02 Apr The 600 Club
No, we haven’t been taken over by Pat Robertson. We’ve just decided to take a break from “pipe” puns for blog posts that involve exhausts.
With April Fool’s Day out of the way, it’s time to return to our regularly scheduled blog programming. Since we haven’t visited the build in a couple weeks’ time, let’s catch you back up on Tom’s Mercedes-Benz SL600, which is undergoing a build of decent proportions. As you’ve seen earlier, we’ve been upgrading the engine bay’s aesthetics and power as well as fabricating a custom exhaust. We’ve already powdercoated the valve covers red, so now it’s time to bring a little power into the equation. A while back, we sent out Tom’s intake manifold to be thoroughly ported through one of the companies we’ve come to trust with this type of job. Once it returned, we sent it straight off to the powdercoater for a fresh coat of crinkle black. Now it’s returned, so we figured we’d show it off. The lighting doesn’t really do it justice in the first pic, but in the second you can get an idea for the true shade of this massive manifold.
We still have a couple modifications to add to the manifold before installing it, so we’ll be returning to that piece of the car soon. However, in the meantime, we’ll be rotating underneath the vehicle and continuing the saga of its custom exhaust fabrication. When we last looked at Tom’s exhaust, we had built a set of merge pipes that connected the pair of headers on each bank into a single, V-banded outlet. With that out of the way, it’s time to focus on building the remainder of the SL600’s piping.
As always, we started from the V-band clamp and began working our way backwards. The two waypoints we needed to hit were the bolt-based mount brackets on either side of the transmission and the pair of pass-through resonators that we will be placing at the exhaust’s halfway point (or thereabouts). As always, the pipes are hand-fitted together at first, then taped together in case we need to make any adjustments as we go. From there, we use the welder to tack the pipes together before bringing them over to the welding table.
And, as always, we’re willing to share the fruits of our welding labor with you. For those of you who don’t know, our TIG welds are laid down entirely by human hands, and they’re backpurged with inert gas (argon, in this case) to prevent oxidization on the inside of the pipe. Oxidization creates nasty weld slag (buildup) inside the pipe, which cuts down on laminar exhaust flow, and that will cut into both the power and sound characteristics of the exhaust. No shortcuts here.
Once the pipes were fully welded up to the resonators, we placed them back on the vehicle and began preparing the brackets that would connect the pipes to their mounting brackets on either side of the transmission. Each exhaust needs precise mounting, or else excess movement of the exhaust during vehicle operation can cause the pipes to come in contact with other surfaces underneath the vehicle. If you’ve ever had an exhaust rattle, you can understand how annoying it might be. In keeping with the OEM+ nature of this vehicle, we’ll be utilizing the stock mounting system of two bolts through the bracket, so our corresponding fabricated bracket on the exhaust will more or less mirror the one on the car.
And once again, we return to the welding table. Even though these brackets take up a very small amount of space where they are welded to the exhaust, they can still create oxidization that can hamper flow. Therefore, we broke the argon out once again and started welding. The results, as one may expect, are rather pleasant.
We’ve got plenty more action taking place in both service and fabrication this week, so we’ll be back here tomorrow to bring you more exciting, original content you won’t see anywhere else on the internet! Have a great day!