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I’m in the process of tearing apart my 73 big block Coupe as part of my restomod project.
Today I removed the radiator shroud and radiator.
As part of my project, I’m replacing the radiator and shroud for a DeWitts aluminum radiator, shroud and dual Spal fans.
After I removed the stock shroud and radiator I noticed that the area between the bottom of the radiator and front crossmember was now open where with the stock shroud in place this area was sealed by the shroud.
Will this cause any known problems with air flow through the radiator?
Last edited by OldCarBum; Jun 24, 2022 at 11:21 PM.
in my experience, yes. Every engine and set up is different, but not having that bottom part of the shroud caused overheating issues for me.
I cut the shroud to just be the lower portion and reinstalled it.
You could always try without the shroud, if you have temp issues you know what to do.
I’m in the process of tearing apart my 73 big block Coupe as part of my restomod project.
Today I removed the radiator shroud and radiator.
As part of my project, I’m replacing the radiator and shroud for a DeWitts aluminum radiator, shroud and dual Spal fans.
After I removed the stock shroud and radiator I noticed that the area between the bottom of the radiator and front crossmember was now open where with the stock shroud in place this area was sealed by the shroud.
Will this cause any known problems with air flow through the radiator?
It did not for me but I run the "be cool" spal cloned that had the be cool logos ground off and are sold cheap on ebay (seconds I guess?) I also have a 3 row champion rad. My car is adjusted now to stay around 180 degrees but when I had a different state and the fans setup for 165 the car never went over 174 I have the spal aluminum mounting plates and no weatherstripping between the fan shroud and rad. if anything my engine compartment stays cooler with the new setup. this was after the car was running for 45 mins and I was cruising through town about 30mph stop light to stoplight... bottom temp is a sensor mounted 5 inches from the passenger sidepipe header/head mount. 124 degrees under the hood.. top temp of 83 is a sensor inside my air cleaner housing. (new diy CAI) it was about 80 degrees outside yesterday. engine temps were 168 here since i was playing around with when the fans kicked on and they were both adusted to come on too early. ignore the afr the camera caught it mid refresh rate, thats not what it was displaying.
If Dewitt’s rad and shroud…i would call them to confirm and question why open.
I found them very responsive and for the money spent expect the best turnkey.
i like that big one fan they are advertising, but i would expect from them some good consultation…
good luck!
Yup, it's open with dual Spal fans. The only reason it is not open with the stock shroud is to ensure that the clutch fan draws air through the radiator. No problems in my 80, but that year got a redesign to flow even more air into the radiator.
As long as the lip spoiler and perimeter seals are intact, you'll be fine. Your fans are unlikely to come on unless stopped at idle.
Last edited by Bikespace; Jun 25, 2022 at 08:36 AM.
Thanks everyone.
My thoughts were the same as everyone’s, but thought it doesn’t hurt to ask.
It will be nice to have more open space under the engine compartment so air can circulate and allow more heat to escape when parked.
I’m also adding a vent to the hood to allow heat to escape.
Thanks again!
I’m replacing the radiator and shroud for a DeWitts aluminum radiator, shroud and dual Spal fans.
Running the same combo in my '73 with no issues as far as engine cooling performance. I did have one electrical gremlin that cropped up years later. The two white plastic wiring connectors that came with the dual Spal kit, had begun to discolor as the connections were overheating. The wiring connection itself was green with corrosion. I replaced those connectors with some good Weatherpack connectors and all is well again.
GM learned something after 1977 about c-3's. It was called the chin spoiler directly below the radiator. The idea is to stop air flow under the car which created high pressure under the hood. Not only front end lift as speed increases, but also pressure behind the radiator which slows flow through the radiator.
You want low pressure behind the radiator which the chin spoiler creates.
Thanks, and I’m planning to add a new wider chin spoiler.
I’ll make my own unless I can find a nice one offered by one of the vendors.
Most of the ones I see offered for sale aren’t ones I would be interested in.
That looks correct. I don't have a good photo right now. There is also a 79 only extension spoiler, that screws onto it. It should work for other years, too.
My 73 is setup the same as interpon. You should have a chin spoiler along with whatever that cover piece is under the chin. With this setup relatively no air can get past the radiator without going through the radiator. Works well on mine. I dont have pics of that piece of my car handy, but basically the same.
My 73 is setup the same as interpon. You should have a chin spoiler along with whatever that cover piece is under the chin. With this setup relatively no air can get past the radiator without going through the radiator. Works well on mine. I dont have pics of that piece of my car handy, but basically the same.
I have the stock oem chin spoiler but I also want the extension for the additional cooling factor.
Thanks!
2020 Corvette of the Year Finalist (performance mods)
2019 C3 of Year Winner (performance mods)
2016 C3 of Year Finalist
Originally Posted by OldCarBum
I’m in the process of tearing apart my 73 big block Coupe as part of my restomod project.
Today I removed the radiator shroud and radiator.
As part of my project, I’m replacing the radiator and shroud for a DeWitts aluminum radiator, shroud and dual Spal fans.
After I removed the stock shroud and radiator I noticed that the area between the bottom of the radiator and front crossmember was now open where with the stock shroud in place this area was sealed by the shroud.
Will this cause any known problems with air flow through the radiator?
Yes it will as air will flow with the path of least resistance. For exaple the 68 has a smaller radiator support and used rubber seals in alot of those places your shroud had sealed. You can probably find something like a heavy inner tube, make something out of tin or fiberglass and RTV it in there to seal it up, you will notice on the highway but not in very slow traffic
Yes it will as air will flow with the path of least resistance. For exaple the 68 has a smaller radiator support and used rubber seals in alot of those places your shroud had sealed. You can probably find something like a heavy inner tube, make something out of tin or fiberglass and RTV it in there to seal it up, you will notice on the highway but not in very slow traffic
As others like myself running this setup have said, It does not effect cooling other than in a positive way because the shroud is mounted against the rad with the fans mounted on it. its sealed up better than the stock shroud and fan was. When the fans are off while the car is moving the air coming in through the front is still just as effectively pushed through the radiator. it does NOT matter where the hot air thats already been used to cool the rad on the goes on the backside. The engine is liquid cooled not air cooled from hot rad exhaust if im on the highway my engine temps hang out at about 174 with the 180 degree stat and this setup.
Last edited by augiedoggy; Jun 28, 2022 at 11:29 PM.
Air Flow Issue?
