Dodge Magnum 239 3.9l V6 Exhaust Flange Guide

thingiverse

When replacing the trans in my truck I used this time to also fix the bad exhaust leak I had on the drivers side. Like many of these Chrysler LA engines, my 2000 V6 magnum with 170k miles broke 2 of the 4 exhaust manifold studs. The 2 rear most ones (re: the ones with the least access) and I wanted to build a guide that would give me a better than average shot of drilling and tapping these holes. My first foolish attempt was to drill the center of the broken stud and try a helical bolt extractor. It snapped off in the hole making a bigger mess to now drill out. I drill it out with cobalt bits and decided to drill the whole thing out larger and just re-tap the hole. Well the cheap tap I had snapped off right at the bottom. It was my fault I was using a plug tap not a bottoming tap so the tapered end hit the back of the hole and stopped forward movement... so snap. After 2 more breaks I used this guide to make sure it did drill and tap straight. I designed this flange using the exhaust manifold gasket as my reference. Since the V6 is quite simply a V8 with 2 cylinders chopped off things like the gaskets are basically just cut down V8 parts. Those V8 versions have larger exhaust port openings, So this is why the guide looks like it does not fit the head well, it does fine and most importantly the bolt holes line up. Like a couple of my other items this is a super specific design that likely no one else will ever need but I like the idea of sharing to offset the many other fine designs I've used over the years.