Saturday, 10 April 2021

Cylinder Heads Returned

 It is a long time since the 18th July 2019, when the rather sad looking cylinder heads were being dispatched to T&L Engineering…

Now they’re back and in the words of Madonna look shiny and new:

The new cylinder liners are expected soon too, so we are starting to accumulate quite a number of large components ready for re-assembly. While all this is exciting, the focus now needs to move from the big bits to the small bits, of which there are many!

This diagram is an edited extract from the MDB Running Instructions book (cropped to show the heads only). Sorting out the tappet rods (M) which run through the two brass lined holes in the photo above, together with the associated Fork Holders (9) & Check Nuts (10) is now on the to-do list. The Rocker Levers (N) & the Rocker Lever Brackets (11) need some TLC and are marinating in a bucket of Diesel. Lacking Ricks’ efficiency at recording progress I forgot to take a photo of them. A Diesel bath will not fix them, but it will hopefully make them easier to dismantle.

After spending an afternoon rooting through bins of rusty bits that will one day live and breathe fire it looks like there will be a need to make some new Torch Holders (i). The running instructions provide guidance on the use of the torch holders when starting the two or three cylinder engines (which are started by hand) but make no reference to their use when  an auxiliary engine is used (as is the case with 4415). 

The elephant not in the room regarding all of this is of course the atomisers. We think we have sufficient knowledge & information to instruct the construction of these vital components. Some aspects of this project are challenging, ordering injectors to your own specification makes the instruction to make a new crankshaft feel quite mundane.

Tempting though it is to leave the guidance on the use of the Torch Holders hanging, the opportunity to restore the MDB2 and roll some roads still remains. That group of people needs to know that you have to:

    • Remove the Torch Holders, turn the engine 10 to 12 revolutions with the release screws on the atomisers (injectors) open (i.e. not injecting).

    • In cold weather injecting a small drop of paraffin through the torch holder fitting will assist starting

    • Close release screws on atomisers (now injecting fuel)

    • Place torch papers (cigarette paper) in holders, ignite them and screw them into the heads, being careful to put each holder back into the correct cylinder

    • Crank away with the compression relief lever open (to the left); when the engine is up to speed, move the compression lever to the middle (half compression) and the engine will fire (the instructions say)