Engine damage from motorsailing?

[jdoe71]

This question came up on another board and it's something I've wondered about. One fellow stated he was told on a charter not to motorsail because he might damage the engine, the theory being oil would drain away from the pump pickup when heeled.

This sounds possible to me, but I would think the hell angle required would be pretty extreme. Can anyone shed any light on this? What's generally the maximum safe heel when motorsailing??

Thanks.

[AutumnBorne1]

The maximum heel angle is strictly dependent upon boat geometry, and engine and sump design (sump depth, oil pick-up location in the oil-sump).
Oil return from the upper end of the engine might become a factor in extreme cases.
You'd have to keep an eye on the oil pressure gauge. A really good eye... because it wouldn't take long to destroy the bearings under a zero oil pressure condition.

I think you'll find that most cruising boats will work just fine in a motor-sailing scenario.... if you're using the "iron-jenny" to make a harbor before dark, etc., under light air conditions... the heel won't be excessive (light wind).
Just keep an eye on that oil pressure.

Good luck.
AutumnBorne
Dean

[Sandero]

Guilty as charged MD17D, but it's been running for 21 years. I rarely motor sail when heeled. If there is enough wind to heel the boat the motor doesn't do much. In light air the heel is not more than 5 or 10°.

If it is blowing hard on the nose and your not going to beat then motor head to wind or close to that and you won't heel over... reef if you must.

jef
sv shiva

[hellosailor]

Sounds like the charter company wanted to keep down the number of hours on their engines. A properly set up engine will not just have an oil pressure gauge, it should also have a low-pressure alarm. (I knew one 42'er that was set up using a fire alarm bell for this, and the first step in leaving a marina between midnight and dawn was "Go muffle the alarm bell." < g > )

[TaoJones]

Originally Posted by jdope71

This sounds possible to me, but I would think the hell angle required would be pretty extreme.

I think you've inadvertently added another arrow to the multihullers' quiver with the most descriptive term hell angle, jdope71. I suppose this could be descriptive, too, of a zealous missionary's conversion strategy.

TaoJones

[slomotion]

I agree with Jef - extreme heeling with the motor on might well cause problems with oil, cooling, or fuel. But all cruisers know that the prevailing conditions are:

1. Too much wind

2. Not enough wind

3. Good wind from the wrong direction

Motor sailing is common but tends to be confined to #2 and 3 and these are unlikely to involve extreme heeling - er, hell angles.

[Ex-Calif]

Anyone remember geometry? The engine sump is aligned with the longitudinal axis of the boat. The pickup is roughly on the centerline of the engine. The pan is about 8-12 inches deep. The pickup is in the bottom third for sure.

I reckon you'd have to be 45 degrees plus before you got close to uncorking the pickup.


However I'd still be monitoring the guages ;-)

[Pblais]

I reckon you'd have to be 45 degrees plus before you got close to uncorking the pickup.

Sounds right to me. If you are motor sailing with that much heel you must be sailing. I've only heeled that much in a close haul going very fast crashing through waves with the motor off because with motor on I've never been able to go that fast. Motor sailing is best in light winds. If it get worse than that I pull in the sails.

[Tropic Cat]

Heel? What's Heeling? (sorry.... Me bad...I just couldn't help myself)

[Lynx]

Interesting, anybody read in their manual about this?

With the number of off road SUV's I would think that this has been handled by now.

[jdoe71]

My manual doesn't say anything about it. I just have to believe this is covered, even in car engines they try to stick the pump intake as deep in the sump as they can. I used to race bone stock cars in showroom stock racing and we could get them pulling over a G pretty regularly and in long corners it would give the oil plenty of time to pile up on one side, I never saw a blip once. But you just sometimes wonder, like why on a marinized engine that is going to be mounted on an angle do the put the sump drain at the front? How dumb is that?
I think hell angle is a pretty good description of it especially after a day of beating, I wish I could say I thought that up, unfortunately, it was just crappy typing!

[slomotion]

In production sports car racing (not showroom stock) we always installed a large external sump with a high pressure pump.

[roverhi]

Because of the stellar windward sailing performance in a chop of the W32, we did a bit of motorsailing. Never had a problem. We would often be at a pretty good angle of heel because we had enough wind, just too bluff a bow to point high in choppy conditions. Usually had the Volvo MD2 ticking over at about 1500rpm or less and could point easily above 45 degrees and make 5 knots

I'd say as long as the low oilpressure warning buzzer or light doesn't come on, it's no different than just motoring. As a word of caution, be sure your motor mounts are in good condition, heard of at least one boat that severely shifted it's iron ballast to leeward.

Aloha
Peter O.

[never monday]

Most of the engine builders will publish a deg of operation for a given unit. From memory, most being 20*. Not only does heel come into play but also pitching in steep seas. The generators have a larger problem with this than drive engines on sail boats.

[Alan Wheeler]

As a word of caution, be sure your motor mounts are in good condition, heard of at least one boat that severely shifted it's iron ballast to leeward.

But the engine doesn't have to be running for that to happen. It's a case of if the mounts are that far gone, then the engine is going to shift no matter what. Yikes, it brings to mind all sorts of possible calamities that could have taken place if the guy was in a rough sea state. :-(