[Ricci]

Originally Posted by Sutripta

Guys, any I5 which one could buy just by walking into a (MB? Volvo?) showroom here in India? If so did these have balance shafts?

Any I4s with balance shafts sold in India?

Regards
Sutripta

I think only the Volvo now remains with a 5 cylinder engine. MB has long discontinued theirs.

As for I4s, every 600+cc motorcycle engine has a balance shaft.

[giri1.8]

Originally Posted by Sutripta

eg. The D200/ D390. Just by riding one one would not believe that these have balance shafts. Now what could be the reason? Being KTM, certainly not engineering incompetence. I think it is marketing related. What to you and me would be rough and agricultural is to the target demographic raw and primal. And desirable.

Regards
Sutripta

Couldn't be further from the truth! Duke 200 feels so raw and full of character I sold off my RX100, well refined bike would have surely made riding less interesting. On the other hand, even slight vibrations on a comfort oriented car would annoy me. Older 390 was too raw as per some owners, so how much vibes seems to be the key here.

[Sutripta]

Originally Posted by Ricci

As for I4s, every 600+cc motorcycle engine has a balance shaft.

Thanks. Could you help with an exploded parts view.

My question on I4s was more meant for cars, but your observation begs the question o why the difference between cars and mobikes.

Originally Posted by giri1.8

Couldn't be further from the truth!

Can't make out what you are disagreeing with!

Regards
Sutripta

[giri1.8]

Originally Posted by Sutripta

Can't make out what you are disagreeing with!

Regards
Sutripta

Oops, meant the other way! not sure what was I thinking I do agree with what you have said.

[Sutripta]

Does someone have access to Triumph (Motorcycles) shop manual and parts catalogue?
The Thunderbird I2 has 2 balance shafts. And the basic engine comes (came?) in two flavours, with slightly different firing angles.
So
What advantages of two balance shafts over one? Will the reasoning be the same for single cylinder engines.
Are the balance shafts the same (same part number) for the two different setups?
And how are the balance shafts phased relative to crank for the two setups?

Can anyone throw light on the Nano's balance shaft?

Regards
Sutripta

[avinash_clt]

Originally Posted by Sutripta

Guys, any I5 which one could buy just by walking into a (MB? Volvo?) showroom here in India? If so did these have balance shafts?

Any I4s with balance shafts sold in India?

Regards
Sutripta

Rexton has 5-cyl MB derived diesel engine. Don't know about the presence of balance shafts.

From VW stable, among I-4, EA189 2.0TDI has balance shafts in all its variants (110PS/140PS/170PS). The balance shafts were orderable as a module with integrated coolant pump, as can be seen here.. The newer EA288 2.0TDI is stated to have twin balance shafts in some of its variants, but don't have info if they are on variants sold in India.

Among VW I-4 petrols, I believe the older 1.8 TPI (port injection) in Octy mk1 vRS had balance shafts. The EA888 gen 2 1.8TSI in Laura/Superb Mk2, A4, A6 and gen 3 1.8TSI in Octavia mk3/Superb mk3, A3 also have balance shafts.

Pictures below from 1.8TSI in Laura. It uses two balance shafts, one on either side of the block, driven by chains. At the other end of the forward facing balance shaft is the drive for the coolant pump (a costlier and advanced unit than the pump in 2.0TDI). At the timing end, where balance shafts also get the drive from, there are three concentric sprockets. 1st plane containing the chain drive and tensioners for the balance shafts. 2nd plane contains the chain drive and tensioners for the camshaft timing. 3rd and outermost plane contains the chain drive and tensioners for the oil pump. Had the unfortunate pleasure of the knowing these gritty details as the timing chain tensioner in our Laura 1.8TSI failed partially.

Balance shaft drives in 1.8TSI


Two balance shafts on either side of the block


The busy chain/sprocket/drive of the 1.8TSI when viewed head on


The tensioner that caused the trouble and other drives. Source of image

[Sutripta]

^^^
Thanks.

What would be of relevance in India would be the I3 and single cylinder engines. But the thread has died well before reaching there!

Regards
Sutripta

[avinash_clt]

Originally Posted by Sutripta

eg. The D200/ D390. Just by riding one one would not believe that these have balance shafts. Now what could be the reason? Being KTM, certainly not engineering incompetence. I think it is marketing related. What to you and me would be rough and agricultural is to the target demographic raw and primal. And desirable.

Other readers on this forum will have different takes (maybe including that these engines are the last word in smoothness!), and it would be interesting to know their thoughts.

On another note, isn't a significant part of this perceived roughness a function of the exhaust note (than actual vibrations)? Yes the production CBR250 is refined and smooth, but a race spec CBR250 used in National one-make championships (major modification being only a remap and exhaust change on the engine side) sounds equally coarse and unrefined like a D390. Well all those exhausts on a race weekend sounds raw and unrefined, but the actual vibrations felt on your hands, pegs and bum isn't much different - as observed my brother who races them.

Originally Posted by Sutripta

My question on I4s was more meant for cars, but your observation begs the question o why the difference between cars and mobikes.

