1st gear CLACK

[JustPassinThru_imp]

You're fron Chicago? I never lived there. Is traffic in my lil' ol' burg in the mountains - admittedly, growing like a weed, and full of college kids...but is it worse here than in the Second City?

How did that knot of twelve get behind me? We were moving in a clot to the light. The knot formed, on Reserve Street, at the freeway cloverleaf and the first signal; and we move as if in a parade all the way to our destinations...which are mostly one of two busy intersections.

So they stopped when I stopped, since the traffic lights somehow manage mostly to drop in my face. So, three minutes at Expressway Blvd, another three minutes at Union Pacific; and then SIX at Moran. And, on a summer afternoon, the mercury in the high nineties.

There is really nothing to do for that engine to prevent catastrophic overheating, other than shut it down at those lights. I love this machine; but one thing the modern water-cooled rides have over it, is their radiators, mostly with fans.

As for the escape route...nice theory they teach. I've never needed it; and to be able to avail, you'd have to be looking in your mirror AT THE EXACT SECOND OF INCIDENT. Which means staring in the mirror. Not watching the traffic or the light.

Now, if I was naked at that stop...the first and only one out...that's another matter. Of course I'd be watching. But the only time that happens out here is between 3am and six.

[veech_imp]

My Harleys ran MUCH hotter when sitting at stoplights than my CB does, both brands air cooled, and I never had a heat related issue with any Harley motor in the last 25 years while living in Chicago. Honestly, I would have to be sitting in Nevada desert like heat at a stoplight for a really extended time before I would start getting concerned about overheating on the CB. I think this issue is more of a theoretical arguement than a practical concern-I would say to worry less and ride more. The air fins on the CB motor are very well designed and were one of the biggest manufacturing challenges for Honda when deciding to produce our bikes. I think they did a great job.

[kmoney_imp]

Yeah. I've never shut off for traffic lights, but temporary construction delays on highways or clearing accidents on bridges etc... anything over 4 or 5 mins and looking to be longer sure.

My fear wouldn't be so much about getting in rear ended, as traffic has long backed up by this point, but losing all my oil flown as soon as I kill the engine. I get that you are also killing the biggest heat generator (combustion itself) but you are also effectively losing all your oil related cooling to the engine's hotspots.

[veech_imp]

Good point about the oil cooling kmoney. The only time I really ever shut off is when sitting waiting for a freight train to pass. Those can take a while.

[JustPassinThru_imp]

Yeah. I've never shut off for traffic lights, but temporary construction delays on highways or clearing accidents on bridges etc... anything over 4 or 5 mins and looking to be longer sure.

My fear wouldn't be so much about getting in rear ended, as traffic has long backed up by this point, but losing all my oil flown as soon as I kill the engine. I get that you are also killing the biggest heat generator (combustion itself) but you are also effectively losing all your oil related cooling to the engine's hotspots.

Idling versus sitting dead, hot.

The oil contributes to cooling...WHILE MOVING. Stationary and idling, it just gets hotter.

Shutting down, the engine generates no heat. The inner hotter areas radiate to the external surfaces...but that's more an equalization of temperatures than it is, it getting hotter. It's a valid concern but it doesn't seem to me as if the momentarily higher temperatures inside the valve train, are going to be worse than the ever-rising temperatures of a long idle standing still.

[ClassicVW_imp]

Yeah. I've never shut off for traffic lights, but temporary construction delays on highways or clearing accidents on bridges etc... anything over 4 or 5 mins and looking to be longer sure.

My fear wouldn't be so much about getting in rear ended, as traffic has long backed up by this point, but losing all my oil flown as soon as I kill the engine. I get that you are also killing the biggest heat generator (combustion itself) but you are also effectively losing all your oil related cooling to the engine's hotspots.

Idling versus sitting dead, hot.

The oil contributes to cooling...WHILE MOVING. Stationary and idling, it just gets hotter.

Shutting down, the engine generates no heat. The inner hotter areas radiate to the external surfaces...but that's more an equalization of temperatures than it is, it getting hotter. It's a valid concern but it doesn't seem to me as if the momentarily higher temperatures inside the valve train, are going to be worse than the ever-rising temperatures of a long idle standing still.

Idling versus sitting dead, hot.

The oil contributes to cooling...WHILE MOVING. Stationary and idling, it just gets hotter.

Shutting down, the engine generates no heat. The inner hotter areas radiate to the external surfaces...but that's more an equalization of temperatures than it is, it getting hotter. It's a valid concern but it doesn't seem to me as if the momentarily higher temperatures inside the valve train, are going to be worse than the ever-rising temperatures of a long idle standing still.
If that helps you sleep at night, fine. When shutting down, your oil drains back to the sump. Every engine, at each startup there is a momentary oil starvation and it's an undisputed fact that that is when most engine wear occurs. You may think you're doing right by your engine, but you're not.

BTW- you're only guessing that your engine is entering dangerous temperature territory. Without exact readings in degrees, it's all guessing. Isn't there a warning light on our bikes for entering dangerous temp zone?

EDIT: I've seen in another post that our oil warning light comes ion at 342 F. That does seem high, but the API tests oil at 350deg for 100 solid hours, so, if you are using API approved oil... IOW- I don't know of a traffic signal that stays red for over 100 hours....

[JustPassinThru_imp]

Yeah. I've never shut off for traffic lights, but temporary construction delays on highways or clearing accidents on bridges etc... anything over 4 or 5 mins and looking to be longer sure.

My fear wouldn't be so much about getting in rear ended, as traffic has long backed up by this point, but losing all my oil flown as soon as I kill the engine. I get that you are also killing the biggest heat generator (combustion itself) but you are also effectively losing all your oil related cooling to the engine's hotspots.

