Topic: How about a temperature gage?

[calj737]

You literally just proved my point with that statement.

As I said, scrambling. Your entire assertion from the onset was about air-cooled motors and temperature issues.

Your own words...

I have seen countless air cooled bikes that absolutely chug blue smoke, especially when slowing down (due to fried valve guides/seals). It's even more common on the dual-sport on/off road air cooled bikes.  I see multiple threads every month on this very forum that discuss oil consumption and oil burning issues these bikes tend to get. I see even more threads about bikes with low to mediocre compression (90-100 PSI) - almost certainly from wear caused by sustained high temperature operation.

It seems that your posts have been focused on air-cooled motors run hotter than water-cooled and are thus, expected to sustain premature engine wear. There is simply not evidence this is true. Air-cooled motors are dependent upon air flow, but, a few minutes of time resting in traffic while running won’t destroy them. If that were true, VWs, every Japanese and BMW motorcycle before 1980 would be an oil burning chimney with fewer than 10,000 miles on them. And there’s countless vehicles that completely refute that.

Everyone understands the merits of gauges and information relative to engine condition, but there’s no empirical need to install a temp gauge to prevent engine damage in these bikes. Certainly not a good choice for commmuting in California summers, but anyone dumb enough  to do that on an air-cooled bike deserves the results.

[PeWe]

The oil tank thermometer work fine.
Example of overheated rods and pistons, especially 2-3
It would have been fine if I should had that installed almost exact 34 years ago when this happened, see photo. Small end bluish
The rods that replaced these looked fine after 3 more long tourings, some days very hot. Had to ride over 160 kph to get fresh air and cool down in north Italy.
I think the melt down and bluish rods were helped by some pinging, ign not correctly set. The pistons had maybe closer to 11:1 than 10:1.

I have later understood that the play of the advancer unit must set F about 3-4 degrees later compared with case mark to avoid advanced timing by 3-4 degrees. This if it is tightened in its clockwise position. Max counterclockwise, T lines up perfectly with case mark when checked with piston stop and degree wheel. I have stamped an alternative mark in case 3mm clockwise from std mark.
This can explain the pinging, ign at least 3 degrees advanced, 2-3 maybe more since I might have forgot to check it last time, only doing 1-4.
It overheated but not due to hot weather.

[American Locomotive]

It seems that your posts have been focused on air-cooled motors run hotter than water-cooled and are thus, expected to sustain premature engine wear. There is simply not evidence this is true.
Air-cooled motors are dependent upon air flow, but, a few minutes of time resting in traffic while running won’t destroy them. If that were true, VWs, every Japanese and BMW motorcycle before 1980 would be an oil burning chimney with fewer than 10,000 miles on them. And there’s countless vehicles that completely refute that.

I never said a few minutes in traffic will destroy them. Not once. Once again, that's your own perversion of my statements. I'm saying, in certain situations a passively cooled air cooled engine (like on a motorcycle) can have its temperatures skyrocket, accelerating engine wear significantly and causing some engine harm. Heavy stop/go traffic just inching along will result in very high cylinder, and cylinder head temperatures. Sitting at a stop light for 45 seconds is not the same thing as 10 minutes of stop-go bumper to bumper traffic. Over time, these periods of very high temperatures can lead to low compression and excessive oil consumption. It's not something that happens at the snap of your fingers, it's gradual.

You also can't compare bikes to air cooled automobiles. VWs, Porsches, and every air cooled automobile don't have passively cooled engines. They all have powerful cooling fans designed to keep the engine cool in heavy traffic. Even then, high oil consumption is generally considered "acceptable" among air-cooled VW and Porsche groups.

How about this: I will buy the gauge, I will install it, and I will monitor and take note of temperatures in various scenarios. I will then let you guys know how hot these engines actually get in traffic. That way we can settle it.

P.S. modern BMW air cooled boxer bikes come with temperature gauges

[jgger]

You literally just proved my point with that statement.

As I said, scrambling. Your entire assertion from the onset was about air-cooled motors and temperature issues.

Your own words...

I have seen countless air cooled bikes that absolutely chug blue smoke, especially when slowing down (due to fried valve guides/seals). It's even more common on the dual-sport on/off road air cooled bikes.  I see multiple threads every month on this very forum that discuss oil consumption and oil burning issues these bikes tend to get. I see even more threads about bikes with low to mediocre compression (90-100 PSI) - almost certainly from wear caused by sustained high temperature operation.

