It was a busy weekend! Most of the work accomplished in the last few days was important, but tedious and time consuming. It was time to turn attention to the engine, and that meant tackling a lot of little jobs, along with the obvious changes, such as the exhaust manifolds and the accessories. I have to say that overall, the exhaust manifolds went smoothly, but it seems stressful, whenever you take an air cutoff wheel to hard to find parts! Despite knowing what I was getting in to, the manifolds are still the craziest design I have ever seen! The "double hull" likely provides a hedge against thermal cracking and warping.

Let's begin. In the shop, I have not only this M113K, but also an M112K from a wrecked SRT-6. That engine is a good running engine. After removing it from the wrecked car, I pulled a plug on each cylinder, and dumped some oil into each one, turning the engine over several times to distribute it. What I didn't think about, nor realize was that the oil would wind up inside both "hulls" of the exhaust manifold. When I removed the manifolds from the M112K for this project, I dumped a little oil out of them. As I was cutting them open, oil began leaking out all over the place! Just a little cautionary tale, when trying to pickle one of these engines!

Measuring the mid point between cylinder 2 & 3 and 6 & 7, I then moved about 0.150" towards the rear, and made a cut all the way around. One the M112K manifolds (same as M112, BTW), I did a similar thing, but offset towards the front of the engine, cutting the front port off of each one. Doing this left me with way too much material. It was tedious, but I ground on them for a long time, getting a nice even fit. I paid a lot of attention to where the manifold to cylinder studs were lining up, trying to keep them centered, and without any side loading. After completion, I bead blasted all of the parts.

The necessary 'hybrid' exhaust manifold for the V8 swap

Next it was time to weld them. I must preface this by saying that I am an engineer by day, and not a welder. It shows. The first attempt involved a recently acquired TIG welder, and some 308L rod. Practicing on the scraps of the manifolds, I thought I had a handle on it, so began work on the actual pieces. Boy! Was I wrong! It was coming out horrible, and nothing seemed to work right. Lots of reading online commenced, attempting to figure out what settings on the welder were wrong, and reattempting. Started to sort of work, but seemed to take more effort than any of the aluminum I had previously welded with it. And then, near disaster! A burn through. At this point, hours had been wasted on the TIG attempt. Time for Plan B! Getting out the trusty Lincoln MIG, and loading it with some 316L .030" wire, it went along as well as could be! Filled in the rather larger burn through, and stitched the rest up. Now, please, be gentle! I know almost anyone else with a welder is better at this than me. I thought about calling a half dozen people I know who will actually call themselves a welder. Nah! Push through. Results are what they are, but I think they are sealed up, and will hold together. (They were tacked together bolted to the engine, BTW)




Literally, the most stressful part of the project is now out of the way!