Purpose-Trapdoor in 1979-80 Fan Shroud
 

Apparently the 1979-80 L-82 fan shroud had a trapdoor at the bottom. What is the purpose of that trapdoor? Would someone with an L-82 of that vintage take a peek and let me know if it is there?

Here is a pic.

https://temp.corvetteforum.net/c3/pa...fan-shroud.jpg


[Modified by paul79, 10:17 AM 12/29/2002]

Re: Purpose-Trapdoor in 1979-80 Fan Shroud (paul79)
 

It is there but I have no correct idea as to why.

I want a :steering:

Re: Purpose-Trapdoor in 1979-80 Fan Shroud (paul79)
 

i dont claim to "know" what it is or why its there...BUT...i do have a pretty good guess because unfortunately i have had to remove mine too many times althought the other day i removed it for the last time cause im going to an elec fan and getting rid of that huge thing that is just in the way...IMHO
anyway...
judging from the way it comes out of that tight space it seems to me that the "slot" that they have cut out of it is for clearance getting by the water pump...it almost seems that without it there it would be impossible to remove...
and i dont think its a "trap door" as much as it is a "slot"... because i have never actually seen a "door" there covering that cut out "slot"
i may be wrong but thats what it seems like to me...

Re: Purpose-Trapdoor in 1979-80 Fan Shroud (Xracer)
 

To release pressure. The shrould can impead air flow at high speeds.

:cool:

Re: Purpose-Trapdoor in 1979-80 Fan Shroud (SIGNGUY)
 

There is a slot there (at the back side) and for the purpose you have stated. But there is a hinged door on the front side also. It shows in the pic above. As does the slot.

Re: Purpose-Trapdoor in 1979-80 Fan Shroud (paul79)
 

hhhmmm...i know not of what you speak...? :confused: :confused: :confused: :confused:

Re: Purpose-Trapdoor in 1979-80 Fan Shroud (Ganey)
 

So the door opens with air pressure: a simple mechanical device?

Re: Purpose-Trapdoor in 1979-80 Fan Shroud (paul79)
 

Paul, have a trap door on my 79 W/L82.Beat guess is that the radiator needed more air?? :crazy:

Re: Purpose-Trapdoor in 1979-80 Fan Shroud (paul79)
 

From your picture you are showing a new GM shroud with the trap door.
I thought that item was discontinued from GM and only available in
reproduction? Is there a current GM part no. for this item?

Re: Purpose-Trapdoor in 1979-80 Fan Shroud (Ganey)
 

Ganey is 100% correct. Your big ole clutch fan becomes a closed door at high speed so the shroud door swings open to let pressure out.

Re: Purpose-Trapdoor in 1979-80 Fan Shroud (gkull)
 

Dumb question: Does the fan pull or push air through the radiator? I always thought it pulled... :confused:

Re: Purpose-Trapdoor in 1979-80 Fan Shroud (mark79,80)
 

The GM number is 14016176, new old stock (NOS). It is available from Dr. Rebuild as 1277312 (NOS) or 1277225 (Repro).

Re: Purpose-Trapdoor in 1979-80 Fan Shroud (gkull)
 

So at speeds of less than 90mph or so there is no need for the trapdoor?

Re: Purpose-Trapdoor in 1979-80 Fan Shroud (paul79)
 

My 'vette has a cut made at the top-back of the rad shroud, just above the rad seals. A long slit, just under half an inch thick and about 1.5 feet long. Chuck Harmon hypothesized that it was there for the same reason... that's the only reason I could think.

In my naivety, I thought it was the result of a bad motor mount, but the cut really is too smooth for that.

-Steve

Re: Purpose-Trapdoor in 1979-80 Fan Shroud (paul79)
 

hmmmmmmmmmmm........

Re: Purpose-Trapdoor in 1979-80 Fan Shroud (BSeery)
 

Mmmmmmmmm? Oops what is them meaning of that?


[Modified by paul79, 8:37 PM 12/29/2002]