Workshop Journal: Mark’s S14B23 Engine Build

There are sadly not too many sightings of E30 M3s in the world these days, especially not ones being driven properly. But fear not, our customer Mark has been pounding his M3 around the tracks and the roads of Jersey for many years and as part of some restoration work on the car he’s carrying out, he decided to send the engine to us for the specialist love and care that we offer.

Though tired and sporting pitted cams, worn bearings, oil leaks, worn chain guides and more, it made the perfect base for a complete transformation.

The internals chosen for the engine made for a list of the best in the business. CP-Carrillo pistons married to Arrow rods, with the original crankshaft reground and dynamically balanced to perfection.

From here, the dry-builds can begin. Measuring of all operating clearances including bearing oil clearances, piston to wall clearance, piston to valve clearance, compression ratio and much more.

Almost all of the aluminium engine externals were vapour-blasted, with zinc-plated fasteners used everywhere possible. The chain guides, chains, oil pump and gaskets were all renewed.

Once the dry-builds were complete, it was time for the final assembly. Everything was cleaned one last time, painted and then built to all the same specifications used in the dry-builds for perfect precision and repeatability.

The cylinder head was fitted with the full array of Supertech valvetrain, including new valve guides.

The dry-builds showed us that clearancing of the cam tray would be required, and so this was done on the mill. Slight modifications were also needed to a number of valvetrain components to give us the clearances required for safe and reliable running.

The camshaft pulleys were modified to allow for adjustable cam timing, meaning that the Schrick cams could be dialled in perfectly.

And there we have it! One perfect S14B23 engine ready to head back to its owner, complete with Hack Engineering engine stands.

Specification