<VV> CHT Re: valve seats and "Ping"

[Mark Durham]

John, there is more to it than a more efficient fan design. The
production fan, while terrible does provide the required pressurized
air in the box on top of the cylinders for adequate cooling. I am not
an engineer, so cannot spout the data to prove or disprove the need for
a more efficient fan, because all it needs to do is to provide the air
pressure to move the air through the cylinders and oil cooler. A more
efficient fan may not improve cooling because there are other
limitations to the system like fin design on the heads and cylinders,
lower shroud design, and others. The fact that accessories like the
Otto adjustable pulley which changes the fan speed, lowers it, tells me
the fan produces plenty of air for cooling, given the system design.
Mark Durham

Sent from my Windows Phone
From: jvhroberts at aol.com
Sent: 5/14/2012 18:19
To: FrankCB at aol.com; patiomatt at aol.com; virtualvairs at corvair.org
Subject: Re: <VV> CHT Re: valve seats and "Ping"

 But did you REALLY need a gauge to tell you there was a problem? Of
course not.

And Tom had better cooling. A LOT. The problem with Bonneville is the
power is on for a long haul. Alas, the engine can't store that much
heat, like it could in a drag strip run, so, something more was
needed. And yes, as awful as water injection is, it does provide
improved cooling, well, as long as the tank holds out.

And yes, a better fan would offer better cooling. Of course, the
silver lining here is, the stocker is HORRIBLE, so, any well designed
replacement will beat the stocker hands down. And obviously,
intercoolers are a proven technology, and that's why all turbo cars
made today have at least one, and none have water injection!



John Roberts




-----Original Message-----
From: FrankCB <FrankCB at aol.com>
To: jvhroberts <jvhroberts at aol.com>; patiomatt <patiomatt at aol.com>;
virtualvairs <virtualvairs at corvair.org>
Sent: Mon, May 14, 2012 5:16 pm
Subject: Re: <VV> CHT Re:  valve seats and "Ping"


John,
     Of course gauges don't FIX any problem.  But they do alert you to
the developing problem that will shut down your engine if you don't
take measures to prevent it.  Without CHT gauges I never would have
made it home on 3 cylinders one time, or with NO functioning fan
another time.
     Wonder why Tom Keosababian used water injection at Bonneville
instead of just using "better cooling".  Maybe he just couldn't find a
better FAN or an INTERCOOLER good enough to do the job.
     Frank Burkhard
     Boonton, NJ


In a message dated 5/13/2012 9:02:13 P.M. Eastern Daylight Time,
jvhroberts at aol.com writes:
Too hot.   If the heads were cooler, there wouldn't be so much
pinging. Gages don't fix   this problem, we all know it's there.
Better cooling does!

Sure, Viton   and synthetic oil survive this kind of heat a lot
better, but it doesn't   change how hot the combustion chambers are
operating.



John   Roberts




-----Original Message-----
From: FrankCB   <FrankCB at aol.com>
To: patiomatt <patiomatt at aol.com>; jvhroberts   <jvhroberts at aol.com>;
virtualvairs   <virtualvairs at corvair.org>
Sent: Sun, May 13, 2012 2:16   pm
Subject: CHT Re: <VV> valve seats and "Ping"


Matt and   John,
     Some decades ago when I drove my 1965 180   regularly to work, it
would NORMALLY run at 400 deg.F (stock gauge and   thermistor) on
level highways at 55 to 70 mph.  Occasionally I would   "floor it"
going up a long hill to see what boost I got and the stock CHT   would
go to 450 deg.F. but I did have a electronic knock eliminator (Carter
 EKE) which may have saved me.  The boost reached 8 psig on a non
stock   gauge.  It was only after I insulated the exhaust piping
UPSTREAM of the   turbo that I was able to get 10 psig.  But the stock
exhaust piping   lasted only about 6 months before it disintegrated at
the UP-bend due to   overheating of the metal (according to the chief
metallurgist at the chemical   plant where I worked).
     My other Corvairs (110 and 95 hp   models) I ran with an
aftermarket CHT gauge installed.  This was a   Stewart Warner "Corvair
Cylinder Head Temperature Gauge" (Model 366-LW) with a   gauge that
ran from an indicated 200 to 500 deg.F. and included a thermistor
that was installed in the STOCK 3/8 in. tapped hole in the "forward
portion of   the left cylinder head".  I checked the calibration of
the gauge in   boiling water and it was right on using 14 volts.  In
operation both the   110 and 95 hp engines normally indicated 350 deg.
F.  Except for the two   times when I let it get up to 450.  One time
I had to drive home on only   3 cylinders due to only one functioning
carb fortunately on the left   bank.  The other time I had to drive
home local roads with NO functioning   fan due to harmonic balancer
separation.  Both times when the temp got   over 450, I stopped for a
time and let the engine cool off before resuming my   trip.  Both
times the engine suffered no appa
 rent damage, but it did   ha
ve the advantage of synthetic engine oil and Viton O-rings.
       That's why I believe EVERY Corvair needs at least ONE CHT   gauge.
Frank "likes gauges" Burkhard
Boonton, NJ




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