It seems that your posts have been focused on air-cooled motors run hotter than water-cooled and are thus, expected to sustain premature engine wear. There is simply not evidence this is true. Air-cooled motors are dependent upon air flow, but, a few minutes of time resting in traffic while running won’t destroy them. If that were true, VWs, every Japanese and BMW motorcycle before 1980 would be an oil burning chimney with fewer than 10,000 miles on them. And there’s countless vehicles that completely refute that.

Everyone understands the merits of gauges and information relative to engine condition, but there’s no empirical need to install a temp gauge to prevent engine damage in these bikes. Certainly not a good choice for commmuting in California summers, but anyone dumb enough  to do that on an air-cooled bike deserves the results.

As DUMB as a lot of things are here in Commiefornia , air cooled motorcycles are the reason that lane splitting is legal here . One of the few wins here on the left coast!

[Don R]

 I was on my 76super sport once in a huge traffic jam. The best part was is was all downhill and slow enough I could roll along. I'd say the oil tank or other type of temp. gauge would be helpful to anyone that sees high heat and slow driving. What's so hard about agreeing to that? 

[TwoTired]

What's so hard about agreeing to that?

Well, since you asked... 
The oil tank gauge, like an oil pressure gauge down by your feet are horrible places for your eyes to attend while riding about with other drivers intent on shortening your life.  And, a gauge you don't look at is pretty superfluous.

If you must put add on gauges to the bike, at least put them in the area of the clocks, for a quick glance reference, while that truck or soccer mom SUV is cutting you off.

IMO.


Cheers,

[PeWe]

The temp is OK to check now and then to see max temp. Better than nothing.
Visible gauge beside the other instruments to see when engine is fully warmed up and ready for some twisting.
Pressure is something I would see while riding. But the final alarm will warn, by red lamp that is seen OK at every start-up shining red. If not replace bulb.

We have a really good summer here, best in decades. Like 1993 (4 weeks with warm sunny weather from last week of April) and 1994 (sunny warm July) together and even better!
I'll have a ride tomorrow and see how high the temp will rise in the warm summer weather, 27-30C. I'll try to cruise in legal speeds

[Don R]

 I guess I incorrectly assume everyone has common sense. IMO.

[seanbarney41]

my 82 gs1100 has an oil temp gauge right next to the tach...sensor is in the main oil galley similar to the oil pressure switch on a cb750KIMG0205 by Sean Barney, on Flickr

[carnivorous chicken]

I disagree with some of that.
 If you owned your four for a few seasons, I think you would be able to tel, if it was overheating..
 I used to kill mine at lights and re kickstart.
 My buddy's 1080 with finless block ran hot, and it let you know..

This -- and to add some anecdotal evidence:

I lived in Phoenix for 20 years, with a few jaunts here and there. I owned a 350F the entire time, a 400F for several years, a 550 for several years, a cb160 for ten years, and a bunch of other SOHC fours for shorter periods. I rode during the summer, even on 110+degree days (although not a ton, but some freeway time, some surface street time). Never had an overheating issue, but could tell when the bikes were getting hot as 754 states. Good oil and common sense go a long way.

I'm also not trying to talk the PO out of a temp gauge if that's what he wants.

It was 120 in 2016 too (or maybe 118?).

Knew a guy who rode to work every day, year round, about 30 miles. He'd soak his leathers in water prior to leaving and at work prior to coming home. I've done the same thing, just dumping water on me before going for a ride.

[PeWe]

WOW!  That's really hot! Cannot be fun to ride a bike in +40C (over 100F). Really fat oil cooler must be mandatory too.
Longer rides in +30C (+86F) need thicker oil?
I should use 20W-60 that's for sure.
I'm thinking about testing that in my K6 that get high oil temp in tank + 245F (just touch the 120C area)

Interesting read about oil viscosity, film strenght and pressure.
https://rennlist.com/forums/928-forum/1041459-engine-oil-and-last-century-porsche-road-engines-some-light-reading.html
It is the post 12-31-2017, 11:38 PM #1  by JET951 that is interesting
(a later post show Motul 300V oil that has sludged into syrup really quick..also interesting since it should be a high quality oil)

Not a CB but still air cooled engines (when old 911 is discussed) and warmer climate. Valve stems that must get proper lubrication by splashes of oil most cleaned off by the valve seal, if not guide wear. Con rods that will fail with too thin oil which means too low oil pressure. Hotter ambient temp means higher oil temp and thinner oil-lower pressure. These engine were also recommended to use 20W-50 back in their days when oils were OK, before removal of ZDDP.

