Restoring a Top Hat

[Parazine]

This week.....

Well, not quite finished by Sunday but should be mostly completed tomorrow. 

   

Here's proof that a 1 5/16" Phoenix crank WILL fit in a mag crankcase, mighty tight though, especially at the front end!

   

Timing case finished, always a fiddly job on these magneto engines.

   

Block and crankcase ready for fitting together.

   

Mustn't forget these guys


Just one more week before work starts again.....

[Zetomagneto]

There is no doubt they will fit in a mag crankcase, but you will have to relieve the inside of the crankcase
on the RH side where the case wall goes inward to take the magneto. The rod nuts will hit at that point.

[Ruairidh Dunford]

I have fitted around a dozen into magneto crankcases and never had that issue.

[Ian Williams]

Perhaps Zeto is thinking of the phoenix rather than austin rods, I have never fitted a set in a mag case personally, but they are tight in a Sand cast coil case.

---

I would throw those bloody stupid oil traps away as well

[Zetomagneto]

1 and 5/16" crank in magneto crankcase with Austin rods. The castings must vary perhaps I have been 
unlucky. Good to see you have fitted so many Rory, can't understand why people bother to fit new 1 and an 1/8" cranks.

[Mike Costigan]

... can't understand why people bother to fit new 1 and an 1/8" cranks.

Less reciprocating mass, better acceleration from low speeds?

[Ruairidh Dunford]

Increasing scarcity of 1 5/16" three speed flywheels (although 4-speed flywheels can successfully be adapted) and usable 1 5/16" rods are the main reason people are now considering them a good idea Gene.

[Parazine]

I have fitted around a dozen into magneto crankcases and never had that issue.

I've fitted a few of these now, perhaps 3 or 4, not had a problem with the rod nuts hitting the case side although, as I said, it's mighty tight in there!

Re: The oil traps (I call them "Cocoa tin lids"), I always fit them because basically I'm a masochist and I relish the challenge, the struggle and the cut finger tips getting them into position!
I don't know whether they do anything at all; I suspect with modern 4 ring pistons they are redundant.

[Parazine]

Engine is finished!

Final job was to machine the front crankshaft oil seal housing to accept a modern oil seal. The housing is 1 15/16" in diameter but the oil seals available are either slightly too small or a full 2" O/D.

I went for the larger size and a 5 min machining job:

   

Final fitment:

   

And the completed engine:

   

   


All the mag engines I have built since the 'eighties have had the front lower pulley secured with a roll pin, hammered through a parallel hole in the pulley. However, I managed to get some 1/4" taper pins on eBay recently and experimented with fitting the pulley the factory way. I drilled a hole on the large side with a "D" letter drill and a number "2" on the small side, having experimented with a piece of aluminium scrap, then hammered the pin through. Make a nice snug fit.

Standing back though, I'm still unhappy with the stance of the car, it still leans to the N/S. I did a lot of bouncing and observing plus measuring and established that the N/S rear spring is soft; it's lost its springiness, probably through overloading in the past. 

   

I ordered a replacement set of springs from Mr Dunford (senior) and they're ready for fitting now, don't they look nice!

   

I need to remove the body one more time to fit these, rather than struggle underneath. I won't do it today though as it's raining and I'll need to push the Chummy out of the garage for a couple of days while I sort this out....

[flywheel1935]

Once you sit in it it will sit level ?????? :-) unless you overindulging over lockdown !!!!