Works Rally side vents

The Works Competition Department of Austin Healey quickly discovered that they needed more ventilation to cool the big 6 Healey engine when competing in international rallies.  One of the solutions was to install vents in the fenders (wings) to allow the underhood heat to escape.  These vents became associated with competition Healeys.  As I am replicating the look of those Works rally cars, I needed to make this modification to my car. 

In addition to the visual correctness, I was very interested in the practical aspect of improved cooling since, with the A/C that I've added, the engine compartment could see higher temperatures. 

When I began investigating the size, contour, and placement of the vents, I was fortunate to be in England.  While there, I had the opportunity to see two authentic original Works Rally cars, one at the British Heritage Motor Centre in Gaydon and the other at Jonathan Everard's shop (JME) in Leamington, Spa.  During my inspection of the Heritage Motor Centre car, I was disappointed to see the utilitarian implementation of these vents (read as, they were crudely done and slapped together).  This shouldn't have surprised me since these cars were competition cars, and you don't get extra points for being pretty when you are charging through Europe on a mountain road.  What did surprise me was that the inside of the footwells were not cut back to allow a better fit (Pic 1) which, in turn, would allow a better air flow for evacuating the engine heat.  To make the louvers fit, the rear louvers were trimmed to fit around the footwells which didn't look very good on close inspection.  Nevertheless, they looked good from a distance, and I decided to go for the "look" while improving upon the fit and finish. 

At the JME shop I was able to view the Pat Moss Works Healey SMO 745 up close and personal.  Jonathan was kind enough to allow me to take a rubbing of the original works vent to get the exact dimensions and contours.  When I got back to my home in Colorado, I ordered a set of Kilmartin Works side vents.  The vents were very nicely done and quite accurate but were a bit larger than the rubbing I had made of the Moss car.  So, I made a template and had an expert body man, Brad Aregood, remake them to match my templates. (Pic 2)  I worked with the template to get the vent contours to match the character lines of the Healey. (Pic 3)  This is one of the steps on which the AH Competition Dept. didn't spend much time.

 

Picture 4 shows you the obstruction that is introduced by the footwell in the passenger side, the driver side is the same.  The solution is to reshape them to clear the side vents without needing to trim the vent louvers. (Pic 5)  As you can see, you do need to relocate the wheel well brace.  The reshaping doesn't reduce the interior footwell space in any appreciable way since it is high in the corner, and it would take a size 25+ shoe size to have an issue with it. (Pic 6)  

 

 

The results (Pic 7) are a cleaner air flow path, and the vent louvers do not need to be trimmed as the ones you see back in Pic 1.  The final vents fit the body character line contours, have evenly proportioned louvers, and provide a unobstructed airflow for venting the engine heat. (Pic 8)  A word of caution, I would encourage you to tack weld the side vents in place with the fender mounted on the car.  It may not be alot, but the fenders I've mounted have had to be pushed pretty hard to get the top and bottom bolted in (this increased the curvature)....they were definitely stressed.  The point being, if you weld the vents in unstressed (on a table or saw horses) it may be really difficult to mount them back up later.  So note the "flat-to-curve" stress when building! 

 

While this doesn't replicate the roughness of the Competition Department's installation, it does match the size and shape of the original. (Pic 9)

The next modification I am making is adding stainless steel (ss) mesh to the back of the side vents.  I'm primarily doing this to provide a visual demarcation point for the louvers.  I don't want the viewer's sight line to go past the vents into the engine compartment.  I think the ss mesh will provide this visual break.  If I attached the mesh directly to the vents I could, at some point, have a problem which would be exacerbated by having permanently mounted mesh.  So I am making the mesh removable.  To mount removable mesh backing, I had to make a frame that I could attach the mesh to and that can be mounted on the side vents.  (Pic 10)

Then I took stainless steel mesh and wrapped it around the removable frame.  Welding it on the frame is tricky as it requires low temperature welding to prevent the mesh from burning away before it is welded to the frame. (Pic 11, 12)  Now I just have to paint the metal edge to keep it from rusting.

The stainless steel mesh does break the sight lines into the engine compartment as I wanted.  (Pic 13)

The other advantage to making the ss mesh removable is that it was much easier to do the final painting with the mesh out of the fender.  Then, with the paint done, the mesh was attached.  (Pic 13)  What I end up with is the original rally vent configuration taken to a higher level of fit and finish.

 

Steve Thomton  

This project paper was originally posted in June 2009. 

Updated July 10, 2009,

Updated July 26, 2009 with Pic 11,12, 13 and accommpanying description.

Updated March 3, 2010 with new Pic #13.