I’m back with an update, all be it a small and relatively tiny step but progress all the same. Life has took a huge tangent since the last update and basically monthly disposable income has completely vanished and thus progress has also had to halt. But I’m working hard with some diversification tactics which should help massively, however this won’t happen overnight so sit tight for further progress ongoing. I’ll second this update with a dedication to a Triumph Spitfire guru Mr Rob Turner who sadly passed away back in February from an aggressive Cancer diagnosis back from the previous August. Rob knew EVERYTHING about Spitfires and in great depth. He has helped me out on a fair few occasions. I purchased his USB technical bible a good while ago and it has and will continue to be imperative to this project, so thank you Rob you will/are sadly missed within the community.
So what have I done since the last update, well next to nothing really. I was sorting out the loft above my garage which was full of hoarded bits and pieces along with loads of junk from the previous owners of the house. But amongst it all I found the original air box for my engine/carburettors. This was a good find because I thought I had thrown it out and I have been researching about peoples carb problems when replacing this with pancake filters. The advantage of this air box is that it will feed cooler fresh air directly to the internal filters and thus into the carbs, making a better combustion and hopefully a smoother running.
The pancake filters have a tendency to suck warmer engine bay air (directly above the manifold) which does effect the tuning of the carbs and engine running so the original air box was used for this exact reason. The issue I faced was that when the air box is fitted to the carbs it now voids on the inside of the bonnet and restricts the closing clearance…. So let’s get a big warty looking bulge… or a bonnet booby.
I had an idea of a teardrop style bulge blended into the bonnet to allow the clearance needed which should also look period to the car and style.
I started with a good old cereal box cardboard template. My idea was to create a flange which is contoured to the bonnet radius and then create the bulge around that allowing for a perfect fit to the bonnet radius and curves. Once I was happy with the initial shape and dimensions I covered the bonnet area with masking tape and a layer of kitchen cling film tensioned on top. I marked out the outline area of the template and then started to apply a layer of resin and fibreglass, slowly building up a few layers and creating a good thickness. This was then left 24hours to cure off, but once done I simply cut out the template shape using a jig saw which left me with my ridged flange ready to start the bulge area. This is where it starts to get tricky.
The bulge area needs to be a smooth radius section that blends nicely with the bonnet. I created this by using a party balloon as an mould and again layering with more resin and fibreglass, building up a good thickness and then leaving it to cure again. Once this was done its was easy enough to trim up to roughly fit inside the flange. My plan was to bond these two parts together and then once the bonnet was cut I would bond the whole part onto the opening and blend it all back, similar to when I did the bonnet louvres. This actually turned out not how I completed this change. I was thinking of having the flange surface mounted on the bonnet with possibly rivets or bolts fixing it through the bonnet, but after a good period of looking and contemplating the finished look I made a slight change.
The bulge that I had made was really ridged and firm so I traced the outline of this directly to the area of the bonnet I wanted it to sit. And once I made the commitment I cut the bonnet opening and stepped the edge slightly so the bulge just fitted within that area.
This I bonded into place by using some fibreglass filler, along with a skim coat over the outer surface of the bulge. After it had cured it was just a tedious process of sanding back and creating the profile I wanted. This is a process that was repeated two or three times to correct the imperfections that appear as you sand it back.
It was starting to look fantastic and with every added layer of fibreglass it was getting seriously stronger. I feathered the internal edge also with fibreglass and sanded it back to keep everything smooth clean lines.
Next after inhaling pretty much 90 percentage of everything I had sanded back, I gave the whole area a skim of fine surface filler (stopper) and again sanded this back. This process was repeated two or three more times with each pass eliminating any pinholes or low spots that appeared along with adding the contours for the shape as it develops.
This was really taking shape now, literally. So next was to apply a guide coat of primer and see what areas needed more attention for blending and sanding again. Fairly straightforward process and very rewarding as you see the area you’re working on take shape and start to look finished. Once I was fairly happy with it all I gave the area a good coat of filler primer which helps uniform it all and get better perspective of the finish product. This was also sanded back and repeated two or three times more flattening back with a finer grade of paper each time. And then I could really stand back and get a good feel for how it would look….. awesome!
I refitted the bonnet and the clearance was perfect. The bonnet closes properly again, although I still need to gap it evenly and radius the edges. But the power bulge is looking on point and I’m extremely pleased with how it has turned out. It’s debatable how much “power” the bulge will add, but I’d guess at least 25bhp!! Haha. It has added another unique feature to my build and has turned out much better than I had visioned.
Stay tuned for more updates, but they could be a while. I’m determined to finish this project and not allow life to beat me and dissolve my desire to create fantastic cars.
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