Follower clacking
- Thread starter willy mac
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That depends entirely on what is going wrong with it.
From what i have observed, and here, there are (at least !) 4 different things that can be involved.
And remember these engines are now ~40 years old.
The stellite pad or parts thereof can fall off,
the cams can be soft and grind away,
the follower can be run dry and getting worn/scored/seized in its bore,
and the cam can wear odd bits off it or into odd wear patterns.
A cam I had had a slight odd wear, was no longer a smooth round lobe, and had a slight 'click' to it.
It clicked no matter what. A subsequent owner changed it at rebuild time.
Made no difference to the performance..
What be ye problemo ?
From what i have observed, and here, there are (at least !) 4 different things that can be involved.
And remember these engines are now ~40 years old.
The stellite pad or parts thereof can fall off,
the cams can be soft and grind away,
the follower can be run dry and getting worn/scored/seized in its bore,
and the cam can wear odd bits off it or into odd wear patterns.
A cam I had had a slight odd wear, was no longer a smooth round lobe, and had a slight 'click' to it.
It clicked no matter what. A subsequent owner changed it at rebuild time.
Made no difference to the performance..
What be ye problemo ?
A 5th (and 6th ?) problem can be that pushrods can rub on protruding headgaskets,
or even on rather tight pushrod tunnel walls.
This has about zero affect on anything, but can produce some odd noises....
A good stethescope could probably sort out any of which of these is at play,
but you'd pay through the nose to find a good Norton doctor ??
or even on rather tight pushrod tunnel walls.
This has about zero affect on anything, but can produce some odd noises....
A good stethescope could probably sort out any of which of these is at play,
but you'd pay through the nose to find a good Norton doctor ??
Rohan said:
I fitted a Dave Taylor head steady and it seemed as if since fitting it the clacking noise arrived , so I'm thinking because the head is now bolted directly to the frame rather than having the 2 rubber mounts the noise is just being amplified, so to confirm this I refitted the old rubber mounted one and took it for a run, no change the clacking is still there. It's more pronounced when accelerating, I checked the timing to make sure that was ok and it wasn't "Pinking" (28/29 BTDC ish) It runs lovely and pulls like a train but just noisy, I've not checked the valve clearances yet as I thought that if they were too big the noise would be there even at idle. Loosing the pad on the bottom of the follower I imagine would result in a huge valve clearance too, I'll maybe check them tomorrow. They're not the quietest of engines I know and someone posted a video of a newly rebuilt racer that sounded like a bag of spanners on top of a spin dryer but this is one of those noises that makes you think "Is it supposed to sound like that or not" ?
Fast Eddie
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Why do you suspect the cam followers to do the source of the clacking specifically?
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Could be a piece of throttle slide sucked inside even. Like a drunk looking for lost keys after dark, ya start where there's best light then stumble into the darker places. So how lucky an ego do ya feel to keep operating with a new and abnormal sound? Traditional way is run till failure makes ya stop to figure out the triggering event of the obvious damage.
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hobot said:
Fast Eddie said:
Hi Eddie, I'm not sure it is really, I'm just trying to get some feedback from guys that have had a problem in that area, it seems to be noisiest at the tunnels, but noise does travel. Plus i'm wondering if they would make more noise under load if they were a bit worn, it's all theory at the moment but there's a few more areas for me to look at now after the recent posts.
Get your biggest screwdriver. Yes the biggest longest one u have (plastic handle is best) and jam it in your ear (handle end) then work your way around the key points of your engine. Not rocker covers as they will act as a giant speaker. Check sound roughly where cam followers are, rockers at the pinions etcetera. It will help narrow down the area you need to investigate.
Better still a stethoscope with alloy rod instead of chest plate (the cold bit that doctors put on your chest to make sure your not dying).
Better still a stethoscope with alloy rod instead of chest plate (the cold bit that doctors put on your chest to make sure your not dying).
Dkt26 said:
Just done that all round the engine with a proper mechanics stethoscope and there's no point where the noise becomes more acute, the only time I can hear it is with the bike on the road and the engine under load and accelerating, if I roll the throttle off to a steady cruise the noise stops.
There is nothing in the sump strainer and the oil drained out after it's wet sumped is clean.
The investigation continues!
You mentioned the DT steady. Are you sure its not hitting something under accel? My homebrew copy of the Taglieri steady was fouling when I sat on the bike but only with my weight on it, consequently it took ages to find the offending source and tapping. You can just see the mark made by the Nylock head..........picture off stand.
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Thot the switching out of DT head steady to factory one eliminated that area as noise source but could ride a bit carefully sans headsteady to know for sure. May be something in primary getting slung around but likely would hear it coming from there. Peel's top link had just over 5" radius rod that did foul IS tank tunnel with noise and vibes and tank erosion till I shortened up the head plate mount and relieved some off rod end eye. Maybe a tube with drill bit probe in one end, other stuck in ear may reveal where its loudest to direct attention to.
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