Restoring a Top Hat

[Ivor Hawkins]

Every time I see the progress on this car it’s a delight...I love the way the ash tray includes a rest for your pipe!

[Parazine]

A Muddle of Magnetos!

I don't know what the collective term is for a quantity of magnetos but in this case, muddle seems appropriate.

I'll probably get shot down in flames by the purists but I like to use the post war Lucas "Tractor Mag", the SR4. I have had bad experiences with vintage magnetos, including
a four mile walk when the Watford on my RF saloon exploded. Using the SR4 is a good solution for a driving mag engine car, being strong, reliable,
holding their magnetism well and having most spares available. The downside of course is that there is no manual control of the spark so you have to run with fixed timing.

   

The pile of bits seen here has been tested, several of the HT coils are open circuit and need rewinding. The key is to find one that is about 5K ohms from the
HT connection to the primary wire. Much more indicates a bad connection, much less, shorted turns. I found a coil at 4.8K Ohms and built it into a casing with a good
rotor. Lubricated the bearings with HMP grease and tested. It gives a good spark at 60 RPM, so I'll try that one on the car. The problem is getting a rebuilt, stiff engine
turning over fast enough to get the magneto sparking.

   


I have one magneto with the "Flick" drive, otherwise known as an "Impulse Starter". Unfortunately, it has a drive flange with 20 teeth on it intead of the 19 we require,
so will take some re-engineering to use. The Flick drive operates at speeds below 250 RPM where it retards the magneto and then spins it quickly over the point that the spark
is timed, helping to start the engine. Maybe I'll try and incorporate that on the Mag for the Top Hat if I have time

   

Here's the finished product, ready to fit.

Whilst I'm rebuilding SR4's, I must have a look at the one fitted to my Chummy, which has been operating for a few years now and needs the bearings greasing.

I'm still hoping to attempt to start the Top Hat engine over Christmas but I also have to remove the RK saloon engine to sort out a badly oiled clutch.

[Renaud]

A glutton for mags... why not!
Surely the right drive flange can be found, no? I'm sure I saw that somewhere.

[Parazine]

Compete Automobilist (Paul Beck) or whatever they're called this week were selling the 19 tooth flanges, I have one. It needs machining and fitting........

[steve hoare]

You mention different wheel rims. What are the originals?  I have a 1926 austin script wheel with the earlier rim as fitted to the 6" braked wheels which I assume is very early post 6" wheel.  Its good original though you might choose to re spoke it and has a tyre. Would exchange it for a later 28/9 wheel.

[Parazine]

You mention different wheel rims. What are the originals?  I have a 1926 austin script wheel with the earlier rim as fitted to the 6" braked wheels which I assume is very early post 6" wheel.  Its good original though you might choose to re spoke it and has a tyre. Would exchange it for a later 28/9 wheel.

On my car, three wheels are like this:

   

And the two remaining are like this:

   

I think the first type rim was shared between the first "balloon" tyre, open centre wheels and the first closed centre, scripted wheels (March 1926 on). The second type was introduced sometime in 1927, Wyatt doesn't mention the rim change, neither does Purves.

My car was manufactured December 1926, so the three earlier type wheels are probably original. I think two wheels were changed on this car due to the accident.

I stand to be corrected on this, anybody know different?

[Ruairidh Dunford]

My friend’s 1927 Chummy has a set of those rims too Tim. They are difficult (but not impossible) to find in my experience.

[Parazine]

It Speaks!

Where have the holidays gone? Back to work tomorrow  

The garage is still blocked up with RK saloon; I took the flywheel off to reline the clutch and thought I'd better fit a new oil seal (it was the lip seal type). Ordered one from Jamie, which arrived on Christmas eve but then found that the flywheel had been machined and the fitted seal was a non-standard size (44 x 72mm). Ordered one from a bearing supplier but they seem to be shut until 4th Jan. I was going to move the RK out of the way but then got nagged re-prioritised into repairing a leaking shower in the house, which was actually a lifesaver because it has been flippin' cold in the garage this week!
Having got the shower under control, I thought I'd have a go at the Top Hat on my last free day. I rebuilt the magneto again, this time putting the impulse (Flick) drive onto the front of it, timed and fitted it, filled up with petrol, oil, water and pressed the button hopefully. I was rewarded with a running engine! I spent half an hour zooming up and down the drive; at the end of that time, the engine was running nice and smoothly, no nasty noises, clutch works, 1st and reverse work, speedometer works and so does the wiper motor!

   

So that's it for a few weeks, working until mid January, then I may get some garage time time, although I have to do a lot of work on my MGF this spring, including replacing the suspension bottles, cambelt, water pump etc.

Next Top Hat work will be wiring and then trim but it may be a few months before there's an update.

[Parazine]

Link to the video:

https://vimeo.com/496687390

Enjoy!

[Mike Costigan]

Excellent! A major milestone achieved.