Annoying knock from camshaft front pulley area

[Lowbarn]

1931 RN saloon 2 bearing crank.
From running perfectly fir the last two years, last week developed a buzzing noise from the front of the engine that migrated into a knock during the day.
Looked into the sump. No signs of any damage. Front crank bearing has been upgraded with bolt on lip.
Dynamo bearings were both a bit loose, replaced them.
Put it back together and now there is a knock only at tickover coming from the area of the front camshaft pulley.
Engine runs well otherwise.

Would I be right in suspecting play in the front camshaft bearing leading to interference with the dynamo drive gear?

[AustinWood]

Could be camshaft end float.

[Alan]

More likely end float than radial clearance. Check that the cam bush locating peg isn’t worn it’s the first place I’d look.

[Steve kay]

Absolutely, go out immediately and check the camshaft locating peg. Writes a man who had to deal with the significant aftereffects of one failing.

[Lowbarn]

Well that was very helpful chaps.
Didn’t expect such a speedy response.
Perhaps I’ll post some more queries as and when.
You’ve probably realised I’m new to Austin 7’s. Impressed with the little car so far. It’s a lot safer than the Sylvia Stiker  I built 10 years ago and now daren't drive!. Fitting a supercharger wasn’t the best idea.


Can’t get in the garage now, wife’s home!
But I will get in there with the first sparrows in the morning.

Richard.

[Graham Barker]

My 1937 Ruby (done about 91,000 miles in total) has a similar knock coming from the vicinity of the front camshaft bush.  Only at a very slow idle.  The engine was reconditioned (allegedly professionally) for the previous owner about 1,000 miles previously.
I cannot detect any fore and aft movement of the camshaft when I lever the camshaft pulley with a big screwdriver.  Would there be a better way to check this while the engine is in the car?
I like the ideas for refastening this bush given in this thread and similar ideas given in other A7 websites.  However, is there any way to sort it out while the engine is still in the car?
Regards
Graham

[Lowbarn]

Quick question.
Is it necessary to remove the cylinder block to get at the camshaft retaining bolt?

[Malcolm Parker]

If it is the original square headed retaining bolt, then yes. I think you could raise the block sufficient to remove the retaining bolt without disturbing the pistons in the block.

[Charles P]

If it is the original square headed retaining bolt, then yes.  I think you could raise the block sufficient to remove the retaining bolt without disturbing the pistons in the block.

The other option is to use a Dremel to shave down the square headed bolt and then butcher it out with mole grips or similar.  Take great case with the mess though.

C

[Lowbarn]

Thanks for that. 
I think I’ll go for the butcher approach using my dremel in the first instance.
The engine looks to have been fairly recently refurbed so nibbling round the problem sounds a good approach.

I think if the block needs to come off I’ll have the complete engine checked / overhauled.
This might be challenging to meet the centenary bash in July!


I presume the square bolt can be replaced with a standard bolt and lock nut?

Richard.