Bits and pieces.

June 12th, 2014

I’ve been doing a few little odds and ends while I wait for my block and head to be done. My distributor arrived from Willie at Austin Repro. That was very quick!

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They do look rather modern. But it’s a special so I am not too worried. Worrying about keeping the car looking correct seems silly when I will have a very Japanese looking blower mounted right up the top of the engine bay. I can tone things down a bit though so they don’t leap out at you. I can paint the cap with acrylic paint and I might paint the body black. The spring clips were a yellow zinc passivated colour but I changed that.

One thing people in the local club have been playing with is zinc plating parts. Marcus did a demo for people at a VAR garage visit and Ian has also got it working. I gave it a try once before but without good results but now I worked out what I was doing wrong. Initially I just had one zinc anode and used far too much current. I tried again using zinc from two old zinc/carbon D batteries (actually not old, I bought new ones but zinc/carbon cells are cheap). I just removed all the innards and cleaned the zinc casings then cut and, more or less, flattened them. I used two, either end of a little margarine tub, with a copper wire soldered between them to join them electrically.

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I then either hang the pieces to plate off little copper wires dangling off a piece of copper pipe across the top of the tub or else just sting them on a copper wire and sit that in the solution. Of course you have to make sure the parts are not touching the zinc, that would be a dead short. The current flows because of the solution we are using. I am using a current of between 100-200mA per square inch. And I think it works better if the parts you are plating are surrounded by zinc (so I need two more batteries). These electrolysis type processes work more in less in a line of sight way.

The solution itself is white vinegar with 100gm/litre of Epsom salts and 120g/litre of sugar mixed in. The zinc plates are connected to the positive of your power supply and the parts to be plated are connected to the negative. I am using a bench supply with current limiting although I still found I had to add a small light bulb in series to limit the current further. I leave them in there 10-30 minutes.

In the picture above I am using 110mA at 2.5 volts.

The biggest thing is making sure the parts are perfectly clean and degreased. I have found the best way is wire brush them to get all the dirt and loose rust off (I use little brass brushes in the Dremel) then I drop them in a hydrochloric acid then rinse them in water and finally drop them in a tub full of water and a little baking soda. The water stops them flash rusting quickly and the baking soda just helps neutralise any remaining acid. When wiring them up I use gloves to avoid touching the parts so they remain clean.

The little screws were from the RB106 regulator I had. I also took off the spring clips on the dizzy and plated them. Dropping those in the hydrochloric acid almost instantly removed the existing coating. I also plated all the steel parts off my carburetor linkage.

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The parts come out of the bath dull grey as you see above on the left.  I then just polish them up with a bit of #000 steel wool.

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That results in a  nice, bright finish. You can see on the choke lever above where I had polished one side but not the other. I don’t bother polishing them too much.  I don’t want things to look new, just not rusty! The spring clips on the dizzy look much better silver instead of yellow.

I also got hold of an oil filter for my remote filter adaptor.

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It’s a full flow Fram TG3614 filter. I went for the shortest one that didn’t look too small on the housing. But also one that is common. This is used on various Toyotas apparently so it is commong, cheap and easy to get. I still need to get the hose barbs for the remote. I also ordered some brass barbs for the crankcase. The threads in that are 1/4 inch BSP but they are parallel thread. I couldn’t find anyone who actually sells parallel thread barbs in New Zealand so I ordered some on eBay (and that’s probably cheaper than getting them here even if I could find them)!

I also had another go at cleaning the crankcase. I was pretty clean but then I remembered I had a bottle of Armour All alloy wheel cleaner in the shed so I tried that. It worked brilliantly. It really dissolves the black crud inside the crankcase within seconds. Apparently it contains alkaline salts so after spraying it on I made sure I washed the whole thing down extremely well with clean water. You don’t want to leave any of that stuff in there corroding the crankcase away.

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I started looking at fixing the stripped threads and also removed the oil oil jets. To remove those you need to punch them out from the inside. If you try to use a normal punch you’ll just squash the ends up so I drilled a short hole in the end of a bolt that slid over the end of the jet and used that as a punch. Once the jet was mostly out I used a pin punch to fully remove it.

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They’ll drop out of the jet cleaning plug holes. I need to repair these on my crankcase as they are well flogged out. I’ll probably plug them then re-drill and tap them. You can also see one of the threads I marked for helicoiling. Before I attempt that I will make a little engine stand for the crankcase as described here on the ever useful Cornwall A7 site.

