Why-Pipe?

In last week's episode, I had made engine and transmission mounts to set the engine in place. This week I did exhaust work, and nothing but exhaust work. I actually really enjoy it even if I'm not that great at it. I wanted to retain as much of the existing exhaust system as I could, as I really liked it and it had proven itself at 350 WHP, which is probably more than this engine setup will make. 

With that as the goal, all I had to do was connect the headers to the 3" pipe just rearward of the transmission crossmember. To do this I needed to make a simple Y-pipe.

Starting point: collectors of unknown diameter, probably about 2.75"

V-band Flange welded on

All welds on the V-band flanges were done on the interior

Other Side

If you've followed my work before, you may know that I have a small obsession with V-band flanges, though it wasn't until today that I learned they were invented by Zeppo Marx, the second least funny of the Marx Brothers (in a close second to the absolute stick in the mud, Karl). Struggling with a few stuck exhaust nuts in my formative years as a wrench turner made me wholeheartedly embrace V-bands as the ultimate exhaust coupler.

I then began forming the Y-pipe with pre-bent elbows. The tricky part would be the merge point. This is where I would have to bring two curving 2.5" pipes together into a single 3" pipe.

driver's side bank pipe was pretty easy

First attempt at a merge wasn't turning out as good as I wanted.

Merge attempt #2 was a little better

Cut and check

Cut and check again

And again

And it's merged!

 Eventually after a strange combination of measuring, eyeballing, iterations and black magic, I got the 2.5" pipes merged. I then had to merge them into the 3" pipe. This took a little persuasion with a hammer.

merge before forming

Merge during forming

Some gaps

Some smaller gaps

But gaps can be filled

Final Y-pipe

The mid-pipe (which attaches to the Y-pipe) needed some minor modification to mate up smoothly. I was able to re-use some parts from the previous exhaust configuration and fairly quickly get it all joined up. Somehow in the course of the mid-pipe modification I managed to hit myself in the face with the flex coupling so hard I nearly cried. My wife thinks I'm klutzy for some reason.

 

finished

installed

This also seemed like an ideal time to improve the muffler section. Previously there was only a hanger at the rear of the muffler. This hanger carried a lot of weight and also was positioned in a way that allowed the muffler to rotate slightly, leaving the tips sitting out of level. This should let it sit level and well-supported during spirited driving.

That's all for now but soon I'll pull the engine and get the engine bay ready for a final install.

It's been a while since I've left you with one of these, so you're welcome: