[highlander]

Originally Posted by srini1785

Extrapolating to 2L engine of a AR spider , you may well end up with 6L. However i am yet to come across a 2L bike.

Triumph Rocket 3 displaces 2458cc and your math is correct, it needs a little over 5.2 liters of oil. Luckily this is an annual affair or 10K Kms.

[bj96]

Originally Posted by abhi9044

...oil in a bike has to protect gears, engine and as well as the clutch...

Nitpicking- mostly correct, except for old CI Bullets and same generation engines

Bullets have three separate Oil requirements (1) 20w50 for Engine, (2)10w30 for Clutch and (3)75w EP for gearbox. In right side shifter models, grease is required in gear box. The drain intervals for my Electra is 6000 kilometres for clutch and GB while 3000 kilometres for Engine oil.

-BJ

[Kosfactor]

Motorbikes that have oil cooler \ water cooled engines or both- do they have a longer oil drain interval in comparison to draft air cooled engines?

[motonomad]

I think there are couple of other factors I would like to point out to add to what others have already shared:
> Cost - I have seen some people coming in for first service even at KTM service surprised at how much 1.5 litre of oil costs. And the change interval on D390 is 7500 kms and it is not really a mass product here. For a lot of people, majorly in commuter segment, what they are paying in a transaction matters more than overall costs which is probably part of the reason we haven't seen significant change.
> Parts - Apart from the higher average operating RPMs and added function of cooling like others mentioned, I believe there is a general difference in material and quality of engine parts owing to low costs and general product life. I am assuming that is complemented by higher wear which has to be cleared out with more frequent changes.

[srini1785]

I wonder if any one has actually measured the viscosity of used motor oil before replacement. The viscosity of used motor oil is actually in the measuring range of a standard ford cup viscometer which is actually not that costly.

Here is one such cup:



https://www.amazon.in/BEXCO-Brass-Fo...=1&ext_vrnc=hi

and the standard viscosity tables:




The process is fairly simple. Take a sample amount of used motor oil and pour it into the measurement cup at the top which has a standard orifice and measure the time taken for complete draining. Higher the viscosity higher the flow time.

Standard flow times are available for comparison https://en.wikipedia.org/wiki/Flow_cups

It would at least make bare claims of companies about replacement intervals.

P.S : Cst is centipoise. A SI unit of measurement of viscosity.

[Jeroen]

Originally Posted by srini1785

It would at least make bare claims of companies about replacement intervals.
.

Which suggest that viscosity is a direct and all inclusive measurement of the overall state of the oil. Which it simply is not. It is an indicator. If they viscosity is way off its definitely time to change the oil. But oil viscosity can still fall within the acceptable range whereas the additives are really not working any more. So an acceptable viscosity is not a guarantee of the state of your oil.

Note that these test are done at room temperature and part of what an oil is all about is what the viscosity is during normal operating conditions. One state can not be extrapolated to the other.

The only way to get a real idea of the state of your oil is to have full lab test done. Usually the cost of a simple oil change is less, so simply not economical for bikes and cars. It is done for larger engines though, a marine engines, big stationary diesel powering generators. Lab testing includes viscosity but also a range of other test, including looking for (metal) parts in the oil.

In my merchant navy days we took samples of the lub oil of all engines on a weekly basis. On board testing for the obvious, which was viscosity and water content. I also recall having one other test, pH perhaps. On a monthly basis we would send samples to be tested fully at a lab.

Jeroen

[Gansan]

Originally Posted by Jeroen

In my merchant navy days we took samples of the lub oil of all engines on a weekly basis. On board testing for the obvious, which was viscosity and water content. I also recall having one other test, pH perhaps. On a monthly basis we would send samples to be tested fully at a lab.

Jeroen

What was the typical sump capacity for those engines?

[ArizonaJim]

As Jeroen said, the viscosity of the oil is only a part of the issue when it comes to determining if engine oil needs replacing.

Modern engine oils contain many additives like viscosity stabilizers, anti-corrosion materials, anti-foaming materials, anti-friction materials, detergents, disperant's which keep particles in suspension to prevent sludge and other important things to keep an engine running up to par.

