I am thinking of adding some louvers to the bonnet of the Mk2 and wondered what other peoples experience with them is. If anyone has them did they get them pressed, riveted or welded in ?
I was speaking to a fabrication firm today who specialize in high end bodywork restoration and they mentioned about inverting the louvers so the pressed out section is pointing down into the engine bay and not sticking out the top of the bonnet if you see what I mean. Have never seen them like that.

 

I think Doug welded some in, you can get them pressed directly into the bonnet, Sportscar Metalworks in Bucks do them and they are close to you.

There is some argument that they let water into the bonnet directly on top of the engine and HT leads, this would be even worse if they were pressed down.

I have not had them, so can't comment from personal experience.

 

Hi again TilleyJon, I contacted them last night and awaiting a reply.
I see what you mean about water ingress being worse, water being pushed up the bonnet while driving and running down the louver instead of around it. Could make up some collectors under the bonnet but starting to defeat the purpose of letting hot air out.

 

Collectors have been an option adopted with the Coombs vents by some, if you are looking at engine bay cooling, look at Primaz's thread re his sleeper 3.8S, he has incorporated an air ram and engine bay vents, which I have also done/will do.

I have used the same vents in the inner wings, but have yet to fabricate/install the air ram. Primaz has posted pics on my thread of his air ram also, neat and tidy, and far better ventilation.

 

Do you have any pics of the inner wing vents in situ.
Thanks

 

Have a look here

https://www.jaguarforums.com/forum/m...-173766/page3/

 

Jon is right with the ram air vent scoop underneath the front valance it will scoop large amounts of air and then I have a sheet metal "V" that then directs that air around the engine and then the air vents out thru the triangular holes which Jon posted pics of. I do want to point out that it is the combination of both that enable the engine bay to keep cool. I had the triangular vent holes prior to the ram air intake and that did NOT keep the engine bay cool, in fact it was a oven until the addition of the ram air intake. The Jaguar as a poor design to vent out air out of the engine bay but with these mods it is not an issue which is key in stop and go driving.

 

Thanks Primaz,

by the way, you don't by any chance have any fabrication drawings for the ram do you ?

 

no, but if you would pay the cost of shipping from California, my body shop designed it for me and they can make a set for you. The shop is Market Auto, 140 San Jose Avenue, San Jose, California 95125. Dave Hoang 408 561-5644 themarket9898@sbcglobal.net

What is ironic is that my car came with a louvered hood that was stamped typical of most old hot rods but I did not like the looks as I wanted my car to be a sleeper so that nobody would suspect that it was a fast modern restomod car. I never ran my current V8 with the old hood so I do not know if that would have kept the engine bay cool enough. I still suspect that you would have to put a lot of louvers to really help as what was weird was the previous owner had a pony radiator under the front fenders? To me my original car as a half *** attempt to put a V8 and it was an iron block heavy not that powerful Chevy 350. Sorry A1lry, I sold the hood locally to a Jag owner. Now with the LS1 being lighter than the stock 6 and so much more power the car is exactly what I was hoping for...

 

Thanks for this, how far does the ram air come down below the front bumper ?

 

Not that much at all. There will be no clearance issues at all, as my 3.8s is highly customized with a coil over suspension, custom lower control arms that has dropped the car down around 4 to 5" off the ground. My car is substantially lower than any stock Jaguar and I have no issues with the ram air under the valance. Also my car has a custom flexible front valance added as the stock Jaguar had nothing to cover the front frame, etc. We took a front valance from a newer car and adapted it so that it now has a front black flexible valance around 3-4" tall and the ram air is another 1-2.5" below. You hardly see the aluminum ram air but it creates tremendous airflow. I did so many other things prior such as all the fancy special insulated hose covers, heat shields, etc. which did NOT fix the heat issues; the ram air did the trick.

 

Thanks Primaz,
I will look at shipping costs, but the import duties etc usually double the cost of the item, so may outweigh the design time.

Looking again at the pics, I assume I won't need the lower scoop as this is for an oil cooler, is that correct ?

 

Yes, I added a steering fluid cooler as that was one of the areas that was affected by the previously high engine bay temps prior to the ram air being added.

 

Thank you Primaz, I will have a play when I get closer, may have more questions, so have your tape measure handy !

 

@primaz Amazing car you have built! With cooling upgrades, mine (mostly stock) runs at around 180 deg. so I think it's ok.
Though I am struck by the oven-like feeling it has. Was thinking of cutting or making a vent by the exhaust manifold like you did. This gives me some encouragement.
I do have the fabrication skills to make a scoop under the car's valance panel.
A prior owner did install kind of a plastic air dam *I believe* is what you're referring to as a "valence".

Old thread I realize, but if you are still around.......what is the aluminum V type shield in front of your engine the resembles the bow of a boat?

 

He was here yesterday at 12:00 A.M.

 

Here are some pics, the main thing was the front aluminum valence that scoops the air up and inside the engine compartment and in my case being a V8 I put a "V" to route the air around both sides of the engine and the openings at the rear of the inner fender wells allows the air to exit and flow. The "V" section directs the air on each side of the engine and both rear inner fender wells have that triangle shaped opening so the air flows around both sides of the engine and exits at that rear triangle openings right before the firewall. The other more expensive things like special high temp coating of the headers, fancy heatshield wrapping of wires, hoses, etc., increased radiator, etc. I am sure helped but none of those to me made as much of an impact as the valance scooping massive air funneling it around the engine/hot exhaust headers and then out of the engine bay. Prior to that I did all of the heat treatment increased radiator, etc. but the engine compartment just turned into an oven where the heat was trapped.

 

Thanks very much for the added pix. On the left side (?) you were smart to keep the shape rounded like in an aircraft to help maintain rigidity.
Instead of cutting large holes, I'm thinking of cutting slits with a cut-off wheel and bending them into louvers. And a round hole at each end of the slits to stop cracking.
Or maybe drill a series of round holes instead of one big one.


I like the originality of my car but this part of the design just seems poorly thought out.

 

a1lry
Don't put louvers in your bonnet. The bonnet is not just there to look pretty. It is there to stop weather getting at your engine bay.
Many years ago, a friend had louvers put into his car and it was forever playing up with ignition problems when it rained
In the end I convinced him to blank off the louvers with a metal plate. That fixed the problem.
Those louvers may look "cool" on a competition car, but for everyday use they will turn out to be a pain.
Cheers

 

Coombs had very little call for bonnet louvres. Water drips into the plug V of the engine. They severely weaken the structure.