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On Sun, 22 Apr 2007 14:41:03 -0700, Josh Assing
wrote: I got an Apollo SS 13 1/4 X 17 it runs my little boat 40 mph with a 90 HP motor. IMHO They work great and are relatively inexpensive. There's a lot more than just HP that relates to the speed. I have a 19pitch on my 18' boat with a v6 and it is perfect for the boat --that same prop isn't so good on the 22'.... I'm leaning towards a 4 blade based on some reading & information I gleemed from "those in the business" (but not salesmen) Thanks I hae a four blade on my ETEC - I would never go back to three blade props. |
#12
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posted to rec.boats
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The whole subject of this thread is about loads on engines with too big a
pitch. If you don't know the consequeces of that then I suggest going to a "propellor selection" website or listening to your reputable marine supplier. A boat engine endures much much more stress than an automobile engine that goes up & down hills. Load on a boat engine is continuous for long periods of time. Most marine shops will tell you to find the propellor that allows desired WOT revs & then still drop one more size. Depending on your gearing, the load remains constant right thru the rev range. eg, at 20% throttle you have 90% load. 60% throttle you still have 90% load So you can see it appears you have 105% load on yours & your motor WILL die prematurely. You are not one size below. You are not equal. You are one size over!!! Get it? If you don't listen , then be prepared for both a motor PLUS a downsize prop!!! (not to mention excess fuel you're chewing thru) "Short Wave Sportfishing" wrote in message ... On Sun, 22 Apr 2007 14:41:03 -0700, Josh Assing wrote: I got an Apollo SS 13 1/4 X 17 it runs my little boat 40 mph with a 90 HP motor. IMHO They work great and are relatively inexpensive. There's a lot more than just HP that relates to the speed. I have a 19pitch on my 18' boat with a v6 and it is perfect for the boat --that same prop isn't so good on the 22'.... I'm leaning towards a 4 blade based on some reading & information I gleemed from "those in the business" (but not salesmen) Thanks I hae a four blade on my ETEC - I would never go back to three blade props. |
#13
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posted to rec.boats
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BruceM wrote:
The whole subject of this thread is about loads on engines with too big a pitch. If you don't know the consequeces of that then I suggest going to a "propellor selection" website or listening to your reputable marine supplier. A boat engine endures much much more stress than an automobile engine that goes up & down hills. Load on a boat engine is continuous for long periods of time. Most marine shops will tell you to find the propellor that allows desired WOT revs & then still drop one more size. Depending on your gearing, the load remains constant right thru the rev range. eg, at 20% throttle you have 90% load. 60% throttle you still have 90% load So you can see it appears you have 105% load on yours & your motor WILL die prematurely. You are not one size below. You are not equal. You are one size over!!! Get it? If you don't listen , then be prepared for both a motor PLUS a downsize prop!!! (not to mention excess fuel you're chewing thru) "Short Wave Sportfishing" wrote in message ... On Sun, 22 Apr 2007 14:41:03 -0700, Josh Assing wrote: I got an Apollo SS 13 1/4 X 17 it runs my little boat 40 mph with a 90 HP motor. IMHO They work great and are relatively inexpensive. There's a lot more than just HP that relates to the speed. I have a 19pitch on my 18' boat with a v6 and it is perfect for the boat --that same prop isn't so good on the 22'.... I'm leaning towards a 4 blade based on some reading & information I gleemed from "those in the business" (but not salesmen) Thanks I hae a four blade on my ETEC - I would never go back to three blade props. IMHO I was always told you should prop your motor for WOT RPM and never to change the speed of the boat! IMHO If that is a problem you should get a bigger motor. Liberally Yours, 1.20.09 Fredo |
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