Engine Design Philosophy

[Matt Suffern]

The context of the original e-mail:  Single- vs. double-row chain.

-Matt


On Mon, Nov 14, 2011 at 2:37 PM, Bernie Benz <b.benz at charter.net> wrote:
> 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
>>>
>>>
>
>