BB hood vents
Thread Starter
Safety Car
Joined: Oct 1999
Posts: 4,101
Likes: 10
From: NorCal
BB hood vents
I didn't want to hijack the L-88 hood thread, so here's my question. If I buy repop chrome hood inserts for the 427 hood, cut them out, cut the 'glass in the hood and keep the original chrome for the rainy season, how much will the additional ventilation help, exactly?
The openings would be right about water pump level, right? Right now most of the hot air flows out the side vents and under the car, and I want to improve air flow through the radiator and out of the engine compartment. All feedback is appreciated.
Hans
The openings would be right about water pump level, right? Right now most of the hot air flows out the side vents and under the car, and I want to improve air flow through the radiator and out of the engine compartment. All feedback is appreciated.
Hans
Tech Contributor
Joined: Jun 2004
Posts: 20,847
Likes: 959
From: I tend to be leery of any guy who doesn't own a chainsaw or a handgun.
I can't quantify how much it would help, but remember, the hot air exiting those vents will enter a rear facing L-88 hood (and into the carb) or will enter the cowl fresh air inlet for the passenger area.
Just something to consider.
Just something to consider.
Le Mans Master
Joined: Apr 2007
Posts: 7,353
Likes: 72
From: Graceland in a Not Correctly Restored Stingray
I haven't yet had the opportunity to measure pressure differentials (∆P) from beneath to above the hood to evaluate for this (on my list if I ever get my shark back on the road), but there's a good chance sufficient ∆P is present at that point to vent some of the underhood air. However, I'd hesitate to suppose the benefits from the size openings you propose would be a great amount, as such openings as often found on racecars are usually far larger, and typically duct air out directly from the rad. And, 69427's caution might well prove valid also. If you do cut them out, you can do a tuft test to at least verify air is moving out at all speeds.
TSW
TSW
Last edited by TheSkunkWorks; Oct 22, 2010 at 07:57 PM.
Thread Starter
Safety Car
Joined: Oct 1999
Posts: 4,101
Likes: 10
From: NorCal
I agree that it would be of limited worth, if any, but I'm finding that every little thing I do seems to help. My main thrust on this is low speed cooling/venting in hot weather, A/C on in MAX mode. This eliminates any concerns regarding hot, ambient air entering the cowl vent, and any help venting heated air away from the engine side of the radiator can't hurt.
I don't have to worry about value on this hood, since I've already had to repair a 14" hole in the center cut by a previous owner
Hans
I don't have to worry about value on this hood, since I've already had to repair a 14" hole in the center cut by a previous owner
Hans
Burning Brakes
Joined: Oct 2008
Posts: 955
Likes: 50
From: Jersey Shore
You can see the rad support of you look closely here:
closer shot:
The cutouts are just barely behind the radiator. I cut out my bezels as well, and drive in the rain no problem. The crossmember gets a little wet is all. The alternator is far enough back to stay dry
closer shot:
The cutouts are just barely behind the radiator. I cut out my bezels as well, and drive in the rain no problem. The crossmember gets a little wet is all. The alternator is far enough back to stay dry
Thread Starter
Safety Car
Joined: Oct 1999
Posts: 4,101
Likes: 10
From: NorCal
Boy, it's right there. It looks like it would help more at speed, developing a (little?) low pressure area there, especially with the trim in place. One sure advantage would be heat venting with the engine off. That's the perfect spot to vent the radiator when it's not moving. I'm gonna go for it and tuft the area with yarn, set up a small video camera on the windshield and see what happens.
Again, here in NorCal, it's hotter than the face of the sun for about 20 - 30 days in the summer, so the A/C and cooling system need all the help they can get. I'm insulating the hardtop as we speak.
Hans
Again, here in NorCal, it's hotter than the face of the sun for about 20 - 30 days in the summer, so the A/C and cooling system need all the help they can get. I'm insulating the hardtop as we speak.
Hans
