[Shotimes] M3 vs. GSX part 2 (long)

[Ron Childs]

As I recall, Buick extended the life of their V6
(which is today's GM 3800) by going to the "even fire"
crankshaft. I think that many newer engines have
offset cranks because of odd cylinder bank angles. 

As I had mentioned previously, the "even fire" cranks
will make the engines smoother because the cylinders
fire at even intervals but they will not help with the
inherent imbalance cylinder bank angles mismatched
with the number of cylinders. Balance shafts do. 

I think (somebody chime in if I am wrong) that
horizontally opposed engines (Porsche, Subaru, etc.)
are the best as far as natural balance. 

-Ron 

--- BJamesjr@aol.com wrote:
> I spotted my 97 Helms manual on the bookshelf so I
> did a bit of looking.  The 
> manual clearly shows offset crank journals on the V8
> crankshaft.  I can't 
> tell if they offset them enough to even out the
> firing pulses or not.  I 
> thought I remembered that GM offset the crank
> journals on some of their 90 
> degree V6's to help with this.
> 
> Also I found a diagram of the front of the engine
> that would lead me to 
> believe that the balance shaft turns at crankshaft
> speed.  The only diagrams 
> I can find that show part of the balance shaft
> basically show a shaft with an 
> eccentric weight on it, sort of like a camshaft with
> a single very long lobe 
> on it.