<VV> LM turbo's and no lower shrouds

[ScottyGrover at aol.com]

Eric- re: overheating--have you tried getting a combination vacuum  
advance/pressure retard instead of the retard-only system that comes  stock?  
Anything that promotes a more correct timing not only improves fuel  mileage but 
may reduce the overheating.  If any doubt exists, e-mail Frank  
Burkhard--he's the turbo expert.
 
Scotty from Hollyweird
 
 
In a message dated 10/23/2011 11:04:05 A.M. Pacific Daylight Time,  
wrokit at hotmail.com writes:


Eric- I think your head temps have alot to do with you being at  a higher 
elevation than others. At 8000 ft, the dynamic compression ratio of  your 
engine is approximately 1.5 points lower than at sea level, which would  make 
your engine run cooler compared to sea level operation. Also, the  
carburetor, because it is getting less air, but the jetting didnt change,  gives the 
engine a richer mixture at altitude, causing the engine to run  cooler than 
it normally would. I do live at sea level, and have a early turbo  and know 
others with early turbo's, and can assure you, 430 degree's cruising  down    
the freeway at 70mph during the summer temps of 80 degree's  IS fairly 
normal, unless you do something about it.  Kevin Nash
>  > -----Original Message-----
> > From:  virtualvairs-bounces at corvair.org
> >  [mailto:virtualvairs-bounces at corvair.org] On Behalf Of Eric S.  
Eberhard
> > Sent: Sunday, October 23, 2011 2:29 AM
> > To:  virtualvairs at corvair.org
> > 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.
> > 
> > I  believe that those that overheat and think they need to 
> >  remove/modify shrouds simply have other problem they are compensating 
>  > for.  Mine is a 62 EM and perhaps it is different, but I have had to  
> > EM turbos as well and neither ever had a heating  problem.
> > And we get 20 degrees in the winter, so having those  shrouds on then 
> > is crucial and I don't need the hassle of  swapping them on and off.
> > 
> > One writer pointed out  the correct heat is required for quick 
> > boost.   Correct.  Some people even wrap their exhaust to push temp 
> >  even higher, for that reason.  Some people mistakenly use a "free  
> > flowing" muffler which actually reduces boost and is bad.   I used an 
> > NOS turbo muffler.
> > 
> > Keep it  stock and it will be absolutely reliable (my only mods are 
> >  electronic ignition and related upgrades).
> > 
> > If you  have heating problems -- are your plugs too hot?  I use Nology 
>  > Silverstone plugs and they perform very well with a 38 gap and hot  
> > ignition, no overheating.  They are made for vintage  cars.  They are 
> > expensive, but I have over 30k on them and  they are clean as a whistle.
> > 
> > BTW -- opinions are  like belly buttons and so I have one.  I respect 
> > others, as  other people have done neat things.  I am not a good 
> > enough  amateur mechanic to re-engineer things.  But I believe a 
> >  properly set up stock system -- not all that hard to achieve -- is 
>  > going to be reliable.  Doing the ignition and putting a Judson on  one 
> > of my cars is sort of the limit of my explorations.   However, my 
> > Spyder always has instant boost (no lag), boosts at  2000 rpm in 4th, 
> > pulls to redline, and I can't overheat  it.
> > 
> > So if you are in the mood, you might try making  it factory spec 
> > first, seeing how that goes, and then  modify.  Otherwise, you might 
> > mask a problem that later  gets ugly.
> > 
> > Eric 
> > 

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