ex. https://orlando.craigslist.org/bpo/6024954499.html

Questions abound... Do I need cupped props? Is the use of bronze props (with a shaft anode that appears to be working as it should), a major no-no?
Have folks purchased used or Old-new stock online successfully? If so, what pointers would you advise to ensure making a good purchase?

Comments appreciated.

Bill
Bill & Sharon Cassedy
"Sunset Seeker"
'88 32' Sedan Bridge
Located in Aurora, In.
Twin 318cu in Chrysler
1.5:1 Velvet drive trannies
Fresh water only

jralbert
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Re: Propeller purchasing - comments on...

Postby jralbert » Sat Mar 11, 2017 9:40 pm

Bill, I had Nibral, 16x15 and they were cupped. Had them reconditioned once but don't remember condition of blade edges. I think it was just some pitch adjusting and balancing. I'd be sure Nibral can't be touched up before investing $1800. Lots of prop shops to choose from
-joel-
former owner 1988 '32 FB Sedan
Chesapeake Bay
twin 318 / 240 hp
Potomac MD

EWRice
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Re: Propeller purchasing - comments on...

Postby EWRice » Sat Mar 11, 2017 10:09 pm

My understanding was that Nibral is much easier to repair than bronze. I have seen some VERY chewed up props repaired like new. I just pulled a set of 36x34 bronze that had major edge repairs done a few years ago. I've got two shops in MI that do all my props, and would be happy to refer you. Pictures? I can check and see if I have a spare 15x15 hanging on my wall.
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bcassedy
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Re: Propeller purchasing - comments on...

Postby bcassedy » Sun Mar 12, 2017 8:05 am

EW...
Would like to have your shop's names. One thing my shop guy had mentioned was the thinness of the blade's edges and that he couldn't build the blades up to get them back into shape. I'd like to keep the 16x15's as primary (believe this were the recommended size for my boat).

Thx!
Bill
Bill & Sharon Cassedy
"Sunset Seeker"
'88 32' Sedan Bridge
Located in Aurora, In.
Twin 318cu in Chrysler
1.5:1 Velvet drive trannies
Fresh water only

Fastjeff
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Re: Propeller purchasing - comments on...

Postby Fastjeff » Mon Mar 13, 2017 7:35 am

Don't sweat corrosion worries using bronze props--just keep good anodes on the shafts.

On prop sizes...assuming your boat is NOT overloaded with 'stuff', and tons of passengers, then the stock recommended props tend to be UNDER pitched. (If she'll jump onto plane with your standard load at less then full throttle, your props are under pitched.) Accordingly, you can add some pitch--or cup, the result is the same--and gain gas mileage. It also reduces engine damage by requiring less rpm at cruise speed.

A case in point: My old 32 footer (360s and 1.52:1 drives) required 3,200 rpms at cruise speed with stock props. After I added an inch of pitch (and an inch of diameter) this dropped to 2,500 rpm. Gas mileage increased as well (didn't have a FloScan before the change) engines were much 'happier', and it would still send you flying if the "Admiral" mashed the throttles without warning.

Jeff
"We live at the bottom of an ocean of air, not at the top." General Marvage Slatington

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bcassedy
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Re: Propeller purchasing - comments on...

Postby bcassedy » Mon Mar 13, 2017 7:49 am

Thanks, Jeff...
Bill & Sharon Cassedy
"Sunset Seeker"
'88 32' Sedan Bridge
Located in Aurora, In.
Twin 318cu in Chrysler
1.5:1 Velvet drive trannies
Fresh water only

Tranquilo
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Re: Propeller purchasing - comments on...

Postby Tranquilo » Mon Mar 13, 2017 10:25 am

Jeff, are you saying you shouldn't reach plane under full throttle?

Shouldn't you get on plane at 1/2?
2x 1973 28 Express - Single 318
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Re: Propeller purchasing - comments on...

Postby jralbert » Mon Mar 13, 2017 11:27 am

Fastjeff wrote:Don't sweat corrosion worries using bronze props--just keep good anodes on the shafts. Jeff
I'd revise that a bit to say making sure your shafts are isolated is key here. I used the shaft zincs and they never wore, a sign that there was no shaft corrosion going on (and there never was) because the isolation was intact.
-joel-
former owner 1988 '32 FB Sedan
Chesapeake Bay
twin 318 / 240 hp
Potomac MD

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Re: Propeller purchasing - comments on...

Postby Fastjeff » Tue Mar 14, 2017 6:04 am

..."Jeff, are you saying you shouldn't reach plane under full throttle? "

Hell no! The "Admiral" once did a full throttle plane off on me without warning. I went flying backwards, destroying a deck chair in the process. From then on she was instructed to, One, say "Going up!" before planning off, and Two: use no more than 1/2 throttle. And this was with those over-pitched props I put on. With the stock props the thing could have won boat drag races!

Jeff

PS: My boating buddy, with his wheezing Sea Ray (28 footer), was stunned at how my big M leapt out of the water. His boat need full throttle to get on top, and it would fall off plane below 3 grand. He was REALLY stunned when I made a full lock turn through 360 degrees at only 2,000 rpm without loosing plane. Hell of a boat!
"We live at the bottom of an ocean of air, not at the top." General Marvage Slatington

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bcassedy
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Re: Propeller purchasing - comments on...

Postby bcassedy » Tue Mar 14, 2017 8:30 am

Jeff,

Ok... to paraphrase... :-) "Inquiring minds would (really!!!) like to know..." What was the size of the "over pitched" props you used. And knowing you, these were intended to get the most bang for the buck (ie. gas mileage/gph)?

The current price of gas isn't gonna stay as low as it is, even though marinas seem to think it's a necessity to charge close to a $1.00 more per gallon. So being in a position to maximize our gas consumption ahead of the game is a good thing.

Thx,
Bill
Bill & Sharon Cassedy
"Sunset Seeker"
'88 32' Sedan Bridge
Located in Aurora, In.
Twin 318cu in Chrysler
1.5:1 Velvet drive trannies
Fresh water only