Cooling question

[mt.stalker]

When you know your saw is hot from extended use , do you let it cool by sitting/idleing , or by shutting it off immediately ?
What are the pros and cons vs each ?

I would think an engine would cool faster by shutting it off , as internal combustion and friction would still be present while idleing .

 

[w8ye]

I let it idle for about 10 sec before shutting it down

 

[Johny Utah]

shut it down, it isn't liquid cooled so it has no way to dissipate heat at idle.

 

[Aussie Dave]

shut it down, it isn't liquid cooled so it has no way to dissipate heat at idle.

yep i agree

 

[bob15]

shut it down, it isn't liquid cooled so it has no way to dissipate heat at idle.

There is a reason why they have a fins on the flywheel. No different than any other small engine (Briggs, Tecumseh, Kohler), they also have cooling fins on the flywheels. Without them, the engine would heat seize.

bob

 

[albert]

shut it down, it isn't liquid cooled so it has no way to dissipate heat at idle.

Liquid or air cooled engines should be idled for a minute or two before shut down if worked hard. Both have cooling systems that only function while engine is turning. Temps will actually rise if engine is shut off right away. Idling the engine will rid the engine and components near it of excess heat.

 

[Stumpys Customs]

Let it idle for a little while before shutting it down.

 

[splitpost]

:taped:

 

[Aussie Dave]

There is a reason why they have a fins on the flywheel. No different than any other small engine (Briggs, Tecumseh, Kohler), they also have cooling fins on the flywheels. Without them, the engine would heat seize.

bob

Yeah thats correct,but i have often wondered how effective that cooling system is at idle?

 

[lentil]

They still rotate around 3K a minute, surely that would move quite a bit of air through the spaces between engine and any covers on it?

 

[Aussie Dave]

They still rotate around 3K a minute, surely that would move quite a bit of air through the spaces between engine and any covers on it?

Yeah youve got a good point there :msp_smile:

 

[Stumpys Customs]

They still rotate around 3K a minute, surely that would move quite a bit of air through the spaces between engine and any covers on it?

It will move more air than if you shut it off.:msp_wink: Just sayin.:msp_biggrin:

 

[o8f150]

i always let mine idle for a bit before i shut it off

 

[stihlrookie]

I always let mine idle for a minute or two after running hard for a bit. As was said already, the flywheel has fins to move air. Don't think it does anything? Try this, toss a handful of sawchips at the side cover and see what happens. Turning a saw, or any small engine for that matter, off immediately after operating hard could actually raise the temperature of the engine and components briefly since you just eliminated the only way it can cool itself.

 

[CentaurG2]

It’s a chainsaw not a turbo diesel. Just shut it off.

 

[carym2a]

I always let it set for a minute or so, it needs to cool down, just like, let it warm up a little before putting a big load on it.

Cary

 

[Johny Utah]

Liquid or air cooled engines should be idled for a minute or two before shut down if worked hard. Both have cooling systems that only function while engine is turning. Temps will actually rise if engine is shut off right away. Idling the engine will rid the engine and components near it of excess heat.

I disagree. The most amount of cooling you are gonna get is at full throttle because the air the fan is moving is at maximum velocity.

Shut it down, don't worry engine components that aren't moving will cool faster when not producing more heat and friction by letting it run even at idle. I've never heard of engine damage occuring while engine isn't running.:bang:

 

[carym2a]

An aircooled just like oil or water cooled 2 or 4 stroke will cool down at an idle after being worked.

 

[McCulloch1-52]

letting it idling for a long is bad too because I had a weed trimmer that I let run for a long time I shut it down hour later I pulled on the recoil and it was locked up I took a ratchet to the flywheel nut to broke it lose I think the piston rings was hot enough to weld itself to the piston wall, so I always pull on the recoil when I am done using it. For a Chainsaw I would let it idle for 10 seconds then I would shut it down, Remember In a 4 stroke engine is different from 2 stoke because, There more oil in a 4 stroke that helps cool the engine.

 

[CTYank]

letting it idling for a long is bad too because I had a weed trimmer that I let run for a long time I shut it down hour later I pulled on the recoil and it was locked up I took a ratchet to the flywheel nut to broke it lose I think the piston rings was hot enough to weld itself to the piston wall, so I always pull on the recoil when I am done using it. For a Chainsaw I would let it idle for 10 seconds then I would shut it down, Remember In a 4 stroke engine is different from 2 stoke because, There more oil in a 4 stroke that helps cool the engine.

That 4-stroke oil isn't going to cool much of anything, sitting down there in the sump. A water-jacket would benefit cooling after shut-down.

Hot areas are cylinder/head in 2 & 4 stroke, where the COOLING fins are also. Dull (as-cast) fins are good at radiating heat (outside any shrouding). Moving air past fins, with engine running near idle will conduct heat away under anything like normal ambient. (Was oxy-acetylene involved, maybe?)

IMHO, this anecdote about welding rings to cylinder wall is bs. Not likely even if straight-gassed. Piston would melt onto ring(s) waaaaaay before fusing onto cylinder, and sealing would go bye-bye. Myth BUSTED. Nice try.