Tuesday 6 February 2024

Clutch pipe and gas pedal

 First of the new jobs, the clutch pipe. This would be a fairly simple job, but it turned out a bit more awkward than I thought. First issue was the Wilwood master cylinder is based on a DIN connector, but everything else on the car is SAE. Fortunately I had accidentally bought some DIN brake pipe nuts, but I didn't have a DIN flaring tool.

A quick google suggests that since kunifer is softer than steel, if an SAE flare is tightened down on to a DIN fitting, it will make a sufficient seal. While I wouldn't have done that on the brake lines, the clutch line is at far less pressure so I gave it a go. As it turns out, yes it does work, so now I have a clutch line;


By the way, the loop is based on the original MX5 fitting, and I believe it's to allow the engine to move without affecting the pipe too much. It also makes fitting the pipe a lot easier, as both ends are slightly flexible. Had I used the exact length I think it would have been so much harder to fit. 

Now on to more frustrating times. Well, not frustrating, as I did expect at least a few occasions. Basically everything I've built has been done as a single item, then taken back off the car. At some point, all these single items have to live together. The first conflict I expected was actually the steering rack and the starter motor bracket, apparently that is a very common one but I managed to avoid that one due to me putting an angle into the steering column. It does pass very close to the chassis tube but 'close' isn't 'touching'.

What it does touch is the gas pedal bracket. I had preserved the hinge on the gas pedal to work the same as it did in the MX5, unfortunately when I put the steering column and the gas pedal on to the car they want to occupy the same space. Since I can't do anything more with the steering column, it means I have to modify the gas pedal. 

However this is one of those 'two birds one stone' occasions. The gas pedal cable requires a bracket to pull against, and I'd not budgeted for that anywhere. So as I move the pedal I can also incorporate a bracket. It's got to be tough though, it's got the force of my foot and the force of the throttle springs acting against it. I'm thinking a length of 19mm tube with a suitable end is required, and possibly even triangulated against something.

Back to the pedal though. The original is cranked to the right, so moving the pedal away from the steering column puts the pedal into the side of the footwell. What I need to do is create a left cranked version. This picture shows the crank as well as my solution;






The cut metal is actually perpendicular to the hinge, but the pedal is at least a couple of inches off the surface. What I'll do here is weld the upper part of the plate to the original (thereby preserving the cable hook), then cut off the lower part of the original (below the hinge). I'll then transplant the pedal on to the new plate, and that should give me the clearance I need to move the hinge over. The plate is a similar thickness to the other two pedals which get much more force so I'm not expecting any issues.

Then the plan will be to create the hinge for the pedal, at the bottom of the bracket where the cable will attach. The top just needs to be a hole, and the tension of the cable on the pedal will keep it in place. I'll use a nut and bolt as a back stop to limit the travel when the pedal is released. 

And there I was thinking the gas pedal had been the easiest one to deal with. I still need to figure out what to do with the scuttle though, all this was driven by the need to put a hole through the scuttle for things to work properly. The gap for the steering column is fairly clear to see but it's only when I added the gas pedal that I realised things no longer work.

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