Prowler V6

[ECMnut at aol.com]

This thread has taken some interesting turns.
The forged vs cast crankshaft debate has many points.
Don't think that you absolutely must have a forged
crank in a street car (even with a turbo).
 I very much agree with you, regarding the the flex 
and superior durability of forged crankshafts. 
A relative of mine builds Chevs & some SB Mopars
for NHRA Super Stock class cars, and he insists that 
the cast cranks flex less, resulting for more accurate
spark/valve/combustion events from cylinder to cylinder.
Cast cranks have some potential,  but it is limited..
A typical SB chev V8 in a class car, (let's say a camaro)
is required to use the GM Quadrajet and correct casting
number cylinder heads, (1.94 intakes) as well as factory 
compression.  They make big power numbers because of 
insane roller cam profiles, and 8,500+ rpm.  ($ yes, it takes
a hoot of a tough a valve train $)   When doing this with a
cast crank, it is mandatory to throw the fatigued crank
away at the end of the season.  A typical 10.25 to 1 compr
small block 350 quadrajet engine in a 2900 pound Camaro
had better turn high 9's or it won't compete.   This is not to
say that they don't use forged cranks too. The use both.  
EFI content -  DFI's & other EFI systems are showing up in
many Stock & Super stock classes as of late.  Carb jetting
will FINALLY be replaced by software tweaking.  
Mike V
Hoping to see Nascar go EFI someday soon.


>     The reason for using a forged crank as compared to a cast one is
>  actually more a matter of "flexability." with a cast crank the material
>  isn't as flexable as the forged counterpart. When you consider the abuse a
>  crankshaft takes during engine operation, the constant twist and untwist as
>  power pulses are applied, it becomes fairly evident why the forged steel
>  crank tends to "live" longer. Especially when engine speed is taken above
>  5,000 revs