Re: stiffer valve springs

[PDQSHIP@aol.com]

In a message dated 95-12-30 09:50:48 EST, you write:


>    BUT - is it a good idea?  I don't think so.  Especially just done
>    by itself; done with a much hotter cam that needs stiffer springs
>    might be another story.  Reasons why I don't think so:
>
>	a)  stiffer springs will cause greater wear on the cam lobes
>	    and lifters.
Big Time
>	b)  as long as you can rev to whatever your redline is, and
>	    don't get valve float or hydraulic lifter pump up, then
>	    the stiffer springs won't do a thing for you.
Agreed
>	c)  If ya accidently rev it past the redline, stiffer springs
>	    will probably keep the valves working to whatever higher
>	    rev point where something else breaks ... rod bearings
>	    anyone?
And you don't rebuild the bottom end of the turbo cars, you replace the whole
thing, and with two of us working the tally was about 35hours labor
>	d)  if this is a turbo engine, there are tons of things you want
>	    to do before you even consider a higher rev limit.
Exactly
>
>Here's some open questions for everybody - 
>    what did the factory use for a rev limit on their hotrods? 
Well most of them used the mechanical cam, so not sure apples to apples
here.....   Most had a 72-7500 cut out.......
>    what gives up first when you consistently rev it past what point?
Mechanical cam will spit the shims.......  Hydraulic will tend to float in a
big way, some cylinder wash, some rod bearing prolllums, then no oil pressure
at all
>    what's the RPM range and red line on the Schrick cam grind?
Which one, they make a 268, 272, and 276 app for the turbo cars, and I know a
few folks with 300 cams (abt), the Schrick folks leave the revs the
same.......   I have the 272 with one tooth advance, and it comes on by 3k
and runs to a 7k cutoff (no cam adv it comes on BIG at 4200 to redline)......
  Increasing the rev limiter is a dangerous endeavor......  Do it based on
research; not just thinkin, cuz chances are, the tradeoffs to that extra
500rpm is not worth the sacrifice to the audi gods.......  Get into a lot of
available mods everywhere else before you start tweeking the rev limiter,
your wallet will thank you....


Scott