I start to understand why some of the crank bearings got scuff mark really quick a rebuild or 2 back with brown shells as the measured clearance should have. Went to green with more clearance and more oil flow.
This might have been the oil only. Too long with bad brake-in oil such as 10W-40 Castrol Actevo with low ZZDP.

[carnivorous chicken]

WOW!  That's really hot! Cannot be fun to ride a bike in +40C (over 100F). Really fat oil cooler must be mandatory too.

No, not really. This is what we're trying to say -- normal riding (not a lot of stop and go or sitting still) is fine in over 100-degree heat.

[rotortiller]

You also can't compare bikes to air cooled automobiles. VWs, Porsches, and every air cooled automobile don't have passively cooled engines. They all have powerful cooling fans designed to keep the engine cool in heavy traffic.

Exactly. You clearly know what you are talking about. It is very kind of you to educate other less informed guys. The cars also have well designed cylinder baffles and ducting for superior cooling.

[PeWe]

We had over 32C (90F) today (again) which is warm for Sweden. Thick leathers felt fine. I can cope with it better now since I have lost some of the overweight. Oil temp 120C after some twisting with old biker friends from the first half of the 80's.

Thanks to this  thread I searched more among Porsche threads I have seen discussed oil quality vs high engine temp and air cooled engines before. The link in my previous post made me to think.....a little bit extra....
I think I have solved my old mystery when I blew a piston, the piston beside going to get a hole too when it had a dent. Photo in previous post.
It must have been the oil. Oil and ambient temperature + raised engine temperature due to higher CR have a relation.

I do not remember which oil I used, but it must have been too thin relative the temperature and lost the pressure, wrist pins in contact with rods small ends running hotter making rods bluish and engine even hotter pistons included. Either wrong oil (too thin) or it was worn out, lost all additives making it to a 50 oil from a base 20. When this happen the oil is a plain base oil of viscosity 20 and metals will connect since the pressure will be lost, not enough oil film between the metals.

Single grade Quaker State from Pennsylvania with the best base oil molecules in the world  (extra long) was popular back then. Or Vance & Hines oil. Quaker State might have been thinner than single 50.
I know it happened after my long touring, It must have got refill along the road but might have got wrong type or just crashed oil viscosity.
It comes to the oil again even if that is seen as popcorn for many.

I'll put 20W-60 synth oil in my 120C  (248F) oil tank bike!

It is not the high ambient temperature that kills the engines if happen, It's the oil that is not good enough for that high temperature.

[MessnerMoto]

Nice find about 20W-60. I will investigate and maybe put it in my engine also...

[PeWe]

Nice find about 20W-60. I will investigate and maybe put it in my engine also...

Your engine runs rather warm too?
My Billet block K6 has this now: https://www.redlineoil.com/20w50-motorcycle-oil
No clutch slip.
Gearbox feels much smoother than with Motul 5100 and 7100

I'll order some of this after my vacation.
https://www.redlineoil.com/20w60-motorcycle-oil

[krksquared]

As the OP on this thread, thanks for all of the feedback. I thought it would be appropriate to show my solution to this issue. Now I can determine what's really going on underneath me. I think this raises the value of my bike at least double. This is how Honda should have done it  Stay tuned for another thought provoking question...

[PeWe]

Ready for take off Houston!

One more detail about temp gauges. There is an oil pan drain plug with temp sensor possible to connect with a temp gauge like VDO.
I do not remember which brand of drain plug, MRieck mentioned that in another thread.

[rotortiller]

ITT and Ng look a little high krksquared

[MessnerMoto]

Nice find about 20W-60. I will investigate and maybe put it in my engine also...

