Min engine temp before 'hit it'

[Wiltok]

On my last boat, which I owned over 20 years with no engine issues, I would warm my boat to 140 deg before my first pull. Cost a lot of fuel and engine hours not to mention time. What's the collective wisdom of this group regarding min operating temp before 'hit it'? 

[ToddA]

@Wiltok, I personally agree.  We have a 1999 SN, and I like it to be up to temperature before pushing the torque.  140* would be about where we sit.

[MDB1056]

Simply good practice to let it reach normal operating temperature. Engines and liquids (oil & trans) are all temperature sensitive so letting them all acclimate helps ensure all are set for optimal performance. Who would turn the key and floor it on any completely cold engine in any Motorsport? 

[LOTW]

Don’t forget to let it cool down before you turn it off too. 

[Mastercrafter]

I am usually on the highway in my truck in below zero temperatures before the needle moves off cold. 
 

A friend of mine does failure testing on modern engines, which boats use, and they get something like 1000’s of full- throttle starts from a chilled & frozen engine. 

We idle a couple hundred yards from dock to end or lake to start, and I’m confident that’s plenty. 

Pre-2000’s boat.. sure.. let me warm up a bit more to be safe. 

 

 

 

[MISkier]

I seem to recall, a few years ago, the boat companies were failing the AWSA acceleration tests when the catalytic converters were introduced on inboards.  Apparently, one such company figured out it was related to engine heat and heat produced by the cats.  They passed their test by starting the boat completely cold and doing the test immediately.

Heck, a semi-cold engine is nothing.  A family member was notoriously late leaving for work.  I don't even think the starter bendix retracted before the car was in reverse and gone.  At times, it seemed the garage door might not rise fast enough, either.  We're talking northern Michigan temperatures, too.  That car seemed to hold up OK, as it was sold after 15 years and 140,000 miles and still ran well.

Edited:  Full disclosure - I warm up my personal boat and the club boat before any high speed passes.  And, I tend to at least let my vehicle run a bit before backing out and driving at residential speeds.  By the time I get to a higher speed road, it's been a few minutes.

Edited April 23, 2023 by MISkier

[03RLXi]

Indmar manual states

"Once the engine is started, allow it to reach operating
temperatures of at least 120°-140° F (49˚-60˚ C)
before accelerating to speeds above 3000 RPM".

I thought the manual mentioned the ECM having a low temperature limiter that prevented >3000rpm but I can't see it when just looked. Did find mention of a tapered RPM reduction for high temperatures.   

 

[MDB1056]

11 minutes ago, 03RLXi said:

Indmar manual states

"Once the engine is started, allow it to reach operating
temperatures of at least 120°-140° F (49˚-60˚ C)
before accelerating to speeds above 3000 RPM".

 

I tend to give credibility to what the manufacturer says……

[ReallyGottaSki]

Consider how rare for  cars to hold half throttle or more continuously after startup. Regular driving takes 20-40 HP to get down the road, thats not much heat energy. car driving is basically a warmup by itself. 

Skiing   is high-load both immediately and continuously,  so ask why risk scuffing the cylinder from rapidly expanding pistons in stone-cold cylinders that are slow to both warm and expand due to all the thermal mass of the iron and water. Hot slugs in cold jugs, so to speak. 

If the engine still has ambient heat in it from the morning run before , i suspect risk is highly mitigated by the time one drops in to go. But this time of year and everything can be starting from 40-45 degrees or less if the engine was not used for a couple days. 

Edited April 24, 2023 by ReallyGottaSki

[Windsurfnut]

I prefer to wait till its up to operating temp before taking off, however once I see that temp gauge coming up I often ease it up on plane.    Note that we have a bit of a ride to get to our ski course, so either idling or easing up plane once its "warm enough" gives us time to finish our coffee's on our ride.

[Horton]

@Wiltok

unless it is COLD how much gas & time are you ready using to warm up a boat? Is a couple minutes or so at idle not enough? 

[BraceMaker]

I think if you look at it purely from an engine perspective the safest bet would be to fire it up and immediately start driving around the lake at around 1500-2000 rpm in gear until the engine reaches operating temp.  The fuel injection system is just going to dump extra fuel at a cold engine at idle and that can wash down the cylinder walls.  So atleast if you aren't going to drive it pop it in neutral and bring the RPM a tad for the first couple minutes.  Which gets the oil volume up and cuts back on the enrichment.

Unless your skier is in a vest on the dock ski on when you get there the engine should be getting pretty close by the time the skier is ready if they were helping get the boat set and not making you do all the work.

[kmenard]

Start it, get off the trailer, putt putt the course, spin around, hit it. Usually half way down the course I get a temp reading. 

Incidentally, I am a little surprised they don't put oil temps on these, that is the temp you really want moving...at least in the old days...now with zero weight synthetics it probably doesn't matter as much. 

[6balls]

Guilty never really paid attention.  More-so paid attention to overheat cuz we skied on a weed pit.  Had to clear the filter with regularity to restore flow.

[BrennanKMN]

The water and air are cold in the early and late season in MN. By the time the boat is off the trailer, idled over to the course and the skier is ready it is usually warm enough. I watch it, but not super carefully. We are slower in the cold anyway, takes me awhile to warm up at 40* too!

If it was driven like a car I wouldn't care, but I don't drive my car from 600 to 3400RPM. I have a nice 1700RPM neighborhood run to get heat into the oil and circulate things around before hitting the highway or other heavy acceleration. 

[DW]

Before a significant load is applied to the propulsion unit, a few areas that are sensitive - filling lifters & lifter bores, cylinder walls & piston skirts and bearings.  Also, cheaper oil filters are not as robust when hit by cold high pressure oil.  To the OP, I like to warm things up before the skier says hit it, my indicator is when the oil pressure starts to drop off the cold start up level, at that point I know everything has lubrication.

But - when the old one lap qualifying session was in effect in NASCAR, best power is with a cold air-fuel mixture so the teams pumped cold water through the engine just before the car went on the track and had the radiator covered so by the end of the lap it would be overheating and blowing steam out the vent.  Note:  these engines were specially built to handle it, so don't do this at home:-)  On the flip side, there was an extensive start up routine (which included heating the oil) on the road race IMSA / Indy engines.  The teams can't start the engines without a manufacturer tech monitoring the engine start up.

[MichaelWiebe]

Perhaps electric propulsion resolves this topic. But of course it brings up others. 

[Ski_Dad]

140 which is about 2 mins. 

[Taynton]

@MichaelWiebe cooking a steak in the microwave solves a lot of problems as well. Doesn't mean its a good idea.

[The_MS]

Depends on the octane of the gas being used