Diesel Engines annoy the hell out of me with their vibration

[Ferraricalifornia]

sure they are....

 

but they're nowhere as refined as petrol engines.....

 

gotta give and take lor.....

[Mini-itx]

sure they are....

 

but they're nowhere as refined as petrol engines.....

 

gotta give and take lor.....

 

Actually its not so much about refinement. Its mainly due to the RPM they operate at. Petrol engines idle 800-1000RPM (and now new ones have balancer shafts). Of course they are much smoother and cause less vibration.

 

Diesel engines idle at much lower RPM, thats why vibration is much more pronounce at idle. If you have driven a manual car before, you will know. If the RPM drops till around 500-600 (going to stall because you didn't clutch in), you will notice the massive vibration as well.

 

IF you managed to look at the tachometer of the SBS bus, see how low the RPM is when they are moving. Its much lower than diesel cabs.

 

Bigger engines will also naturally operate at lower RPM due to Physics limitation. Just like tiny bike engines revving till 10-12K easily but cars cannot.

Edited September 22, 2010 by Mini-itx

[inlinesix]

Actually its not so much about refinement. Its mainly due to the RPM they operate at. Petrol engines idle 800-1000RPM (and now new ones have balancer shafts). Of course they are much smoother and cause less vibration.

 

Diesel engines idle at much lower RPM, thats why vibration is much more pronounce at idle. If you have driven a manual car before, you will know. If the RPM drops till around 500-600 (going to stall because you didn't clutch in), you will notice the massive vibration as well.

 

IF you managed to look at the tachometer of the SBS bus, see how low the RPM is when they are moving. Its much lower than diesel cabs.

 

Bigger engines will also naturally operate at lower RPM due to Physics limitation. Just like tiny bike engines revving till 10-12K easily but cars cannot.

I used to drive E36 325. Idling < 500 rpm. Damn smooth.

[Mini-itx]

I used to drive E36 325. Idling < 500 rpm. Damn smooth.

 

Yours should be the M50B25 engine right? Good stuff!! Cast iron block!!

 

Btw, inline 6 engine is inheriently balanced. Thats why vibration way less pronounced compared to a inline 4 (all inline 4s are not balanced, V engines are not balanced as well), coupled with hydraulic engine mounts. Very smooth idling.

 

I used to have E39 528 and E36 318is as well. Very smooth engine for the M52B28 engine. But the M42B18 not so because its inline 4.

 

Btw, long strokes affects vibration as well. The bus engines have very long strokes compared to cars.

 

New diesel engines today should be alot more smooth compared to old engines.

[Happily1986]

actually regarding the vibration of the buses,

 

wait till you sit in those old Hino's or UD buses by SMRT.....

 

Most Hinos are already gone or at the most in lay up. Mai siao siao kay. Hinos have the largest displacement engines of all buses thus far. 13000cc.

[Alechi]

Daytime noisy ... Imagine night time. Sigh ...

[Ferraricalifornia]

those new LE500 are a godsend for my estate nia....

 

much quieter than the older Mercedes buses as well as bendy buses....