These additives break down over time due to the severe environment they must live in and their breakdown isn't easily determined without expensive lab tests.

Then we have the thermal breakdown of the oil itself.
Petroleum engine oils actually contain several different kinds of oil in them. Some of these oils are very durable and some of them are weak and break down into carbon deposits or they lose their ability to prevent wear after being heated to high temperatures.
Remember, although the oil in the sump may be 80 to 100 degrees C, the oil in the small spaces between the moving parts can easily be temporary heated to over 200 degrees C. and that heat can cause the oil to break down.
That is where the synthetic oils beat regular petroleum oils.
Because it is man made, the people who make it do not create the types of oil that rapidly break down. Instead, they use the types of molecules that are very temperature resistant and can last a long time.

Then, we have the water that ends up in the oil. Water is created when petrol burns and some of it will end up in the oil. If the machine is ridden short distances and the oil never gets up to operating temperature the water can remain in the oil. Water is a very poor lubricant and it also can cause the metal parts in an engine to corrode.

Dirt and carbon are both abrasives and can cause wear on all of the moving parts in an engine. Yes, a clean oil filter will remove most of these but if the oil filter is not changed, it will go into "bypass" mode where all of the oil will flow past it and directly into the bearings. (This is a fail safe condition where the designers decided it is better to allow some dirt to slowly wear out the bearings than it would be to allow all of the oil flow to be blocked off by the dirty filter and have the bearings instantly burn out because of a lack of oil.)

All in all, changing the engine oil and the oil filter is a easy, low cost insurance that will add thousands of hours of life to an engine.
Be grateful that we have modern motor oils and high quality filters rather than the old kinds of oil we had 60 years ago that needed replacing every 1500 km.
Oh. I forgot to mention the differences between the air cooled engine and the liquid cooled engines and why the air cooled engines need to have their oil changed more often.

Air cooled engines have some areas that get very hot. Much hotter than a liquid cooled engine. These hot areas will cause thermal breakdown of the oil that contacts them causing carbon to be formed. The resulting carbon contaminates the oil resulting in the need to change it more often.

The engineers who designed the engine know which oils to use in their engines and they know how long it will last before it needs to be changed. They are not in cahoots with the big oil companies trying to make money for them. They want their engines to work well for a long period of time so the customers will remain happy so, they tell owners how often to change the oil and filter. The least we can do is to follow their recommendations.

[Jeroen]

Originally Posted by Gansan

What was the typical sump capacity for those engines?

It really varies by size and type. The so called medium speed engines less than the massive two strokes engines. But we are talking hundreds if not thousands of liters!

These large diesel do use a lot of lub oil as well. Particularly through cilinder lubrication. I have sailed on a vessel where the maximum range was not determined by the amount of fuel, but the amount of lub oil we could carry.

Here is a article explaining many aspects of lubrications of marine diesels

https://www.marineinsight.com/tech/s...tem-explained/

A big difference with cars/bikes is also that lub oil on a ships engine get constantly circulated through an oil separator. In essence a very large certrifuge which separates out all particles and water content.

https://www.youtube.com/watch?v=sDhueH3q6Y4

The type of fuel the engine burns has a big impact on the lub oil. These so call heavy oil are particularly dirty and cause all sorts of problems for the lub oil.

jeroen

[mvadg]

Originally Posted by NiInJa

I used to change my FZ16's oil with the cheapest one available (I think 250 Rs per 900 ml/1 litre Shell Yellow colored can ) and the bike would start...

Most commuter scooters don't have an oil filter, only a strainer - which is as good as useless for filtering out debris. This is one of the reasons why they need more frequent oil changes, especially in dusty environments. Talk about taking shortcuts!

[Motard_Blr]

Originally Posted by mvadg

Most commuter scooters don't have an oil filter, only a strainer - which is as good as useless for filtering out debris. This is one of the reasons why they need more frequent oil changes, especially in dusty environments. Talk about taking shortcuts!

