Campbell Sailor Prop

[Brian]

Installed a Campbell Sailor Prop on my H380 over the weekend. Overall, the performance was much better than the original prop. I was able to get over 6 kts at a little over 2000 rpm's and 7kts at about 2800 rpm's. The boat also seems to do better under sail as well, but it is much harder to make an accurate comparison due to wind variables etc ...I have the Yanmar 3JH3E 40hp on the boat. The new prop is a three blade, Right Hand rotation, 16" diameter, 10.5" pitch. My max rpm now is about 3200 rpm underway. My old 3 blade prop (standerd Hunter prop, a Michigan I think) would allow the engine to achieve 3800 rpm underway. I assume that the engine is now loaded up at 3200 rpm, but pushing the throttle wide open doesn't produce black smoke that would indicate a loaded engine...Should I be getting more rpm's?Does it matter if I don't?If 3200 rpm's is ok, what should be my normal cruising rpm now?If I should be getting more than 3200 rpm's, what might be the cause? ( All the fuel filters have been changed, throttle linkage checked etc) Anybody had a similiar experience or thoughts?ThanksBrian C.s/v CREW REST

 

[Don Alexander]

Overheating

Brian,The pitch you state as 10.5" looks a little fine as I would have expected to see about 15". Are you sure it is only 10.5 because at 16" diameter the engine RPM should get up to the limiter.My 376 (same engine) was supplied with a 2 blade 17" x 15" pitch.There is a new fashion these days in the specification of props. In order to limit emissions, props are specified at much finer pitches. This means the engine runs faster for a given boat speed and this - they say - reduces emissions. I think it is a 'European Recreational Craft Directive' thing.Owners this side of the long pond often fit coarser props to get back to sensible engine RPMs.If your engine really cannot reach 3600 with the boat moving in calm water then it would appear that the pitch is too coarse. Maybe you were tied to the dock?Also the end result will be overheating after a long(ish) run. I set my feathering prop too coarse and the engine over temp alarm would sound after about an hours' running. We just used to turn on the hot faucets and the alarm would stop after a few seconds.Then we proceeded at a more moderate speed.

 

[Brian]

Specs

Those were the specs Campbell gave me. Motored 4 hours straight without any overheating problem..Brians/v CREW REST

 

[Robert Pugh]

I installed a campbell sailor three blade prop last April and have had the same results. First, the prop is designed to be smaller so that you do not have the drag of a normal 3 balde prop. Call Norm Ross at NorthByWest (Campbell Sailor folks) to get all the info on this. I noticed a reduction in my max rpm also. Although it could be the blade, it is probably due to the control cable from the cockpit to the engine needing adjustment. It really doesn't matter anyway since the Yanmar web site shows that you will get 90% of your power at 2800 rpm. There is an article in the current month Cruising World about engine performance. I tested it over the weekend and got 6.5 knots from my 380 with a slight ebb tide at 2800 rpm. You waste fuel (unless you are in a big hurry and then why do you have a sailboat)running at higher rpms and may overheat your engine and have to find the reset button on your water heater. Unfortunately, I know from experience and it is not fun to take cold showers. Hope this helps.