Monday 3 November 2014

Exhausting work.

 The time has come to do something about the exhaust system. I had looked long and hard at a set of extractors available for this particular engine for swapping into late model Nissan Patrols. They exited in around the right spot but still didn't look like they'd quite be right without some work, and $650.00 is a lot of money for maybe then hacking them up!
 So I bought some header flanges and a Summit weld up shorty header kit for small block Chevs and decided to have a go! I bought the SBC kit for several reasons, mainly price ( I knew I would be hacking the pipes up so no need for anything special) and that the kit used 1 5/8" primary tubes, which is all this engine needs and being smaller, are easier to snake around for clearance.
 The header flanges:

And the header kit:


 I also bought a power tool I've been avoiding buying for years, always finding an excuse not to spend the money. Seeing how quickly it cuts through the exhaust tubing, I was a fool for not buying a cut off saw years ago! Such are the joys of being a tight ass!

To make a bit more room for the exhaust and to ensure that extra room reduced any heat soak issues for the starter, I also bought a mini starter, which was good for several extra inches of clearance. This is the original starter:

And the mini starter. Not only is it shorter, but much more room between starter and frame:

Then it was on to the interesting part, the actual header construction. I've never built a set of headers before, so I chose to start on the easier side first, the passenger side. There was no steering shaft in the way on this side so it was a fairly straight run down. There's not too much to say about fabricating headers except that I found it easiest to put the collector where I wanted it under the car on a stand and work towards it with the tubes. I found it best to make several cuts to arrive at the correct angle rather than a large first cut as angles can change a lot when you shorten a pipe, especially near the middle or edge of a bend!:


Here is the passenger side collector, I was worried about finishing the inside of the collectors (for fear of exhaust leaks), but it was pretty straightforward:

Here is the header welded up but waiting to have the collector trimmed to size. I wanted to finish weld the headers, then get them mounted and offer up the bend I needed to make the transition under the car. This allowed me to get the right length:

O2 sensor bung welded in:

And the 90 degree bend I had to get right both in height and direction:

Ended up with good ground clearance and enough room for a catalytic converter beside the gearbox, tucked up out of harm's way. Note that I used three bolt flanges, I HATE two bolt flanges! They always bend, leak and are a general pain in the ass!:

 The exhaust is 3" tube coming out of the headers, it will step down to 2.5" into the cats and then down to 2" out of the cats. This will keep the velocity up and create a little bit more heat in the cats, which will help them do their job better. I don't really need to run cats by law, but I want to as I want this car to be totally emissions legal for the engine year being swapped in. Car guys don't have to ruin the planet just because they can!
 These are the cool reducers I got for the exhaust system. They step down a little at a time, just cut them at the diameter you want. They are also cool because the step downs are more like a cone reducer, so much less of a bottle neck in the system. The other advantage is that you can use both parts of the reducer if you are stepping the exhaust system down, eliminating throwing away the other half!:


 And here is the beginning of the much trickier driver's side header. It's REALLY tight around the steering shaft, but it's getting there. The engine mount and A/C compressor bracket isn't helping either. Yes, this car will have functioning air conditioning when done.
 The front header pipe will run along the top then duck back down behind the rear pipe.....somehow! No seriously, there is enough room, it'll just take some time to sort out and some right angle spark plug boots:




 Once I have the driver's side done and cats mounted, I can run the exhaust back. Plan is to run 2" pipe past the transmission and maybe use a 2" in/ 2" out open chamber muffler behind the trans, then two large oval mufflers in the normal Jaguar spot under the rear seat.
 From there I'll buy a pair of new over axle/through rear suspension cage pipes and then out to the back of the car. That'll save fabrication those difficult through cage pipes and should allow good flow whilst being relatively quiet. Once the exhaust is routed, I'll sort out the driveshaft, then pull the rear cage down and rebuild the rear suspension and differential.
 More exhaust pics to follow as everything gets done.


Front suspension and crossmembers again!

Well, everything is now completed with the two crossmembers. I'm pretty pleased with how they've worked out. The transmission cross member has plenty of room around it for exhausts, shift cables, future maintenance etc:

 And the engine cross member has as much room around the mounts as I could get for exhaust clearances:


I've also finished the front suspension completely now. New bushes, balljoints, rotors, bearings, caliper rebuild etc. All painted in the tough 2k epoxy so it'll stay looking good for a very long time!
In the photo below, the stub axle is frosty with condensation as I froze them for 48 hours before installation, this ensures a nice, tight fit for the taper the stub axle and hub are connected by:

 And a couple of photos of the finished suspension. I'm a bit worried about the front spring stiffness. When jacking up under a control arm, they barely compress an inch before the body comes off the stands. I'm hoping there is a LOT more weight to go onto the front of the car still!: