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Faulty cam follower

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Faulty cam follower

Posted by william_youngson at October 05. 2017

Has anyone had this problem with cam followers, I purchased new cam followers off eBay during a complete engine rebuild,when completed I took the bike for its MOT, a 50 mile round trip,engine running great,then about a week later I started it up,horrible clatter from engine, I stripped the engine and found that the end of the cam follower had become detached and caused a lot of damage as it flew around the crankshaft,bottom of barrels at the cam follower tunnels burst,con rod gouged,camshaft damaged,crankcase damaged and the cam follower of course,all of which will have to be replaced. Ouch! Expensive!

 

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Re: Faulty cam follower

Posted by ian_goodhall at October 05. 2017

Were they new?

Re: Faulty cam follower

Posted by david_evans at October 05. 2017

The latest cam followers have a stellite foot that is recessed into the base of the follower i believe before brazing. I must say that the machining of those two followers looks poor and nothing like the genuine article. So almost certainly pirate copies. I hope the damage to the rest of the engine is recoverable. I tend to buy engine components from Andover Norton. con rod bolts, crank fixing screws etc.  The problem is that if you send back items that have lead to a failure, the vendors first question is "what are the qualifications of the engine builder" as if we are all rank amateurs. Many of us so called amateurs have engineering qualifications far in excess of those in the "trade"

I sent my cam followers to be re-faced by a company that had done a very accurate rebore for me. Presuming they would be done on a surface grinder with an angle plate The result had obviously been done on a linisher and was way out of square. They refunded my £20 without a word of apology

Re: Faulty cam follower

Posted by william_youngson at October 05. 2017

Previously ian_goodhall wrote:

Were they new?

Yes

Re: Faulty cam follower

Posted by william_youngson at October 05. 2017

Previously david_evans wrote:

The latest cam followers have a stellite foot that is recessed into the base of the follower i believe before brazing. I must say that the machining of those two followers looks poor and nothing like the genuine article. So almost certainly pirate copies. I hope the damage to the rest of the engine is recoverable. I tend to buy engine components from Andover Norton. con rod bolts, crank fixing screws etc.  The problem is that if you send back items that have lead to a failure, the vendors first question is "what are the qualifications of the engine builder" as if we are all rank amateurs. Many of us so called amateurs have engineering qualifications far in excess of those in the "trade"

I sent my cam followers to be re-faced by a company that had done a very accurate rebore for me. Presuming they would be done on a surface grinder with an angle plate The result had obviously been done on a linisher and was way out of square. They refunded my £20 without a word of apology

The crankcase I can repair but the barrels,camshaft,conrod and cam followers will need replacing.

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Re: Faulty cam follower

Posted by william_youngson at October 05. 2017

Previously william_youngson wrote:

Previously david_evans wrote:

The latest cam followers have a stellite foot that is recessed into the base of the follower i believe before brazing. I must say that the machining of those two followers looks poor and nothing like the genuine article. So almost certainly pirate copies. I hope the damage to the rest of the engine is recoverable. I tend to buy engine components from Andover Norton. con rod bolts, crank fixing screws etc.  The problem is that if you send back items that have lead to a failure, the vendors first question is "what are the qualifications of the engine builder" as if we are all rank amateurs. Many of us so called amateurs have engineering qualifications far in excess of those in the "trade"

I sent my cam followers to be re-faced by a company that had done a very accurate rebore for me. Presuming they would be done on a surface grinder with an angle plate The result had obviously been done on a linisher and was way out of square. They refunded my £20 without a word of apology

The crankcase I can repair but the barrels,camshaft,conrod and cam followers will need replacing.

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Re: Faulty cam follower

Posted by Gordon Johnston at October 05. 2017

I had the same thing happen with my Mk 3 Commando. They were the original Norton ones. I replaced them with a spare set of Dominator ones which as far as I know are still going strong, the Commando having since been sold.

I was lucky and didn't suffer any extra damage when it happened to me.

Re: Faulty cam follower

Posted by robert_tuck at October 06. 2017

Thats heartbreaking, and one of the reasons I reused many old and partworn components when i rebuilt my engines 20+ years ago,including big end and crankshaft bolts. I would hope that Andover takes more care over checking and testing components than suppliers have done in the past.

Re: Faulty cam follower

Posted by david_evans at October 06. 2017

Hi William,

If you want I have a single con rod surplus after replacing both of mine after a seizure due to a anti wet sump valve failure, also a set of cam followers that as i said in my first reply will need refacing. (They will probably be 0.040" shorter after that) Both these are from My 1970 engine and are original The con rod has genuine AN bolts and I have a further two genuine bolts, I would fit new nuts. In an effort to keep your costs down You can have them for nothing as they will just sit around collecting dust.

I also have an original camshaft in good condition after fitting a PW3 (In hindsight I would not bother with a PW3 again as the original cam is quite a good performer in the real world) I can send you the lobe dimensions if you are interested in that.

I Dont know where you are in the world but you might speak to Jim Comstock who is well known in the American Norton scene you might be able to have the barrel tunnel sleeved though I suspect that a sleeve might break through into some stud holes. Barrels will be your biggest outlay as 750 ones are becoming rare. I believe there are some advertise in this months roadholder

Re: Faulty cam follower

Posted by joe_seifert at October 06. 2017

David Evans got it right- these cam followers don't look like the real deal, not even like old NOS ones. There are certain dealers out there Andover Norton decline to supply who make their own parts, and this looks like a typical example.

As for Mk3 camfollowers failing, I had the Stellite tip fall off on my then new Mk3, too (must have been in 1977 or 1978).

