<VV> Cooling the Corvair Engine

[James Davis]

Case in point.  UV #388 with stock 140 exhaust system and de-flashed 
heads - could not use full throttle for more than five minutes on a 
90 F degree day (cylinder head temps 480+ F).  Removed the air doors, 
kept the lower shrouds, and reversed the cast iron exhaust - 400-450 
F degree cylinder head temps on 90 degree day @ 3,600 rpm full 
throttle (60 mph) for 30 minutes.  Replaced the cast iron manifolds 
and replaced with Clark's headers (lower shrouds in place) - 300-360 
F cylinder head temperatures on 90 degree day @ 3,600 rpm for 30 
minutes  Replaced the 65 fan and top shroud with a 61 radial blade 
(24 blade) steel fan and matching shroud - 280-320 F cylinder head 
temps on 90 degree day @ 3,600 rpm full throttle for 30 
minutes  .  Cylinder head temperatures measured with VDO instruments 
with thermocouples on both heads in thermosister location. Same 
engine, differential and transmission for 79,000 miles.
Jim Davis


   At 07:20 PM 8/3/2007, FrankCB at aol.com wrote:
>
>Guys,
>     I haven't seen anyone mention what I think is a  good possibility for
>improving the cooling of the engine.  How about  PREVENTING the heat from the
>manifolds and engine compartment piping (in the  case of the turbos) 
>from getting
>back to the engine by thermally coating the  inside AND the outside of the
>headers and turbo pipes with a ceramic  coating as offered by 
>outfits like Swain
>and Jet Hot.  The inside coating  would help protect the metal from excessive
>expansion as well as keeping the  exhaust gas HOTTER so it's more effective
>when it hits the turbine wheel in the  turbo.  The outside coating would keep
>the manifold and engine compartment  piping from sending heated air back into
>the cooling system.
>     Comments???
>     Frank "cooler heads needed" Burkhard
>
>
>In a message dated 8/3/2007 3:56:27 PM Eastern Daylight Time, ronh at owt.com
>writes:
>
>The  manifolds won't be radiating, they will be convecting and the heated air
>
>will rise up through the engine and into the engine  compartment.
>RonH
>
>----- Original Message -----
>From: "Tony  Underwood" <tonyu at roava.net>
>To:  <virtualvairs at corvair.org>
>Sent: Friday, August 03, 2007 3:14  PM
>Subject: Re: <VV> Re: VirtualVairs Digest, Vol 31, Issue  7
>
>
> > At 10:49 PM 8/2/2007, Roger Gault  wrote:
> >>Tony,
> >>I wondered about the logs heating the heads  too.  In particular, I
> >>wondered
> >>if that was the  reason the left side thermistor reads higher (under the
> >>log).   So, I insulated the area between the logs and the heads with
> >>multiple
> >>layers of aluminum foil to block any  radiation.  I was shocked to find
> >>that
> >>I couldn't  see any difference in the thermistor reading (actually,  a
> >>thermocouple mounted on a bolt in that  position).
> >>
> >>I still think the logs should heat the  heads, since they're probably
> >>running
> >>somewhere above  1000F at highway speeds, but I don't know how to explain
> >>away my  experimental results.
> >
> >
> > As long as the fan is blowing  air through the heads, it's likely the
> > manifolds won't contribute  much.   But when you shut down the engine and
> > it sits there  with the hot manifolds radiating, the heat soak  begins.
> >
> >
> > It's as good a reason to look at headers as  any other.
> >
> >
> >
> > tony..