Strange noise......

[mikeinatruck]

I have recently changed the SU's on my V8 landy to a newer better condition pair of HIF 44's I changed the inlet manifold as well and the new one does not have a water pipe from it to the rear of the water pump, tempretures are the same as they where before and its not overheating. I have set up the carbs a bit on the rich side 4% at tick over and changed the needles I had fitted (BBW) as on the gas analyser it dropped to -0.2 at 2000rpm. So I have re profiled and old set of needles and it stays happily at 8% now when you build the revs up.

Thing is it has got a horrible tinkling sounds a bit like pinking but not quite? I thought it was because it was lean but it still seems to be there, its apparent under light throttle.

The plugs appear to be okay, not showing rich or too lean.. I have a feeling I might have the wrong plugs in its a High compression RR engine originally with the EGR disconnected.

What plugs should be in it? At the moment its on NGK V groove BP5E I think.

[mikeinatruck]

I was chatting to my neighbour who has a very highly tuned Subaru, he said I have what they call 'sparkling' its a bit like pinking but it does not happen under load.

I think i might try setting it up without the vacuum advance connected and lock of the plate.

Tried with a fixed dizzy and no Vac advance but it made little if any difference.
I also tried with different needles, timing and mixtures, but no change.
Bit stumped now! Starting to wonder if I have some dodgy fuel now?

I did check compressions and though a bit varied are not too bad.

[Paul B]

I was chatting to my neighbour who has a very highly tuned Subaru, he said I have what they call 'sparkling' its a bit like pinking but it does not happen under load.

I think i might try setting it up without the vacuum advance connected and lock of the plate.

Tried with a fixed dizzy and no Vac advance but it made little if any difference.
I also tried with different needles, timing and mixtures, but no change.
Bit stumped now! Starting to wonder if I have some dodgy fuel now?

I did check compressions and though a bit varied are not too bad.

Sparkling? That's a new one on me. Did he mention what it actually is?

Is it something as simple as an exhaust leak? I've had them before that sound like a tinkling mechanical noise.

[mikeinatruck]

I wondered that myself but it is only there at about 2000rpm and light throttle.
I have to go to Holland for work now so it'll have to wait till next weekend, but i'll double check the exhaust again anyway.

It sounds very much light pinking, a hollow tinny metallic sound.

Oh well if the engine goes bang it'll just be an excuse to rebuild it bigger and better..!