<VV> LM turbos and no lower shrouds

Eric S. Eberhard flash at vicsmba.com
Tue Oct 25 15:26:24 EDT 2011


Hmm ... Mobil1.com mentions their oils are safe at sustained temps 
over 500 degrees.  Of course I would expect most of the rest of the 
car to melt down!  Although my diesel run EGT temps over 1300 degrees 
for very long sustained periods and nothing has melted on that!  The 
idiot light on the Corvair comes on over 280, maybe 290, or so.  260 
is NOT hot.  In fact my Judson car does not even run well until I get 
the oil temps over 260 (head temps be darned).  If I advance the 
timing on that car I can make it so that the idiot light wants to 
come on going up the hot steep grades, so I do have to keep it (not 
surprisingly) close to stock.

Cooler is NOT always better.  The dampers on my cars seem to regulate 
temps -- rarely, in fact, are they fully open.  Generally they are 
partially open unless hot and flogging it.  With normal driving head 
temp rarely change, except on long grades when boost goes up, they 
will rise.  I suspect the doors are fully open but I never ran back 
to check while driving :-)   Check this article on Corvair oils out 
... you will note that until the oil is over 210F you are not even 
getting good lubrication and likely are bypassing the oil filter and 
using dirty oil.  Prolonging warm-up and running too cold is BAD, not 
good.  Yes it is cooler, cooler not always good.

http://www.widman.biz/uploads/Corvair_oil.pdf     (this is excellent info BTW)

Note that he points out that 320F+ temps are found in turbos ... I'd 
think the idiot light would scream as my 102 with Judson will scream 
before 290 ...

You do know they use mostly stock Corvair engine on 
airplanes?  Without any cooling fan?  With turbo motors?

I wonder if you have actually tried a more or less stock car that was 
correct?  For example, some discount the muffler design or change the 
carb.  Both of these were designed to limit boost.  If you changed 
these out ... you are running more boost than was intended, which is 
when the can of worms is opened.  Have you tried one with everything 
in place with correct carb, muffler, timing, etc?  Dwell 
correct?  All that good stuff.  And then seen if it over heats?

