Discussion
While putting the finishing touches to my XJ13 recreation (the car is now in the paintshop), I added a detail under the bonnet which had me puzzled at first. The original has it so I added it anyway. I know it was there before the crash because the bonnet survived intact. I reckon I now know what it was for - although it was never used as such. I could be completely wrong of course but thought I'd see if any of you had any other ideas of what it was meant to be.
If you look at the XJ13's bonnet, you will see a NACA duct close to its leading edge. It is set off to the right-hand side and looks like this:
If you look underneath the bonnet, you will see the following "duct" (copied from the original):
When in position, it points directly at the steering rack. It is also in the vicinity of the brake/clutch fluid reservoirs. Rather than being centrally-mounted, the NACA duct is positioned to the right.
Any guesses?
For those who have asked, my car is now in the paintshop (thanks for the interest
). My Christmas present to myself is to see how it drives sometime before the end of December. Here's a few pics etc for you fellow XJ13-geeks:
Latest blog entry
If you look at the XJ13's bonnet, you will see a NACA duct close to its leading edge. It is set off to the right-hand side and looks like this:
If you look underneath the bonnet, you will see the following "duct" (copied from the original):
When in position, it points directly at the steering rack. It is also in the vicinity of the brake/clutch fluid reservoirs. Rather than being centrally-mounted, the NACA duct is positioned to the right.
Any guesses?
For those who have asked, my car is now in the paintshop (thanks for the interest
). My Christmas present to myself is to see how it drives sometime before the end of December. Here's a few pics etc for you fellow XJ13-geeks:Latest blog entry
V8 FOU said:
Neville. Once again I doff my hat!
Please keep us updated on the paint etc.
Did you have any problems with the brakes, being one off castings? Does the oil tank and system work OK?
In period, Jaguar commissioned brakes from Dunlop as there wasn't anything suitable off the shelf. They changed to Girling later in development because the Dunlops could potentially "spread" under hard braking. I wanted to stick with the 1966 original design/setup so commissioned some of my own. The difference being these are heavily "beefed-up" to ensure there is no danger of spreading. They also give me the opportunity to swap for different piston diameters at will. The proof of the pudding will come later next year as the car is developed/tested under duress.Please keep us updated on the paint etc.
Did you have any problems with the brakes, being one off castings? Does the oil tank and system work OK?
The oil tank and system is (pretty much) an exact replica of that used in the original car. It was tested in period (throughout 1967) and no problems were reported even after extensive and heavy testing at MIRA. De-aeration seems to have been effective as the detailed engine records show no evidence of bearing damage etc when examined. However, as with the braking setup, the real test will come when the car is put through its paces.
Time will tell!
TA14 said:
XJ13 said:
When in position, it points directly at the steering rack. It is also in the vicinity of the brake/clutch fluid reservoirs.
Could it simply be cooling for the brake/clutch fluid reservoirs?lowdrag said:
Are we allowed 20 questions? Was there a hose connected to the alloy duct that conveyed the ram air somewhere?
There's no definitive "yes - that is what it was" answer to the question. However, I reckon Dryden (above) has come closest when he suggested it was something to do with driver ventilation (although it may never have been used as such). It wouldn't have taken much to attach some sort of flexible hose and routed it so that it squirted cold air at the driver as Tony (Lowdrag) suggests.One clue pointing to this is that it is positioned on the driver's side rather than centrally. It is unlikely it had anything to do with the brake fluid reservoirs as these simply don't get hot enough to warrant cooling. I can't see it having anything to do with aero-dynamics either? The louvres should be sufficient to remove air passing through the radiator. It must have had some definite purpose as Sayer would not have tolerated anything to disrupt airflow in that area otherwise - he even insisted in the use of flush rivets across the car's nose (these were replaced with raised ones during the car's rebuild in 1972). There's an account of Bob Blake (builder of the original car) adding a small recess in the nose of the car so he could add a discrete flush Jaguar badge. Sayer made him hammer it flat!
If I can find a definitive answer I will report back here. In the meantime, I am going with the "ventilation" suggestion.
Firstly, we are in awe of this project... well done!
A few thoughts. This car was designed primarily for Le-Mans and other big circuits, and would regularly do 200MPH (ish) with high back scuttle side widows and no roof. I wonder if all the air got sucked out the cockpit when those speeds are sustained? and the vent is literally for breathing!??
As you said, they would not put such an aerodynamic hindrance there if it was not vital!
Being mid engined, there is no forward heat from the engine, and with no roof, I do not think it would have been (just) for driver cooling.
A few thoughts. This car was designed primarily for Le-Mans and other big circuits, and would regularly do 200MPH (ish) with high back scuttle side widows and no roof. I wonder if all the air got sucked out the cockpit when those speeds are sustained? and the vent is literally for breathing!??
As you said, they would not put such an aerodynamic hindrance there if it was not vital!
Being mid engined, there is no forward heat from the engine, and with no roof, I do not think it would have been (just) for driver cooling.
Gassing Station | Classic Cars and Yesterday's Heroes | Top of Page | What's New | My Stuff