<VV> Running an engine without shrouds

RoboMan91324 at aol.com RoboMan91324 at aol.com
Wed Sep 23 13:10:46 EDT 2015


Bob,
 
Yes you can.  .... on the following  assumptions.
 
You said "before I install it."  I assume you are  running it on a pallet 
or other test bed.  If this is  the case, I don't see how having the shrouds 
on or off will make any  difference.  Installed shrouding inside an engine 
compartment is designed  to pull air from a particular direction and seal off 
from other  directions.  The engine being free of the engine compartment 
will allow the  fan to suck from anywhere with or without shrouds.  With the 
motor "hanging  out there" the cooling may be better.
 
On that note, I assume you are talking about motor to body  sheet metal, 
right?  That assumes that the other sheet  metal between the heads, turkey 
roaster, etc. is where it should  be.
 
I assume you are not going to run it under  heavy load.  If this is the 
case, cooling needs will be minimal  anyway.  The thermostat controlled 
shrouding under the motor will probably  not be necessary for test purposes.
 
Keep in mind that the shrouds are there to duct fresh air in  from the top 
of the car or sides of the FC so you aren't sucking up as much road  debris. 
 In the summer, the air from above is usually cooler than the  air that 
might be pulled up from just above a hot roadway.  Also, the  factory system is 
designed to minimize sucking in exhaust fumes.  While the  exhaust fumes 
issue would cause minimal problems for cooling, you don't  want that stuff 
circulating through your passenger compartment heating system  which comes off 
the motor.  Exhaust from running the  motor for test purposes shouldn't be a 
cooling issue but make sure you don't run  the motor in an enclosed garage. 
 People die that way ... and quickly  depending on the garage volume.
 
Not to be morbid but running a motor in an attached garage can  be deadly 
to everyone in the house and not just the garage.  This is  especially the 
case with people (and pets) already suffering from lung  ailments.
 
Lastly, I don't know what your test setup looks like.  If  you try to run 
your motor on an engine stand and give it a hardy goose of the  gas, the rig 
might want to flip over with resulting disaster to the motor, your  knees, a 
fender, etc.  When the rotating mass (flywheel, crankshaft, etc.)  wants to 
accelerate in one direction, the "stationary" mass (block, heads,  
cylinders, etc.) wants to turn in the other direction.  You have probably  seen a 
motor in an engine compartment tilt over when you give it a good shot of  gas. 
 The only thing keeping the engine from spinning wildly in the engine  
compartment are the motor mounts attached to the significant mass of the  car.  
A motor on the floor strapped on a pallet is much more stable than  one 
sitting up in the air on a stand that may be a bit wobbly to begin  with.
 
Be careful,
 
Doc
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
In a message dated 9/23/2015 9:02:10 A.M. Pacific Daylight Time,  
virtualvairs-request at corvair.org writes:

Message:  1
Date: Wed, 23 Sep 2015 08:33:06 -0700
From: "Bob"  <bgilbert at gilberts-bc.ca>
To:  <virtualvairs at corvair.org>
Subject: <VV> Running an engine  without shrouds
Message-ID:  <002201d0f615$25ee3a60$71caaf20$@gilberts-bc.ca>
Content-Type:  text/plain;    charset="us-ascii"

HI,

I've just  started the rebuild of my 3.1 engine for my UltraVan and this 
time I want to  test run it before I install it.

Can I safely run the engine without  shrouds?

Thanks,

Bob

66 Corsa 180 convertible

68  UltraVan



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