7 November, 2021. Making random parts and the brakes better.
Leaks no more.
Part of the previous exercises in messing with the engine was to stress test the cooling system a bit, at some point the cars going to go to be set up on a dyno and the last thing I’ll need then is it failing on the day due to a water leak or some such.
When I’d bent some of the tubes for the cooling system, they’d been pulled out of round at the ends this was making it difficult for the hose clamp to pull down properly on to the tube., causing some leaks. So form a 25mm thick piece of steel I have I made a clamp to squash the end back to round again.
Everything was going great with making the clamp until I snapped the tap in one of the bolt holes and couldn’t get it out. But using the clamp in the bench vice worked just as well, so all good.
Next on the agenda were some improvement’s to the brakes, fundamentally I’m sure I’d got the math wrong at the first attempt. Resulting in over sized master cylinders and not enough pressure for the brakes to work sensibly. On top of that the clutch master cylinder was the wrong size being too small.
So the clutch master cylinder was changed from a 3/4″ to a 1″ unit, the front brake went from 1″ to 7/8″ and the rear brake went from 3/4″ to 5/8″. This doesn’t sound like much but 1″ to 7/8″ is a 23% smaller area, so a big difference.
The other changed was to move from Wilwood high volume master cylinders to Tilton 74 series units, primarily to get the required sizes, secondarily the remote reservoirs could be brought further away from the windscreen or at least they’d have to be remotely mounted as they would not fit under the windscreen when mounted straight to the master cylinder anyway.
A brace was added to cut down on flex (the black bit above) it has a adjustable bolt on it to push against a bracket if the pedal assembly trys to flex. The proportioning valve was changed in location too. Below is the evolution of the bracket to hold it on. The final one is on the right.
Its now properly tucked out of the way when its all fitted to the car.
Some other math I got wrong was the pressure transducer for the rear brakes, this was changed from a 500psi unit to a 2000psi range one. I think I did a much better job with this version of the install that the previous setup.
The original plan was to use the supplied reservoir brackets, but they were too tall, or I could not figure out a sensible location to use them and not be in the line of sight of the driver, so that wasn’t going to work.
The next plan was to make my own brackets for the reservoirs, starting off with this bit of 20mm thick plate:
I made the 3 adapters on the lath and a plate to attach them to was cut out on the MPCNC. To make this lot:
The reservoir holders were then messily glued onto the bracket. With a lot more time being spent on cleaning the glue off of where it shouldn’t be. Here’s the final result:
I’m happy with the result, they’re not obviously in the line of sight now and they’re still high enough to supply the master cylinders properly. Now all that remains is to get the setup correct with the balance bar and proportioning valve.
The fuel tank needs to breath through a Charcoal canister to catch errant fuel vapour trying to escape, the canister then needs to have itself purged by sucking the vapours from there back into the engine when its running.
I sourced a (new) charcoal canister from a Ford Focus and cut all the brackets off of it, then attempted to 3D print a new arrangement in nylon. This went badly to start with.
Eventually I got bits usable enough to sit there, though I will replace them when I get better at nylon.
Next was a bracket to hold the Bosch purge valve.
And here it is all assembled.
Next for this is to wire it in and figure out how to control it.
Another source of irritation has been the chassis tubes near the drivers feet. I made a cover for this area in 1.5mm aluminium sheet. first plotted off to check for fit.
Then machined out the real one on the MPCNC, this is within a few mm of the biggest bit the machine can do, so I go lucky there.
I’ve yet to figure out how its going to be held in place, but this is a definite improvement.
So more random stuff done and some more to be done. Until next time.