fan/shroud clearance
Thread Starter
Navigator
Joined: Jul 2011
Posts: 9
Likes: 0
fan/shroud clearance
My 69 350/350 runs hot when in traffic on a hot day(85+). The car has been changed around a bit and I am trying to make it original as possible. There is about a 3/4" clearance from the front of the fan and the back of the shroud, so I know some air is slipping past between and not going through the rad. I have been told that the fan should fit inside the shroud, it should extend back and around the fan...i can slip a piece of cardboard between the shroud and the fan. I think there are different water pumps that project further forward and I believe I have the right pump. The AIR is gone, so the belts are not right, there may not be the right stackup on the water pump...I dont know. Should the fan be inside the shroud?
I have pulled the thermostat which didnt really help. I can see flow through the rad with the cap off and engine running, I pulled the rad and had it flushed and flow tested and was told its in great shape....so I'm grasping at straws.
I have pulled the thermostat which didnt really help. I can see flow through the rad with the cap off and engine running, I pulled the rad and had it flushed and flow tested and was told its in great shape....so I'm grasping at straws.
Last edited by hughman321; May 29, 2012 at 09:32 PM. Reason: more info
Burning Brakes
Joined: Mar 2006
Posts: 793
Likes: 1
From: Houston Texas
My 69 350/350 runs hot when in traffic on a hot day(85+). The car has been changed around a bit and I am trying to make it original as possible. There is about a 3/4" clearance from the front of the fan and the back of the shroud, so I know some air is slipping past between and not going through the rad. I have been told that the fan should fit inside the shroud, it should extend back and around the fan...i can slip a piece of cardboard between the shroud and the fan. I think there are different water pumps that project further forward and I believe I have the right pump. The AIR is gone, so the belts are not right, there may not be the right stackup on the water pump...I dont know. Should the fan be inside the shroud?
I have pulled the thermostat which didnt really help. I can see flow through the rad with the cap off and engine running, I pulled the rad and had it flushed and flow tested and was told its in great shape....so I'm grasping at straws.
I have pulled the thermostat which didnt really help. I can see flow through the rad with the cap off and engine running, I pulled the rad and had it flushed and flow tested and was told its in great shape....so I'm grasping at straws.
Dan
Team Owner
Joined: Sep 2006
Posts: 31,287
Likes: 4,375
From: Westminster Maryland
Hi h,
Are you using a fan clutch, and if so, is it working?
Do you have the various foam seals that are used on all four sides of the shroud and on top of the core support? These are important since they force the air to go through the radiator not around it.
There's also a rubber 'flap' about 3"x36" that's stapled to the lower valance in front of the core support... is it there? It forces the air coming up through the 2 breathing holes in the front valance to go through the radiator.
Maybe a combination of things?
Regards,
Alan
Are you using a fan clutch, and if so, is it working?
Do you have the various foam seals that are used on all four sides of the shroud and on top of the core support? These are important since they force the air to go through the radiator not around it.
There's also a rubber 'flap' about 3"x36" that's stapled to the lower valance in front of the core support... is it there? It forces the air coming up through the 2 breathing holes in the front valance to go through the radiator.
Maybe a combination of things?
Regards,
Alan
Melting Slicks
Joined: Aug 2008
Posts: 2,200
Likes: 3
From: Lehigh county Pennsylvania
My '69 doesn't have that 'flap.' Would you happen to have one of your fabulous pics to illustrate it?
Drifting
Joined: Jul 2002
Posts: 1,944
Likes: 20
From: The only Corvettes in Highett Victoria
Good advice above.
hughman,
Years ago I used to sell diesel engines for a living and one thing I learned about them was the correct position of the engine driven cooling fan. Ideally, about two thirds of the fan should be INSIDE the fan shroud, and about one third OUTSIDE. Obviously this applies to all internal combustion engines, regardless of fuel type.
Sounds like you need a spacer that goes between the water pump and the fan, along with longer bolts. A cheap fix, let's know how it works.
Regards from Down Under.
aussiejohn
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Verdad Gallardo
Team Owner
Joined: Sep 2006
Posts: 31,287
Likes: 4,375
From: Westminster Maryland
Hi 69 C,
It's such a pleasure to finally be able to post a couple pictures for YOU!
You contribute so much, and ask for so little in return!
Regards,
Alan
Flap - right side
Flap - right/center side
Flap - left side
It's such a pleasure to finally be able to post a couple pictures for YOU!
You contribute so much, and ask for so little in return!
Regards,
Alan
Flap - right side
Flap - right/center side
Flap - left side
Last edited by Alan 71; Jun 2, 2012 at 03:44 PM.