1973 AC Model 70 Invacar, Visitors & Occasional Distractions

I had a spare hour (ish) this afternoon so made another pass at the "clean the secondary pulley game" on the Invacar.

A metre of threaded rod was all of £1.85 from Toolstation. That, a couple of bolts and a few washers allowed me to create this potentially lethal contraption out of my poor innocent workbench and even more horribly abused (yet apparently indestructible) power drill.



It's actually infinitely less terrifying than it looks courtesy of the pulley (as you would expect) being really insanely well balanced. It wobbles a bit at around 500rpm, but then smooths out totally up to the free running speed of the drill. What is scary is that *stopping* from that speed takes the best part of a minute thanks to the rotational inertia involved...

I only did that once though, more out of curiousity as to how well balanced stuff was, while being ready to leg it at a moment's notice.

For reference this is the pulley surface we started with following my first pass at cleaning it with the polycarbide mop on the grinder last week.



An hour or so of working at it with a combination of a chisel (ooooh...sparks!) and several grades of Emery cloth resulted in the surface looking like this. 





While there's still a lot of visible tarnish there the pulleys surface is now smooth to the touch across the full running surface. Whether this will help things or not I will hopefully find out tomorrow. It's hard to express quite how much smoother that pulley face feels than it looks in the photo.

Realistically, this is as good as the pulley surface is going to get without being able to throw it onto an actual lathe with a suitable cutter to reface the running surfaces properly. It just ain't going to get any better in my hands...so if it still eats belts I'll probably need to get a machine shop involved.

The last thing I did before packing up this evening was throw (not literally of course) a load of filler at the bodywork.





The area behind the nearside wheelarch should benefit a lot from this (remember, there was a huge crack there). I'll hit it with the sander and some paint tomorrow (or another coat of filler if needed - I'm going for presentable from twenty paces here) to tidy things up a bit. Obviously will be a fair amount more needed, but it's the first time I've used this exact stuff so I wanted to start simple. Plus to be brutally honest I'm more interested in driving this car right now than making it pretty... 

In theory you could probably alter things fractionally this way...though being realistic it's just a bit of pressed steel so there's not really enough to take that sort of amount off. Tweaking the belt tension, width or the spring weights in the governor are far easier ways to mess with the gearing profile of the CVT.

Having had a think about it further this morning I went to confirm the identification of my brake master cylinder so I could get either a service kit or new cylinder ordered.

Nice to see that the fluid level hasn't moved in the slightest since I've started driving it, I know there's no reason it should have, but it's still nice to see the fluid staying where it should be.



Yep, there's the number which I couldn't remember or find written down anywhere.



Doing a bit of digging around on the internet to see what I could find. When did the search function on everything become so utterly useless? Why when I type in "Girling 625 master cylinder service kit" are the first five items for Lockheed cylinders or totally different complete cylinders before anything starts to turn up that's useful?

Anyhow...eventually managed to track down some rebuild kits. They're a good bit more expensive than I'd expected...not far off the same price that genuine Girling cylinders seem to go for (£60 or thereabouts). Though there are a plethora of off brand ones for £20-30 out there. Though quite what sort of quality to expect at that point I'm not sure.

I did however decide to grab one. Basically because A: I've had gift money sitting in my Amazon account for about two years now so it's essentially free. B: Because it will at least let me prove the rest of the system behaves or not. If it does behave perfectly then I at least know that the MC is the issue...if I can't then make one good cylinder out of the two or am actually satisfied with the one from Amazon that turns up, I'll get a proper new Girling one ordered up. As the one I've ordered is essentially free it seemed worth a shot though.

Bodywork wise I've given things over the back a sand down (man I'd forgotten how much dust that creates!) and blew a quick bit of paint over it.



Definitely heading in the right direction... here's the same panel when the car arrived on my driveway.



Will want another coat or three of filler, but we're definitely making progress. I'll make sure I actually have enough on hand next time!



She's never going to be a concourse show winner, but hoping that a finish that's presentable from ten or twenty paces should be doable.

What I was really interested in seeing though was whether my messing about with the CVT secondary pulley yesterday had actually done anything useful.

The answer is a definite yes. While I've only been able to do testing up to 30mph today courtesy of rush hour, things have obviously improved. The pickup from a standing start is smoother and changes to throttle setting are far more quickly responded to now. It's also way quieter.

Have a *really* shaky video showing how things are behaving now. I'll hopefully make a run out onto a faster road tomorrow to see how it behaves.

While I was on Amazon earlier this afternoon a better phone mount was also ordered...so hopefully any future footage recorded on that will be something resembling stable. I can only apologise for how awful the footage here is.



Feels like we're getting quite close to a car which is actually usable now.

Brilliant work, the CVT can be an to iron out.
The bodywork is looking better too, being a painter it's a job that's unforgiving.

body work looks great!...a vast improvement. each time you add more filler, it smoothes out more. well done.

JP

Had a bit of a special day today as the owner of TWC was due to pay me a visit. His rescue from a field and restoration of TWC was responsible for me discovering what an Invacar was. I'd never heard of them until then. Shortly after wound up with one which was missing a large portion of the bodywork but was generally sound mechanically...then once TWC was back on the road, I bought TPA, the original spares car for the restoration of TWC. She was missing her entire drivetrain by this point...but I had essentially precisely what I needed to make one working car out of the two by fitting the drivetrain from my original car. We did get a couple of photos of them together back last summer, but TPA was still a fair ways from roadworthy back then.

This was going to be the first time they'd been in one spot while both were roadworthy, so obviously we wanted to get a few photos of them together, have a little drive out in convoy etc.

In preparation for that I wanted to finish off the cosmetic work I'd been doing yesterday. Quick splash of paint first.



Still going to need a little more filler, but a LOT better than it was.



While I had the paint out I gave the fan shroud a quick splash as well. The original paint was flaking off and it was bugging me.



Then gave the interior a quick clean as it was covered in filler dust and rust powder which the heater is still shedding despite my best efforts to clean it out.



Really need to get a wet and dry vacuum on the driver's seat as it is quite grubby (sitting in the back of the garage for two years will do that, not to mention the 200K miles in the donor vehicle).

Soon after I was done with that my guest arrived and we went out for our little drive, stopping at a local from park which has some nice greenery in the background so is a good place to take car photos.









That was quite a fun afternoon. Yes, we did get some properly confused looks when we were out driving in convoy.

Wonderful seeing two together. I love this thread

They actually look happy to see each other in the last pic

Great photo.






Love the progress, a little every day.

Well done.