Slow Car Fast
February 20, 2010 - Of course, building the exhaust means building the headers.
I've been digging around trying to find recommendations on primary tube length, but to no avail. A diameter of around 1.625" or 1.75" seems to be the one to use, and since the last header I built used the latter I will probably do so again as I have some spare parts - including this collector.
The header flange is GM part 12480130, and it's 7/16" thick. Beefy! The blue pool hose? Well, that's how I do my initial layout testing. I'll figure out the general routing of the tubes first then fine-tune them with a very cool tool that will be making an appearance soon.
But there's no need for it. When I installed the steering column and started to figure out where the collector was going to go, it became obvious that there was no way to run a long-tube header in the car. I simply don't have the room - and that's with the collector in the wheel well! So it appears I'll have to settle for good flow instead of a nice extraction design. Oh well, it'll be an improvement over the stock units at least. And it should be easier to make this way.
entry 291 - tags: header, headers, exhaust
May 18, 2010 - The two finished headers.
You can see where I had to cheat the angle of the collector on the driver's header (seen here on the right side) a little bit, but I'm pretty happy with the result. They fit well, give me full access to spark plugs, can be installed without removing the engine and should give decent performance even if they're not all equal length. I just have to finish one more more 2.5" tube to connect the right header to the X pipe, add a couple of O2 sensor bungs, and the exhaust will be complete. Woohoo!
entry 328 - tags: exhaust, headers
May 18, 2010 - The debris of header building.
They were built out of mandrel U bends. If I have the count right, it took one with a 2.5" radius, one 2" radius, four 3" radius and a couple of other bits and pieces that were left over from previous projects. The primary tools were a chop saw and a belt sander.
entry 329 - tags: headers, exhaust
August 31, 2010 - I'm working on routing all the various hoses and wires, and I have to make sure they stay clear of the hot stuff.
Which means it's time to bolt the headers on. And oooooh, do they look good. Yum!
However, I did discover a problem. When I built the headers, I bolted the flanges on to the head using just the two end bolts. I did the same every time I checked fitment as well. Except this time, when I decided to put in another couple. And that's when I realized that I'd welded the flange on upside down on the driver's side! The end holes are symmetrical, but the others aren't. Oooops.
Luckily, there's a lot of meat on the flange and so all I have to do drill some new holes. I can use the gasket as a template. So at the moment, it looks as if my mistake won't be difficult to fix.
entry 381 - tags: headers, mistake