I have been slack at updating this blog lately, just not had time, but not much has been happening anyway, again lack of time! With an hour here or there I have been making the headers. They are a shorty block-hugger 4-into-1 design, to allow me to put the CATs under the bonnet, nice and close to the engine. The shorty block huggers that are available off the shelf are not short enough and come to close to the chassis, hence I am making my own!
I bought a bunch of mandrel bends and started cutting. The cuts are made mostly with a chop saw, also a couple by hand with a hacksaw.
On each side I have one pipe which is one piece, the other three pipes are two or three pieces each. The driver's side front port needs a fair kink in it to clear the steering column, I will add more pics as the headers continue to come together.
I have welded up the pipes with a scratch start TIG setup. The welder is a 140amp DC inverter stick welder, it is tiny! Plugged in a TIG torch to the negative, hooked up a bottle of argon and got TIGging! I have never TIG welded before, so spent a good couple of hours practicing on scrap. It took a couple of hours to get the muscle memory going that you need to remember to turn the gas on at the torch! The hardest part was the scratch start without the electrode sticking, but once you have the knack it is quite easy to start. With this scratch start TIG setup I can weld steel and stainless steel, but no aluminium as that needs AC. I decided to go the scratch start setup as I can't justify $1,000 for a decent hi-frequency AC/DC welder and I have no aluminium welding to do as of now. As you will see from the welds I am no weldmaster, but a flap disc will do wonders!
Below you can see the length of the single piece pipe. I am using 1 & 3/4" pipe. I'm more interested in low and mid-range torque than high-end HP, so from what I have read on these engines this is better suited than 1 & 7/8".
The trolley, big-old MIG on the top, AC stick on the bottom, and the DC stick that I'm using for TIG is hiding in the middle!
This thing is tiny! I have been welding up most of the joins at about 40amps.
The TIG torch cost more than the welder! It's a 17V with the valve for the gas. Also I added a gas lens kit from weldmongerstore.com. I have been using 2.4mm (3/32") ceriated tungsten electrodes and they seem to be working well.
Read for a tack
Not too bad, will clean them up with a flap disc. Once complete the headers will get HPC ceramic coated. If you can get the mating surfaces nicely matched then almost no filler metal is needed.
Over the last couple of weeks I have got the driver and passenger side roll bars completed. They are a hoop with a third leg, 3mm wall thickness tube. The third leg gets welded to a plate that bolts through the boot floor and through the chassis underneath. Once the leg is welded to the plate the only way out for the leg is down and out, yet it is too long to pull out so it needed to be cut and sleeved. The sleeve is 4mm wall thickness chromoly tube and bolted through with M12 bolts.
After tack welding the third leg to the plate and the top bracket to the hoop in the car, it all got pulled out to be fully welded and then the welds blended out smooth and ready for finishing. These will be black and I think I will get them powder coated.
Many moons ago I mocked up the aluminium dash panel with print-outs of my gauges. This is an excellent way of deciding on a layout without cutting any holes.
But I thought I would be doubly sure before cutting holes in that aluminium, so I mocked up a panel out of 3mm MDF and used the real guages and switches, happy with this layout I will proceed to wire up this mock-up and switch everything over to the aluminium panel before getting on the road.