Topic: How about a temperature gage?

[krksquared]

Just wondering if anyone here ever successfully installed some kind of a temperature gauge on their SOHC4? Supposed to be 113 today here in Phoenix. Just wondering how an air cooled engine handles such heat. I'm want to keep my classic running a long time.

[scottly]

I used to have a VDO oil temp gauge, with the sender replacing the stock drain bolt in the sump. Just hit 99.9 F up here.

[Don R]

 Our jr dragsters had a head temp sensor that went under the spark plug. We always left the staging lanes at 140. It was very consistent. I'm trying to remember the name of them, they recorded rpm, head temp and several other things.

[krksquared]

That's an idea. Any idea what a safe upper limit should be for the oil temp? I was thinking of monitoring upper cylinder temp but I guess one could infer that from the oil temp. I remember back in 1991 or 1992 it hit 122 degrees in Phoenix! Not a good day to ride a bike.

[American Locomotive]

You can't really accurately infer cylinder head temp from oil temp. Oil isn't a particularly good heat conductor, and oil temperature variations will lag behind cylinder head temperature changes by a lot. It's also unlikely the oil will ever get as hot as the cylinder heads, either. Cylinder head temps can shoot up rapidly in stop/go traffic.

Trail Tech makes a very basic CHT temperature sensor kit. It's just a gauge, with a spark plug temperature sensor. It's basically just a little washer that goes between the plug and cylinder head: https://www.amazon.com/Trail-Tech-Surface-Universal-Temperature/dp/B071HKW8R9

[spanners]

Although oil temp and cylinder head temp might be interesting to see, (and I know it was not your question)  but if I was going to have just one extra gauge it would be oil pressure.  If oil gets too hot or too old it loses (amongst other things ) its shear strength and viscosity and system pressure drops.   First signs of lower oil pressure than you normally get when riding for whatever reason you can look into it. 

[scottly]

If the gauge reads high, what are you going to do about it? Pull over into the break-down lane on the freeway to let it cool off? Better to install an oil cooler that actually does something. Personally, there is no freaking way I would ride in temps over 100*.

[PeWe]

Good if oiltemp is over 100C so condensed water can vaporise. Water in oil no good. My temp gauge in CB750 dipstick has red area from 120C (248F)
If engine runs warm, important to NOT use cheap oil.
Change oil more often and use a better oil that withstand higher temperature. Synthetic withstand high temp better.
Porsche 911 threads have discussions about oil temp around 240F

[dave500]

these have been doing fine aswell as other aircooled makes for ever,dont sweat it,they can handle it,so whatcha gonna do?pussy out and shut it off?oil coolers do #$%* all,just ride the #$%*ing things!

[strynboen]

you can smell ,vhen it start to burn/smoke... the leaking oil from the head gasket...then it are time to cool dovn..

[PeWe]

I had plans to install a temp gauge on the handle bar to see when engine is completely warm so I could twist the throttle.

[IVPeters]

FWIW I installed an oil temp gauge, tapped the sender into the main gallery plug - there are probably better spots as it just made another potential leak spot since it's on the pressure side of the system.
It works though.

[754]

I have crossed the deserts midday a few times, no cooler.
 Came into Baker one day it was 115.
 Remember entering Vegas between noon and 4 a few times. 
 Went El Paso to San Diego one day, remember getting out of the desert around 5 pm. Its Hot real hot.
On a stocker, i would put in an extra qt of oil.. i run about 65 mph. My buddy would run 55 with a cooler, scared all the way.
 Honda tested the piss  out of the 750 in the desert, tried to break them..it was difficult..
 I have coolers now and plan to use them, they don't always makecitvon the bike by leave time.

[dave500]

as long as theres wind blowing over them they'll be fine.

[American Locomotive]

these have been doing fine aswell as other aircooled makes for ever,dont sweat it,they can handle it,so whatcha gonna do?pussy out and shut it off?oil coolers do #$%* all,just ride the #$%*ing things!

Yeah, and nearly every other older air cooled bike I've seen burns oil if the engine hasn't been rebuilt. Air cooled engines are notorious for wearing valve guides and rings out. The CB four cylinder bikes are no exception to that rule. High cylinder head temperatures will decrease valve guide and valve seal life, and cause your piston rings to wear faster.

If you see high oil temps or high cylinder head temps, you can make adjustments to what you're doing to reduce those temperatures. You could decrease your speed somewhat, shift up into a higher gear, turn your bike off at idle if you're at a stop light. As the bikes get older, and parts become harder to find, keeping the engine at a happy temperature will become more important.

[754]

 Its easy run a K model  ..F has more top end trouble, unless your name is Ofreen.

[rotortiller]

IVPeters, nice looking instrument cluster.

rt

[HondaMan]

With today's gasolines, the carb bowls will boil LONG before the engine's oil gets too hot, and that will make the bike act up (or stop, in city traffic). I had to baffle the fronts of the carbs (with a piece of cardboard I found on the road) once when it got over 102 degrees F here in the Denver area and the traffic lights all quit (typical power outage, due to too many A/C units running), making nasty traffic. The engine got so hot that the carbs were boiling and spitting gas out their overflows at the traffic lights, so I stuck a piece of old cardboard between the engine and lower float bowls for the rest of that bad day. About 1 minute after slipping in the cardboard, the overflows stopped dribbling and I could keep the bike lit while sitting still. And sitting....I found it entertaining to watch the various brands of cars losing their engines from the same issues, most which had carbs, too.

