TAIPAN MK1 RESTORATION

Well we have certainly been presented with a literal rubbish bin rescue job with this EXTREMELY sad little Aussie as he was all but dead and buried when our good ozzy mate Callum Henderson sent him over to us for resurrection. What a very sad state of affairs this is.........

Well here he is as he arrived in our E.D. well and truly on death's doorstep.

While this poor boy looks very sad here, the real trauma is underneath, as seen in these photos.

Unfortunately, this engine has suffered some rather serious crash damage which looks to have resulted in a badly cracked crankcase which then has been complicated somewhat by a well meaning but perhaps inexperienced person who has gone ahead and welded the case without dismantling and properly cleaning or heat sink reinforcing the case which means we are slightly concerned at what we'll find once we start dismantling the engine and reprofiling the outside of the case. Here's to hoping the weld is not porus.

Unfortunately upon dismantling the engine to start our restoration we have discovered a somewhat slight complication.

 

Although hard to spot in this photo the crankshaft is fouling on the bottom edge of the case back face and required some degree of persuasion to be removed from the case. What's happened is that when the case was welded it has distorted due to insufficient rigidity and lack of heat sinking around the welded  area and has bent the crankshaft plain bearing area upwards causing the crank web to foul on the lower edge of the back plate portion of the case. Thankfully it's not super way out and I'm fairly sure we will be able to remove the plain bearing bush and true up the crankshaft/case center line with the cylinder/case center line and salvage the case for reuse.

 

Next step in the process is to re profile the weld repair to look less like bird droppings and more like crankcase.

Stage one, rough file the worst of the weld away and see how much, if any, porosity is there.

Looking hopeful here.........

 

Now we'll set the case up in the milling machine and clean up the hard to reach section under the venturi.

Having carried out the machine work, then spending an eternity behind a file we have finally managed to return the case to look something more like a crankcase that may well be useable. After which we carried out some case refinishing work and the results can be seen below. While it's not perfect it is certainly much much better than when it arrived in our workshop. Unfortunately there was some degree of porosity lurking under the surface which became evident during our processes but thankfully it looks like it'll be gas proof so should end up being a very nice engine, considering the starting point.

We're not too keen to try and reweld at this stage as more often than not you end up with a pile of molten slag on the bench where there used to be a crankcase, so we'll be leaving the weld repair as it stands now.

Here we have the venturi straightened and remachined to look more like it should and the cylinder liner face, which will become our reference datum face, is also nice and clean.

Next step is make up some specialised tooling to remove the plain bearing bush safely and set up the case in the mill to true up the crankshaft center of rotation line true to the cylinder center line.