Hi Just wanted to find out from other users out there what kind of speed one can expect from 3GM30 on Hunter vison 32 I get around 5.4 knots att 2500-2700 rpm and how far can you push that engine rpm wise?? I have heard that diesel engines like lower rpm would chnaging the prop from stock to 3 blade help ? I woul like to get around 6- 6.5 knouts out of her possible?? Thanks in advance Paul.W Caledon, Ont
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My 35.5...
with same engine makes 6 1/2 kts. @ 2800 all day long with clean bottom and 3 blade fixed. I believe I'm a bit heavier than the 32 Vision. I think 3600 is so called red-line, but diesels are made to be run at 75-80% of max. for extended periods which puts you at 2700-2900 for the sweet spot. At least monthly, you need to run it up to 3000-3200 and run it awhile to keep it blown out, otherwise it will "coke up" on you.
with same engine makes 6 1/2 kts. @ 2800 all day long with clean bottom and 3 blade fixed. I believe I'm a bit heavier than the 32 Vision. I think 3600 is so called red-line, but diesels are made to be run at 75-80% of max. for extended periods which puts you at 2700-2900 for the sweet spot. At least monthly, you need to run it up to 3000-3200 and run it awhile to keep it blown out, otherwise it will "coke up" on you.
6.2 Knots All Day Long
I had a Vision 32 for nine years. At 3200 RPM, it would do between 5.9 and 6.5 depending on the wind, etc. Beware the knot meter, tho. They are all over the ball park and rarely calibrated. Calculate it from known diatance and time, and factor current. Having said all that, DON'T run it too slow. What you have heard from others about running a diesel at low RPM is 180 degrees from the truth relating to modern high-speed diesels like yours. Your max RPM is 3600 as I recall. That is a one hour rating. You should run her at wide open throttle for five minutes a month after a full warm up to keep it from coking up just like Honeyman says. Don't let it idle for long periods or motor sail when you can make almost the same time sailing. Let it cool off by a fast idle for about five minutes before you shut her down after a fast run. These diesels DO NOT LIKE running without load or low RPM. This is all per a seminar with the distributor. Best cruising RPM is 80-90% of max rpm. Check your manual and trust it. Rick D.
I had a Vision 32 for nine years. At 3200 RPM, it would do between 5.9 and 6.5 depending on the wind, etc. Beware the knot meter, tho. They are all over the ball park and rarely calibrated. Calculate it from known diatance and time, and factor current. Having said all that, DON'T run it too slow. What you have heard from others about running a diesel at low RPM is 180 degrees from the truth relating to modern high-speed diesels like yours. Your max RPM is 3600 as I recall. That is a one hour rating. You should run her at wide open throttle for five minutes a month after a full warm up to keep it from coking up just like Honeyman says. Don't let it idle for long periods or motor sail when you can make almost the same time sailing. Let it cool off by a fast idle for about five minutes before you shut her down after a fast run. These diesels DO NOT LIKE running without load or low RPM. This is all per a seminar with the distributor. Best cruising RPM is 80-90% of max rpm. Check your manual and trust it. Rick D.
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