I will take a guess of this being due to 1) Higher engine rpms the inline-4 in bikes operate (13,000+), 2) Often the engine being mounted rigidly to the chassis (acting as a stressed member), no damping mounts unlike cars and 3) aside from rider comfort, vibrations could significantly affect a motorcycle's dynamics, especially mid corner.

Just thinking out loud, vibrations/mechanics weren't my best subject, advanced apologies if I am wrong on all counts

[dracul]

Originally Posted by Sutripta

Guys, any I5 which one could buy just by walking into a (MB? Volvo?) showroom here in India? If so did these have balance shafts?

Any I4s with balance shafts sold in India?

Regards
Sutripta

Sonata Gold G4JP 2.0 I4 have two balance shaft.

[abhishek46]

Originally Posted by avinash_clt

On another note, isn't a significant part of this perceived roughness a function of the exhaust note (than actual vibrations)?

In my humble opinion, the exhaust is just one component in the full NVH jigsaw.

Refined engines should have very less clatter, buzz or whine. A louder exhaust may mask this engine noise, but it will still exist.

Refined engines should have low (if not zero) vibrations at idle, and almost zero vibrations when running. An exhaust can do little to fix vibrations.

[avinash_clt]

Focusing on the source of vibration vs insulating passenger cabin: Coming to cars, a 1.8TSI is quite silent inside the cabin of our Laura. But the actual sound/clatter/vibrations of the engine is not so good compared to creamy smooth four cylinders from Hyundai or Honda of similar displacement. So the germans focused/invested on insulating the cabin (perhaps owing to limitations of being a direct injection petrol).

Coming to four cylinder diesels around the 2.0L mark, with the hood open, a 2.2L mHawk from XUV or 2.2L varicor from Storme actually sounds more refined than a 2.0L TDI that goes into many VAG cars. However inside the car, while moving, it is a different story. So between OEMs, isn't there two schools of thoughts, for one to work on reducing the vibration/noise at the source itself, and another to invest on insulating the cabin better?

Originally Posted by abhishek46

In my humble opinion, the exhaust is just one component in the full NVH jigsaw.

Refined engines should have very less clatter, buzz or whine. A louder exhaust may mask this engine noise, but it will still exist.

Refined engines should have low (if not zero) vibrations at idle, and almost zero vibrations when running. An exhaust can do little to fix vibrations.

Agree on all counts, and hence my question of 'perceived' roughness. Restricting the discussion to only physical vibrations as felt by the rider (ignoring exhaust note, engine clatter etc): I know my RE Thunderbird wishes to massage my limbs and hide everything in the rear view mirror as revs build up. A D390 is a smooth machine relatively, even with the clatter beneath me. A CBR 250 is smooth and 'sounds' refined. But from a D390 to CBR250 is there any signigcant improvement in the buzz that is transmitted to a rider's body via the handlebars,pegs, tanks, seats?

[Sutripta]

Originally Posted by avinash_clt

On another note, isn't a significant part of this perceived roughness a function of the exhaust note (than actual vibrations)? Yes the production CBR250 is refined and smooth, but a race spec CBR250 used in National one-make championships (major modification being only a remap and exhaust change on the engine side) sounds equally coarse and unrefined like a D390. Well all those exhausts on a race weekend sounds raw and unrefined, but the actual vibrations felt on your hands, pegs and bum isn't much different - as observed my brother who races them.

Sound (most people think of exhaust, but what about say the intake roar of twin DCOEs + trumpets/ no air filters?) has a huge influence on ones perception of power.

Re: CBR250R, do check that the balance shaft has not been removed, and the crank rebalanced.
In the US at least, removing balance shafts is a time honoured way of 'increasing' power. I would guess mainly because power is usually measured with an inertial dyno.

I will take a guess of this being due to 1) Higher engine rpms the inline-4 in bikes operate (13,000+), 2) Often the engine being mounted rigidly to the chassis (acting as a stressed member), no damping mounts unlike cars and 3) aside from rider comfort, vibrations could significantly affect a motorcycle's dynamics, especially mid corner.

Agree with the first two points.
Even at the risk of having a barrage of posts pointing out, say, Yamaha/ firing order change/ handling improvement, I would disagree with the third. (We are not talking of gyroscopic effects of longitudinally aligned engines.)

But from a D390 to CBR250 is there any signigcant improvement in the buzz that is transmitted to a rider's body via the handlebars,pegs, tanks, seats?

But the Dukes are IMO vibey for an engine with balance shafts.

Anecdotal 'evidence'. Once on a longish ride, my friend was on a Duke. His watch came off!

Regards
Sutripta

PS- Going off the grid from tomorrow. So next installment, if any, after a week!

[GTO]

The Jeep Compass' 2.0L diesel also gets a balancer shaft.

[Sutripta]

The EcoBoost did not have a balance shaft. And much was made of its 'solution'.
The Dragon is a iteration of the EcoBoost (without the boost! but that is irrelevant here), but this time the 1.5 includes a balance shaft! Though rumour says the 1.2 does not.
Will be interesting comparing the three engines side by side.

Regards
Sutripta

[dracul]

Once we rebuilt a Toyota 3rz engine with a brand new crankshaft. The balance shaft is 'deleted' due to the non availability of the bushes. Destroyed the new crankshaft with in 100km and we replaced the whole engine.