The first work on the A112 block for the Fiat 850 at Broos Revisie in Breda has started. After a thorough cleaning, the block was bored to 67.8mm (3rd oversize) and skimmed slightly. The crankshaft, connecting rods, pistons and bearings will also be installed after all rotating parts are balanced.

And for the main bearings, they are "back home" again: my father once sold old stock to Broos and he now installs the main bearings from that stock in my engine.

850 blok broos 850 lagers

I had bought the original connecting rods with the block. Because the Autobianchi engine has press-on piston pins and the pistons from Scuderia Abarth use pins with clips, there was some room between the eyes of the connecting rods and the piston pins. That is not really conducive to a long life. This is solved by machining phosphor bronze bushings:

850 drijfstangbus 1 850 drijfstangbus 2

The cylinder head had suffered quite a bit from the standard ailments of the 850 engine: lean mixture in the outer cylinders and excessive heat: quite a bit of pitting at the valve seats. Slightly larger valves than standard have been chosen for the head; exhaust 27.5 instead of 26mm, inlet 30.5 instead of 29mm (valves of a Fiat Seicento Sporting have the same length and stem diameter. And one groove) and, of course, also new valve seats. This means that a large part of the pitting has disappeared immediately.

850 kop broos

The setup for the cylinder head to be overhauled. And this is the head (almost) ready for use:
850 cilinderkop klaar

Inlet and outlet channels have been milled a bit and everything neatly installed.

The camshaft has also arrived, a 296° one from Abarth-online / Scuderia Topolino. The cam followers I had in stock look good, they are only polished a bit. And this is the new camshaft housing:

850 nokkenas nieuw 850 nokkenaslagers nieuw

Plus some weight has been removed from the flywheel.