<VV> Running an engine without shrouds

Bob bgilbert at gilberts-bc.ca
Wed Sep 23 17:23:47 EDT 2015


Thanks for the comprehensive reply. Much appreciated.

It will be mounted on an engine stand but not one purchased. It was made
many year ago by my father and it is VERY sturdy. The main bearing that
holds the engine is almost a foot in diameter  and was originally the hub
from a large bulldozer wheel. The frame is from thick walled 6 inch pipe. In
past lives it has supported heavy diesel engines; my father built things to
last! 

The stand will be in my garage right by the door with the dual exhausts
supported and extending about 8 feet outside the door. 

All I want to do is run it for 15-20 minutes or so at 1500 RPM or so and
make sure that there are no leaks or anything else not as it should be
before I remount it in the UltraVan. Getting it in and out of the UltraVan
is a lot more difficult than a car due to the much tighter clearances in the
UltraVan. I just want to make sure that, before I put it in that I have done
everything I can to make sure it is going to be OK.  This is engine
installation number 3 in this vehicle and I really don't want to do a 4th.

Regards,

Bob

 

 

From: RoboMan91324 at aol.com [mailto:RoboMan91324 at aol.com] 
Sent: September 23, 2015 10:11 AM
To: virtualvairs at corvair.org; bgilbert at gilberts-bc.ca
Subject: Running an engine without shrouds 

 

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 <mailto:virtualvairs-request at corvair.org>
writes:

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