Engine overheating when motorsailing upwind

[wingssail]

Originally Posted by theglo

Thanks. I know I am not a particularly good sailor... but, am learning. We swapped out the 125 Genoa in the DR and replaced it with a 100 JIB. Running that with a reefed main worked fantastic for the first 100 miles out of Puerto Plata on our most recent run towards Puerto Rico. My guess is it would work well as well for the sailing I was doing the other night. My only hold back was, I'm not a fantastic sailor, motorsailing was working, and we were doing all these passages in the middle of the night, with my wife and 3 kids on board. The motorsailing was working, albeit slowly, and I didn't want to mess with it as long as it was. BUT, from here on out down the Caribbean we have a bunch of short sails each day and, before I hit Grenada, I'm going to know how to sail this boat.

That's the spirit. To make things less scary, reef early and maybe put in two reefs. You'll be surprised how well that will work in 20 knots of wind.

If your boat has an adjustable backstay, in waves use it to put pressure on the mast and head stay, set the baby stay if you have one, and the windward running backstay if you have that. Then sheet the sails hard and fly. But with fore and aft lower shrouds, even without all the extra stuff I just mentioned, you will be good. But backstay pressure is helpful if you have it available.

I have to say that the sound of the engine running and the boat pounding is often very unsettling to someone below deck, while a boat just quietly sailing upwind, (occasionally slamming, sorry, but it's doing that anyhow) is very peaceful. Family resting on the leeward settees, it's makes you all into sailors.

[theglo]

Originally Posted by wingssail

That's the spirit. To make things less scary, reef early and maybe put in two reefs. You'll be surprised how well that will work in 20 knots of wind.

If your boat has an adjustable backstay, in waves use it to put pressure on the mast and head stay, set the baby stay if you have one, and the windward running backstay if you have that. Then sheet the sails hard and fly. But with fore and aft lower shrouds, even without all the extra stuff I just mentioned, you will be good. But backstay pressure is helpful if you have it available.

I have to say that the sound of the engine running and the boat pounding is often very unsettling to someone below deck, while a boat just quietly sailing upwind, (occasionally slamming, sorry, but it's doing that anyhow) is very peaceful. Family resting on the leeward settees, it's makes you all into sailors.

LOL appreciate the feedback. I actually do have all those things on this boat and not the slightest idea on how to use them correctly. I say that in all honestly having just sailed this boat over 5 months from Key West to Puerto Rico. Baby steps on learning the sexy kit.

We have run with a double reefed main for most of the time since leaving Turks and Caicos. I think the double reef plus 100% is the sweet spot for us and I'm excited to prove that over the next few trips.

We had a 120GENOA with single reef for a lot of the Bahamas Out Islands and we FLEW thru them, 6-8 knots, upwind, very heeled over. My wife was not a fan of the lean and we switched to a slow motor sail for the last leg to TCI.

I haven't put it thru its paces again with a 100JIB and double reef... but, that may just be the answer.

I've noted your tips on the other items and will implement them next time we're out in a week or so. Thanks

[skipperpete]

You’re absolutely correct, all engine alignments assume that the position of the propeller shaft is central in the stern tube... this is the starting point and is not negotiable. Once this is established, the engine can then be adjusted to accurately align the gearbox output flange with the propshaft flange and pilot.
Is it possible that the temp gauge is faulty, can you check with a laser temp gun to verify that the engine is warming up?
I’m a bit curious as to why you slowed down and went astern while motor sailing.
There seems to be a bit of confusion regarding engine governor function on yachts. While it’s true that some of the engines we use are derived from industrial models... (Yanmar and Kubota are two of the most obvious) the governors that control them vary depending on whether the engine is used in a generator or some other constant speed application or as a propulsion engine.
One is a constant speed governor and will maintain a specific rpm with changes in load without using a manual control lever (tractors and bobcats etc do have a lever but it only changes the constant rpm set point) this is the governor on your generator.
The other type is variable speed where the operator responds to the change in load by re adjusting the governor ...like in your car with the accelerator pedal as you go up a slight hill in top gear. This is the governor type on the majority of small marine propulsion engines but the operation is just not obvious ( until the boat is practically stopped by head seas and more power is applied to make headway)
There is a lot more to governors than this brief outline but a slightly flawed example of the difference is the cruise control on your car, you set the road speed at 100klm/hr in top gear and it stays at that speed and rpm across varying terrain by controlling the accelerator link position effectively becoming a constant rpm governor,..... click off the cruise control and then any change in engine load must be adjusted to maintain road speed by physically pushing harder on the accelerator pedal.

