Neat video on MB-AMG website!
Thread Starter
Joined: Feb 2006
Posts: 11
Likes: 0
From: Dallas area
Neat video on MB-AMG website!
I was checking out the AMG (performance) part of Mercedes-Benz. They have a neat video on their website showing an engine being assembled.
http://www.mercedes-amg.com/ Go to: Engine Room/Guided Tour
Which brings me to my question(s):
1) Are the engines in our cars hand built too or do they just shoot them down an assembly line?
2) Is the rotating assembly balanced? With how smooth the engine feels and the fact that it is a MB power plant I would guess yes but was wondering if anyone knew for certain.
Just curious.
Edit: Oops forgot to even search to see if this had been posted before, if so forgive me...I'm a Newbie!
http://www.mercedes-amg.com/ Go to: Engine Room/Guided Tour
Which brings me to my question(s):
1) Are the engines in our cars hand built too or do they just shoot them down an assembly line?
2) Is the rotating assembly balanced? With how smooth the engine feels and the fact that it is a MB power plant I would guess yes but was wondering if anyone knew for certain.
Just curious.
Edit: Oops forgot to even search to see if this had been posted before, if so forgive me...I'm a Newbie!
Joined: May 2006
Posts: 40
Likes: 0
Re: Neat video on MB-AMG website!
According to the magazine road tests and DCX press releases, the SRT6 engine is "hand assembled" the same as other AMG power plants. Of course, the phrase itself allows for a wide variety of interpretations.
ALL mass assembled auto engines go through some form of balance checking/testing as part of the assembly process, even the cheapest units coming from Indonesia or Malaysia. For most, this is simply to check that the various reciprocating masses are all within tolerances -- which range from wide to surgically precise (guess which end AMG is at).
The 3.2 Merc V-6 is a 90 degree unit. For a V-6 to have perfect primary balance it would need to be either 60 degrees or 65 degrees. In order to achieve a smooth result from a 90 degree unit the crankshaft must have offset throws, and this will still only achieve balance within a limited range of revs. The engine will go through various resonant phases as it climbs and descends its range. I believe that the unit in the Crossfire uses conter weighted balance shafts (a Mitsubishi patent, by the way, which Porsche also used in their 944/968 engines) to quell these unavoidable vibes. While balance shafts DO work, they add total weigh to the engine and their rotating mass affects the engine's willingness to change revs quickly. This is one of the reasons the Crossfire's redline is so low for a modern design.
In other words, a band-aid, however effective. Apparently M-B though it was worth it for the packaging advantages of the shorter (top to bottom) 90 degree design (or the ability to build the engines on the same line as their V-8 engines).
As GM has shown with their LS-6 and LS-7 V-8s (Corvette, GTO, etc.), there are more ways than just DOHC and high revs to make a modern motor.
Rob Gold
ALL mass assembled auto engines go through some form of balance checking/testing as part of the assembly process, even the cheapest units coming from Indonesia or Malaysia. For most, this is simply to check that the various reciprocating masses are all within tolerances -- which range from wide to surgically precise (guess which end AMG is at).
The 3.2 Merc V-6 is a 90 degree unit. For a V-6 to have perfect primary balance it would need to be either 60 degrees or 65 degrees. In order to achieve a smooth result from a 90 degree unit the crankshaft must have offset throws, and this will still only achieve balance within a limited range of revs. The engine will go through various resonant phases as it climbs and descends its range. I believe that the unit in the Crossfire uses conter weighted balance shafts (a Mitsubishi patent, by the way, which Porsche also used in their 944/968 engines) to quell these unavoidable vibes. While balance shafts DO work, they add total weigh to the engine and their rotating mass affects the engine's willingness to change revs quickly. This is one of the reasons the Crossfire's redline is so low for a modern design.
In other words, a band-aid, however effective. Apparently M-B though it was worth it for the packaging advantages of the shorter (top to bottom) 90 degree design (or the ability to build the engines on the same line as their V-8 engines).
As GM has shown with their LS-6 and LS-7 V-8s (Corvette, GTO, etc.), there are more ways than just DOHC and high revs to make a modern motor.
Rob Gold
Thread
Thread Starter
Forum
Replies
Last Post
ty_ty37
Crossfire Coupe
29
Jun 27, 2024 10:42 AM
ala_xfire
Audio, Video and Electronics
3
Sep 28, 2015 05:51 PM
Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)