MDB4 Progress

 

You have to do a lot of scrolling back to find the last progress report on the McLaren-Benz MDB4 engine, 3 September 2021. This described the decision to dispatch the engine to a specialist restorer of vintage IC engines, Formhalls, to have the bearings re-metalled & the cylinder liners fitted. They are based a Salisbury, which is close to Stonehenge and consequently time moves at a different speed in Wiltshire. Their six weeks of Wiltshire time is two & half years of Gwynedd time. Ironically, when they heard we had had a crankshaft made by Farndons, they had the gall to mock their lack of communication & delivery skills. Mr Pot, meet Mrs Kettle!

Enough bitching, on the 13th March the engine arrived back at Boston Lodge, new crankcase bearings, whitemettalled & bore, big ends re-metalled, and cylinder liners fitted. Credit where it is due, there also find all sorts of little cracks radiating from the cylinder head studs & these have been laser welded up.

Line boring the crankshaft (image courtesy of Farndon Engineering)

The completed crankcase and bearings (image courtesy of Farndon Engineering)

A very sexy row of crankshafts (image courtesy of Farndon Engineering)

Laser welded repairs to cylinder head (image courtesy of Farndon Engineering)

Cylindrical grinding of cylinder liners prior to fitting (image courtesy of Farndon Engineering)

Cylinder liners ready to fit (image courtesy of Farndon Engineering)

Fortunately the return of the engine coincided with a period of leave for Rick, who duly got carried away. Job number one was to remove the plugs giving access to the oil ways. How the lubrication system works was described in the blog entry for 5 March 2018.

The illustration above is diagrammatic; the ‘pipes’ which lead to the crank shaft bearings are, in practice formed of a series of interconnected oilways drilled into the crank case and engine block. There is an oil way from one end of the block to the other, with individual branches leading to each crank shaft bearing location. At the end of each run there is a plug. When you remove the plugs and poke a small bottle brush in this is what you get out:

The cylinder heads had been overhauled earlier in the project (blog 10 April 2021) and in a moment of wild excitement one was trial fitted onto the cylinder block, with one of the MDB2 rocker covers. The rocker cover castings are still in Chris Barrys’ workshop. Wife, Kids, Dog, 7.5” rebuilds, pah! Come on Rimmer pull your finger out.

A frenzy of painting has ensured, so the cylinder block now looks like this, complete with replica McLaren-Benz plate.

It is not just the block that has been painted, the cylinder heads look lovely too

As do the myriad of cover plates etc. Even the MDB2 rocker covers have had a look-in

Next on the agenda is gasket manufacture. One down,

Some way still to go!