Engine Design Philosophy

[Bernie Benz]

Row what?

On Nov 14, 2011, at 10:48 AM, Matt Suffern wrote:

> That would be single- vs. double-row.
>
> -Matt
>
>
>
> On Mon, Nov 14, 2011 at 1:47 PM, Bernie Benz <b.benz at charter.net>  
> wrote:
>> Please explain your meanings of simplex vs. duplex in this respect.
>>
>> Bernie
>> On Nov 14, 2011, at 8:21 AM, Matt Suffern wrote:
>>
>>> Someone explain this to me.  Looking through the parts catalog I  
>>> study
>>> the valvetrain diagram for the 3B.  I notice Audi has retained a
>>> timing belt design with a simplex chain to link the exhaust camshaft
>>> with the intake.  My BMW 525's M50, by contrast, has a duplex timing
>>> CHAIN with, again, a simplex chain linking camshafts.
>>>
>>> Both engines can last upwards of 300K miles.  So why the overkill on
>>> BMW's part?  Four more valves to operate (1 more cylinder)?  Or did
>>> they just assume people aren't going to do regular maintenance like
>>> timing belt changes?  It just seems like an awful lot of added
>>> complexity and valvetrain inertia to avoid a procedure most people
>>> assume is going to have to be done anyway.
>>>
>>> Curious.
>>>
>>>
>>> Matt
>>> Winston-Salem, NC
>>> www.spannerhead.com
>>> _______________________________________________
>>> 200q20v mailing list     http://www.audifans.com/mailman/listinfo/ 
>>> 200q20v
>>
>>