I had a sea trial on a new 36 today (trading in a 33 with 3ym30 engine which has had overheating problems now yanmar is cleaning the heat exchanger) Speed at 3400 rpms (3ym30 engine with 2 blade)was only 6.5 knots (gps)on the 36. Wide open was 3800 rpms and about 7 knots. I had expected and hoped for hull speed to be 7+knots at around 3200 rpms which appears to be a better cruising speed. Am I being unrealistic? Would a 3 blade help??? Help!!!!
Poor sea trial results????????
- Thread starter Jack19643
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Check GPS or buy power boat
YOu may want to check your speed via GPS if the boat is used. Speedo may not be accurately reporting speed. If you want to really go full hull speed maybe you should buy a power boat. Remember sailing is about enjoying the trip-I have to remind myself of that all the time-esp. when the wind dies
YOu may want to check your speed via GPS if the boat is used. Speedo may not be accurately reporting speed. If you want to really go full hull speed maybe you should buy a power boat. Remember sailing is about enjoying the trip-I have to remind myself of that all the time-esp. when the wind dies
Reply to Bob
At age 66 I'm hardly a rev head. In Puget Sound we don't have much wind in the summer and therefore we motor about 200 hours a year to the many beautiful sights here and in Canada. I was checking the speed by GPS. My question really is to 36 owners. What speeds do you find at various rpms? What speed seems to be the "sweetest" for your boat?
At age 66 I'm hardly a rev head. In Puget Sound we don't have much wind in the summer and therefore we motor about 200 hours a year to the many beautiful sights here and in Canada. I was checking the speed by GPS. My question really is to 36 owners. What speeds do you find at various rpms? What speed seems to be the "sweetest" for your boat?
Jack
you are probably(or should be) aware that GPS speed factors in such things as current, wind, tide. Also the condition of the bottom and the amount of gear onboard will affect boat speed, especially fuel and water tankage. A 3 blade prop will give better motoring performance BUT the cost comes at sailing performance. A far better alternative would be a feathering prop.
you are probably(or should be) aware that GPS speed factors in such things as current, wind, tide. Also the condition of the bottom and the amount of gear onboard will affect boat speed, especially fuel and water tankage. A 3 blade prop will give better motoring performance BUT the cost comes at sailing performance. A far better alternative would be a feathering prop.
Are we talking a new 36
Some times I would love to have more power and speed so I can go out east of shelter island which is a far trip for a day trip and not have much wind to help make the trip. I have a 290 and with the right conditionss it will do 6.5 no problem so 7. for a 36 should be no problem. nick
Some times I would love to have more power and speed so I can go out east of shelter island which is a far trip for a day trip and not have much wind to help make the trip. I have a 290 and with the right conditionss it will do 6.5 no problem so 7. for a 36 should be no problem. nick
Max Prop - 3 blade
If correctly set up, a 3 blade Max Prop like I have will give near hull speed in the conditions you encountered. I get 6.2 knots at 2800 and 7.4 at 3400. I don't run much over 2800 when motoring, as that is about 80% of max rpm and is the desired cruising rpm. I sail much better with the max prop. I changed the prop at commissioning and never did use the standard 2 blade from Hunter. I have developed a spreadsheet for RPM/Speed if you would like, e-mail me at jclark@caarchitects.com. It will vary some year to year with a clean bottom.
If correctly set up, a 3 blade Max Prop like I have will give near hull speed in the conditions you encountered. I get 6.2 knots at 2800 and 7.4 at 3400. I don't run much over 2800 when motoring, as that is about 80% of max rpm and is the desired cruising rpm. I sail much better with the max prop. I changed the prop at commissioning and never did use the standard 2 blade from Hunter. I have developed a spreadsheet for RPM/Speed if you would like, e-mail me at jclark@caarchitects.com. It will vary some year to year with a clean bottom.
H356 speeds/rpm
The H356 and H36 share the same hull only the deck is different. Have a 3GM30 with 3 blade fixed prop. At 2200rpm we get about 5.3kts at 2800 (sweet spot) we wil do 6.5/6.8 kts maybe 7 with clean hull. Jim S/V Java
The H356 and H36 share the same hull only the deck is different. Have a 3GM30 with 3 blade fixed prop. At 2200rpm we get about 5.3kts at 2800 (sweet spot) we wil do 6.5/6.8 kts maybe 7 with clean hull. Jim S/V Java
What About the Bottom????
