[Zed]

Originally Posted by Ashley2

The statement what I have given was from the service front.
If you could check the engine oil change frequency its the same between ISBe and 6BT engines - Just 8000 kms for a city duty cycle and 18000 kms for long haul cycle. Its less than half of the competition models.(Scope : India)

Looking into this only I told there is nothing much of reason and only a marketing terminology used by Cummins.

Ashely - Going by this logic all engines that have similar intervals of oil change are the same. Maybe im missing something here but your argument of a Marketing terminology - after having got detailed reply regrading the differences between the 6BT ans ISBe - just goes above my head.

What you are essentially saying is that the Honda accord and Honda City, if they have the same recommended service intervals, are similar cars just marketed with different names.

[Transsenger]

AFAIK, the ISBe used in TML Prima trucks here needs engine oil change at every 40K Kms. They use Valvoline Premium Blue15W40 oil for ISBe unlike the usual Castrol15w40 used in 6BT & 697. And for BS3 6BT & 697 the oil change is at 18K & 36K for city & long route respectively.

[Ashley2]

Spot the difference between these two?

[urzdeepu]

Originally Posted by Ashley2

Spot the difference between these two?
Attachment 606341

The first one is definitely not a Volvo. But a volvo clone made by Azad!! It is evident from the back grille and the wheel is having a cup too!!

[silversteed]

Originally Posted by Ashley2

Spot the difference between these two?

Royal Express seems to be a Volvo-like body built on a 12M chassis, while Prithvi Travels is an authentic Volvo.

[girishglg]

Tried to check out the Royal Express website listed below-

Welcome to Royal Express
(None of the other links work in their website!!)

Can see the front face of the same bus. Definitely not a Volvo. At least they have not attempted to paste the V logo.

Originally Posted by Ashley2

Spot the difference between these two?
Attachment 606341

[Ashley2]

Yes, Its a AL 12M build by Azad.
They are using the same profile for coach. Striking resemblance for a newbie.
Its Azad's time to take revenge (in a lighter way) on Volvo.

[Ashley2]

Originally Posted by julupani

..
From the service point of view, true, they are still not exactly made for Indian conditions. Thus the comparatively safe 8000km oil change intervals. ..

Safe interval may be safe for a engine but not for the customer, considering the service costs its incurring.
If the ISBe engine is safe for only about 8000 kms (its 9000 and not 8000 - typo error by me in earlier post) aganist the competition engines which offers upto 18000 kms, do I need to tell anything about ISBe.
Decide it on!

Originally Posted by julupani

Though I am not sure, I think the ISBe had moved to a 10 or 12K interval.

ISBe is definitely in 9000 kms range only and have not inched further.

Originally Posted by julupani

But, what has improved in that the new engines are now designed for running without overhauling for 4L kms, instead of the older 2L kms. The major advantage here is a higher longevity of the engine, compared to the older ones.

Are you sure about this statement.
In tamil there is something in grammer called - Vanja Puzhalchi Ani - Meaning, you will praise one part of the world by degrading the other. This is of similar note.
The 6BT's definitely lasted for more than 4 lakh kilometers.
If at all they were to be overhauled in 2 lks km, that's the worst possible design of a engine for a Commercial Vehicle - Thank God its not of that kind..
The average annual running mileage of a Intercity bus is 2 lks kms.
Is this means that the engine to be over hauled once in a year?

Let ISBe be better but not at the expense of 6BT's.

Originally Posted by julupani

But overall considering the massive performance boost, I dont think I would call it only marketing terminology.

OK let me tell you the complete story.
Version 1 :Cummins when developed B series it was 5.9 litre (6 cylinder version) was a DI engine, termed as 6BT.
Version 2 :This 6BT when later took a electronic avatar with Bosch it was termed as ISB - Interact System B series.
Version3:Then in the same older 5.9 litre engine capacity was increased upto 6.7 litre and was called as 6.7B. This engine is was DI only.
Version4:Finally when this 6.7 litre engine fitted with the Common rail system, gave birth to ISBe.
Hope the history is clear. The version 2 and version 3 never came to India and so its unlikely that many of us will be knowing.
These are the reasons for my statement both 6BT and ISBe are one and the same except for the Common rail system. Of course you will have increased power and torque but still the overall life ( read it as service) will be same.

