A mini review of a Campbell Sailor 3-blade prop - UPDATED
I had been running a Martec geared folder on our 1996 Hunter 280 since we bought the boat 4 years ago. The prop did what it was designed to do with the limitations exhibited by a folding 2-blade: poor reverse, unpleasant vibrations and excellent (low) drag characteristics. I bought a Capri TR/FK this spring to scratch my racing itch and resolved to make the power side of our Hunter more pleasant.
This morning, I pulled the Martec and installed the Campbell Sailor - 14 x 8 RH for a 1" shaft. My engine is a 2GM20F w/ a Kanzaki KM2P - 2.62 gearing. After launch, we motored out to the channel and started opening the throttle and ran it at 1000, 1500, 2000, 2500, 3000 and 3400 rpm. Ninety percent of the vibrations are gone. I forgot my GPS so I don't have speeds yet but will post those when I go back out. Unfortunately, the little Yanmar smoked quite a bit between 3100-3400 rpm (accelerating all the way) but since the proper running rpm is 2800-2900 rpm, I'll be avoiding those rpm anyway. She really does sing at 2800!
Reverse is very much improved. Prop walk in reverse is apparent but not too bad; something I intend to learn to use. Didn't notice much in forward but I'm sure it is there.
Sadly, we didn't get a chance to sail with the new prop so that'll have to wait for another post.
Fair Winds,
Clark
UPDATE: Ran the boat yesterday and got these averages (2 runs, one against and one with the wind) with a GPS - no current - clean bottom -speed in knots:
RPM -------1st Run ------2nd Run -----Avg.
2000-------- 4.1 -----------4.4 ----------4.2
2500-------- 5.0 -----------5.4 ----------5.2
3000-------- 5.8 -----------6.2 ----------6.0
3500 WOT 6.3 -----------6.7 ----------6.5
yanmarhelp.com states MAX is 3600 and cruise speed should be 2900. Based on that, I may be slightly over-propped. However, calculated hull speed for our boat is somewhere around 6.7 kt so according to that, I am not reaching hull speed even at WOT so does that imply an engine down on HP a bit?
(ugh, tables don't work too well)
I had been running a Martec geared folder on our 1996 Hunter 280 since we bought the boat 4 years ago. The prop did what it was designed to do with the limitations exhibited by a folding 2-blade: poor reverse, unpleasant vibrations and excellent (low) drag characteristics. I bought a Capri TR/FK this spring to scratch my racing itch and resolved to make the power side of our Hunter more pleasant.
This morning, I pulled the Martec and installed the Campbell Sailor - 14 x 8 RH for a 1" shaft. My engine is a 2GM20F w/ a Kanzaki KM2P - 2.62 gearing. After launch, we motored out to the channel and started opening the throttle and ran it at 1000, 1500, 2000, 2500, 3000 and 3400 rpm. Ninety percent of the vibrations are gone. I forgot my GPS so I don't have speeds yet but will post those when I go back out. Unfortunately, the little Yanmar smoked quite a bit between 3100-3400 rpm (accelerating all the way) but since the proper running rpm is 2800-2900 rpm, I'll be avoiding those rpm anyway. She really does sing at 2800!
Reverse is very much improved. Prop walk in reverse is apparent but not too bad; something I intend to learn to use. Didn't notice much in forward but I'm sure it is there.
Sadly, we didn't get a chance to sail with the new prop so that'll have to wait for another post.
Fair Winds,
Clark
UPDATE: Ran the boat yesterday and got these averages (2 runs, one against and one with the wind) with a GPS - no current - clean bottom -speed in knots:
RPM -------1st Run ------2nd Run -----Avg.
2000-------- 4.1 -----------4.4 ----------4.2
2500-------- 5.0 -----------5.4 ----------5.2
3000-------- 5.8 -----------6.2 ----------6.0
3500 WOT 6.3 -----------6.7 ----------6.5
yanmarhelp.com states MAX is 3600 and cruise speed should be 2900. Based on that, I may be slightly over-propped. However, calculated hull speed for our boat is somewhere around 6.7 kt so according to that, I am not reaching hull speed even at WOT so does that imply an engine down on HP a bit?
(ugh, tables don't work too well)
Last edited: