Phoenix crank location

[Chris KC]

For reference, the Austin crankshaft 'nose' was dimensioned 1.12475" - 1.125" i.e. nominal to - 1/4 thou on diameter.

[Colin Wilks]

Many thanks for explaining that. I had envisaged a solid emery wheel rather than a flap wheel, and completely forgotten the timing gear. Off for a lie down now!

[Ian Williams]

When I fit bearings I use a bit of heat to alleviate tightness, a warm bearing will drop straight onto a cold crank journal and then immediately tighten as the temperatures normalise. I do exactly the same with housings such as the crank case, I have seen far to many things ruined by previous builders always knocking bearings in and out cold, every time you do so you the journal and or housing size are affected slightly until eventually you end up in a situation where the bearings are no longer a good fight fit. This is particularly a problem with the rear main as the bearing then frets on the journal causing more wear, someone recently brought round an engine with Phoenix crank damaged by just such practice.

[Howard Wright]

Hi All

Added to the fact that turning down a crank needs a reasonable size lathe.  Turning a thou or two off a bearing can be done even in my little Myford M2! Or with a flap wheel according to Terry.

Precisely what I did to create dummy bearings so I could put the crank in and out several times without heat or hammer!

Cheers

Howard

[Robert Leigh]

If your crankcase did suffer a broken lip, and was not machined back enough for correct crankshaft location, I do have a tool for taking a bit more off. It is a bar which runs in front and rear bearings with a cutter fitted, and it can be turned using a standard electric drill at lowish speed. I am prepared to lend it to a careful borrower. I am just north of Cambridge.
Robert Leigh

[John3528]

Once again, I must say thank you for all the advice and also for the particularly kind offer of the special tool to machine the crankcase.

I believe that I have now reached the point where I know what I am going to do. Camshaft end float is within limits at 2 thou and there are no shims behind the crankshaft gear. The two gears currently line up perfectly which tells me that, irrespective of the Phoenix crank, the crankcase has been properly machined with the new lip in the correct place. If I now take some meat off the crankcase to move the crank forward, not only will I spoil it for any future crank of the correct dimensions, but also I shall have to take some meat off the back of the crankshaft gear to make it line up once more with the cam gear wheel. I do have a definite gap, albeit a small one, between the worst little end and its gudgeon pin boss so the con rod is not actually forcing the piston against the cylinder wall.

On balance therefore, I propose to follow Jim's advice and leave well alone. It is a road car in which I hope to do some very modest trialling one day and, whilst the bottom end is not perfect it will probably suffice. There is also the very strong possibility that I would do more harm than good trying to remove the crank from the crankcase.

If, following my decision, the engine goes bang soon after the car is back on the road, I'll let you all know that it was the wrong decision!

My sincere thanks to everyone for their help and advice,

John.