Radiator - 2010

First some background information. This is the best description I’ve found on the intricacies of an Aprilia radiator.

From “The Light Car” January 7, 1938.

The engine , gearbox and radiator are carried as a unit upon four leaf springs; the purpose of this form of construction will be evident when the arrangement of the dynamo and cooling system is described. The springs are each made of three steel leaves of orthodox type, with friction distance pieces between the ends of the leaves. The floating end of each spring is bolted, through a rubber bush, to bearer arms on the engine block, the other end being attached by two bolts to the chassis of the car. The front bearers have forged extensions, which carry the radiator block, so that it moves with the engine, this method of assembly doing away with the more usual long, flexible waterpipe connections, which in this case, are very small diameter and as short as possible.

In the centre of the radiator core there is a circular housing built into the block itself, in which the constant voltage dynamo is carried. This component is reversed, the pulley, on which are cast two fan blades, being at the back, between the radiator and the front of the engine. The cut-out, fixed to the dynamo, and the brush gear protrude in front of the radiator and are reached for attention by detaching the radiator cowl.

The water pump, in which is incorporated a very accessible drain tap, is mounted on the bottom of the radiator, instead of on the engine as in more orthodox designs, and is driven by a three-point vee belt from the crankshaft, which also drives the dynamo. As the pump is apparently not in the circulating system, some explanation of its arrangement is necessary.

The lower tank of the radiator is divided into two by a transverse baffle, the water passing down the radiator block to the front of it. On the near side of the radiator is the pump, which has two ports, one in front of the other, water in front of the baffle is drawn down the front port, through the impeller and up the rear port into the rear division of the tank. The water then crosses this tank, through the bottom waterpipe on the off side, and so to the engine. The driving belt is adjusted by rotating the dynamo, the armature shaft being mounted eccentrically in the housing.

OK now that we have a basic understanding of how this thing works I’ll get on with this abbreviated version of the story. In my defence before I bought the car I was totally ignorant of most things Aprilia, the radiator included.

Part 1  - September 2007

The radiator develops a leak around the centre dynamo core. Take it to local business, not interested, grumpy bugger told me to “piss off”

Someone recommends a company in Preston (‘Company A’), 800 km round trip to drop it off. Two weeks later collect it. Has new core fitted. On inspection there was a large amount of loose solder inside, managed to get most out.

On reassembly the fan belt and dynamo don’t quite align. They made a new centre and it was too deep, just got a compromise with the fan belt touching the timing chain cover as Castlemaine rally was a few days away.

I had also checked the water pump and discovered it wasn’t working. It was missing the spacer at the back end of the impeller so it wasn’t engaging the pulley. Strange as I didn’t have any overheating problems. Made spacer and re-fitted pump to radiator.

Part 2 – 2008.

Removed engine/gearbox/radiator assembly to repair broken clutch. Needed to get centre of radiator adjusted to fit. New recommendation for company ‘B’, Supa–Trik Radiators, Richard Janssen, in Dandenong.  They say they can do it, will take about four weeks. Seven months later, after many phone calls, emails and three times visiting the factory, it’s not done. Get back the results of their “labours” – see pic ➜.

Part 3 – 2009

Take it to Huntingdale Radiators, company ‘C’,  Ron Thompson is terrific (unfortunately he has since retired) After doing the repairs he tests it and discovers the ‘new’ core is stuffed, ‘Company A’ had failed to flush it correctly and it has corroded out. Ron organises new core. Collect it in March. On fitting discover the dynamo bracket is on the wrong side, not Ron’s fault, see drawing above. Take it back to Ron. Collect again a few days later. Further inspection reveals the internal channels for the water pump aren’t in place, so back again for another fix!

On re-fitting all seems fine until I put the radiator grill back on, the radiator is now too high and too far forward. On checking the bottom mounts are out of alignment so attempt own repair. Succeed in creating leak from bottom of core. Take it to local radiator repair man, company ‘D’,  who solders it back up for me. It still doesn’t fit very well.

Part 4 – 2009/10

A new old stock second series radiator appears on the internet in Italy. €400, too good to pass up, get it shipped.

Order correct mounting hardware and screw on radiator cap from Cavalitto.

After rear end rebuild is finished install the new radiator and it fits perfectly. Everything lines up and there is ample clearance under the grill. It did have a small leak from around the top stay bracket. Also made up extension for water pump tap so it could be located correctly.


In the end I worked out the old radiator had been stuffed around so much the top and bottom tanks were too far out of alignment to fit, plus the modern cores have large rims that mess things up.

The cost of all this?

On the old radiator I spent just on $2600 and traveled 3900 km in the Land Rover getting the repairs done, I’d only done 1500 km in the Aprilia. The new radiator cost a total of $880. An interesting note back in 1991 the radiator was repaired for £558.

The above is actually just a small account of what happened. There were countless hours of head scratching, trial fittings, pulling engine mounts apart, turning up bits on the lathe, getting more advise than was necessary from some and on and on. But thank goodness for the internet and a specially big thank you to Andrew, Peter, Joe, Don & Enrico.

You just have to love these wonderful little cars.


October 2010

Sept 2007. Original radiator installation. Note modern core and drain tap at the front. The car also has an oil cooler fitted as part of a modern spin on filter set-up & a modern regulator on the dynamo

2nd series rebuilt water pump, new sealed bearing & stainless steel tang. The body has been modified so a modern seal can be fitted to the impeller.

After 7 months at Supa-Trik this is what I get back.

No space under grill, too high and too far forward!

New radiator mounting hardware. This is for 2nd series. 1st series are bolted solid to the mounts.

The new one in place, note the excellent fit! The water pump, dyno and crankshaft all align. Unusually this radiator has a screw on cap.

Now with sender for mechanical temperature gauge fitted on the inlet pipe.

The new radiator manufactures plate:

S.A Fabbrica Italiana Radiatori

Per Automobilt

Via Nicola Fabrizi 83 Torino

1st series radiator manufactures plate. Same company, different address.

Notice the weight, 17Kg. 2nd series weigh 16Kg. Why the 1kg difference? 1st series have an extra honeycomb mesh piece on the front, maybe that’s it.

Get a copy of Bill Smith’s excellent booklet on corrosion in Lamdba engines, the information is very relevant to Aprilias. It might also scare the living daylights out of you.

Available from the Australian Lancia Register.