Jul 262012

Cooling on the original Series 1 cars was provided by a thin single two bladed cooling fan. This was uprated for the Series 2 with the introduction of twin four bladed fans. One of the popular upgrades is to improve the cooling by installing kits from Kenlowe or Coolcat, which are probably more suited to the stop-starting of today’s congested roads. I’m not sure if this upgrade is more targeted for the S1, so my aim is to restore all three fans, pick the better two for the rebuild and keep the third as a spare. I will then re-evaluate once I’ve driven the car for a period of time.

Motor body prior to shot-blastingThe alloy end plates were sent off to be ultrasonically cleaned while I renovated the motor body and internals. The renovation of the motor bodies ended up being a bit of a palaver and took several goes before I was happy with the end result. They were quite heavily rusted and after shot-blasting revealed quite heavy pitting. Rather optimistically, I thought this would be hidden when they were painted with silver Hammerite. What I soon learnt was that paint is not a good filler as the pitting was still clearly visible through the paint. Also I wasn’t happy with the colour of the silver Hammerite compared with the original finish which was a dark silver grey.All the bodies were quite badly pitted

Unfortunately Hammerite have stopped making the dark silver paint and it took quite a while before I managed to find a suitable equivalent, Rust-oleum paint code 7388.0.4. In the meantime the motor bodies had been shot-blasted again and the pitting filled with Isopon Metalik filler. The first attempt with the Rust-oleum was a disaster. The paint seemed to effervesce on contact, presumably to obtain the hammered effect, but the bubbles created remained in the final finish.

Colour difference between the Hammerite and Rust-oleum ... the wiper motor will now be re-painted to match!I finally managed to get a reasonable result by heating the spray can in hot water and the motor body in a low oven. This reduced the viscosity of the paint sufficiently to allow the bubbles to burst and then the paint to level sufficiently before it started to ‘skin’.

The photo to the left shows the motor body painted with Rust-oleum compared with the wiper motor painted in silver hammerite. I’ll now re-paint the wiper motor body in the darker grey.

The armatures were next to be tackled. The rusted iron parts forming the electromagnet were carefully wire brushed before being polished. Then Gtechniq S1 Smartmetal was applied to give a hydrophobic coating which hopefully might delay the onset of rusting in future. Finally the copper contacts were polished with good old Brasso, the gaps between the contacts cleaned out and new brush sets obtained, Lucas part BR1 743171.

Before …

and after

New brush sets

Armature condition as removed from the fan motor

Armature after cleaning and polishing

New motor brush sets purchased on eBay

The stator and the various bolts, washers and screws where then zinc-nickel plated using a kit purchased from Gateros Plating. The electroplating is surprisingly simple and good results can easily be achieved. The components were finally ready for the rebuild.

The rebuild process is, to use the overused terminology from Haynes manual, the ‘reverse sequence’ of the dismantling … but in this case it is as simple as that!

Plated stator

Armature refitted

Completed fan motor

The fan mounting brackets and the radiator cowl were originally a black, crinkle finish. Suitable crinkle paint spray cans are readily available but, while researching it, I found out that it’s possible to get a powder coating with a crinkle finish. After the disaster with the Rust-oleum hammered paint, I decided to go down the powder coated route.

However, it appears that the crinkle finish look must have fallen out of favour as I’d contacted almost all the local powder coating firms and none of them stocked it. I was about to give up when I found a small firm who had a small supply tucked away. A few days later and the parts were returned. I do hope that, after all this effort, the fans are up to the job!!

When the cars left the factory there were two plastic shields which covered the opening in the rear end plate for the electrical connections but these were missing. Fortunately SNG Barratt now remanufacturer these but I’m not convinced how effective they will be at keeping water out. I guess they’re better than nothing.

Cooling Fan with plastic shroud

Cooling fans – ready to fit

Before shot of the cooling fans

Fans and cowling restored to their former glory. Fingers crossed they're up to the job!

The before shot of the fans and shrouds