Discussion
http://www.pistonheads.com/gassing/topic.asp?t=316...
Do you have the standard fuel pump?
If so, you have had the same issue I had.
Time for more BHP.
Do you have the standard fuel pump?
If so, you have had the same issue I had.
Time for more BHP.
hi all
jnm have had a look at the car and decided it is the big end bearing that's the problem. engine now coming out to assess whats happened. it had the fuel pump upgrade, though not sure when this was done. when jnm remapped the car recently they said it was one of the american engines that noble used for around 10 of the m400's. they said there were around 10 'other' spec engines used as well. when they'd seen this problem before it was on one of the american or 'other' spec engines.
i've only had car about 2 months so hopefully warranty will cover some cost.
immediate thoughts were for more bhp when work being done on the car though i've not had much chance to experience the 430bhp in standard form yet after remap. will keep you posted
conleth
jnm have had a look at the car and decided it is the big end bearing that's the problem. engine now coming out to assess whats happened. it had the fuel pump upgrade, though not sure when this was done. when jnm remapped the car recently they said it was one of the american engines that noble used for around 10 of the m400's. they said there were around 10 'other' spec engines used as well. when they'd seen this problem before it was on one of the american or 'other' spec engines.
i've only had car about 2 months so hopefully warranty will cover some cost.
immediate thoughts were for more bhp when work being done on the car though i've not had much chance to experience the 430bhp in standard form yet after remap. will keep you posted
conleth
CTO3 said:
hi all
jnm have had a look at the car and decided it is the big end bearing that's the problem. engine now coming out to assess whats happened. it had the fuel pump upgrade, though not sure when this was done. when jnm remapped the car recently they said it was one of the american engines that noble used for around 10 of the m400's. they said there were around 10 'other' spec engines used as well. when they'd seen this problem before it was on one of the american or 'other' spec engines.
i've only had car about 2 months so hopefully warranty will cover some cost.
immediate thoughts were for more bhp when work being done on the car though i've not had much chance to experience the 430bhp in standard form yet after remap. will keep you posted
conleth
I don't want to be to negative, but! JNM remapped the car and then it went bang? did they increase the boost on an unknown engine? how much power was it making before they remapped it? and how much boost was it running then?jnm have had a look at the car and decided it is the big end bearing that's the problem. engine now coming out to assess whats happened. it had the fuel pump upgrade, though not sure when this was done. when jnm remapped the car recently they said it was one of the american engines that noble used for around 10 of the m400's. they said there were around 10 'other' spec engines used as well. when they'd seen this problem before it was on one of the american or 'other' spec engines.
i've only had car about 2 months so hopefully warranty will cover some cost.
immediate thoughts were for more bhp when work being done on the car though i've not had much chance to experience the 430bhp in standard form yet after remap. will keep you posted
conleth
GTO400 said:
Don't see why JNM remap has anything to do with Main bearing failure !, personally l can't recommend them high enough, great people and great work.
Because the stresses on the bottom end increase drematicaly, remember this engine was designed to produce 205bhp. my comments wernt a pop at JNM, However i did ask for the before and answer not able to say what the car was producing before the remap as wasn't running well - large flat spot/misfire - bad presale service garage had the wrong plugs installed and were gapped incorrectly in any case. but boost standard and untouched before and after. i had done around 400 miles since remap before donny
conleth
conleth
Adrian W said:
I don't want to be to negative, but! JNM remapped the car and then it went bang? did they increase the boost on an unknown engine? how much power was it making before they remapped it? and how much boost was it running then?
That's an entirely valid question.A remap makes use of the safety headroom within the map, optimising it for performance, with the high rigours and stress placed upon the engine during a track day, its likely that high intake temperatures are more likely to bring about the onset of in cylinder detonation. Particularly so if ignition advance has been pushed too far during the remap?
Detonation causes a HUGE pressure increase on top of the piston while it's still rising towards the optimum ignition firing point, the end result of that can quite easily bring about a big end failure.
The massive shock load caused if an engine is experiencing det, carries that additional shock load down the con rod and to the crank. The pressure is so great, that it can punch through the oil film which exists between the big end shell and the crank.
This can cause failure in itself, but if bad enough can cause the big end to pick up as it breaks the oil film, gripping the shell, spinning it and blocking of the big end oil feed.
Given that at circa 6500rpm, the cylinder is on its firing cycle maybe 55 times a second, (and seeing tdc around 110 times a second) it's easy to see how even short instances of det can take their toll!
While I'm in no way at all suggesting that this is the cause, I'm merely putting some meat onto the bones that it wouldn't be an act of madness to consider what was done during the remap only a short while before and to include it on the list of possible suspects?
It could also be poor quality fuel, reduced fuel pressure, spark plug temperature range too hot, oil level, oil quality.............. (the list goes on).
Mike
Edited by Mike Tuckwood on Tuesday 18th December 23:32
Mike Tuckwood said:
Adrian W said:
I don't want to be to negative, but! JNM remapped the car and then it went bang? did they increase the boost on an unknown engine? how much power was it making before they remapped it? and how much boost was it running then?
That's an entirely valid question.A remap makes use of the safety headroom within the map, optimising it for performance, with the high rigours and stress placed upon the engine during a track day, its likely that high intake temperatures are more likely to bring about the onset of in cylinder detonation. Particularly so if ignition advance has been pushed too far during the remap?
Detonation causes a HUGE pressure increase on top of the piston while it's still rising towards the optimum ignition firing point, the end result of that can quite easily bring about a big end failure.
The massive shock load caused if an engine is experiencing det, carries that additional shock load down the con rod and to the crank. The pressure is so great, that it can punch through the oil film which exists between the big end shell and the crank.
This can cause failure in itself, but if bad enough can cause the big end to pick up as it breaks the oil film, gripping the shell, spinning it and blocking of the big end oil feed.
Given that at circa 6500rpm, the cylinder is on its firing cycle maybe 55 times a second, (and seeing tdc around 110 times a second) it's easy to see how even short instances of det can take their toll!
While I'm in no way at all suggesting that this is the cause, I'm merely putting some meat onto the bones that it wouldn't be an act of madness to consider what was done during the remap only a short while before and to include it on the list of possible suspects?
It could also be poor quality fuel, reduced fuel pressure, spark plug temperature range too hot, oil level, oil quality.............. (the list goes on).
Mike
Edited by Mike Tuckwood on Tuesday 18th December 23:32
As for the failure, I suspect a combination of low oil level and oil starvation due to hi-g cornering and braking played a role. Bearings do not react well to a loss of lubrication--even a short one.
Edited by JLSELAN on Wednesday 19th December 07:28
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