Hole -- what happened here?

[TimDevetski]

See the photo. Any ideas what happened?

[Dave Erickson]

Is the cooling fan still intact?

[Sebastian Gaeta]

The damage looks like it is external. Are we looking down at the right side carb?

Perhaps a tool or a nut/bolt left in the engine compartment got the slingshot effect from the fan belt?

[C J Murray]

Did somebody make room for some wacky throttle linkage like Delorto or Weber?

Easy enough to fix.

[TimDevetski]

Yes, looking down from the right side. Sorry the picture is askew. Almost looks like something hit it a few times, lower and lower in progression until it went through.

[Mike Wilson]

I was thinking the same thing, Cliff. Instead of creating an indentation, a cut-out was made for the throttle lever.

[Sebastian Gaeta]

TimD,

I guess the question is did it look like that when you got the car, or did the hole just appear one day?

[Martin Benade]

Just today using a Dremel with an 1/8" burr I made a similar mess of a piece of plastic (it didn't matter). It appears that was done to your air duct. Your throttle lever looks a bit chewed up as well.

[John Brooks]

I believe that is foreign object damage (FOD), something has been induced into the cooling intake duct and this is exit damaged from the fan spinning. A nut, shroud screw maybe. If it were me I would pull the generator and fan and do a visual inspection. It's hard to see the exit shear points in the photos, but it would bet there is witness marks in the fan, this is a exit point in the shroud. Look around the engine shelf, there may be a loose screw laying in the corner.

[Martin Benade]

We will have to hear from Tim as to when this happened. I have doubts that the fan could get a screw going fast enough to go through metal, especially after making a 90 degree turn from the plane of the fan. That is a European heat duct I assume?

[Sebastian Gaeta]

This is great! It's like one of those forensic crime solving dramas, what with "exit shear points" and discussing the velocity of an object making a 90 degree turn etc.

"CSI 356"

[Martin Benade]

My grandfather and father were physicists, does that make me grandfathered in to know stuff that I don't know?

[Mike Wilson]

Absolutely, Martin! It's in your DNA!

[Larry Coreth]

This looks intentional, check out the "file" marks on the hole !

[John Brooks]

This looks intentional, check out the "file" marks on the hole !

Or threads from a bolt coming through from the inside. Bolt head at the bottom shank up. I would almost bet, if the rubber shelf seal is good, there is a loose bolt still on the shelf.