Annoying knock from camshaft front pulley area

[Howard Wright]

Hi

I think once the square bolt is out you will find it holds the cam bearing with an unthreaded portion at its end.  

The typical repair is to drill and then tap the brass bearing. Then replace with a cap head bolt and fibre or Dowty washer.  The replacement bolt needs to be the right length so as not to bear on the camshaft.

This site details the repair better than I can explain  .


http://www.austin7.org/Technical%20Artic...ush%20mod/

Cheers

Howard

[Alan]

The problem and potential fixes have been discussed at length on this forum if you do a search. The main thing is to understand what has to be done before you start. Personally I’d take the engine out, remove the camshaft and do it properly. Although it could be done with the engine in the car I’d rather not have the attendant risks, also you have a much better chance of correctly diagnosing the problem with an engine in pieces.

[flywheel1935]

IMO the insurance price increases are the downside of the of old car values rocketing in the last few years.


[quote="Graham Barker" pid='81962' dateline='1651379479']
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

I also had my Ruby engine rebuilt by a so called 'professional'
, and the cam bearing moved for and aft so much that the timing was out by over 20 degrees at times, maybe it was the same 'builder' !!!!

[Howard Wright]

Hi

I agree fully with Alan.

Cheers

Howard

[Ian Williams]

Camshaft location and end float are so often overlooked and not done correctly, the other thing besides this and timing gear lash which often causes knocking is dynamo end float.....there should be none. My personal preference to improving the camshaft location is to the thread the bush and use a stud as the Mag engines had, add Dowty washer under the nut ..... no leaks and a very secure bush

[Charles P]

Camshaft location and end float are so often overlooked and not done correctly, the other thing besides this and timing gear lash which often causes knocking is dynamo end float.....there should be none. My personal preference to improving the camshaft location is to the thread the bush and use a stud as the Mag engines had, add Dowty washer under the nut ..... no leaks and a very secure bush

I agree. 
The peg and hole approach to location is a bit rubbish really

c

[dickie65]

I have gone into the bush from the side of the case with a secondary bsf set bolt tapped into the brass camshaft bush, loctite and Dowty washer used.
Camshaft end float must be controlled to a minimum to prevent the big end from hitting a lobe.

[Alan]

Especially if you have a high lift cam and Phoenix rods. Don’t ask me how I know that.

[Charles P]

Especially if you have a high lift cam and Phoenix rods. Don’t ask me how I know that.

+1

[Austin in the Shed]

Odd really as the mag engines had one of the dynamo housing studs threaded into the front bush,exactly as this mod.