Regarding removing the thermostat:
You use a replacement restriction (blanking sleeve, gutted thermostat) in the
system to approximate the original flow pattern, not to change flow rate. The
original designers (presumably) configured the system with a thernostat
(restrictor)in mind. If you remove it entirely you MAY change or divert the
flow pattern in certain areas which MAY cause local hotspots in the engine.
It's been known to happen in SOME engines when the stat was removed, thus the
recommendation (wisely) to at least approximate the thermostat with a
restrictor if you remove it. The point is, unless you know your engine's
cooling flow pattern you shouldn't monkey with it by removing the restriction
entirely.
Removing the thermostat is pretty pointless for street driving anyway.
Removing the thermostat to cure overheating is a false repair, unless the
thermostat itself is sticking. Sometimes people remove them cause they're sick
of replacing faulty ones, but they serve a purpose, especially for cars with
coolant-operated chokes (late Midgets). Use a high quality one, the cheap ones
fail stuck or disentegrate.
This business about fast flow being unable to "grab" heat is nonsense. Without
boring anyone with talk of delta T, film coefficients, etc. let's just say
faster flow also cools, just with a smaller increase in the coolant temp
(assuming the radiator is up to dumping the heat, and other things being
essentially equal, and yet other things being within certain limits, blah blah
blah). In an oversimplified explanation, you could say you are moving more mass
(higher flow) at a lower temp gain (delta T) to transfer the same amount of
heat as the lower flow with a higher temp gain (q = mf*Const*deltaT). We used
to speed up the flow of coolant in industrial heat exchangers to keep the
ultimate temp of the coolant down - I can assure you it "grabbed" the heat just
fine. All that being said, I doubt removing the thermostat in a car
significantly alters the flow, and that's not why you're removing it anyway
(see my first comment above).
Mike D.
--- Chris Kotting <ckotting@iwaynet.net> wrote:
> Oh boy. Here we go again. <grin>
>
> We've hashed this one out before, so it may be helpful to go and take a
> look at the archives.
>
> Chris Kotting
> ckotting@iwaynet.net
>
> Jeff Boatright wrote:
> >
> > What is this based on? I don't think it's true for the flow rates that can
> > be obtained in these engines. In fact, I'm not sure it's ture at any flow
> > rate, given a closed system. But, I can be convinced.
> >
> > At 10:23 AM -0400 8/23/99, shawn tobin wrote:
> > > Yes, you should at least have an old housing with the valve ripped out of
> it
> > > to meter the flow of fluid. Otherwise it won't stay in the radiator log
> > > enough to cool down or stay in the block long enough to grab the heat.
> > >
> > > Shawn Tobin
> > > Midget MK III 5spd
> > > Jaguar Series 3 VDP
> > >
> >
> > Jeffrey H. Boatright, PhD
> > Senior Editor, Molecular Vision
> > http://www.molvis.org/molvis
> > Mailto:jboatri@emory.edu
> > 404-778-4113
>
===
Michael B. Dietsche, P.E.
Bid and sell for free at http://auctions.yahoo.com
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