On Wed, 9 Jul 2003 10:05:14 -0400, "Jacques Mertens"
wrote:

Maybe I misunderstand but are you asking about the little round ones close
to the sole?
I don't know where to find them but if that is all the venting for that
engine box, your engine will not get enough air.
It would not be sufficient for a gas engine but diesels need twice the air
of a gas engine.
There should be large louver vents on the front or side of the engine cover.
If that is not possible esthetically, you may want a blower that sends air
in the bilges.

PS: engine installations where my primary business for 10 years.

Aren't you puzzled by your observance that Chris-Craft designed an
engine box which would prevent an engine from running?

Actually, the engine is not totally dependent on these small vents for
air for the engine. The engine box is not somehow hermetically sealed
to the floorboards. Many, if not most, runabouts have no holes in
the engine box. In a runabout the air flows from the bow of the boat
to the rear. Typically, a runabout has a forward facing vent on the
foredeck. This vent typically has a tube underneath it which extends
to the bilge. Also, the area between the dashboard and the upper
floorboards (placed at a roughly 45 degree angle) is almost always
open on a runabout. Usually, a runabout will have another set of
forward-facing vents at the forward end of the engine compartment. On
a "utlity" type of boat (engine in a box) like Mr. Warner's, these
vents are on the side decks. These vents have a tube underneath also.
On the rear deck there will be two aft facing vents. These have no
tubes. The whole idea is, of course, to promote air circulation low in
the bilge so that explosive vapors do not accumulate. Most runabouts
are designed so that there is nothing to impede air flow in the bilge
from stem to stern.

Air supply for the engine comes to some extent from the air flow
provided by this on deck vent arrangement. However, I suppose most air
for the engine comes from the bilge area. And the main supply for this
area is the space between the dashboard and floorboards forward.

My guess is that the vents on Mr. Warner's Sea Skiff are there largely
for style considerations. Some Sea Skiffs have a plywood "bulkhead"
forward of the dashboard which goes from keel to deck. If this Sea
Skiff has this bulkhead, the additional vents on the box might
actually be providing additional marginal air supply. However, a Sea
Skiff has steam bent frames. There will always be a opening for air
circulation between these frames where the floorboards meet the hull
sides.

Chris-Craft would not design a boat in which the engine was sealed so
that it would not run.