While I appreciate your comments... I disagree... less heat is better... any
effort that would lower the temp of the intake, especially on a hot day, is a
good move... provided the cost (as per the discussion about damage to the
exhaust manifold) is balanced... Of course, a stock system works... and it
was designed to work... and it will function... but that doesn't mean you
can't improve on the design... and if you can lower the amount of heat under
the bonnet...it can help a lot of items last longer.... starter, generator,
battery.... and if you have an electric cooling fan... maybe it won't have to
run as much...
People have long experimented with heat shields... cooler air ducted from
outside the engine compartment, etc... Clearly, a thin high performance
exhaust header creates more under bonnet heat... and can even be seen to
glow... but the cast iron manifold does produce heat... a significant amount
of heat.
I'm not experiencing any problems... my car runs great... but I'm always
looking for a little extra power, reliability, etc... why not? That's what
it's about for me. Those who would like to just keep their car stock and not
tinker... can just leave it stone stock. It works. Personally, I like to
keep things relatively stock... and just enhance things... (hence a stock
header, but maybe wrapped) (Or a much better valve cover gasket!!! : )
Others... might drop a V8 under the hood... it's their call...
So... back to my original post... has anyone wrapped a cast header and
experienced negative effects?
--Justin
Shawn Loseke wrote:
> Are you referring to a cast iron manifold? If so, why bother wrapping it.
> It doesn't put out as much heat as headers do. Sure you wouldn't want to
> touch either one after a few minutes of running, but the stock manifold
> shouldn't boil gas or cause a heat soak problem with the starter. Which are
> the best reasons for any type of heat shield anyway. The headers have
> thinner walls and more surface area to radiate heat from. Hence the larger
> amount of heat output from the "extractor" (header) system over the stock
> manifold. If you are experiencing those problems with the stock manifold.
> You have problems elsewhere that need to be examined. Those components are
> designed to withstand the heat from a stock, properly tuned set up.
>
> Shawn
> -------------
> Original Text
> From: "jmwagner" <jmwagner@greenheart.com>, on 10/4/98 2:17 PM:
> What I'm wondering is.... I can fully understand why a typical thin
> walled
> steel header would simply fall apart in time with the wrapping.... BUT....
> what about a stock cast header.... these things are thick! If a stock
> header
> will only last half as long, if wrapped... who cares... what's 1/2 of
> forever? I'm just curious if anyone wrapped a stock cast header, and
> found
> problems later? I've been tempted to do the wrapping... it would seem to
> me
> to be a good thing... considering the close proximity of the generator,
> starter and intake manifold/carbs....
>
> --Justin
>
> Shawn Loseke wrote:
>
> > That's an easy question to answer. When you unwrap the header, it falls
> > apart. I've seen it happen more than once. In all cases, the owners did
> not
> > re-wrap their new headers. Remember that when you see racers use the
> stuff,
> > that doesn't mean it will work correctly for you. They often replace
> > everything every few races anyway. Their idea of longevity is for the
> > product to finish the race. Ours is usually a little longer.
> >
> > Shawn
> > -------------
> > Original Text
> > From: "Jim Hill" <Jim_Hill@chsra.wisc.edu>, on 10/1/98 4:09 PM:
> > Alan Myers wrote:
> >
> > > In lieu of a heat shield, has anyone on the list tried the high
> > > temperature insulation wrap available for headers (and probably most
> > > standard manifolds)? . . . it is supposed to not only help keep the
> > > entire engine bay much cooler, but also accelerate exhaust gasses
> > > passing through the system
> >
> > Ted Schumacher's right (DUH!):
> > > be careful of header wrap. on the dyno the header wrap has been
> > causing
> > > the exhaust to rust. you would be better off to either ceramic coat or
> > > just fabricate a heat shield.
> >
> > The price of keeping the engine bay cooler by wrapping the exhaust
> > header is that all the exhaust heat stays inside, raising the
> > temperature of the header and hastening its eventual demise. Ask someone
> > what happens when you unwrap the header for inspection after a couple of
> > years.
> >
> > Jim Hill
> >
> > d
>
> e
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