Prop Choice
- Thread starter Da Nag
- Start date
The three blade aluminum "chopper" (cut off square at the back of the blade) prop that came with my new motor (Yamaha) seems very hard to beat for versatility. I've got four blade Solas that I think will be a little less vibration at low speeds, but no miracle breakthrough (but we'll just have to wait and see).
Despite all the advantages of stainless, the big turn off for me is the weight (really the mass) of the prop when engaging the gears. A 3.5 lb aluminum prop is a lot easier on the shift dogs than the 11-13 lb stainless prop. Just from the sound of the two, I'd say the impact on the sift dogs (CCClllluuuuunnnkkkk!!!!!) is proportional to the mass of the props. (Not too surprising a conclusion!)
Maybe not a big deal if you only shift occasionally to get in and out of marinas, but I still don't like the heavy clunking and thuds, and definitely wouldn't want to use a stainless prop on a workboat pushing things around and shifting in and out of gears all day long.
The shift dog design is not very sophisticated and is totally without a clutch, torque converter, or synchromesh servos, and is a real basic crude mechanical device: it's in gear or out of gear with these flattish, slotted faced bronze engagement clogs. It's kind of like shifting a car with a stick shift without a clutch from a standing start. No need to make the start up mass any larger than necessary with a triple weight prop.
Considering the design limitations, it's no wonder that they encourage you to shift into gear fairly quickly from neutral to avoid grinding the dogs for an unnecessarily long period. You do, however, want to wait for the prop to stop turning in neutral before going from forward to reverse or vis-a'-verse.
Another advantage of aluminum props:
minor damage---repair it yourself with leather mallet, file, sandpaper and new paint.
major damage---have it repaired, or simply buy a new one at the discount internet or ebay rate for the same amount of money. I can get the Yamaha factory aluminum prop mentioned above for $55-$65 if thoughtfully done, and the full repair of an aluminum prop that requires welding is $75 or more. My 2 pesos. Joe
Despite all the advantages of stainless, the big turn off for me is the weight (really the mass) of the prop when engaging the gears. A 3.5 lb aluminum prop is a lot easier on the shift dogs than the 11-13 lb stainless prop. Just from the sound of the two, I'd say the impact on the sift dogs (CCClllluuuuunnnkkkk!!!!!) is proportional to the mass of the props. (Not too surprising a conclusion!)
Maybe not a big deal if you only shift occasionally to get in and out of marinas, but I still don't like the heavy clunking and thuds, and definitely wouldn't want to use a stainless prop on a workboat pushing things around and shifting in and out of gears all day long.
The shift dog design is not very sophisticated and is totally without a clutch, torque converter, or synchromesh servos, and is a real basic crude mechanical device: it's in gear or out of gear with these flattish, slotted faced bronze engagement clogs. It's kind of like shifting a car with a stick shift without a clutch from a standing start. No need to make the start up mass any larger than necessary with a triple weight prop.
Considering the design limitations, it's no wonder that they encourage you to shift into gear fairly quickly from neutral to avoid grinding the dogs for an unnecessarily long period. You do, however, want to wait for the prop to stop turning in neutral before going from forward to reverse or vis-a'-verse.
Another advantage of aluminum props:
minor damage---repair it yourself with leather mallet, file, sandpaper and new paint.
major damage---have it repaired, or simply buy a new one at the discount internet or ebay rate for the same amount of money. I can get the Yamaha factory aluminum prop mentioned above for $55-$65 if thoughtfully done, and the full repair of an aluminum prop that requires welding is $75 or more. My 2 pesos. Joe
Well I voted for the 3 blade aluminum mostly because I know mine works well. I would love to try out one of the composite props. One of those may have saved me a prop shaft replacement. My only fear is that if I hit something that would normally ding my alum prop, would probably destroy the "plastic" prop. Please correct me if I'm wrong as I am quite ignorant to comp props. How do they handle the occasional "ding"?
Well when I will have about 3000 or so hours on this great C-Dory I might be able to let you know what my choice would be . But for know I running 3 blades factory aluminum, next set probably will try Ring Prop if they do work. It will be nice if the don't well, I will sadly be out of about 500 big ones!... Gary
I'm currently running a 4 blade Solas 15 pitch on a 90 ETEC, get 5100 WOT and just shy of 32 mph. Next summer I'm going to try a 4 blade Propulse to see what I get with a 16 pitch composite. I voted for the 4 blade as it seems to generate more thrust when applying the throttle from moderate RPM trying to stay up with a following sea.
A
Anonymous
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I voted (now that I'm back 
) I'm for the OEM 3-blade as well. Tried a lot of props... what works best in almost all situations is the stock Yamaha props :thup
Hey... how come the stupid spell checker does not know "I'm" .... irritatin :!: :amgry can ya smarten-it-up any :?:
:disgust
) I'm for the OEM 3-blade as well. Tried a lot of props... what works best in almost all situations is the stock Yamaha props :thup Hey... how come the stupid spell checker does not know "I'm" .... irritatin :!: :amgry can ya smarten-it-up any :?:
:disgust
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Anonymous
Guest
... daooh ... :embarrased
journey on
New member
Bought a propulse prop. Adjusted it to 16" pitch. The first check now shows performance similar to the Honda data. However, this was Labor Day, and anything over 15 knts was asking for trouble. I'll run a curve later.
boris
boris