Proper temps for best performance : Yamaha R1 Forum

ERnurse · 11-01-2012, 06:32 PM

I was just reading an interesting thread on coolants on another forum. Someone there was saying that if engine temps fall below 180F for prolonged periods your cylinder walls wear faster, oil sludges, and increase fuel consumption. I hope thats BS because my 2010 routinely runs around 160-170 in the spring/fall. I thought the whole idea was to stay as cool as possible.

Meister37 · 11-01-2012, 06:35 PM

It's bs, You can change oil to suit the temp, fuel consumption should be better due to the air being more dense and the cylinder walls? I have no idea WTH the guy is thinking.

tnole23 · 11-02-2012, 05:29 AM

i'd say it's bs. cooler air is better, not necessarily a cooler engine. he may be thinking that cooler metal contracts and will contract on the rings and thus wear faster. not sure about that. i'd be more concerned with integrity of cylinders when cold more so than wearing on walls. colder metal is more brittle, which is def bad. being warm at operating temp, whatever that is, is fine. can't imagine it getting too cold unless u running co2 as the coolant or something. i wouldn't worry about it. it's the air intake temp, not coolant temp, that gives u the power.

greenc51 · 11-02-2012, 05:43 AM

he may be thinking in terms of cars. car engines increase fuel consumption in order to reach operating temperature. so if the engine temp is lower, it will constantly try to inject more fuel in order to help heat up the engine to a more nominal operating temp

TwistedSprocket · 11-02-2012, 09:20 AM

I'm calling BS. Just because your coolant is a little cooler because of the cold air docent mean that the temp of your pistons and cylinder walls Is much lower if any. Just running a little cool is no big deal. If your cars thermostat is stuck open during winter that's another issue.

greenc51 · 11-02-2012, 09:49 AM

well we get the engine temp from the coolant dont we?

TwistedSprocket · 11-02-2012, 09:54 AM

Yup

Gdiddy88 · 11-02-2012, 10:17 AM

Quote:

Originally Posted by greenc51

he may be thinking in terms of cars. car engines increase fuel consumption in order to reach operating temperature. so if the engine temp is lower, it will constantly try to inject more fuel in order to help heat up the engine to a more nominal operating temp

Fuel injected engines do not add more or reduce the fuel injected to regulate temperatures. The amount if fuel injected is calculated by the amount of air going into the engine. If the air is cold it is more dense and there will be more fuel injected to make the most efficient combustion. If the air/fuel ratio is rich, that will cool the operating temp of the engine.

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Rex1585 · 11-13-2012, 07:39 AM

Quote:

Originally Posted by Gdiddy88

Fuel injected engines do not add more or reduce the fuel injected to regulate temperatures. The amount if fuel injected is calculated by the amount of air going into the engine. If the air is cold it is more dense and there will be more fuel injected to make the most efficient combustion. If the air/fuel ratio is rich, that will cool the operating temp of the engine.

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While this is partly correct, if an engine never gets out of its ASE (after start enrichment) cycle, it WILL consume more fuel, which increases hydrocarbons, increased exhaust gas emissions, increased wear on the cylinder walls and the piston rings/pistons. As when engines are cold the require more fuel to get up to temperature as the metal surrounding the fuel/air mixture isn't able to help with the atomization of the fuel (cold causes condensation), which directly affects how efficient the catalization of the fuel/air mixture. More dense air will require more fuel yes. The incomplete burning of the mixture will create an increase in emissions.

Poor cold starting issues are usually r/t to lean a/f ratios. Supporting evidence is the Megasquirt Manual.

If the engine is not at temperature, then the clearances that the engine has been designed to run at may or may not be reached. If the clearances in the Piston rings aren't met, they may or may not create a floating and bending effect which will increase wear on the edges of the piston rings and cylinder walls. If the piston rings cannot seal, unburned air/fuel mixture as well exhaust gases will be allowed to sneak past the piston rings into the crankcase and mix with oil more easily.

TLDR;

Cold temps cause wear and tear that an engine at temp would not.