RE: <tech> DOHC vs. SOHC

[Thi VanAusdal <tvanausdal@xxxxxxxxxxxxx>]

You *could* have a SOHC, 4-valve motor.  I'd be a mess with 
16/24/32 valves and rocker arms.

The DOHC means you trade reciprocating mass (rocker arms)
for rotating mass (cam and gear).  You also don't have to
adjust eccentrics if you go with hydraulic lifters (E36 M3?).

- - thi v.

> KC asks
> >What's the advantage of having two cams versus one?  I can see an
> >advantage with VANOS on one or both (more leeway for adjustment).  Is
> >there anything else that two cams do better than one?
> >
> 
> don't you *have* to have 2 cams to work a multi valve engine ?
> 
> if you have 2 valves per cylinder they can be side by side 
> (in the same
> direction as cylinders) and 1 cam can operate both valves..
> 
> but if you want 3 or 4 (or more?) valves per cylinder you have 
> a cluster of 4, and 2 can be operated from one side, but the other
> two have to be operated from the other side of the bank of cylinders
> which means another cam
> 
> is there such a thing as a sohc multivalve engine ?
> 
> 
> chris pawlowicz
> '89 325i
> '74 2002
> 
> 

------------------------------