Faulty cam follower

Were they new?

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

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.

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.

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

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.

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.

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.

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

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