Jack - there are two VERY important items missing out of your post: 1) Bottom condition: This is EVERYTHING. Unless the bottom is really, really clean you won't get near the top end you're looking for. How old is the bottom paint? If the bottom isn't REALLY clean it can cost you an easy knot or more. Naturally the drag will vary with the amount of slime but it doesn't take very much. That's why racers give their boat bottom a once-over before every race! Even a week after a new botom paint job the boat is measurably slower and it's only downhill from there. 2) GPS speed - unless you're on a lake (Lake Union???) - and you probably aren't because the police would come after you - this is next to meaningless! There is nowhere around or in Puget Sound, and especially Gig Harbor, that I know of where there is NO current so GPS speed is basically doesn't mean anything if done in one direction. If done in two directions then you MIGHT have something if you do an average but the currents would have to be EXACTLY, or VERY NEARLY the same. The currents and eddys change so they are unpredictable. Even in front of Brownsville Marina where it floods and ebbs from each direction there are currents. Racers know these and that knowledge will help win or, lack of, loose a race. And of course I suppose this was done on a windless day with very small waves so as not to affect the results. My opinion is you're probably close enough. If you factor in all the things that can slow the boat down then I think you're in the ballpark speed-wise. Besides, by the time you load a couple pickup truck loads of "stuff" on board and fill all the tanks it'll slow down even more! What is the red line on that engine? The 3GM30 is 3600 RPM so apparently that one has a higher red line? By the way, it's a new boat so is the bottom barrier coated?
Jack - there are two VERY important items missing out of your post: 1) Bottom condition: This is EVERYTHING. Unless the bottom is really, really clean you won't get near the top end you're looking for. How old is the bottom paint? If the bottom isn't REALLY clean it can cost you an easy knot or more. Naturally the drag will vary with the amount of slime but it doesn't take very much. That's why racers give their boat bottom a once-over before every race! Even a week after a new botom paint job the boat is measurably slower and it's only downhill from there. 2) GPS speed - unless you're on a lake (Lake Union???) - and you probably aren't because the police would come after you - this is next to meaningless! There is nowhere around or in Puget Sound, and especially Gig Harbor, that I know of where there is NO current so GPS speed is basically doesn't mean anything if done in one direction. If done in two directions then you MIGHT have something if you do an average but the currents would have to be EXACTLY, or VERY NEARLY the same. The currents and eddys change so they are unpredictable. Even in front of Brownsville Marina where it floods and ebbs from each direction there are currents. Racers know these and that knowledge will help win or, lack of, loose a race. And of course I suppose this was done on a windless day with very small waves so as not to affect the results. My opinion is you're probably close enough. If you factor in all the things that can slow the boat down then I think you're in the ballpark speed-wise. Besides, by the time you load a couple pickup truck loads of "stuff" on board and fill all the tanks it'll slow down even more! What is the red line on that engine? The 3GM30 is 3600 RPM so apparently that one has a higher red line? By the way, it's a new boat so is the bottom barrier coated?
I was in Lake Union
We were in Lake Union on the marked course where speed is ok with almost no sea and very little wind. Thanks for your reply.
We were in Lake Union on the marked course where speed is ok with almost no sea and very little wind. Thanks for your reply.
Thanks Jack
Lake Union? That's good because current essentially is no factor there. But.. I'm really surprised that the police allowed you guys to get away with it. Seems whenever I do something like that they're right there. Didn't they have a max speed of something like 4 or 5 knots? For comparison, with regard to speed, with a 27hp engine, the boat has a 13,900 lb displacement as compared with mine which is 24hp and 12,600 lbs. I've added several hundred more pounds with four golfcarts, heater, heaver ground tackle, storm ground tackle, etc. & etc., so the new weight is several hundred more pounds, and plus gear and *stuff*. At 2800/2850 rpm with a year+ old bottom after a diver cleaning I'm getting around 6.3 to 6.35kts on a H35. Hope this helps.
Lake Union? That's good because current essentially is no factor there. But.. I'm really surprised that the police allowed you guys to get away with it. Seems whenever I do something like that they're right there. Didn't they have a max speed of something like 4 or 5 knots? For comparison, with regard to speed, with a 27hp engine, the boat has a 13,900 lb displacement as compared with mine which is 24hp and 12,600 lbs. I've added several hundred more pounds with four golfcarts, heater, heaver ground tackle, storm ground tackle, etc. & etc., so the new weight is several hundred more pounds, and plus gear and *stuff*. At 2800/2850 rpm with a year+ old bottom after a diver cleaning I'm getting around 6.3 to 6.35kts on a H35. Hope this helps.
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