[theglo]

Originally Posted by skipperpete

You’re absolutely correct, all engine alignments assume that the position of the propeller shaft is central in the stern tube... this is the starting point and is not negotiable. Once this is established, the engine can then be adjusted to accurately align the gearbox output flange with the propshaft flange and pilot.
Is it possible that the temp gauge is faulty, can you check with a laser temp gun to verify that the engine is warming up?
I’m a bit curious as to why you slowed down and went astern while motor sailing.
There seems to be a bit of confusion regarding engine governor function on yachts. While it’s true that some of the engines we use are derived from industrial models... (Yanmar and Kubota are two of the most obvious) the governors that control them vary depending on whether the engine is used in a generator or some other constant speed application or as a propulsion engine.
One is a constant speed governor and will maintain a specific rpm with changes in load without using a manual control lever (tractors and bobcats etc do have a lever but it only changes the constant rpm set point) this is the governor on your generator.
The other type is variable speed where the operator responds to the change in load by re adjusting the governor ...like in your car with the accelerator pedal as you go up a slight hill in top gear. This is the governor type on the majority of small marine propulsion engines but the operation is just not obvious ( until the boat is practically stopped by head seas and more power is applied to make headway)
There is a lot more to governors than this brief outline but a slightly flawed example of the difference is the cruise control on your car, you set the road speed at 100klm/hr in top gear and it stays at that speed and rpm across varying terrain by controlling the accelerator link position effectively becoming a constant rpm governor,..... click off the cruise control and then any change in engine load must be adjusted to maintain road speed by physically pushing harder on the accelerator pedal.

I'm quite certain the temp gauge is fine as I've seen it at all points of the rainbow and it seems to be acting appropriately. It's not that accurate. I just use it as, if its pointing to the 1/2 way point it's at operating temperature. Below that it's warming up. Above that it is overheating... above 3/4 I start to worry.

I didn't actually make the boat go in reverse. While motorsailing I just shifting into neutral, wait one, then into reverse, revved it up quickly for a second, then back to neutral, and then back into forward and to cruising RPM.

Thanks!~

[theglo]

same process I use when actually clearing Sargassum Weed off the prop

[theglo]

Originally Posted by GreenWave

on the shaft issue... if you think it gets worse (i.e. drag on shaft) depending on conditions, lean etc then you might check your motor mounts. If one or more are bad then the shaft position can change with boat lean, rpms etc. Ask me how I know.


Aside from that I would be checking coolant levels, raw water intake for debris, and make sure my prop is clean.

So, I checked my engine mounts today and the aft two have backed all the way down, where they are bottomed out. You can see the top tightening nut is sitting a 1/4" or more above the mount.

I'm hoping this is vibration caused or something (maybe I didn't crank them down enough) but am throwing it out to the internets. Any idea why just the aft 2 engine mount bolts would bottom out like this?

I haven't tried to adjust them back upwards yet.

[wingssail]

Originally Posted by theglo

So, I checked my engine mounts today and the aft two have backed all the way down, where they are bottomed out. You can see the top tightening nut is sitting a 1/4" or more above the mount.

I'm hoping this is vibration caused or something (maybe I didn't crank them down enough) but am throwing it out to the internets. Any idea why just the aft 2 engine mount bolts would bottom out like this?

I haven't tried to adjust them back upwards yet.

So if you adjusted the motor mounts to align the shaft when installing the new transmission and now the lower nuts have backed out, we have to presume that the alignment is now out of whack.

Whether it is the cause of the problem you report or not, it needs to be corrected, obviously. And if the loose motor mounts and probable lack of alignment is causing loss of RPM when heeled, then we have to presume that there is some strong friction occurring, and that may have caused some wear. You should find that and correct it also.

[theglo]

Follow up…

Today I raised the aft engine mounts back up to where they used to be (they had bottomed out). I could barely turn the prop shaft by hand in neutral with them bottomed out. Once raised I could turn it easily. I’m assuming the cutlass bearing is well worn. Hoping my shaft isn’t bent. The new transmission… got some good work I guess.

I think (hope) what happened was I neglected to tighten the engine mounts enough so they vibrated down. When heeled over motorsailing the power of the engine wasn’t enough to compensate for the out of alignment engine and it was just running crooked. My guess is when I turned was motoring flat out in calm seas, and perhaps when I threw it into reverse and then back into gear, it had enough force that the propeller actually pushed the engine back up until it hit the upper nuts on the engine mounts and “aligned” itself.

…. Boats.

[Searles]

Your engine is overloaded incomplete fuel burn creates more heat, heat exchanger maybe partley blocked,working on its limit so overheating under load,may also be over proped to add to the load .⛵️⚓️

[bil56]

what engine, what cooling system ?

[dperchlik]

Check engine spec for maximum tilt. If you are heeled over, at some point the pick up tube will not be in oil. As you tilt the engine the oil flows down one side more than the other.

[dperchlik]

Hunter 42 with Yanmar suggests less than 10deg. Perkins 4-108 manual says 25deg without loss of oil pressure.

[dperchlik]

Westerbeke 55b manual says 30deg for no more than 30minutes.

[dperchlik]

From sail magazine, “art of motor sailing” updated Aug 2017
Just like when you’re sailing, when motorsailing you should think in terms of balancing your rig, but with the engine as another factor in the mix. Indeed, running the engine complicates things a bit, because of its vulnerabilities. For example, it is harmful for many marine auxiliary engines to heel too much while running, as this prevents the lubricating oil inside from being properly distributed about the engine block. As a rule, you should not motorsail with your boat heeled past 20 degrees, unless you know for a fact your engine can tolerate it. To verify this, check your engine’s operating manual or consult the manufacturer.

[sailorladd]

I can only concur that when heeled over sailing upwind your cooling water">engine cooling water intake is exposed ... This happened to me as well, so I speak from experience.