Lambretta SIL engine transformed

Lambretta SIL engine casing transformed

SIL engine casings are getting worse and worse and have been for 20 odd years. The tooling must be in a right mess and cracked so you see lots of castings with lots of sharp flashes all over.

You can’t just bead blast or aqua blast them as they look even rougher as the flashes and bad grinding from the factory look even worse.

Now SIL casings are drying up, it looks like the factory is packing in. We’ve had some limited new old stock, but they sell out straight away. Some customers want their casings preparing to look better before we send them out or you supplied one we can do your casing.

Here we have a new casing which has needed the flashing marks and bad grinding marks hand ground down with various tools to blend in the mess. This creates deep scratches, so more hand grinding to work at the alloy to remove the scratches.

Then the casings are individually put in our rumbling machine with a fine grinding media to blend the casing even more – this can take a few days! From here the engine is washed off and dried. Once dried all the thread holes are filled with screws and then fine dry bead blasted all over to get into the tight areas and clean dents and small holes you can’t grind out. It’s then aqua blasted to blend out the dry blasting and give it a bit of a semi shine.

The finish you see isn’t a highly polished casing – as in polished on a polishing wheel – imagine a chrome look. The aqua blast leaves a slightly matted finish with a semi shine – it makes it look more of a new casting thats just popped out of a decent casting mould.