<VV> Shrouds or No?

[BobHelt@aol.com]

In a message dated 12/23/04 7:40:51 PM US Mountain Standard Time, 
RoboMan91324@aol.com writes:

> please give us further 
> explanation on the "turbo" and "wear" issues.  Why would these be effected 
> by 
> missing shrouds?  Would there be additional wear to rings because the 
> cylinders 
> never reach "design" temperature with related expansion?  I would imagine 
> that 
> getting "on" the turbo a lot would tend to increase the operating 
> temperature 
> in various parts of the engine and the missing shrouds would help some of 
> these parts.  Is that what you meant?  Would this increased temp aggravate 
> the 
> wear issue of the rings because the piston/ring temp would rise even more 
> while 
> the cylinder still remains relatively low?
> 
> Inquiring minds want to know.
> 
> Doc
> 
Hi Doc, and everybody,
Yes you have it right. The additional wear would mostly be the piston rings 
and cylinders because of the slow warm up times and the failure, in some cases, 
to reach normal operating temperature. Having the lower shrouds off will 
prolong the time the engine will take to warm up. Testing has proven that ring and 
cylinder wear is greater at temps below design operating temperatures. 
Granted the additional wear may not be of concern, but it is a consideration. 

And as for the turbo operation, again you have hit it right. Bob Benzinger 
has frequently stated that the designers KNEW that the full turbo engine output 
could not be cooled. So that means about one minute (or less) of full turbo 
use before the engine overheats under summer ambients (especially Florida summer 
temps). So by eliminating the lower shrouds, some additional heat dissipation 
is gained which MAY be of an advantage if the customer intends heavy turbo 
useage. Removing the lower shrouds gives some additional cooling that would be 
advantageous in competition, etc., if that is planned by the customer.
I hope that this explains it.
Merry Christmas.
Bob Helt