Next on the short list of things to do is the exhaust system.
I ordered some mandrel bends as well as flanges, gaskets and a couple of flex joints from ECS Engines. The order arrived a couple of days after placing it, which was pretty impressive. The bends all looked impressive, and the flanges were well cut, however there was only one flex joint in the box. Upon inspection, the 2 1/4″ pipe would only insert into one end – the other end looked like it had been damaged and there was no way I could get the pipe in. I contacted ECS, and was disappointed to be told that I had to send the faulty item back before they would send me the pair that I actually had paid for. I think they have a couple of lessons to learn around customer service.
In preparation for the exhaust work I jacked up the front of the car and placed it up on ramps, and also lifted the rear a little to help with clearance. I also put my axle stands under the car just in case. There is no way I want this baby dropping down unexpectedly.
I removed the front pipes which flow from the exhaust manifold to the muffler. This is so I can access the manifolds for to make the flanges, and also so I have a bit of a pattern for the new pipes.
I have decided to build a twin 2 1/4″ exhaust system with a balance pipe installed ( a challenge on a Cadillac with it’s X-frame). Nobody makes a 2 1/4″ flange with 75mm bolt centres, so I have to make my own. I bought flanges from ECS engines with 105mm bolt spacing so I could cut them down. I had hoped to use my friction cutter to trim them, but the wheel really didn’t do much damage to them, so my only option was to use a hacksaw and do it by hand. You can see the difference between the standard flange and the new one.
I started cutting them as a pair, however it was hard going, and I also made a mistake with the first cut. I decided to proceed separately in the end. You can see I have finished cutting one out, and you can see that it is not quite symmetrical. 😦 After cutting them out I cleaned up the profile using a bench grinder, and then marked and drilled the holes using a pedestal drill.
Cutting 10mm mild steel with a hacksaw is really hard going even though I had a brand new 18tpi blade. I got there in the end. The next task was to also modify the gaskets to suit the new bolt hole spacing. I clamped the gaskets between the two flanges with a piece of pipe up through the middle to make sure everything was concentric. I then drilled through the flange hole into the gasket with a freshly sharpened drill. The result was excellent – just as well because I don’t have any spare gaskets!
The stud holes are not perfectly placed so I had to drill the holes in the flanges offset by a couple of mm. At the end of it all I had two flanges and gaskets which line up almost perfectly with the exhaust manifold holes, and a pair of really sore arms! Not my most beautiful work, but totally functional.
Hopefully my flex joints arrive early this week so I can get started. In the meantime I need to practice my MIG welding with some pieces of exhaust pipe.