Interesting spark plug..
Discussion
Generally speaking yes, detonation, weak, bad tuning.
Depends if that is the bulk of the damage or what other problems there are.
And lets hope there isnt also piston damage and that the bit of the plug that melted off didnt also cause some damage.
Give Karl at Norris Motorsport a shout
Depends if that is the bulk of the damage or what other problems there are.
And lets hope there isnt also piston damage and that the bit of the plug that melted off didnt also cause some damage.
Give Karl at Norris Motorsport a shout
It is always difficult 'working out' what we are presented with if we are not there in the flesh and only have a pic as evidence.
The plug looks a little 'oily' to me. If there is any oil contamination I have seen plugs melt really quickly as the combustion process is 'totally' wrong especially in a high power car, oil contamination can be from poorly piston/rings and the three good cylinders power the poorly cylinder to death. If the cylinder in question is perfect and it is not oil contamination is this plug from the known hottest cylinder? If so then as you say straightforward det problem from too much advance and or poor fuel quality? We do get folk who have the car set on top notch fuel with additive then wonder why the engine expires on cheapest fuel available! As Stevie says there may be associated piston damage. If you end up seeing Carl at NMS pop in and say hello to us as we are next door!
Peter
The plug looks a little 'oily' to me. If there is any oil contamination I have seen plugs melt really quickly as the combustion process is 'totally' wrong especially in a high power car, oil contamination can be from poorly piston/rings and the three good cylinders power the poorly cylinder to death. If the cylinder in question is perfect and it is not oil contamination is this plug from the known hottest cylinder? If so then as you say straightforward det problem from too much advance and or poor fuel quality? We do get folk who have the car set on top notch fuel with additive then wonder why the engine expires on cheapest fuel available! As Stevie says there may be associated piston damage. If you end up seeing Carl at NMS pop in and say hello to us as we are next door!
Peter
Hi Peter, will do have owned several MG's so would love to see your place.
The plug was on cylinder 2 and it is oily and so were the other three. There is no sign of the engine burning oil at the tailpipe though but we've had a weird oil leak under boost which we're struggling to track down. Thought it was coming from the breather but hard to pinpoint.
We're going to take it all apart and have a look I guess it could be valve guides but the engine has just been rebuilt so struggling to see how it could be mechanical at this point.
Last time we had an issue it had cracked the block. That was running 1.8 bar of boost its down at 1.5 bar now.
The plug was on cylinder 2 and it is oily and so were the other three. There is no sign of the engine burning oil at the tailpipe though but we've had a weird oil leak under boost which we're struggling to track down. Thought it was coming from the breather but hard to pinpoint.
We're going to take it all apart and have a look I guess it could be valve guides but the engine has just been rebuilt so struggling to see how it could be mechanical at this point.
Last time we had an issue it had cracked the block. That was running 1.8 bar of boost its down at 1.5 bar now.
What is a race plug and how does it know it is one? I always thought the correct plug was one which had the correct heat range for the spec and the correct plug gap to suit the spec, am I missing something?
Peter
I forgot to put, correct projection too!
Peter
I forgot to put, correct projection too!
Edited by PeterBurgess on Saturday 30th July 16:23
There's not enough information to make a diagnosis imo. Clearly the plug stopped igniting hence the fuel contamination. The earth electrode tip is damaged to. What are the other plugs indicating? If they're showing correct heat range and fueling then you have an issue with that cylinder which indicates something mechanical imo.
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