Is this within standard Ariel operating parameters

[adrie.degraaff]

I can hear it if an engine is running to rich, as can many other guy's, the AMAL book discribes it as heavy running.

Back to the noise; I had the same noise when there was a foulty batch of rubber head-barrel seals was going round, they where groing when in contact with modern oil, klamping the pushrods so they wheren't moving in a proper way.
The same is happening if the rockers are to tight.

[brenton.roy]

Thanks Adrie, I'll listen again.

[david.anderson]

Brenton/John
Years ago I systematically went through my VH to try to eliminate rattles. I started with the rockers and had the arms bored out and bushed to closer tolerances and I stellite welded the valve stems to eliminate the valve caps.
I then replaced camshaft bushes and bored and bushed the cam followers (twin lobe) to closer tolerances. I rebored the cylinder and had the piston fitted to minimum clearance (which required a very long run in).
None of the above did much to reduce rattles. I then replaced the little end which gave a considerable reduction in rattle. Since that time on each occasion that my bike (all alloy VH) has become too rattly I have replaced the little end bush (even though the bush would be regarded as serviceable) which has given the desired result. I think that you will find that the main noise in the first bike is the little end.
Other things that can generally be considered if trying to reduce your engine noise are that earlier cam forms did not have quietening ramps and as such the 54 or later cam will also help to reduce engine noise. And the raised oil modification to the timing chest will also help a little.
The earlier rocker boxes are spacered to the end of the rocker shaft. The later rockers have a spring to take up end clearance. The later rocker box is quieter.
Another source of noise can be backlash between cam and half time pinion.
Ariel singles are noisy engines. The major engine noise reduction that has happened to Ariel singles over the years has been the compulsory wearing of helmets. If you need a further reduction in engine noise wear a helmet with a radio and adjust the volume control. For that real Ariel experience that the original owners of our bikes experienced each ride I occasionally take my HT for a ride off road without a helmet.

[nevhunter]

Just a little warning about making the small end running clearance minimal. Some bronzes are a bit soft these days and the interference fit is not maintained once the bush gets hot. Result.. the bush crushes in a bit and seizes on the gudgeon pin. This can destroy the piston as the small end jambs partially or completely. IF it still moves in the piston you are spared. Nev

[brenton.roy]

John, just out of interest - if you have time - would you whip the spark plug out and give it a number from the chart http://www.barkshire.co.uk/AOMCC/Knowle ... spx?id=735
Thanks, Brenton

[admin]

John, just out of interest - if you have time - would you whip the spark plug out and give it a number from the chart http://www.barkshire.co.uk/AOMCC/Knowle ... spx?id=735
Thanks, Brenton

Bit of an unfair comparison, at the moment, as all it's done is idled for a few minutes at a time after being flooded.
The mixture screw is doing it's work as there is a definate sweet spot.

I do have a new small end bush and am considering another strip at the weekend to take a closer look.
It's about an hour to get to the piston and a bit longer to get it back together.

[nevhunter]

A loose small end bush is unlikely to do any real damage. While the alloy heads ring like a bell and bring out all the noises, it is worse when you have the alloy barrel as well. Nev

[brenton.roy]

No worries John. If you get bored at any time in the future... It's only for interest, re Adrie's comments about the sound.

[john.nash]

**update**

stripped back to piston. no broken rings. Piston clearance ok (as it was before - the bore still has the hone sratches in )
Maybe a slight amount of play in the little end. I had a new one; so put it in.

All back together. Only marginally quieter .... ))
Total job about 3 hours .. only because I reground the head spigot and reamed the small end.

At this point .. I ride it

[simon.holyfield]

So when did these anorak awards appear?