The Andover Norton cam followers have been made in the way Dave Evans describes because those failures were known and people like Richard Negus, Bob Rowley and others at Norton knew their Commandos well, so knew what to change on the original design.

The revised drawing with the tip having the "hat" into the tappet body is dated 08th January, 1988, so it is safe to assume tappets sold after 1990 were all the revised and, in my experience, failure-proof type.

Re: Faulty cam follower

Posted by richard_payne at October 06. 2017

When I first bought my Mk3 in 1983, I dismantled it to find a piece of stellite in the bottom with all four followers intact so the PO had replaced followers and not bothered to fish out the stellite foot !

I thought that the lost-wax cast spigotted follwers from Andover were around earlier than 1988. I've never heard of a problem with them.

The lost-wax casting also got around another problem mentioned in the NOC Service Notes - that the factory followers often still had casting sand in them.

Original Norton followers did lose their tips from time to time but the quantity of Commandos eating camshafts through the early 1980s meant that OE followers were not available. I recall being told that those available were supplied by the old Wassell concern. We didn't have much choice but to use them.

I wouldn't install anything other than Andover followers if they're available. eBay and jumbles are a bit scarey for Commando engine parts.

Re: Faulty cam follower

Posted by colin_cheney at October 06. 2017

My MkIII ran quite well until around 1985.  After a long trip it developed a stutter and ran poorly.  I fitted a single carburettor but it still would not run or tick over correctly so I stripped the engine and found that two of the lobes were completely worn out.  In the bottom of the crankcase I found what I thought was a misplaced woodruff key. It turned out to be a foot from one of the cam followers.  The previous owner had brazed a replacement in place (it was a neat job, too).  I re-built the engine with a 4S cam but the cam-follower that had the foot replaced seemed fine so I left it in and it's still there today - probably around 100,000 miles later.   I think I would advise to buy parts only from Andover Norton as a guarantee that they are produced from the correct materials to the appropriate standard.

Good luck with your rebuild; Colin Cheney, Leicestershire.

 

Re: Faulty cam follower

Posted by william_youngson at October 07. 2017

Previously david_evans wrote:

Hi William,

If you want I have a single con rod surplus after replacing both of mine after a seizure due to a anti wet sump valve failure, also a set of cam followers that as i said in my first reply will need refacing. (They will probably be 0.040" shorter after that) Both these are from My 1970 engine and are original The con rod has genuine AN bolts and I have a further two genuine bolts, I would fit new nuts. In an effort to keep your costs down You can have them for nothing as they will just sit around collecting dust.

I also have an original camshaft in good condition after fitting a PW3 (In hindsight I would not bother with a PW3 again as the original cam is quite a good performer in the real world) I can send you the lobe dimensions if you are interested in that.

I Dont know where you are in the world but you might speak to Jim Comstock who is well known in the American Norton scene you might be able to have the barrel tunnel sleeved though I suspect that a sleeve might break through into some stud holes. Barrels will be your biggest outlay as 750 ones are becoming rare. I believe there are some advertise in this months roadholder

Hi David,                                                                                           That's very kind of you to offer these parts,I would be very grateful to have them and quite Happy to pay for them. I have managed to get a good set of barrels from the US and am waiting for these to arrive. I am in Applecross ,north west Scotland.

Re: Faulty cam follower

Posted by william_youngson at October 07. 2017

Previously joe_seifert wrote:

David Evans got it right- these cam followers don't look like the real deal, not even like old NOS ones. There are certain dealers out there Andover Norton decline to supply who make their own parts, and this looks like a typical example.

As for Mk3 camfollowers failing, I had the Stellite tip fall off on my then new Mk3, too (must have been in 1977 or 1978).

The Andover Norton cam followers have been made in the way Dave Evans describes because those failures were known and people like Richard Negus, Bob Rowley and others at Norton knew their Commandos well, so knew what to change on the original design.

The revised drawing with the tip having the "hat" into the tappet body is dated 08th January, 1988, so it is safe to assume tappets sold after 1990 were all the revised and, in my experience, failure-proof type.

Hi Joe,  Thanks for your input,I think David Evans and yourself are right about the cam followers. I have sent a letter with photos of the damage to the supplier to see what they have to say about it.              Billy.

Re: Faulty cam follower

Posted by michael_sullivan at October 07. 2017

William:

You state that you bought the followers off EBAY.

But, did you buy them from a reputable dealer of from a private seller.

Mike

Re: Faulty cam follower

Posted by william_youngson at October 07. 2017

Previously michael_sullivan wrote:

William:

You state that you bought the followers off EBAY.

But, did you buy them from a reputable dealer of from a private seller.

Mike

Hi Mike,   I bought them from Hawkshaw Motorcycles Ltd in Liverpool. They were about the same price as the Andover Norton ones but they were out stock at the time.                                                               Billy.

Re: Faulty cam follower

Posted by michael_sullivan at October 09. 2017

William:

Were the followers represented to you as being Norton factory OEM spare parts?

If they were so represented and were actually not Norton Factory parts I would think that you would have a recourse in the Courts.

Mike

Re: Faulty cam follower

Posted by william_youngson at October 10. 2017

Previously michael_sullivan wrote:

William:

Were the followers represented to you as being Norton factory OEM spare parts?

If they were so represented and were actually not Norton Factory parts I would think that you would have a recourse in the Courts.

Mike

Hi Mike, I have had a look back at the eBay page but all I can get now is the first page but not the item description,I can not remember whether it said original as it was a few months ago. Billy.

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