Engine Design Philosophy

[Matt Suffern]

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
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>
>