Warm up?

[Hadabadachada]

Just curious on peoples thoughts/routines.

 

im used to starting my oilhead and riding off. Mainly because of the literature I’ve read about the airheads, and I gathered they apply that to air cooled bikes, that you don’t want to really “warm it up” just start it and go.

 

now with this camhead, I have the computer and it shows the fuel consumption.

when I start it up and just ride, while it’s still warming up, it’s realllly eating the fuel, obviously, but Like 20mpg on the dash.

 and it just doesn’t feel quite as “sharp” in that warm up stage. 
 

so I’ve started to let it warm to one bar before I ride off. 
I was curious what other folks do.

 

or maybe they advise to not, start it and ride it, on a camhead  and I just don’t know that. 
 

 

[Hosstage]

What does your owners manual say?

[9Mary7]

Start it up and ride off. How many MPGs are you getting when it is running and not moving????

[Hadabadachada]

Better mileage sitting than twisting the throttle.

When it’s warmed up I’m getting 30-40 mpg doing the same pull away. 

I guess I’m just trying to counter inflation harder than most.
 

 

[Etienne Lau]

You get 0mpg while idling to warm up the engine. I start and go with my 2010.

[Hosstage]

What does your manual say?

[szurszewski]

I start mine and go. I live (nearly) on top of a good size hill - I guess I could start it and then let it "warm up" while I coast down the hill... I suspect most of us could increase our MPG by just having less fun (which is to say, make all your starts as smooth/slow as possible, don't overtake, drop your overall speed by a few mph). 

[Hosstage]

Get even better mpg by not going on joy rides, but then, what's the point of living?

 

Do an experiment, one month of starting and riding, one months of warm up, try similar miles and number of starts, keep track of mileage and note the difference.

Also, how long does it take riding cold before it gets to 30-40 mpg, how long idling to get 30-40 mpg riding?

My guess is the difference in actual fuel used will be pretty minimal.

I'm also one to care more about engine health over mpg.

[Hadabadachada]

What causes more wear to an engine? Starting and riding cold or waiting till it warms up? Or is that probably minimal too?

[Hosstage]

Spoiler

 

Spoiler

 

Edit, no hidden contents, I just can't delete it.

 

How long are you letting it idle?

No manuals I've read say to let the motor idle excessively. Even ice cold my car and bike manuals recommend minimal idling. Once the motor sets into a smoothe idle, I'm off. Far less than a minute long.

Idling motors do not warm uniformly. Only under power and underway do they properly warm up, and warm up quicker than idling. Just don't pound on them cold, normal operation is fine.

I'm assuming you are not riding in freezing weather? I do. Even then, my air-cooled carburated bike idles for less than a minute. EFI air-cooled bike, the same.

Believe me, I see guys letting their bikes idle for 5 minutes before setting off (these guys would never ride in weather below 50°F). All I can think is that the motor is loading up and getting way too hot. Good on them.

 

What does your manual say?

 

Edit, no hidden contents, can't delete it.

Spoiler

 

[Skywagon]

Start it, ride it gently for a couple of miles until you see the first bar.  I'm sure you have noticed once these bikes are started it doesn't take long to warm them up.  I wouldn't go thrashing it on first start if it is cold as the issue is getting the oil warm enough to circulate freely (although with proper motorcycle oil ZDDP coats things pretty good).  If you let it idle very long you run the risk of melting the tupperware.  There are plenty of cases on this forum of people melting their panels from idling the bike without airflow.  For what's it worth, I get on the bike, start it, then put on my gloves. However long it takes me to put on my gloves is how long it idles. It probably idles about 30 seconds and then I ride away gently.  I've done it with every BMW I've owned.  Airhead, oilhead, wethead...never owned a cam.  Airhead burned zero oil, oilhead would go half a sight glass at 5000 miles, wethead never burns oil...not a drop.

[Hosstage]

1 hour ago, Hadabadachada said:

What causes more wear to an engine? Starting and riding cold or waiting till it warms up? Or is that probably minimal too?

Excessive idling causes more wear.

[Hadabadachada]

What is excessive?

 

I always get pissed sitting at lights idling forever in the heat. I think that’s why the paint on my cylinder covers is flaking.

 

I track my fill ups but it varies so much https://www.fuelly.com/motorcycle/bmw/r1200r/2013/nakedhider/1203599

 

Does no one have a manual? Everyone keeps asking what it says. I’ll see if I can find mine, can’t remember if it even came with the bike.

[Hosstage]

My manual says to let it warm up for 20 to 30 seconds before riding normally, no excessive acceleration until fully warm.

[Hati]

The idea behind warming the engine up is to allow the oil to flow everywhere it supposed to before the load to the motor is applied. On older bikes (pre-injection)some carburettors wouldn't stabilise until it got to temperature.

 

Now, with modern engines, engineers say that there is no need to idle, just start them and go.

