Camshaft removal problems

[merlinart]

What ho all.

I've been dismanting my 1937 3 bearing engine today, all was going fine until the removal of the camshaft. We removed the rear bearing cap and the squared headed top/front bearing bolt and the mid bearing bolt. The shaft moves fore and aft slightly but is very tight indeed, it still turns OK. The mid being pieces seem to drift forward reasonably OK, but the problem appears to be at the front bearing. I've consulted Woodrow and the Ian Bancroft magazine article. Presumable some heat needs applying around the front bearing I assume, so I wonder if any others have had similar problems and what would you recommend please?

The pistons are +60, and I've read somewhere that +80 thou is the maximum? Would I be better looking for another block which hasn't been so far bored out, thus allowing perhaps an additional rebore in due course, what do any of you think?

Thanks in advance, and sorry if some questions seem dumb, but this is the first time of dismantling an old engine.

Don't laugh....I can't get the crank out at present!

regards

Arthur

[Mike Costigan]

Don't laugh....I can't get the crank out at present!

regards

Arthur

It's an awful long time ago since I last did a 3-bearing engine, but I seem to recall the technique went something like:
1. Twist, shake and rattle the crank for half an hour.
2. Put crankcase down in disgust.
3. Pause, make cup of tea, drink cup of tea.
4. Pick crankcase up to have another go.
5. Crankshaft falls out and clouts shin and lands on foot.
6. Jump up and down in agony.

[merlinart]

Don't laugh....I can't get the crank out at present!

regards

Arthur

It's an awful long time ago since I last did a 3-bearing engine, but I seem to recall the technique went something like:
1. Twist, shake and rattle the crank for half an hour.
2. Put crankcase down in disgust.
3. Pause, make cup of tea, drink cup of tea.
4. Pick crankcase up to have another go.
5. Crankshaft falls out and clouts shin and lands on foot.
6. Jump up and down in agony.

Yes, I suspect it will be like that!

On re-reading Woodrow, I note 2 things; 1) he mentioned localised heating to get the crank bearings out....wish we had tried that, most likely would have been quicker, 2) having unscrewed the oil feed to the centre bearing cap of course, I didn't take it out at the other end, and although it didn't seem to impede the crank...we couldn't get it out, yet Woodrow says to do so, so will try again tomorrow.

Main problem is the camshaft, so advice on this please will be much appreciated.

I have to admit I failed to take Woodrow to the workshop but did have Ian Bancroft's Practical Classics article with me, but noticed that he missed several items, or mad them seem much easier, and his crank was a 2 bearing.

The 3 bearing crank seems a beast to get out though.

I suppose it becomes second nature once one has dismantled several dozen engines!

Arthur

[Reckless Rat]

It went in, so it must come out... bit like those bent wire metal puzzles that frustrate you until you finally work out how to separate the pieces.

[Ruairidh Dunford]

Three bearing crank removal.

1.  Remove the centre main oil pipe feed union.

   

2.  Get rear into the position below (rear will be hard up against where the union above ‘was’).

   

3. Rotate crank clockwise from rear and bring the front up as below.

   

4.  Continue to rotate, bring up and out...

   

5. Remove...

   

[Ruairidh Dunford]

Three bearing camshaft removal - line the cam behind the centre bearing up so that it picks up both halves (i.e. so the cam covers the join), as cam is drawn out it will bring the centre bearing with it.

Front and centre bearing can be tight in the crankcase - heat crankcase in these areas and use a soft drift to carefully drive it all out.

[merlinart]

Three bearing crank removal.

1.  Remove the centre main oil pipe feed union.



2.  Get rear into the position below (rear will be hard up against where the union above ‘was’).



3. Rotate crank clockwise from rear and bring the front up as below.



4.  Continue to rotate, bring up and out...



5. Remove...

Excellent photos and advice, thank you Ruaridh....don't laugh (just guffaw!) we were trying to get it out of the rear bearing housing as per the 2 bearing crank!

I take point about getting the oil feed pipe out completely...the nut remains stubborn and is a problem with a conventional spanner, even a short one, but will persevere tomorrow now.

Just the damn camshaft now, heat I think on this one.

Arthur

[Ruairidh Dunford]

Removal of rear oil pipe union - I have a cut down open jaw spanner - about 1.5” in total. I then use a ring spanner on the shortened end.