Small 4 stroke engines they don't have centrifugal separators instead. For the small oil flow rates in those engines, they do a good job of keeping the oil clean of particles.

See this old thread:
https://www.team-bhp.com/forum/motor...ml#post1202510 (About motorcycle oil filters; esp. HH CBZ-Xtreme)

https://www.team-bhp.com/forum/attac...ntrifugal2.jpg

[Gansan]

Originally Posted by mvadg

Most commuter scooters don't have an oil filter, only a strainer - which is as good as useless for filtering out debris. This is one of the reasons why they need more frequent oil changes, especially in dusty environments. Talk about taking shortcuts!

That is not correct. The 100 cc Splendor has a strainer and a centrifugal filter. Check out the copy of manual attached. The main reason for more frequent oil change is the lesser oil quantity (900 ml for Splendor) and the fact the oil also doubles as a transmission oil. Not sure if the transmission oil bit applies to Activa etc.

Note: My Splendor and this manual are twenty years old. Not sure if the current manual also specifies the same intervals.

[mvadg]

Originally Posted by Motard_Blr

Small 4 stroke engines they don't have centrifugal separators instead.

Originally Posted by Gansan

That is not correct. The 100 cc Splendor has a strainer and a centrifugal filter.

Sorry guys (and me too), guess my Gen 1 Honda Aviator lacks a centrifugal oil separator! Hope someone can correct me if I'm wrong.

[Kosfactor]

Originally Posted by ArizonaJim

I forgot to mention the differences between the air cooled engine and the liquid cooled engines and why the air cooled engines need to have their oil changed more often.

Air cooled engines have some areas that get very hot. Much hotter than a liquid cooled engine. These hot areas will cause thermal breakdown of the oil that contacts them causing carbon to be formed. The resulting carbon contaminates the oil resulting in the need to change it more often.

The engineers who designed the engine know which oils to use in their engines and they know how long it will last before it needs to be changed. They are not in cahoots with the big oil companies trying to make money for them. They want their engines to work well for a long period of time so the customers will remain happy so, they tell owners how often to change the oil and filter. The least we can do is to follow their recommendations.

Thanks for clarifying the air-cooled vs liquid cooled difference, it makes total sense.

I am very respectful of sound engineering recommendations, not being able to be an engineer myself.

Originally Posted by Jeroen

The only way to get a real idea of the state of your oil is to have full lab test done. Usually the cost of a simple oil change is less, so simply not economical for bikes and cars. It is done for larger engines though, a marine engines, big stationary diesel powering generators. Lab testing includes viscosity but also a range of other test, including looking for (metal) parts in the oil.

In my merchant navy days we took samples of the lub oil of all engines on a weekly basis. On board testing for the obvious, which was viscosity and water content. I also recall having one other test, pH perhaps. On a monthly basis we would send samples to be tested fully at a lab.

Jeroen

Is the oil changed based on set limit in terms of % contamination or is there a running time for such massive engines?

[Jeroen]

Originally Posted by Kosfactor

Is the oil changed based on set limit in terms of % contamination or is there a running time for such massive engines?

On the larger engine I have worked with it was always based on the lab results only. Some smaller auxiallery engines went by hours of running time. More or less similar to your car mileage intervals.

The oil seperators are very effective of getting any solid contamination (and water) out of the lub oil. So you don’t worry about the filters. In fact large engine just don’t have lub oil filters as such. They will have the lub oil separator and usually strainers. (i.e. wide mesh filter which will catch say a bolt or a piece of piston ring.

So the life of a main engine lub oil is very much determined by how effective the remaining additives still are. I don’t think in my 10 years as marine engineer I have ever changed the oil of any of the main engines?

Bear in mind, as I said before, these huge diesels use quite a lot of oil. So there is a constant replenishment on the sump oil with fresh oil too!! That is all very different to your car engine. The sump charge more or less gets consumed all the time and replenished.

But things have changed a lot. My experience is quite dated. I know we have some current marine engineers on the forum. Perhaps they can elaborate with current practice if different from before.

Jeroen