Our fuels today (beginning November of 2017) have been switched to a more natural-gas-based type, which boils at lower temps than petroleum-based types. Since there is no much natural gas around, this makes some sense, but it yields lower MPG and less power, and it boils at lower temps. So, add some oil to your gas, about 1-2 ounces per 5-gallon tank, to raise the boiling point back up a little more. Fuel-injected engines recirculate the unused fuel out of the manifold to the tank where it cools off some, but carb'd engines don't have this feature. Nor do bikes, where the engine cooks the gas tank... :/

[IVPeters]

IVPeters, nice looking instrument cluster.

rt

Thanks!

That's damn fascinating Hondaman (love your book btw)

[HondaMan]

Its easy run a K model  ..F has more top end trouble, unless your name is Ofreen.

Ofreen was lucky enough to get a genuine F0! They, like the K0/K1, had the expensive Stellite valve guides that last and last and last...

[American Locomotive]

Our fuels today (beginning November of 2017) have been switched to a more natural-gas-based type, which boils at lower temps than petroleum-based types. Since there is no much natural gas around, this makes some sense, but it yields lower MPG and less power, and it boils at lower temps. So, add some oil to your gas, about 1-2 ounces per 5-gallon tank, to raise the boiling point back up a little more. Fuel-injected engines recirculate the unused fuel out of the manifold to the tank where it cools off some, but carb'd engines don't have this feature. Nor do bikes, where the engine cooks the gas tank... :/

Modern fuel is actually less volatile -  it is harder to boil. Ever tightening EPA hydrocarbon emissions regulations will not allow for gas with lower boiling points. I'm also not sure where you heard that modern gasoline uses a natural gas base stock - it's not true. You can create gasoline from natural gas, but it's an expensive process, requiring very high oil prices to be worthwhile.

[PeWe]

Its easy run a K model  ..F has more top end trouble, unless your name is Ofreen.

Ofreen was lucky enough to get a genuine F0! They, like the K0/K1, had the expensive Stellite valve guides that last and last and last...

My K2 build got a refurbished K1 cyl and head. Head with re-cut valve seats. Guides found to be OK. I'll see how the seal free ex guide will work. It looked funny, higher and coned.

[calj737]

Our fuels today (beginning November of 2017) have been switched to a more natural-gas-based type, which boils at lower temps than petroleum-based types. Since there is no much natural gas around, this makes some sense, but it yields lower MPG and less power, and it boils at lower temps. So, add some oil to your gas, about 1-2 ounces per 5-gallon tank, to raise the boiling point back up a little more. Fuel-injected engines recirculate the unused fuel out of the manifold to the tank where it cools off some, but carb'd engines don't have this feature. Nor do bikes, where the engine cooks the gas tank... :/

Modern fuel is actually less volatile -  it is harder to boil. Ever tightening EPA hydrocarbon emissions regulations will not allow for gas with lower boiling points. I'm also not sure where you heard that modern gasoline uses a natural gas base stock - it's not true. You can create gasoline from natural gas, but it's an expensive process, requiring very high oil prices to be worthwhile.

Further, gasoline companies change formulation up to 4x annually, producing an even less volatile formula for summer months, raising the boiling point.... thereby obviating the need for additional heat management of heat restriction for the fuel system.

[spanners]

Our fuels today (beginning November of 2017) have been switched to a more natural-gas-based type, which boils at lower temps than petroleum-based types. Since there is no much natural gas around, this makes some sense, but it yields lower MPG and less power, and it boils at lower temps. So, add some oil to your gas, about 1-2 ounces per 5-gallon tank, to raise the boiling point back up a little more. Fuel-injected engines recirculate the unused fuel out of the manifold to the tank where it cools off some, but carb'd engines don't have this feature. Nor do bikes, where the engine cooks the gas tank... :/

Modern fuel is actually less volatile -  it is harder to boil. Ever tightening EPA hydrocarbon emissions regulations will not allow for gas with lower boiling points. I'm also not sure where you heard that modern gasoline uses a natural gas base stock - it's not true. You can create gasoline from natural gas, but it's an expensive process, requiring very high oil prices to be worthwhile.

I'm pretty sure they have recently found a way in Texas to drastically reduce the cost of production, petroleum from natural gas. 
Also I thought I read somewhere that the inclusion of the horrible water absorbing 10-15% Ethanol to crude oil distilled petroleum lowered the boil point somewhat.   

[DaveBarbier]

these have been doing fine aswell as other aircooled makes for ever,dont sweat it,they can handle it,so whatcha gonna do?pussy out and shut it off?oil coolers do #$%* all,just ride the #$%*ing things!

Yeah, and nearly every other older air cooled bike I've seen burns oil if the engine hasn't been rebuilt. Air cooled engines are notorious for wearing valve guides and rings out. The CB four cylinder bikes are no exception to that rule. High cylinder head temperatures will decrease valve guide and valve seal life, and cause your piston rings to wear faster.

You’re saying every older air cooled motor burns oil based on that it gets hotter? I guess that could be true, but couldn’t it be true that they’re just OLDER and that’s why they’re burning oil?

It’s kind of obvious that “high cylinder head temperatures will decrease valve guide and valve seal life, and cause your piston rings to wear faster” but does that mean we need to shut our bikes down at idle every time we ride on a hotter day? I don’t think so, that seems a little ridiculous. I’m with Dave, ride the damn bike. These Honda air cooled motors are crazy reliable.