Originally Posted by julupani

At the end of the day, not many people were complaining about the service intervals.

I think the cries of BMTC is not heard by you!
Needless to say about MTC

Originally Posted by julupani

The new B-series I think was more of change to meet the newer and higher power requirements of the CV world all the while getting ready for the next decade of emission norms, rather than reduce maintainance costs.

Hope I have explained in a detailed manner.

Originally Posted by julupani

Service intervals may not have changed, but its still a much better engine offering more power and torque in a lighter engine and is also ready for the future. Most of all, it offers the power and torque of what earlier gen 8L engines were offering, thus allowing for more power while not increasing fuel costs by much.

If a smaller capacity engine and a larger capacity engine producing the same power and torque values and if you say the the smaller engine(here spelt by you as lighter engine) is better I would completely disagree with you.
Just take the example of Multi axle coaches of Volvo and Mercedes Benz
In a broader spec you will see both the power and torque to be matching each other:
Volvo:
Power - 340 hp
Torque - 1600Nm
Mecedes:
Power - 360 hp
Torque - 1600Nm.

But the real secret lies in the Cubic capacity of these engines. The earlier is 9 litre and the later is 12 litre engine. In a longer perspective the higher capacity engine producing same figures as lower capacity engine will have a higher efficiency/overall life.(MB engines are marginally frugal to volvo too - Unbelievable right?)
And only for the want of higher capacity( not as higher power/torque) Volvo is working to bring their 11 litre engines (may even be higher also). It should be noted that even in the current avatar they last as much as 1 million kms with out major over haul.But Volvo wants even more
Hope my statement of higher the engine capacity better the life of the engine life is clear - means ISBe 6.7 cannot ideally match 8 litre engines.
But there should be better reasons(Emission norms etc) than told by you - matching power and torque values.

Originally Posted by Zed

Ashely - Going by this logic all engines that have similar intervals of oil change are the same. Maybe im missing something here but your argument of a Marketing terminology - after having got detailed reply regrading the differences between the 6BT ans ISBe - just goes above my head.

Zed! Hope you have heard explanations from my side too.

Originally Posted by Zed

What you are essentially saying is that the Honda accord and Honda City, if they have the same recommended service intervals, are similar cars just marketed with different names.

Now you can decide!

Originally Posted by Transsenger

AFAIK, the ISBe used in TML Prima trucks here needs engine oil change at every 40K Kms. They use Valvoline Premium Blue15W40 oil for ISBe unlike the usual Castrol15w40 used in 6BT & 697. And for BS3 6BT & 697 the oil change is at 18K & 36K for city & long route respectively.

All these are not under the scope of trucks in India.

Important : No offense on anybody. Just took sometime to explain things.Thanks for reading

[Zed]

@ Ashley

Given this discussion threads heading I was referring to the 6Bt and ISBe in the Indian context. And as you have explained in detail these engines are not the same.

I guess we would have missed this interesting discussion if you had stated that the ISBe evolved from the 6BT - but hey, then I wouldnt have got the lowdown on versions 3 and 4 that you have highlighted. Thanks for that.

As a final comment you will find many voices vouching for the fact that in the recent past the 6BT engines have been the benchmark for Indian CVs. This inspite of the fact that the 6BTs were possible running with drivetrains that were not optimised for their power \ torque characteristics, since the 697 engine family also used the same drivertrains. Do correct me if im wrong, since im not deeply into drivetrains.

Its the high cost of the engine thats been the its biggest weakness, but then again Cummins is one of the most profitable Automotive companies in the US. According to 2010 Data its annualized shareholder returns % in the 10 yr period ( 2000 - 2010 ) was 30%. In comparison the closest automotive organization on the same criteria was caterpillar ( with 23% ). Daimler USA was at 4% . Microsoft was around 5%. Just wanted to highlight this as Cummins as an organization ranks very high in my books not just for its technical competence, global foot print, cross segment presence but also for their financial stewardship during a difficult period in Automotive history. One can safely assume that the JV in India also embodies this DNA.

[julupani]

Originally Posted by Ashley2

Safe interval may be safe for a engine but not for the customer, considering the service costs its incurring.
If the ISBe engine is safe for only about 8000 kms (its 9000 and not 8000 - typo error by me in earlier post) aganist the competition engines which offers upto 18000 kms, do I need to tell anything about ISBe.
Decide it on!

