<VV> Removing lower Shrouds

[Larry Forman]

Hi Russ,
My thoughts are to do whatever you can to lower temps and still retain them 
and THEN, after knowing your temps, do that as one of the the last 
approaches to lower temps.

There are a LOT of things you can do to lower temps.  Some of them are:
1. Deflash your heads really well.  This is the first place to start 
lowering temps.  Once you do a set of heads and compare the difference you 
will be sold.
2. Run with synthetic oil and lower oil temps by about 20 degrees.
3. Run with a 12 plate oil cooler WITH side plates as used on A/C cars.
4. Run with the new style fan, even though there might be arguments for 
another heavier style.
5. I like to paint the outer half of the pushrods with white VHT, even 
though some people say it does nothing.
6. Braze a washer in the outer end of the exhaust pushrod tubes, making 
very sure the inner hole in that washer does not contact the pushrod under 
any cam position.
7. Make sure your thermostat doors are operating properly and adjusted right.
8. Run with a deep oil pan and lowered oil pickup.
9. Maybe have radiused and improved the oil cooling flow path when 
rebuilding the engine and had the crank straightened during the rebuild to 
reduce crank bearing friction.

I am sure there are more and some people might disagree with this list, but 
it is a starting place.  Then start measuring your temps, either oil or 
CHT, and opinions differ for that also.  But, KNOW where your temps are for 
your typical driving style, weather, etc.  Then when you consider removing 
the lower shrouds, you will have the knowledge that you did it for the 
right reason and it really did something for your temps and you know how 
much that was.

The downside of removing the lower shrouds is that the engine does not warm 
up properly, as when the shrouds and damper doors are where they 
belong.  GM did not add this expense and engineering process for no 
reason.  This can create excessive engine wear during the startup 
period.  I understand that running with these removed in the AZ area is 
pretty common in summer.

HTH,

Larry Forman

At 09:21 PM 5/23/2004 -0400, Russ Moorhouse wrote:
>I was reading in the Corsa tech manual that by removing your lower shrouds
>during the summer you can lower your engine and oil temp considerably.  Is
>this something that is still advisable or are there ramifications to doing
>this?
>
>Russ Moorhouse