> From: JT McBride <James.McBride@GDEsystems.COM>
>
> Okay, I'm bit. Talk of full roller rocker valvetrains is making me drool
> for 7500-8000 rpm redlines!
>
> Do the stock '97 roller rocker setups indeed raise the redline on the 318?
I'm not an expert but I'll donate my two cents until the real experts get here:
My tach currently redlines at 4500. Seems pretty low to me. As for running at
7500, I would think that you would need to replace the factory valve springs to
get up into that territory. Even the mighty SBC (small block Chevy) doesn't go
walking in that neigborhood without tough springs.
> On a semi-related subject: How do the stock cast exhaust manifolds compare
> to the tubular headers on the market as far as torque? The implicit
> assumption in that question is that the cast manifolds do better on the
> bottom end, but I know of several small-engine examples where the better
> scavenging of tube systems improve EVERYTHING, including gas mileage.
Again, not an expert on these things: I've heard that the exhaust manifolds on
the Magnum engine are pretty fine when they come from the factory. There
aren't as many horsies to gain in that area as with other mods. This is in
contrast to my SBC that definitely breathes better through its headers.
One thing that Kukukooter told me is not to remove *all* of the back pressure
from your exhaust system unless your engine is specifically tuned for that
configuration. I believe the term "over-scavenging" comes into play here.
> That brings up one of the wonders of these vehicles. The automotive art
> has advanced to the point where I can creep along treacherous backroads
> for days, reach pavement and drop out of 4WD, and zip home at (censored)
> speeds -- all in perfect comfort. Wow! The stock Dakota is truly an
> awe-inspiring jack of (most) all trades. I strive merely to expand the
> horizons a bit...
Oh yeah, it's pretty sweet! :^) :^) :^)
-Scott Vieth http://www.msn.fullfeed.com/~scottv
'68 Camaro RS, 327/PG
'97 Dakota Sport 4x4 Club Cab, 5.2L/5-spd
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