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Posted: Fri Aug 26, 2011 10:44 am
by john.nash
Your Ariel makes a strange noise ?
They all do that, sir !!!

I have a VH500 swingarm.
It shed a gudgeon pin circlip, twice, and ruined the bore. The first time I assumed the noise was an "ariel one" and kept ongoing until the oil cloud behind required me to find out the cause. Rebore required.

After buying a later alloy engine and using its iron barrel to convert my VB600, I put the alloy head onto this VH500.
Just the barrel and a JP piston. Nothing else. I then decided to put a sidecar on it - which took months.
When I finally got it out on the road, it was immediately making a pretty strange noise under load. it wasn't one of the usual ariel noises.

I decided not to follow Len Ore's advice on the subject of noises and leave it alone as "it will get better, get worse or stay the same" and stripped the engine to the crank. I thought it had shed it's gudgeon pin circlip again (similar noise) but no; piston, barrel and pins ok.
As I had the alloy, five stud, barrel on an four stud earlier case I took the opportunity to change the cases (to the right 5 stud ones) and change the bearings.
The big end seemed ok, so I left it alone (I couldn't get my other crank sorted in time - see other posts here)
I spaced the crank, with the right play, and put it all together.
Had a few teething issues.

Noise is still with me, after al this, and probably getting worse.... best described as a clanky whine.
  • Doesn't improve when warmed up.
  • It occurs under load and can just be heard (by me) when revv'd at idle.
  • If you ride with a light throttle, then it can almost be eliminated
  • It can also be reduced by moving to half retard (which causes performance loss and some banging in the exhaust). I have retimed the bike a few times now and also run it over advanced and over -retarded to see.
  • It's not there all the time either, but any quick turn of throttle will usually make it happen (you can ride along and turn the noise on and off by doing this)

It must be an engine noise, as the load and retard have an effect. Right ?

Tell me it's not the JP piston eh ? That was the only thing I really changed ............
I have a hepolite piston now, but I believe the JP runs with more clearance but putting it in will give me a larger ring gap and possible slap.

Posted: Fri Aug 26, 2011 11:56 am
by brenton.roy
Hi John,
These are just my thoughts.
I don't know how good Drags are at reboring, but you really do have to leave lots of clearance for a JP., and they do slap. What you have written doesn't seem to point to piston problems. Did you replace the small end bush?
I can imagine the clanky sound, but not the whine. is it like a dry bearing or metal on metal noise? - or like a motor pinging?
Is there good oil flow to the head and return to the tank?
Old time mechanics would use a long screwdriver as a stethescope (or even better if you have access to the real thing). You might be able to pin the noise to a particular part of the motor... Is it top middle or bottom?
Valves touching pistons can cause strange noises as the shocks go back through the valve train - most of the symptoms you describe could be caused by this. An easy way to find out is to loosen your tappets and reduce valve travel. Don't rev too much with large tappet clearances.
You might not immediately notice a witness mark(s) on the piston crown if it is touching lightly.
If this is the case, it's likely to be pretty easy to fix.
A riding valve could also cause some whining noises in the valve train as the pressure stops oiling on rubbing surfaces - I think the tappet clearances are more with ally motors.
If this fails, try beer.
Good luck and Happy spannering, Brenton

Posted: Fri Aug 26, 2011 2:03 pm
by john.nash
The fact that the noise is almost non-existant at idle or on a feathered throttle, would probebly mean that it isn't valves or suchlike as that would happen everytime.
It is more of a metal on metal situation and surely engine related, given the timing and load effects.

I didn't replace the small end; It was a tight push fit. Plenty of oil up top as well.

Bugger it.
I'll drop off the top end AGAIN and see if anything looks bad....
I don't have a standard hepolite piston to try either

Posted: Fri Aug 26, 2011 9:15 pm
by Simon.Gardiner
I'm not sure this has eliminated the possibility of transmission which can also be affected by load (retarding ignition = less load?)
'whine' sounds more like bearing/gears or possibly chain/sprocket, 'clanky' could be chain, clutch, broken bearing? Or something loose. Or possibly even the camshaft (endfloat or play in the gears can be noisy but aren't usually fatal)
Can you use the screwdriver-to-ear test to work out which area it's coming from (top end/bottom end/timing side/drive side/primary cases/gearbox)? (You might be surprised at how it amplfies the noises!)
Also have a really good look at the oil/filters - if anything is doing metal-to-metal in a big way there should be some evidence.

Posted: Sun Aug 28, 2011 11:31 am
by brenton.roy
Hi John,
working on what you may have assembled when changing motor bits, and maybe before you pull it apart...
Are all the mains new - and were they a good fit in the cases?
Have you allowed enough tappet clearance? 6 and 8 thou.
Is the spark plug a good colour?
Have you got enough oil in the primary - I tried running with spray on lube (once) and it made a fair bit of noise. You can feel a dry chain. Stick your finger through the thingy plug hole.
Have you wired or locked the bolts in the clutch outer drum?
Is the clutch operating as it should and staying adjusted?
Is the cush drive or clutch drum just touching the case / cover?
Is the timing chain too tight or too loose?
It's unlikely some new problem has sprung up, it's far more likely to be related to the repairs you have done.
If the piston hasn't seized, I wouldn't worry about it.
Ally motors transmit noise more than cast iron.

Posted: Mon Aug 29, 2011 7:30 pm
by john.nash
I had my mate sit in the chair to try and isolate the noise, as it's only appparant under load.
Top end, he said, so off with the head and barrel. Some more scuffing on the JP piston, so I filed that smooth again and re-honed the bore.
No appreciable improvement....

I am going to live with it ....

Re: Noise

Posted: Mon Aug 29, 2011 8:47 pm
by adrie.degraaff
Your exhoustvalve is sitting to deep and so hitting the lifter?

Posted: Mon Aug 29, 2011 9:01 pm
by john.nash
I took the lifter completely out ..

If I do find the cause then, rest assured, this forum will know first ..

Re: Noise

Posted: Tue Aug 30, 2011 11:26 am
by adrie.degraaff
Some rockers have rings in stead of springs, if the oil banjo's are titened to much at one point the rockers will turn heavely giving the same problems as you have.

Re: Noise

Posted: Sat Sep 03, 2011 10:21 pm
by john.nash
can't leave it alone.
I cannot "live with it"; it's driving me insane.

The only thing that might not be right, in the entire top end, is that the exhaust valve is a tad loose in it's guide (just under 1mm or .039"). Looks like it should be around 5 thou (taking the stem diameter vs the guide internal diameter).
Guide itself is nice and tight.

Do loose valves make a noticable clatter ?

It was loose-ish, when I originally put it all together, put I thought it would be ok (you know, the "it's not that bad" approach to mechanics)

I'll fix it anyway ......