Idling versus sitting dead, hot.

The oil contributes to cooling...WHILE MOVING. Stationary and idling, it just gets hotter.

Shutting down, the engine generates no heat. The inner hotter areas radiate to the external surfaces...but that's more an equalization of temperatures than it is, it getting hotter. It's a valid concern but it doesn't seem to me as if the momentarily higher temperatures inside the valve train, are going to be worse than the ever-rising temperatures of a long idle standing still.

Idling versus sitting dead, hot.

The oil contributes to cooling...WHILE MOVING. Stationary and idling, it just gets hotter.

Shutting down, the engine generates no heat. The inner hotter areas radiate to the external surfaces...but that's more an equalization of temperatures than it is, it getting hotter. It's a valid concern but it doesn't seem to me as if the momentarily higher temperatures inside the valve train, are going to be worse than the ever-rising temperatures of a long idle standing still.
If that helps you sleep at night, fine. When shutting down, your oil drains back to the sump. Every engine, at each startup there is a momentary oil starvation and it's an undisputed fact that that is when most engine wear occurs. You may think you're doing right by your engine, but you're not.

BTW- you're only guessing that your engine is entering dangerous temperature territory. Without exact readings in degrees, it's all guessing. Isn't there a warning light on our bikes for entering dangerous temp zone?

EDIT: I've seen in another post that our oil warning light comes ion at 342 F. That does seem high, but the API tests oil at 350deg for 100 solid hours, so, if you are using API approved oil... IOW- I don't know of a traffic signal that stays red for over 100 hours....

The oil drains back to the sump, true.

But on a hot engine, just shut down, the lubricated surfaces have a sheen of oil on them. And they are at operating temperatures. And starting up brings oil pressure right back up.

Compare your car, with its oil pressure gauge or light. Starting cold, it takes a moment to build pressure. Restarting after a quick stop, the light goes out almost immediately.

Likewise...you are correct that most engine wear is on starting. COLD starting. Warm starting has virtually no additional wear except to the starter system.

It's not a scientific test, but I have seen this. When I was in my twenties, I drove a cab for a suburban cab company. We used Ford Granadas, with 250 c.i.d. sixes in them.

The company bought them from Hertz, used. They'd have about 50,000 miles on them. We'd run them to about 500,000 miles. And RARELY would the engine let go. The Ford-O-Matic transmissions, yes - but not the engines.

Why not? Because they seldom were left to cool off.

They'd of course get shut down all the time. Stopped on stands. Meal breaks; waiting on fares. But never to cool down...the cabs were run, two 12-hour shifts every day except holidays. Even maintenance was done with them hot...in for an oil change and out 15 minutes later. Guy whose shift it was on would get a break on his lease rate.

All those miles. Even Toyota engines today don't typically go 500,000 miles. Not in typical private-owner use.

Because of the cold shutdowns. Not just any shutdown; but a shutdown to allow complete cooling and draining down of the oil.

[ClassicVW_imp]

Are you 100% certain there's a "sheen"?
What is it's thickness?
And how much of a "sheen" is good enough?

Just like guessing that the engine is getting too hot, you're still guessing.

That's a nice story about the Ford Granadas, but has no bearing on our Honda engines or their expected longevity.
I can tell you an anecdote about Russian tank engines needing replacement after 100 hours, should I expect that from my CB?

You can certainly do as you wish, but I'm making a mental note to not buy any bike you're selling.
(I'm also done beating this dead horse). Going to the garage now.

[immgunn_imp]

Frictional losses when cold aren't solely due to poor oil circulation, but are related to thermal characteristics. Most pistons are "cam ground" meaning the piston isn't perfectly round (like the cylinder) when cold, but is as close to being perfectly round when the engine has reached it's designed operating temperature. This is why cold engines are designed to idle at a higher rpm when cold, to overcome frictional losses. Cold start-ups are the worse. I believe engines actually get hotter for a short period after shut-down. When stopping after riding for a period of time, I let the engine idle to allow for temperatures to equalize to the greatest extent possible, then if it looks like it's gonna' be awhile (train, construction, accident), I'll shut it off.

[JustPassinThru_imp]

Are you 100% certain there's a "sheen"?
What is it's thickness?
And how much of a "sheen" is good enough?

Just like guessing that the engine is getting too hot, you're still guessing.

That's a nice story about the Ford Granadas, but has no bearing on our Honda engines or their expected longevity.
I can tell you an anecdote about Russian tank engines needing replacement after 100 hours, should I expect that from my CB?

You can certainly do as you wish, but I'm making a mental note to not buy any bike you're selling.
(I'm also done beating this dead horse). Going to the garage now.

Sure.

Because I don't let it overheat.

An air-cooled engine without an integral fan...WILL overheat when stationary. Not "might." WILL. It's why the manual tells you not to start it up and leave it idle when cold. It needs air flowing over the cooling fins and through the oil cooler.

A film of oil is all that's on lubricated parts at any given time. They are lubricated where there is metal-to-metal contact. And of course the contact presses off all but a film of oil.

I have explained how I know that repeated hot starts are not, in general, going to damage an engine. I have not seen or heard any contrary evidence. We KNOW what overheating does, even when not severe enough to seize the engine up. Warped heads, misshaped cylinders resulting in piston slap.

Nowhere, in any manual, warning, shop manual or text, does it advise leaving an engine, any engine, idling as opposed to turning it off. Many makers advise the opposite. Toyota, in some European models, has an engine that shuts of at stoplights and restarts upon releasing the brake pedal.

I grant, should someone buy a bike I've owned for a time, they might want to expect they'll be buying a starter and/or battery. But that's it.