Jan 162013
 

Various sections of the exhaust heatshield which protects the brake servo unit had snapped off. I believe the material used contained asbestos and, for obvious reasons, is no longer available. So I needed to look for a replacement and wasn’t too impressed with what I found on offer, mainly the price!

A top corner and a considerable portion of the other side of the heatsield had snapped off The brackets used to mount the heatshield to the engine space frame

I suspect the fragility of the original heat shield is a common problem as a number of others had reported sections had broken off. The repro offerings from the usual players where simply bent sheets of either stainless steel or aluminium plate.

They would provide a physical barrier to limit the areas affected by thermal convention. However, without some form of insulation on the surface facing the exhaust, I thought the shield would get very hot and then conduct heat to the surrounding areas. Some form of heat insulation might be a good idea.

A photo posted by a member of the E-Type forum showing the difference between the original and aftermarket heatshieldsThe photo to the right (posted by a member of the E-Type forum) also shows the differences between the original and repro shields. You’d have thought they would have at least made an attempt to get the size correct but I guess it would provide a greater physical barrier.

The forum member was also kind enough to post the overall dimensions of the shield. That, coupled with the piece I had remaining, meant I could at least have a stab at fabricating my own.

Also the price was excessive as usual, coming in at around £45 once P&P had been added. The sheet of aluminium purchased to make my own was only £7.50! (Although I ended up far exceeding the £45 when I decided to add the thin heat shield material!!)

The original is approximately 3mm thick so I ordered a suitable sheet of 3mm aluminium plate. With hindsight I probably should have opted for 2mm plate as this would easily have been sturdy enough and less weight. The aluminium plate was first cut to size using a jigsaw run along a straight edge to ensure neat edges.

The mounting holes were then drilled and the lower oblong mounting slot profiled from two 5/16″ holes using a dremel. Being aluminium it was very easy to work with, both cutting and drilling.

A length of steel angle (actually some shed roof edging) was used to make sure the aluminium plate was cut to size with straight edges The fixing holes and various dimensions were mapped out on the protective covering - measure twice, cut once etc! Another photo posted by the forum member showed the two bends were roughly the same angle

I now had the problem of getting neat bends into the flat sheet as I didn’t have any sheet metal equipment. The 3mm plate is quite rigid so I was concerned a DIY Heath Robinson solution to bend it would more than likely end up with me making a pig’s ear of it. So I popped out to a local fabrication company to see if they could help.

I think they’re more used to large volume commercial clients! However as it was lunchtime they weren’t busy and one of them kindly offered to put the bends in there and then. The machine used to bend sheet metal was computer controlled press about 15′ long. A few taps later, to program the sheet thickness, distance of the bend from the edges and the required angle, and hey presto! A neatly bent heatshield was returned. Not only that but he wouldn’t take any money for his time!

All that remained was to cover the exhaust side with a heatshield material, rather than leave as bare sheet metal like the repro items. I obtained some self-adhesive heatshield material from a company called Zircotec to line the transmission tunnel area and so also purchased a sheet of their thicker Zircotec II for the heatshield. It might provide a little more protection.

A sheet of Zircotec II was cut slightly oversize to cover the exhaust side of the heatshield The finished heatshield!

The Zircotec sheet was cut 20mm oversize to provide a 10mm excess which could be wrapped around the edges. I was quite pleased with the final result.