aargh - sooty plugs - again

[gav]

Hi all

My run today was ruined after about 10 miles or so by the engine fluffing.

I took out the plugs (NGK B8ECS) and saw soot everywhere. i cleaned the plugs (they didnt need gapping) and the engine ran fine again.

I tend to run between 2-3,000 rpm and when blasting, up to 6,500.

I am running twin webber 40s that were set up on a rolling road a good few years ago but I only cover a handful of miles each year.

Where would be a good place to start the diagnostics?

Thanks
Gavin

[RogerFrench]

Maybe your plugs are too "cold"? Try something hotter, like BP 6ES.

[mbell]

As Roger says try different plugs. The standard plugs were 7's but a lot of people on here seem to run 6's from what I have seen.

I'd buy both and see which works best for you.

[rgh0]

NGK "8" heat range are far to cold for a road engine try a "6" heat range plug - the BP6ES is cheap and works just as well as the more expensive exotic metal plugs in an Elan.

cheers
Rohan

[gav]

Thanks all for your help.

Rohan - the engine is a livlier road spec running vegantune VT1 cams which are a little livlier than sprint. The engine produced 150 BHP/ 129 ft lb on the rollers - do you think that there is there a risk of a hotter plug (say a 6) melting in this scenario when driven hard?

Many thanks
Gavin

[rgh0]

Unless you are driving flat out all day at 6500 rpm then no problem with BP6ES. If autobahn trips are your thing then you may need to go to a BP7ES. BP8ES heat range plugs are really only needed in full race engines ( 12.5 compression ratio, 8000 plus rpm) being driven flat out on the track and even then you need to get the engine hot before trying full load or you will foul them. When I am running a hill climb I go back to BP7ES as the BP8ES I cant warm up properly like I can on the track with a warm up lap

cheers
Rohan

[gav]

Thanks Rohan

I'm only running a 10.8 comp. ratio so sounds like the 6 range should be fine.

All the best

Gavin