Norton 99 1962

[Tomcat]

Originally Posted by ink ink

Can people tell where cracks have started? There might be witness marks if the cracks took time to develop.

You could certainly do NDT (nondestructive testing) on it however that will only show surface breaking cracks and not give you any indication of their depth. You get this sort of result:



The question is, how often should you do it in order to catch the cracks before they propagate through to failure? It's easy on a race engine, you do it every year. How often should you take a road engine apart though?

If of course you're looking at one that's already gone it's quite straightforward:



You can see the striations ("tide marks") each one of which is a stress cycle where the crack extended a little further. It's a classic crank failure mode in that the crack started in the runout radius of the big end and extended into the web until the reduced cross sectional area couldn't take the stress and failed in brittle fracture. Until it went all you'd have seen on the surface was a tiny hairline crack....

[maccecht]

Originally Posted by L_B

PM sent.

It can go next to my other domi.

Pm replied to.

[maccecht]

Think it might have a buyer then LB

[protoborg]

My second bike was a 99, main difference to that fro memory the zorsts, single carb and polished ali primary cover, oh and I had no mirrors

[ink ink]

Twin Amal Mk 2 carbs on rubber hoses, racing magneto, TLS (Triumph?) brake. Could be a good runner.

[maccecht]

Originally Posted by ink ink

Twin Amal Mk 2 carbs on rubber hoses, racing magneto, TLS (Triumph?) brake. Could be a good runner.

1948 clutch lifter twin pulleys under the tank for the throttle bodies built in oil filter aft of the engine Japanese switch gear indicators etc etc Ray the chap in the picture is a bit of a fettler. The chunky black thing on the mirror stem is an anti vibration weight which actually works.

[Rode Drage]

I bought a Domi 99 as a school kid for 5 quid. My mate's garden backed onto another garden and this bloke had a bike stood outside covered over for ages. I went to ask about it and he let me have it. Although it was covered over the crankcases were full to the top with rain water, it served as the local baths for a family of garden frogs, one of whom had a perchance for doing the back stroke.

It was full of water because the barrels had been taken off. The bike was original and complete but in bits. I stripped it all down and with a little guidance from my Dad put it all back together, rebored and new pistons and rings, everything else was cleaned, polished and ground in the old way. I think we put new shells in too. And new points on the Mag.

Despite been rebuilt completely it took three months of pushing it up and down our very long drive, racing side saddle bumping it off to get it going. I'd get my school mates to come down on the pretence of them getting a go on it. I wore out loads over the weeks. It would start and run for about three seconds. I became an expert a racing bump starts and get aways though. Then one day it just suddenly decided to start running properly again. Guess it figured after around 90 days of trying everyday I wasn't going to give up and so it accepted it was out of retirement for good. I later sold it for 15 quid.

I lost a Norton crank once because I'd got some super dupper Blue Rolls Royce Halimer(?) jointing paste and I'd rebuilt the engine with it. Unknown to me a gob of it the size of a pea had dropped into the oil pick up in the bottom of the motor and it was history in no time.

[maccecht]

This was sold last week to someone on here or a close friend of him I think. Speaking to Ray the chap who sold it [he has been crying ever since] it seems to have gone to a good home and will be sorted out.

[oldgit]

Originally Posted by Rode Drage

I lost a Norton crank once because I'd got some super dupper Blue Rolls Royce Halimer(?) jointing paste and I'd rebuilt the engine with it. Unknown to me a gob of it the size of a pea had dropped into the oil pick up in the bottom of the motor and it was history in no time.

Hylomar?

[Tomcat]

Originally Posted by oldgit

Hylomar?

[ink ink]