 

I thought the truth is somewhere in-between, as usual, so  I fire the bike up when I only have the helmet and gloves to put on, giving me maybe 30 seconds to a minute of idling with no load. My mechanical sympathy suffers otherwise :) 

 

You should do what you think is right, it's your bike. Chances are it will be fine. I suspect even under controlled circumstances, you would struggle to find any evidence for or against this side of 200k miles on the motor.

 

I would leave fuel burn out of this, given the amount of time spent idling, the "useless" fuel usage is minimal.

[pwillikers]

 

[Rougarou]

The 2019 GSA has something like a 4k redline when cranked cold that gradually rises to its max.  It won't let you get on it and "get on it" taking off, so you are forced to do a gradual warm up ride.  The '06RT is a get on it and take off bike and the HP4 was get on and take off.

[Joe Frickin' Friday]

On 11/28/2023 at 1:27 AM, Hati said:

The idea behind warming the engine up is to allow the oil to flow everywhere it supposed to before the load to the motor is applied.

 

On every engine I've ever seen that was equipped with an oil pressure gauge, full oil pressure is achieved within a few seconds after starting.  At any time after that, pressure-fed bearings are being properly lubricated, and anything being splash-lubed (e.g. cam lobes or cylinder bores) is being properly splashed.  So lubrication isn't any sort of concern for very long at all. 

 

Cold-start enrichment does cause crummy engine efficiency.  Cold operation is also hard on the engine:

• In a hot engine, fuel vaporizes on the hot walls of the intake port and the back side of the intake valves.  In a cold engine, it doesn't vaporize much before it gets drawn into the combustion chamber (thus the need for enrichment, so that enough fuel does vaporize to create a flammable mixture).  This means you get a lot of unvaporized fuel splattering on the cylinder walls, diluting the oil film there.
• cylinder bores and rings aren't up to full temp yet and so don't seal perfectly, leading to extra combustion products (which includes water and unburned fuel) being driven past the piston rings and down into the sump, contaminating the oil and taxing the additives that are put in the oil to deal with this stuff

Running at high load and high RPM is inadvisable when cold, since parts aren't up to full operating temp and so aren't at their optimal fit.  But idling a cold engine in your driveway for several minutes is also inadvisable: the engine is making just enough power to keep itself spinning, so it's not dumping much heat at all into those engine parts.  It'll take a long time for them to come up to temp, and you'll be dumping unburned fuel and combustion products into the oil the whole time.

 

Best bet is to get rolling down the road as soon as your engine is idling in a stable manner (depending on the bike, maybe 20-30 seconds after start) and put some load on the engine.  with light-to-moderate loads and speeds, the engine will warm up faster, the cold-start enrichment will get dialed back sooner (so your fuel economy will improve), and you can start properly abusing your engine sooner.  For me, once I've puttered five minutes away from home on streets with speed limits of 30-35 MPH, the engine is warmed up enough so that I'm fine with high-load/high-power operation.

[Hosstage]

Well said, Joe.

 

I was just talking with a coworker last night, he said during sub freezing winter storage he starts his bike once a month and lets it idle for 5 to 20 minutes to warm it up. No ride. He didn't have a real reason, other than, "that's just what I do."

I told him to stop, he's doing it no favors. He was a little taken back when I told him he's just dumping condensation into the oil.

A little off topic from the original subject here, but I found it timely.

[Skywagon]

25 minutes ago, Hosstage said:

I told him he's just dumping condensation into the oil.

 

That is exactly right.  Oil needs to get to about 180F for an hour to burn off moisture....so says Continental Air Cooled Aircraft Engines.

[Joe Frickin' Friday]

23 minutes ago, Hosstage said:

He was a little taken back when I told him he's just dumping condensation into the oil.

 

This is why car owner manuals tell you to shorten the oil change interval if you do a lot of winter driving or short-trip driving.  Every cold-start dumps water into the crankcase oil, and the engine needs to get good and hot, and stay hot for a good long while, to drive the water out of it.  

 

Many years ago I saw a video in which a researcher at GM fitted a transparent plastic oil pan to an engine, then put a video camera on it.  They ran it through a bunch of cold-starts, and you could see the crankcase oil gradually become a milkshake as more and more water got into it.  The oil has emulsifiers in it that prevent the water from accumulating and getting sent into the oil pump as one big blob, but it can only take so much water.  

 

...and of course, someone else has done the same thing much more recently, and you can see the milk-shake action immediately.  These are shadetree mechanics, so they don't realize at first  that it's condensate in the oil:

 

 

 

[Rougarou]

How's that handling going with re-bar

 

 

 

 

 

I think years ago, with carbureted engines, it was advisable to warm up, not too sure.  I've not been warming up any vehicle in quite some time,....for winter cages, they warm up the heater quicker than just idling if you get in and go.  The bikes, once cranked are an almost immediate departure.

 

But, the myth of warming up modern engines persists as I've got a co-worker and my oldest daughter still believe, 'cause someone told them, that they need to warm the vehicle up before taking off