I think those vents give the car a little something extra!!!!! If that don't rust out something else will.
today i took the water hose and for 4-5 mins i let water pour in the cowl vents, not a drop of water hit the floor it drained out like it suppose on both side of those drains...... Saturday the combination of rain and me pouring water down the cowl vent had water pouring on the floor.. now i did take a stiff piece of wire and while i was letting water pour into the the cowl vent i going on back and forward with the wire and leaves and dirt seems like it was coming out for days.. i not guessing it like a toothache and going to the dentist when your tooth stop hurting.... this is really got me confused..
Could have just been the drains not letting the water out as fast as it came in, overflowing the chimney.
That is cool to hear that unplugging them seemed to have worked. I started fighting minor cowl problems in mine around 1994 and came up with a mixture of thinned out latex caulk, poured into the vents, with the car jacked up so that the bottom of each side of the cowl tray was close to level, with the excess running out the drain on each side. The car was my daily driver, and could not be idle for any length of time. This was very time-consuming, and it was to fix just a few pinholes ... but it was quite effective as a stop-gap measure and I am sure it is only reason why I still have the car. It weathered outside through tropical storms for the next 6 years after that. Doing this actually put a coating on the inside of the cowl pan for the first time, which is the bulk of the original problem with these. Fast forward to about two years ago ... a little more bubble-gum work (hey... already a "little bit pregnant" and still didn't want to pull the windsheild, etc ... just a little seeping), and one of those cowl hats from the kit you were looking at. My car is A/C, so the driver side has no factory hole. Sealed up tight once again, but my intent is that this car will live in a garage from here on out, and I do have a magnetic cowl cover for journeys out into the world. All that being said ... if you do have a cowl problem and the car is blown apart, get in there and fix it by welding good steel in there, and coating the inside of that lower area with Rust Bullet or something. A couple of folks have cut access holes in the upper cowl without completely removing them, and then reweld the patch. Others have snuck in through the side under the fender, cut the drain area off, coated it, and then reattached the piece. Finally, if you look at the CAMEO website ... Chip there has a tutorial on getting rid of the cowl vents and smoothing that area. If you have A/C, it gets rid of the fresh air function, but here in FL, you just run the air on Max anyway after get the hot air out of the car ( vent a window instead). Here is the website .... look under "Restomod" ... http://www.cameoclub.com/ Best of luck with it ... cowls are one of our biggest issues.
I did the thing where you remove the fender and cut the end of the cowl off to coat, then weld the ends back on. I'm considering eliminating the vent and smoothing the top. Someone on here mentioned that if the ends of the cowl are opened up and a duct run inside the fender / wheelwell you can still get good airflow to the inside of the car.
Using the side of the cowl and sealing the top sounds pretty good. You may want to open up that plastic splash guard a bit. Going one step further is something that some of the guys doing Cobra replicas do .... a fresh air system, with a blower under the fender and a duct that runs from the front of the car. Cobras have alway been known to bake your toes a bit. An aftermarket fresh air kit is mid-way down this page ... this guy is well-known in Factory Five Cobra realm. http://www.cobraearl.com/products/ For that matter ... merely sneaking a duct unpowered back to the side of the cowl could work really well, if done right.
well i waited a few days got my water hose and let water run into the cowl yet again no leaking.... maybe i was dreaming, and maybe not
I welded new sheet metal into cowl vents of my '75. I like the looks of the factory vents better, just because, I like to leave things the way they are. But, I have to say, that it looks as if it came from the factory like it is now. I did a pretty good job on it, if I say so, myself. I litterally, poured POR15 down the cowl, just as if it was water, before I welded the top part in. I then coated the bottom part, of the cowl with POR15. I could also see, where the POR15 had run through the couple of small places, of the cowl, from the bottom side. I feel confident that, My cowl is coated well, with POR15, on top and bottom. I have had no indication that it is not.
I removed the fenders and cut the cowl ends off to address some pinholes in the drivers side. It wasn't too bad, but I wouldn't just do it again for fun. I was looking at pulling air from behind the splash shield while I was there and it's definitely do-able. I wouldn't cut the splash shield at all though, just to keep road wash out of your prospective vent. It would pull plenty of air through the area ahead of the passenger door.