markrinker
New Member
Props have arrived at the marina where TLI is still in storage. They started launching boats yesterday; can't wait to get out on the water and run some tests!!!
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I guess I'll just have to defer to your superior knowledge of diesels...............
But you had us fooled when you started experimenting with props that Sea Ray discontinued using about 20 years ago because they were inefficient, didn't perfom well and caused handling issues on high torque engines.
Cruising around at 2600 rpm all day, I bet the turbos are a nice burnt white color.
There are some very smart people on this forum who are willing to help those that are willing to listen. Some folks have closer ties to Sea Ray and Sea Ray facilities than others and that makes them a bit more qualified to speak.
You can run your boat any way you please. Hopefully, you don't grenade an engine in the process. Frank is too polite and diplomatic to tell you "I told you so." The rest of us aren't.
Best of luck in your experiments.
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I must be missing something here.
The 3 bladed props decrease your speed, the decrease low speed handling and are requiring you to increase rpms. Additionally, Caterpillar established a rated cruise rpms for your engines of 2400, yet it appears you plan to run them at 2500 to 2600. That will also increase fuel burn from roughly 20 gph to approximately 30 gph.
Other than wanting to get to know your Cat mechanic extremely well, I can't see what you have gained by the change..........help me understand.
Ok.....I give up. The source I was using just showed the inboard transmission and not v-drives.
But it is a moot point on boats like the one in question. No matter what the final ratio in A or B settings is, the set op on 400/410/450......and any of the diesel powered boats is that the engines turn so slow (26-2800 rpm) and have so much torque that Sea Ray used the 2.5:1 ratio gearing. That means the prop shaft is turning slow enough that the difference in ratios makes no real difference in performance and the boats are spec'd with the same prop on both sides. The gas engines, however, are a different story. They turn something like 4200 rpm and have 2.0:1 or lower gearing and that makes the prop turn about twice as fast as on a diesel boat. and on hulls like the 340DA, they put .5" more pitch on one side than on the other.
Thanks for keeping me straight...............