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Had a general question about the opening up the hood vents on a C3 big block hood. Has anyone experimented with opening up those two rectangular vents in a 454 hood? This would be the area that is initially blacked out by the vent trim. Vents of this type were common on ferrari of that time period and I assume it would help cooling.
I'm not sure if this will be what you're looking for, but this is what I did to my hood a number of years ago. I designed the grills to make them look, like something from back in the day and had those cut from aluminum and then powder coated. My buddy then cut the hood to match with a half inch inner gap on all sides.
Chevy did this on the 65/66 BB hoods. They have water shields on the underside to keep water from directly hitting water sensitive items. It DOES exhaust a lot of engine compartment heat.
2020 Corvette of the Year Finalist (performance mods)
2019 C3 of Year Winner (performance mods)
2016 C3 of Year Finalist
Someone here has done that. I think its about where the fan shroud is and the problem is the radiator is tilted the wrong way, its actually tilted back where the Ferrari is tilted forward so the heat comes from below up and straight out the hood. There are a lot of threads on hood vents here with options for fender mounts as well as using aftermarket C7 style hood vents. Lots of pics too. I added the Midyear big block vents to my L88 hood to vent the heat from the headers....it seems to work as its not nearly as hot under there when I open the hood. I don't have any actual temperature measurements but some guys actually do. And I didn't use the rain shields as it blocks a lot of air flow
From: I tend to be leery of any guy who doesn't own a chainsaw or a handgun.
I've been kicking around opening up the hood scoop area for quite some time (mostly to help reduce front aero lift), but wanted to put some acceptable looking screening in the holes for a more "finished" look. Recently found some aluminum screen that's a possible candidate. Might start cutting some holes/slots this spring.
I have a buddy that took a sheet of aluminum punched some maybe inch and a half holes in it with a dimple die and covered a couple holes in his hood and it looked good.
Thanks for all the gorgeous photos and specifically Rescue Rogers - you were correct, and I much appreciate the "string" analysis" update in the link supplied. I think I will go-ahead and open up the vents in my hood.
lots of hot air exiting via the air vents, at normal around-town driving. didn't need to go 100mph (gee whiz WTF!) for air to get sucked out. I do have the full complement of foam radiator support seals, and foam seals along the top and sides of the radiator.
the metal hood vent inserts get so hot from the hot air exiting, you'd burn your hand if you rested on it after a 15 minute drive.
if it rains, the hood-vents drip right onto the fan belt (alternator). if it rains a lot, the belt starts slipping. not good, because when it's raining cats-and-dogs, you usually have the blower-fan going full blast to keep the windshield from fogging up, and the windshield-wipers flapping away. speaking from experience.
My front turbo intakes are not opened up (yet) the rear vents are connected to a sealed off DIY CAI setup that works really well. the temp sensor I have inside the air cleaner registers temps that are normally 20-40 degrees cooler than under hood temps.
Last edited by augiedoggy; Jan 10, 2023 at 02:32 PM.
Had a general question about the opening up the hood vents on a C3 big block hood. Has anyone experimented with opening up those two rectangular vents in a 454 hood? This would be the area that is initially blacked out by the vent trim. Vents of this type were common on ferrari of that time period and I assume it would help cooling.
I really don't see how opening these will do much as they are in front of the radiator core support......could relieve some lift at high speed but from a cooling aspect worth nothing.
2020 Corvette of the Year Finalist (performance mods)
2019 C3 of Year Winner (performance mods)
2016 C3 of Year Finalist
I believe the vents are just behind the radiator support as that is where the seal is and the seal hits the hood infront of the vents...Openning them up would let the radiator heated air directly out at the fan....presumably..Im going to remeasure mine and if its right there I am openning mine as well. The weep holes that are already there on my L88 hood drip down onto the belts so I am guessing it will be in a great place
I also started a thread on this very topic last summer. Many of the same folks commented there as well (thanks again all!). Good information. I think a lot of the stuff members have done to vent their cars is creative and looks good, but after all that, I realized it didn't want the trouble of trying to cut openings into the chrome hood trim (which was the only option I would have gone with). (non-l88) 427/LT1 hoods without those chrome trim pieces just don't look quite right to me - looks unfinished.
As clean as the work is from many of the members who have done in adding vents, for me, the only option that would look the most factory-like would be to use the existing fake BB/LT1 vents, and that potentially puts a lot of water all over the front of the motor and frame (during car washes, or even if caught in a flash storm).
For now, I've decided to be content with the 'fake' vents in the (non-L88) BB/LT1 hood, and to leave it be.
Below is the above-thread I created on this forum, for reference:
Opening Hood vents
