8th February 2012 – Build Day 7.75 (The revenge of Nigel’s crankcase)

Wednesday night was set aside to repair Nigel’s crankcase.  If you follow his blog you will know that on dismantling his ‘chummy’ engine he found that a late (non-magneto) crank had been used and was contacting the crank case where the casing is relieved for the magneto.  This had caused a crack to run up the side of the crank case.

So I promised that I would have a go a running a weld up the crack with the tig.  Little did I know what I was letting myself in for!  The main problem seemed to be contamination of the casting, porous ali and 70 years of soaking meant that there was oil everywhere.  In the end we found the best method was running the tig torch up and down the area to heat and clean (you could see the oil moving out of the heated area).  Then I ground out the crack with a die grinder, cleaned with alcohol, heated again.  In the end we got there, I found that increasing the welding frequency also improved things a lot.

Hopefully it will be serviceable Nigel is due to start grinding it back flush this weekend.

We did get something done on the Westie, we dismantled the LHS rear upright and pressed new bearings into both of the uprights.  Managed to blow the seal in my press in the process :(

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