Your engine runs rather warm too?
My Billet block K6 has this now: https://www.redlineoil.com/20w50-motorcycle-oil
No clutch slip.
Gearbox feels much smoother than with Motul 5100 and 7100

I'll order some of this after my vacation.
https://www.redlineoil.com/20w60-motorcycle-oil

I use Motul 7100 20w50 but when warm idle pressure is not good. Below5psi at 1000rpm...  And engine and pump is brand new. Everything is perfect and at the really tight side of allowed tolerances. Compression of my engine is above 10.5... And when warm I can smell oil vaporizing... Idle Head temp is around 115C-120C measured at valve adjustment cap(I have also temp senssor for oil but not positioned good so I don't have good values, ).... There is no smoke or anything just smell of oil vaporizing when idling

I did some research and I think Motul 7100 synth is not good for temperatures above 100C. It is stated in technical documentation that viscosity is 18mm2/s at 100C... So even lower when above 100C probably like you stated closer to 120C....

Mineral 20W50 oils usually have viscosity above 20mm2/s at 100C.... So there is a difference in usual values for  viscosity of synth and mineral 20W50 oils at 100C... Synth have lower values probably because they are not made with air cooled engines in mind....

There is Liqui Moly synt 20W50 HD that has viscosity above 20mm2/s at 100C... This oil is made for air cooled engines

But I think better and correct one for my tuned up engine is Liqui Moly 10W60 it is at 23mm2/s at 100C... Probably at 20mm2/s when at cb750 temps. Also it is relatively affordable in europe...

https://www.ebay.de/sch/i.html?_odkw=liqui+moly+10w60&_osacat=0&_from=R40&_trksid=m570.l1313&_nkw=Liqui+Moly+Motorbike+4T+Synth+10W-60+4l&_sacat=0

I would not go with 20w60 because it is to thick when cold.  It will wear off engine parts when cold.

[spanners]

Whenever I see the abbreviation Moly mentioned within the description of an oil I think of molybdenum.  Which you (I)  would not want near a wet clutch.
Maybe its just a fancy name and nothing to do with Molybdenum, it does state for with or without wet clutches, but still the word Moly would bother me if sticking in a bike with a wet clutch. 

I also wonder if some of the modern day super slippy 100% synthetic oils will slow down the necessary oil scraper rings wear in on a re honed bore. That these oils may just make them more inclined to overheat and glaze up.   On an older design engine the necessary wear in on all parts has to be a lot greater than a modern day engine.  On an engine that is already worn in, maybe a 100% modern synthetic oil is ok.  All I'm saying is I don't think I would be putting a 100% synthetic carlos fandango slippy oil in a 70s engine I had just rebuilt until it was properly run in.   

[calj737]

All I'm saying is I don't think I would be putting a 100% synthetic carlos fandango slippy oil in a 70s engine I had just rebuilt until it was properly run in.   

Sage advice right there. A proper break-in oil, then drain and replace filter and oil with a multi-blend for a couple of thousand miles. Then switch over to full synthetic.

[MessnerMoto]

Liqui Moly is a company/brend name. The oil does not contain Molybdenum disulfat

[PeWe]

I know what smell you feel. Motul smells really strong, especially 7100. They have put perfume in it?
It should withstand higher temp better since it is a full synthetic. Full synth withstand higher temperatures in general, that why they must be used in many installations.
The Red line feels better.
I'll go thicker due to the high oil temp of 120C (248F). If temp should stay 100-110C I'm sure no problem with the 20W-50, but still Red Line full synth. It will cost too much to save a few bucks on oil quality in my modified engine. I have my old bluish rods and not much used blown RC836 pistons I can take a look at, still in a box since 1984, mostly stored in barns where rust could form.

Earlier mentioned engine failures due to high temp might be caused by use of a simple 10W-40 that is written on the side cover label. Using that when riding hard in +30C...failure will come....

Edit: When thinking about oil pressure...I have no gauge for it except oil pressure warning lamp. It does not lit or flicker now when engine is warm just below 1200 rpm, not under 1000 rpm as I saw with Motul oils 5100, 7100 (15W-50) last year. Maybe the 3000 mineral too.

[PeWe]

Back to the TS start with need of a temp gauge
After reading some about high ambient temp and its effect on the oil and engine health, oil pressure gauge visible beside the other instruments seems to be even more important than reading the temperature.
As long the pressure is OK so is the oil and the engine. If oil will reach a temp it it cannot withstand, pressure will drop.

As commented here and I have seen at idle, an expensive oil (Motul 7100) seems not be able to keep up the pressure at not that high temperature in a CB750. Its lubrication capabilities is worthless if it cannot keep up the pressure, metal-metal $$$

Time to look for a  small pressure gauge or multi step/color LED indicator and pressure sensor.