1937 Aprilia 38-1427

[williamcorke]

Thank you Simon, very helpful.

My clutch is, I think SII.

All seems in good condition apart from one of the 3 springs that hold the pressure plate onto the back part of the unit (photo 1 and 2. Clutch plate diameter is 19cm).

Cavalitto has both individual springs and the unit for sale (photos 3 and 4), I'm not sure at what prices yet, have emailed to ask.

Does anyone have any idea how easy it would be to get a new spring riveted to my plate? What tool(s) are need to do this? It seems the rivets originally used where hollow and driven at the hollow end to split and secure them (photo 5). A quick Google suggests these are hollow aka semi-tubular or tubular rivets.

Alternatively, does someone have this part of the clutch (pressure plate with 3 springs) in their parts stash which they would be prepared to part with?

[davidwheeler]

My son has just done this precise job for me, cutting the plates by hand (the laser cutter at work was not available) and we rivetted them on with red hot rivets which then tightened as they cooled.   To him this was basic engineering process.  I fear he is not available for hire but any machine shop should be able to do this for you.   The clutch has just been installed and seems to work fine.

[williamcorke]

Thank you David,

I have ordered some 'semi hollow' steel rivets (5mm dia. 7mm length) and will add heat when I install them; that's a good tip.

[williamcorke]

A visual progress report, cleaned, repaired and parts going back together with new gaskets.

[DavidLaver]

Any excuse to revisit some youtube favourites.

https://www.youtube.com/watch?v=KIUAM28vsI0

https://www.youtube.com/watch?v=fNTlqSPt2c4

https://www.youtube.com/watch?v=Us63Q8LXST8

[williamcorke]

Great David,  Inspiring stuff. I'm planning to film a video of the engine running out of the car, once I get to that point.

Meanwhile, I've now moved on to wiring. None came with the car, so I have several questions about how things are supposed to go together.

1. Battery Isolator (or not to isolate)

I have, salvaged from a rotten Ardennes, the battery isolation switch seen in the photos below.

Is this 'factory'? For French-built Ardennes, Aprilias in general? Or is it aftermarket?

It appears to have been mounted on the LHS of the bulkhead, passing through to the passenger side. The isolator key would clearly have been inside the car (some new holes in the bulkhead would be required to mount it).

I quite like the idea of putting this Ducellier unit in my car, though I'm a bit concerned that it might reduce the current from the battery to the starter.

Does anyone have any thoughts or advice?

In one of the Aprilia documents I read, there was reference to a cut-out switch, and I've seen a photo somewhere of such an item. Is my isolator switch this, or it it something else?

[williamcorke]

Aprilia S2 Oil pump / distributor gear.

Having hoped that I could just clean up and run the engine in 1427, having been told when I bought the car that it had recently been rebuilt, and inspections (oil condition etc.) supporting that story, I decided a few weeks ago that it needed to come apart for inspection.

The main reason for this was 'mechanical resistance'. While the engine turned, it had so much resistance at certain points in its cycle that I couldn't budge it using a starting handle. The 6v starter (tested and OK) couldn't turn the motor at all.

So, in we go...

I like Jonny Smith's 'Late Brake Show' barn find videos, but the show's obsession with getting the engine running immediately, while good for drama, is questionable in my opinion.

Photo 1 is, I think, a salutary lesson in why engines that have been sitting for a while should not be optimistically started without internal investigation. Masses of FeO crud from the head sitting on the gasket.

However, other evidence within is that the engine had indeed been recently rebuilt. Cylinders, pistons, rings, bearings, all look good (though I'm not sure that one of the big ends isn't 'picking up', the oil was grey on No. 4 and the white metal looks different to the others).

The head has been previously repaired - Photo 2, see areas of 'pale' metal - and I think is good to go back on without any more than a good clean-up.

I need to remove the crank to get everything cleaned up and make a new sump gasket. The gear that drives the oil pump and distributor at the front of the crank (bottom of photo 3) obstructs the removal of the crank, so the pump drive needs to be removed.

There appears to be a pin that locates the pump/dizzy drive on the shaft, but trying to punch it out didn't work. Can someone let me know how to remove the drive / shaft please? The parts book isn't informative on this subject as the gear from crank to pump / dizzy drive isn't illustrated.

I'll update on what the reasons for the mechanical resistance might be once I've made more investigations.

[davidwheeler]

Looks like Fe203 to me!     Not nice stuff to get in your radiator.

[williamcorke]

Exactly David. Some of the lumps were solid enough I think they might even have jammed the water pump impeller.

Do you have any insight into how the oil pump drive is removed?

[simonandjuliet]

From memory, I don't think that you have to remove the drive, you rotate the crankshaft and as you do , you slide the gear forward. Mark it before you do so that the correct tooth re-aligns with the distributor drive so that the rotor am is correct later - otherwise the greaser and condensor are in the wrong place