With that I can sit the crankcase level on the drill press to accurately drill the old threads out. Four of the crank to block threads need doing and I will also add the extra middle stud too for extra support.

I also got hold of some cotton tape and rewrapped the dynamo coils. I replaced the insulation that was crumbling off  the wire ends with some heatshrink.

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I then added a coat of polyurethane over the cotton and those are now drying.

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The cotton is filthy because the old coils were filthy after pulling off the old cotton (which mostly just fell off by itself). I didn’t bother trying to clean the grime off them for fear of upsetting the insulation on the windings. A bit of grime shouldn’t hurt I think.  Anyway, hot burning grime gives you that great vintage car smell!

There was also some excitement the other night when there was a big storm. Around 2am there was a massive crash in front of the house. I looked outside but couldn’t see anything. It was one of those nights you worry the rain and wind will break your windows so it was very wild and windy. It was also pitch black as all the power was out. Next morning, about 8:30, I went and had a look outside and found this:

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Seems the tree in front of my house fell over! It was blocking part of the road causing cars to veer over to the wrong side. I rang the council to tell them (apparently no one else bothered) and they said they’d send someone out to it. There were lots of trees down apparently that night so I knew it might take a while. I was waiting to hear some dozy twat drive into it in the night and I did hear a car that obviously scraped throughit but there weren’t any wrecks in it this morning!

Good thing the MG isn’t in that garage as I wouldn’t have been able to get out.

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The Austin would squeak past though I think. Today the council came and cut it up. The trimmed it all down and mulched most of it then went away leaving the trunk cut into logs. I’d just been saying to a friend I wonder if I could ask them to leave the wood so I rang the council to see what happens next. They said they do just leave it there in case anyone wants to collect it as firewood. So I immediately ran outside and nabbed it all!

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So now I have no tree in front of my house but a nice pile of firewood to cut up and a rather flattened flax bush.

Other small jobs done today were painting the dynamo main housing. I couldn’t remember the paint I used on the starter and used the wrong kind at first. When I realised it was wrong I went back to all my spray cans and found the correct one. It’s Plasticoat steel wheel paint. I am mentioning this here so I remember later. I don’t know if it is the ‘proper’ silver colour but it is OK I think.

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That wheel paint is good enamel paint though so it gives a tough finish. I still need to paint the end caps and the bush cover strap black.

I am still looking into how best to do the 12 volt conversion. I am not happy with the idea of just replacing the cutout (with a 12 volt one or a diode) and changing the battery and coil over. The A7 has no voltage regulation. As I am running a modern fuel pump and a modern water pump, both of which use brushless DC motors, I don’t like the idea of the voltage varying about all over the show. It also can’t be good for the battery.

I’ve been chatting to a chap online who knows all about the later regulators. His web site is here and he pointed me to this document about regulators. He suggests I use the regulator 7 scheme which uses a Lucas 12 volt regulator normally used in an alternator with an additional transistor controlling the field winding. The dynamo would be converted to 2 brush operation and the circuit is fused so you can’t draw more than 10 amps. I could make that inside a suitable Lucas housing and it will provide a very stable voltage. I am looking out for a Lucas 37565A regulator. There are a few on eBay, mostly in the states, but I am just waiting for one where the shipping isn’t ridiculous. There is one in Australia  for AUD $16 but for some reason they want AUD$ 46 just to ship to New Zealand!

No rush anyway, I need to rebuild the dynamo first.

 

 

3 Responses to “Bits and pieces.”

  1. Renaud in Brittany Says:

    Hi Simon,
    Good work as usual. Your finish look very good though I prefer the matt one; matter of taste only. I never experimented this; only once in copper plating. I remember that the lower the current intensity the finer the grainy finish. It seems to me that the solution was copper sulfate easily found with garden stores and a copper anode. I would be interested in a method of blackening steel myself.

  2. admin Says:

    Hi Renaud, I am hoping the finish dulls off a bit in time actually. I just gave it a quick scrub with the wire wool. You could actually polish it even more than that!

    People who work with guns have a method for blackening steel (or blueing it) but I am not sure how they do it.

  3. Renaud in Brittany Says:

    Btw what is the sugar for in the solution please? Mysterious for me!

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