Safe is also for the customer, since the customer wants his vehicle on the road earning money, rather than sitting in the garage getting repaired.

Originally Posted by Ashley2

Are you sure about this statement.
In tamil there is something in grammer called - Vanja Puzhalchi Ani - Meaning, you will praise one part of the world by degrading the other. This is of similar note.
The 6BT's definitely lasted for more than 4 lakh kilometers.
If at all they were to be overhauled in 2 lks km, that's the worst possible design of a engine for a Commercial Vehicle - Thank God its not of that kind..
The average annual running mileage of a Intercity bus is 2 lks kms.
Is this means that the engine to be over hauled once in a year?

Let ISBe be better but not at the expense of 6BT's.

By overhaul, I dont mean that in the sense you see from passenger car. Here the 2lakh/4lakh overhauls is more like a scheduled service for the engine component.

Both 6BT and latest ISBe need major overhaul at 10 Lakh kilometers only.

Originally Posted by Ashley2

OK let me tell you the complete story.

Version 1 :Cummins when developed B series it was 5.9 litre (6 cylinder version) was a DI engine, termed as 6BT.
Version 2 :This 6BT when later took a electronic avatar with Bosch it was termed as ISB - Interact System B series.
Version3:Then in the same older 5.9 litre engine capacity was increased upto 6.7 litre and was called as 6.7B. This engine is was DI only.
Version4:Finally when this 6.7 litre engine fitted with the Common rail system, gave birth to ISBe.
Hope the history is clear. The version 2 and version 3 never came to India and so its unlikely that many of us will be knowing.
These are the reasons for my statement both 6BT and ISBe are one and the same except for the Common rail system. Of course you will have increased power and torque but still the overall life ( read it as service) will be same.

I am sorry, but your version history is a bit skewed.

The B series engines have been around since the 80s now. The old 5.9L B-series engines has had a very long history now.

Version1:Inititally it was a mechanical control 12valve operation, till the late ninties.

Version2: Electronic contrtol introduced in the late nineties to meet new Emission norms making it the first ISB.

Version3: The ISB went 24valve, making it an extremely rare multivalve head which still used push rods. A few more changes too were introduced.

Version4: The ISB went common rail, which boosted the power upwards of 300hp if used in light duty trucks used mainly for pick-up trucks in America.

Version5: In mid 2000s the newer generation ISB6.7 engines were introduced, which were a big change from the older engines. Like I have mentioned these used only about 40% of the parts from the older ISB engines. Both bore and stroke were changed resulting in an increase in capacity to 6.7L.

Other further changes were also mentioned by me.

Few DI non CR version of the ISB6.7 were produced in its early years, mostly for the American market. When the ISB6.7 was introduced in the European market, they were only in CR form.

Originally Posted by Ashley2

I think the cries of BMTC is not heard by you!
Needless to say about MTC

I never said, "nobody" is complaining. I said "not many" are complaining. That is borne out of the fact that Tata enjoys 60%+ market share in the heavy CV segment, almost all of which uses Cummins 6BT engines. If you look at sales this year, Tata is the only CV maker who has maintained growth momentum still racking up close to 10% growth over last year, while everybody else are seeing sales falling.

Originally Posted by Ashley2

Hope I have explained in a detailed manner.

At the end of the day, the contention was whether the ISB engines we get in India, that is the ISB6.7 of Cummins, and the 6BT engine we get in India, which is basically a engine from the late 90's with some mild modifications, are the same or not.

I think, everybody will agree that the ISB is a massive improvement over the 6BT we get in India.

True, their service performance may not have improved vastly. If you hinge on that one fact for eternity and based on it call those two engines the same, I am sorry, but I disagree.

Originally Posted by Ashley2

If a smaller capacity engine and a larger capacity engine producing the same power and torque values and if you say the the smaller engine(here spelt by you as lighter engine) is better I would completely disagree with you.
Just take the example of Multi axle coaches of Volvo and Mercedes Benz
In a broader spec you will see both the power and torque to be matching each other:
Volvo:
Power - 340 hp
Torque - 1600Nm
Mecedes:
Power - 360 hp
Torque - 1600Nm.

