I did the opposite, put a sheet metal shield to route air UNDER the cross member as I had heard that air hits the cross member forcing it up into the engine compartment raising underhood pressure and thus less air flow through the radiator. Unfortunately, I do not have the instrumentation to prove this theory.
I would find another hood/bonnet and Louver it.
It’s the best option to let heat escape.
That way you don’t have to mess with the original.
Nice job might just steal that idea, I wonder if it helps with fuel economy (very slightly)
This is the story on the air deflector !
taken from a add on e-bay .
About 30 years ago, a Mark 2 owner,who was an aircraft engineer said he could nut understand why the faster he drove, the higher his temperature gauge read. He concluded that the front suspension crossmember acts as a scoop, forcing air in, with no way to get out. He put air pressure gauges in the engine compartment and confirmed his theory,air pressure raised at speed, cusing little air flow yhrough the radiator.This makes sense; as Coombs Jaguars added bonnet louvres, same as an Etype. For decades, racing MKI and MKII added a block between hinge and bonnet to let hot air out. He told me how to make this panel I did; I believe it made a difference.It is a prototype, you may have to add mounting brackets.It fits behind front bumper and attaches to front crossmember. The notch was cut for oil cooler hoses; as I added a V12 oil cooler behind the front bumper (I am selling one of those on another ad).I liked it because it hid an ugly dirty area of the car; which was a driver, not a show car. It should also fit MKI and 3.8S; possibly 420…I also have other Jaguar Saloon parts.I had a British restoration shop over 30 years , and never threw anything away. Ft Lauderdale Downtown development forced me to move to slow paced Sebring,Florida; where I have an historic downtown building. . Please look on my eBay store; Old English Motor Company, which has 20 categories of parts, 1950-1994; Including Daimler and Jaguar Saloon Parts…You may contact me for free restoration advice or with questions T. 1 954 JAGUARS or C. anytime, 1 954 JAGPART . SHIPPING cost given is by First Class Mail, US and priority overseas… Please give me your phone number for the box. .Thank you, James Dean, thejaguru. Now located in lovely Sebring, the Heart of Old Florida.
Ps , there was no racing Coombs MK2’s with bonnet louvres !
Ian, Thanks for the technical background on my modification.
No problem , I see one for sale a few years back , you can see the idea behind it , and how it would work , most new cars have a tray bolted under the engine now !
I did all this research, and tried the panel pushing air down. It seemed to make no difference. The scoop pushing air up I tried after and it was very noticeable. Perhaps the triangle vents make the difference as there’s a place for the air forced in to escape?
It’s a job to say , as hot air rises , the triangles are quite low down , maybe a in air scoop of some kind on the carb side , and a outlet on the exhuast side would help overheating , but only when moving ,
Would a extractor fan on the exhuast side help !
I could never understand why Jaguar had the carb intake right over the exhuast manifolds , we all know engines run better with cool air , how simple would it have been to make a air intake through the inner wing , carb side .
I don’t have any overheating issues in the UK , especially now I have a uprated rad core , !