V8 exhaust manifold inner wing modifications

V8 exhaust manifold inner wing modifications

Having spent what feels like months replacing both front inner wings with shiny new panels, it’s now time for a little job I’ve been a bit nervous about undertaking. As part of my V8 conversion project, I will be fitting an “MG RV8 style” exhaust system, which means that instead of the factory V8 style “block hugger” exhaust manifolds, the system uses headers, which exit the engine bay through the inner wings. And that of course means I need to rip some massive holes into the inner wings for them to pass through.

The inner wings are structural of course, so when cutting big holes in them it is essential to add some reinforcement. Fortunately, because this was a factory configuration for the RV8, there are Heritage strengthening rings available to weld around the holes to put some rigidity back in. They’re not cheap, and I’m sure many people choose to fabricate their own, but the beauty of them is that they are the right size and can only fit in one position, so they take all the guesswork out of positioning the holes correctly.

I used the strengtheners as a template and scribed around the inside to mark my cut lines.

The strengtheners have a small lip on some of their inside edges which needs to be bent back after it’s been welded in to add some additional rigidity, so my outside lines indicate the slightly larger hole I would need to cut to account for these.

After triple checking my measurements, I cut the holes out using an air body saw…

…and then cleaned back the paint on all the edges ready for spot welding the strengtheners into place. The inner bare metal had a coat of weld-through primer before I started welding.

I clamped the strengtheners in as tightly as possible to ensure a good fit, using the smallest clamps I have so that I could still get the spot welder in.

And then I went to town spot welding both rings into place.

Once welded into place I part folded the inner lips back with some mole grips, before dressing them back properly with a panel beating hammer into a fairly neat flange. These really do help a lot with the strength, once those edges were folded back there was no flex at all in the panels.

And that’s that. I just cleaned up the whole area inside and out and gave them a quick dusting of etch primer to keep any rust away.

That, as far as I’m aware, was my very last welding job, so the next steps for the shell will be stripping any more remaining old paint and surface rust, and starting to get it ready for final paint at last. Next up though, I will probably make a start on refurbishing and reassembling the front suspension and rear axle, so that they will be ready and waiting as soon as the shell comes off the rollover jig.

Leave a Reply

%d bloggers like this: