Running engine without RW input

[Mike Banks]

OF COURSE you do not run an engine out of the water if using a heat exchanger. Otherwise your water pump">raw water pump will be cactus--and your engine exhaust system will be melted (if it uses a plastic silencer)

Why not run your engine BEFORE going to the slip?

The only people who can get away with running an engine out of the water are those using closed-circuit keel-cooling--and only then for a few seconds. The problem is the plastic trap and muffler.

If you have closed circuit freshwater keel-cooling and a dry exhaust system, as do most small commercial vessels, do not star an engine when vessel is out of the water unless you can affix a hose to the raw water inlet and turn it on--and it must be fixed securely so it does not fall out when turned on.

[Wulf]

I wouldn’t do it. Worst way to warm up an engine is at idle under no load conditions. It is far better (healthier) to warm up any engine under light load. It will warm up faster and result in less contaminates bypassing rings (blowby is greatest when cold) than at idle. Your engine will thank you for this over time.

[lateral]

I run mine up on the hard with RW belt off until mixing elbow is warm to touch.
Thinking that this will do damage is bollocks. 2-4mins.

[Stu Jackson]

Originally Posted by lateral

I run mine up on the hard with RW belt off until mixing elbow is warm to touch.
Thinking that this will do damage is bollocks. 2-4mins.

Ah, but my question is why? What does doing that do "for" the engine?

[lateral]

Originally Posted by Stu Jackson

Ah, but my question is why? What does doing that do "for" the engine?

Guarantees the motor starts instantly on relaunch and I do not hold up the travel lift. Mine is a 3gm30f and doesnt start instantly in the middle of winter.
This winter "feature" has been noted by other 3GM owners.
The coolant pump is still circulating, so no hotspots develop over the short period
I'm talking.
FHS, the thermostat would be barely open.
Talk about fear overcoming rationality.

[Dymaxion]

I've run my 1GM10 (raw water cooled) for a couple of minutes while pouring antifreeze into the RW strainer while winterizing. A 5gal water jug in the cockpit with some hose off the spigot to your RW strainer would let you run a few minutes if desperate.

[flyingfin]

You mean like this

https://www.youtube.com/watch?v=TfAELGmn3mU