E

At 03:23 AM 10/25/2011, jvhroberts at aol.com wrote:
>I had an oil temp gage, and overcooled oil wasn't an issue! With oil 
>temps hovering around 260, I should've installed a more effective oil cooler.
>
>The thermostats on a Corvair were never meant to regulate 
>temperature as they do on a water pumper, they're meant to speed 
>warm up, with the possible exception of the 1960 setup. But the less 
>said about the toilet seat the better!!
>
>As such, consistent engine temps are a pipe dream on a Corvair, they 
>just don't happen, as cooling limitations abound.
>
>For a stock turbo car, anything done to improve cooling is a 
>definite improvement. Drive a stock N/A car hard, the same thing is true.
>
>John Roberts
>
>
>-----Original Message-----
>From: Eric S. Eberhard <flash at vicsmba.com>
>To: jvhroberts <jvhroberts at aol.com>; virtualvairs <virtualvairs at corvair.org>
>Cc: virtualvairs <virtualvairs at corvair.org>
>Sent: Mon, Oct 24, 2011 8:48 pm
>Subject: Re: <VV> LM turbos and no lower shrouds
>
>
>I don't think we disagree :-)  I am a turbo owner most of the time
>(don't actually have one now).  It will run cooler without
>shrouds.  No argument.  The argument is whether that is a good thing 
>or not ...
>
>The question is -- will it run consistent temperatures?  Will it warm
>up fast enough?  Will it ever run too cool (oil temps under
>220)?  Will anything be damaged by hot engine parts getting soaked in
>cold water.  How do like all that dirt and crud all over parts of the
>engine never designed to be exposed?  Throw a rock, bend a pushrod
>tube, lose an engine?
>
>And I guess it depends on your definition of "adequate" is ... mine
>is within the range on the gauge and not popping off the idiot light!
>
>The gauge on a Spyder ranges from 200 to 600 ... and generally "in
>the middle" is what is considered the normal operating range.  So 400
>is certainly not too hot.  If your car runs at 300, that is awfully
>cool and is costing you mileage.  If you are driving around town and
>it is under 220 you are sludging your engine horribly.  If you are
>425-450 you are still close to the center of the gauge and I think
>that is fine --  350-450 is pretty normal, I would not get excited
>even 25 more degrees from that.
>
>You might want to go drive it at 300 for a while, then stop, and use
>a heat measuring gun on the oil filter.  I bet you are under 220 and
>you are damaging your engine by being too cool.  Also, I bet you
>drive hard part of the time, and like a commuter most of the time.  I
>bet you have wide swings in temps (shoot it with a heat gun).  That
>also is very hard on the engine.
>
>All I am saying is that cooler is not always better and it is easy to
>keep a stock car where it belongs by leaving the stock cooling system
>alone.  If you modify it, carefully consider the cooling mods as part
>of the project.
>
>E
>
>At 05:23 PM 10/24/2011, <mailto:jvhroberts at aol.com>jvhroberts at aol.com wrote:
> >As a turbo owner, I'd have to say you're dead wrong. Mine definitely
> >ran cooler with the lower shrouds removed, and even then, adequate
> >is NOT a word I would use! These cars can always use more,
> >especially at prolonged full power.
> >
> >John Roberts
> >
> >
> >-----Original Message-----
> >From: Eric S. Eberhard <<mailto:flash at vicsmba.com>flash at vicsmba.com>
> >To: jvhroberts <<mailto:jvhroberts at aol.com>jvhroberts at aol.com>; 
> virtualvairs <<mailto:virtualvairs at corvair.org>virtualvairs at corvair.org>
> >Sent: Mon, Oct 24, 2011 5:36 pm
> >Subject: Re: <VV> LM turbos and no lower shrouds
> >
> >
> >I really think that a stock engine with the stock cooling is more
> >than adequate.  In fact, I would bet money that a stock engine with
> >stock cooling runs COOLER than one with the shrouds removed.  And I
> >dare you to drive spiritedly and get that lower part really hot and
> >then splash through some cold water.  And, I really like my heater in
> >the winter.
> >
> >You don't get much worse (for straining the cooling system) than the
> >spirited driving in AZ where 105 is common, 120 happens .... I never
> >had cooling problems even on steep grades.  I drove my little Spyder
> >30k miles and it never complained.  I've gone over 100 mph in that
> >car when it was over 100.  My coupe has A/C and PG and I can drive it
> >up a 6% grade with A/C on (which blows ice BTW stock except Sanden
> >compressor) at 75 (my engine is tweaked a little, it is a 110 instead
> >of 102) when it is 105 out, no problems.  In fact in all of my life
> >of having Corvairs (including 2 LM turbos and 1 EM turbo) and always
> >with stock shrouds, bellows, doors, and very importantly the sealing
> >of the engine compartment -- I have never had a Corvair
> >overheat.  Not even after losing a belt (STOP fast!).  In fact, if
> >anything I'd complain that it warms up too slow on cold days ...
> >seems to take forever even with the doors closed and the summer
> >plates off.  And I am not in-experienced -- I've had them 35 years,
> >10 more years if count the ones I worked on with my grandpa, and I
> >have owned as many as 10 at a time, never zero, and currently
> >2.  Last time I checked I have had more than 30 Corvairs.  I actually
> >do know what I am talking about.  So I will simply have to agree 
> to disagree.
> >
> >E
> >
> >At 03:30 AM 10/23/2011, 
> <<mailto:jvhroberts at aol.com%3Ejvhroberts at aol.com?>mailto:jvhroberts at aol.com>jvhroberts at aol.com 
> wrote:
> > >Um, the stock system is not all that and a bag o' chips. Sorry. For
> > >those of us who have turbo cars, etc., the cooling is utterly
> > >inadequate. Removing the shrouds produces a noticeable drop in CHT
> > >and oil temperature.
> > >Even on a non turbo car, if driven spiritedly, the cooling system
> > >runs out of breath.
> > >
> > >So, there is, in fact a better system out there. GM simply failed to
> > >install it!!
> > >
> > >John Roberts
> > >
> > >
> > >-----Original Message-----
> > >From: Eric S. Eberhard 
> <<<mailto:flash at vicsmba.com%3Eflash at vicsmba.com?>mailto:flash at vicsmba.com>flash at vicsmba.com>
> > >To: virtualvairs 
> <<<mailto:virtualvairs at corvair.org%3Evirtualvairs at corvair.org?>mailto:virtualvairs at corvair.org>virtualvairs at corvair.org>
> > >Sent: Sun, Oct 23, 2011 2:30 am
> > >Subject: <VV> LM turbos and no lower shrouds
> > >
> > >
> > >
> > >
> > >I am always puzzled by this discussion which comes up every so
> > >often.  The car was designed well from the factory.  If you have
> > >everything correct -- all the shrouds as well as seals and so forth,
> > >there is no better system.  I am in AZ, totally bone-stock, at
> > >altitude (3500-8000 feet), summer temps of 110 ... and I NEVER have
> > >even gotten remotely close to overheating.  Our speed limit is 75 and
> > >I can go up a 6% grade at 80, no over heating.  From my 3500 to 7500
> > >feet happens in 6 miles, no overheat even at 80.
> > >
> > >
> >
> >
> >Eric S. Eberhard
> >(928) 567-3727          Voice
> >(928) 567-6122          Fax
> >(928) 301-7537                           Cell
> >
> >Vertical Integrated Computer Systems, LLC
> >Metropolis Support, LLC
> >
> >For Metropolis support and VICS MBA
> >Support!!!! 
> <<http://www.vicsmba.com%3Ehttp://www.vicsmba.com>http://www.vicsmba.com>http://www.vicsmba.com
> >
> >For
> >pictures:
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> m/ourpics/index.html>http://www.vicsmba.com/ourpics/index.html>http://www.vicsmba.com/ourpics/index.html
> >
> >(You can see why we love this state :-) )
> >
>
>
>Eric S. Eberhard
>(928) 567-3727          Voice
>(928) 567-6122          Fax
>(928) 301-7537                           Cell
>
>Vertical Integrated Computer Systems, LLC
>Metropolis Support, LLC
>
>For Metropolis support and VICS MBA 
>Support!!!!    <http://www.vicsmba.com>http://www.vicsmba.com
>
>For 
>pictures: 
><http://www.vicsmba.com/ourpics/index.html>http://www.vicsmba.com/ourpics/index.html
>
>(You can see why we love this state :-) )
>


Eric S. Eberhard
(928) 567-3727          Voice
(928) 567-6122          Fax
(928) 301-7537                           Cell

Vertical Integrated Computer Systems, LLC
Metropolis Support, LLC

For Metropolis support and VICS MBA Support!!!!    http://www.vicsmba.com

For pictures:  http://www.vicsmba.com/ourpics/index.html

(You can see why we love this state :-) )  



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