But the real secret lies in the Cubic capacity of these engines. The earlier is 9 litre and the later is 12 litre engine. In a longer perspective the higher capacity engine producing same figures as lower capacity engine will have a higher efficiency/overall life.(MB engines are marginally frugal to volvo too - Unbelievable right?)
And only for the want of higher capacity( not as higher power/torque) Volvo is working to bring their 11 litre engines (may even be higher also). It should be noted that even in the current avatar they last as much as 1 million kms with out major over haul.But Volvo wants even more
Hope my statement of higher the engine capacity better the life of the engine life is clear - means ISBe 6.7 cannot ideally match 8 litre engines.
But there should be better reasons(Emission norms etc) than told by you - matching power and torque values.

You always see broad strokes and not the details.

I said the ISB6.7 matches the capabilities of older generation 8L engines. I never said that it is better than a present gen 8L engine. And here by capabilities I dont just mean peak torque and power figures. Thus it allows trucks which earlier required 8L engines, rather than shifting to a new 8L engine, to use a 6.7L engine which is both lighter and more fuel efficient.

There is almost no substitute for brute cubic capacity, when the rest is largely the same. Thus the 12L Mercedes can provide the same peak torque and power figures in a more relaxed state of tune, resulting in less stress and good mileage compared to the 9L Volvo. I am not at all surprised by that.

The bigger engine also allows the Merc to maintain a flat torque value over a wider range of rpm. I have always maintained, with my limited experience of travelling in Mercs, that it is much faster and smoother than the Volvo is in India. The larger engine allows the Merc to do so.

Originally Posted by Ashley2

All these are not under the scope of trucks in India.

The 40,000km oil change interval for the Prima trucks is correct.

[TheARUN]

If the body builders can copy VOLVO so well, then it beats me as to why these guys cannot copy other designs from abroad? There are so many designs available

[Ashley2]

Originally Posted by TheARUN

If the body builders can copy VOLVO so well, then it beats me as to why these guys cannot copy other designs from abroad? There are so many designs available

But designs include the availability of body parts!
Here Volvo parts are available for them to replicate unlike other designes

[volkman10]

Originally Posted by TheARUN

If the body builders can copy VOLVO so well, then it beats me as to why these guys cannot copy other designs from abroad? There are so many designs available

They could land in patent infringement and hence would be careful while copying global designs.

Cheers!

[Ashley2]

@ Zed : I just brought those version details to tell that ISBe'e are developed from 6BT's only. THat's further detailed by Julupani. That's it.

Originally Posted by julupani

By overhaul, I dont mean that in the sense you see from passenger car. Here the 2lakh/4lakh overhauls is more like a scheduled service for the engine component.

Both 6BT and latest ISBe need major overhaul at 10 Lakh kilometers only.

There is nothing about the Overhaul in 2lakhs/4lakhs kms.
Overhaul as a term means that opening engine, changing pistons,Machining block etc.
An engine can be overhauled once in its life time for a intended use.
If its further done the application may be shifted which means it becomes derated.

In reality what we see here with our CV's are the overhaul will be done somewhere in 5 lks to 6 lks kms and after which it will be run for another 1.5lks to 2lks (max) kms and then mostly it will be taken off from the primary purpose and put it into next level.

In 60 years of Indian CV history only Volvo's are able to proove that a CV(read as engine) which can be run left and run for more than 20 hrs a day can last for 10lks kms with out overhaul!
Now MB's are coming up - though very few have neared that as they are relatively new.

Originally Posted by julupani

True, their service performance may not have improved vastly. If you hinge on that one fact for eternity and based on it call those two engines the same, I am sorry, but I disagree.

I never told they are same. Explained that they share / developed from same platform. I stop here

Originally Posted by julupani

The 40,000km oil change interval for the Prima trucks is correct.

Yes, there is no doubt about that.
We were speaking about ISBe's in buses, Julu.

[sagarpadaki]

Hope i am posting in the right thread because i could not find a relevant thread for this.

My query is about the tires used in busses/trucks. Some have grooves in the middle just like car tires and some other have no grooves but instead have sideward facing blocks. What is the difference in functionality of these two designs?

Also i have observed that tires upfront always has grooves.The block types are always used at rear.Please note that i am taking about desi busses/trucks and not volvos/mercedes ones