I have already made two full exhaust systems, one for my old Rover powered Sumo and one for my old friend  Sarge’s Ak and at the time I promised myself I wouldn’t make another set, but here I am again! The ones I made for the Sumo were mirror polished stainless steel and although I was also going to make this system in stainless the plan was to have them satin black rather than polished.

With the engine trial fitted into the engine bay I could map out what route I wanted the exhausts to go each side, keeping in mind such things as where the bulkhead was, where the steering column was going to go and where I wanted the exhausts to exit the body. Once I had that sorted I went and bought the raw metal parts. A got a lot of the bends from OJZ engineering in Nottinghamshire and the 4” tube and baffling from Custom Chrome, Nuneaton who also flared the end with a four-way flare to accommodate the 4-into-1 exhaust system I decided on and did a trial loose fit to see how it all looked.

I struggled to get the sidepipe end cap that I wanted so I bought a couple of 90 bends and made a cut square to the pipe to make the shape I wanted, hopefully the pictures below will explain better. After that I welded on a piece of 6mm stainless bar to make the end safe as per IVA instructions.

I then made up the 4-into-1 collector and welded it up to the sidepipe, ground the welds off smooth and did the other side. I could then rest the sidepipe onto some axle stands at the side of the chassis at the correct height and orientation and see where the collector would enter the engine bay. This would be my starting point. Using a series of bends and a chop saw I started to piece together each “leg” of the exhaust and once I had it about correct the welding could start. I bolted an exhaust flange to a spare head to keep it straight and flat and started to build it up. It took a long long time because I had to check it against my template and check it all fitted together in the engine bay. Eventually I had it done and ground the welds down and painted it in silver heat resistant paint. The sidepipes I painted in spray stove enamel in satin black and I must say, they looked just how I wanted them to.

Cooling system

The cooling system on a cobra replica needs to work quite hard due to the fact that, being an open topped car, they are more often than not driven in the hot summer months plus they have large engines and are generally driven hard! AK recommend fitting a three core radiator from a Rover SD1 so that’s what I have fitted. I bought some SD1 radiator mounting rubbers from Rimmer Brothers and trial fitted the radiator to see where the radiator fan was going to go. I then made up some brackets which I bolted the the upper and lower AK radiator frame and fitted the radiator.

More to come later