Duratec spark plugs

[AMMO]

Seems that the Emerald ECU is not keen on non resistor plugs (Probably not a problem with Weber ECUs). The problem is that we cannot get hard enough plugs in taper seat. 7 grade is as cold as they get. This may be OK for most applications but I would like to see a colder plug in high power engines that are subjected to hard use.

 

Currently investigating two options. Machine the head to accept conventional racing plugs. This can be done if the head is off for porting. There are no racing plugs with a taper seat. Alternatively use a long reach plug with a taper seat adaptor.

 

We will address the problem if the grade 7 plugs show sign of distress. I have given Mike Head some plugs to try in his 260 bhp Duratec for his next track day.

 

Just thought that any of you running Emerald ECUs and non resistor plugs should know that there may be a potential problem with the ECU cutting out.

 

AMMO

[Dobuy]

So what would you suggest for Weber users AMMO, I am using NGK B9EFS and B8EFS in mine, is this cold enough?

 

 

Duratec SV, built in Dubai

[Rob Walker]

I made enquiries with NGK, Champion and Caterham general consensus is that NGK BPR 7EFS is the best plug currently available. Makes no difference if your using Webber , MBE or XYZ the advice is the same resistive plugs are required. Non resistive plugs used with resistive HT leads can still corrupt the ECU with interference.

 

Edited by - Rob Walker on 27 May 2005 17:51:40

[AMMO]

I would prefer NGK to Champion. I was sponsored by both companies and NGK gave us a lot of help over the years. When we had problems they kept sending us more stuff to try until the problem was fixed. We used to destroy grade 9 plugs and worked our way through several different grade 10 plugs until we go the right one

 

I would prefer the non “P” version of the 7 plug. This is what NGK sent me. Still think grade 7 is too soft but at the moment that is all we have. Probably OK for my cooking engine running 10.5: CR, soft cams and driven by me!

 

For more powerful engines that are used hard something colder is needed. I think the solution is to machine the head as it will give you a much wider variety of choice. The taper adaptor for long reach plugs is also a solution that allows you to get the grade of plug but not the earth electrode type. In extreme cases a surface discharge plug may be necessary.

 

Whilst the head is off for porting it is no problem to whack it on the mill and spot face the spark plug seat.

 

Problem solved.

 

Dobuy

 

If you have a Weber Alpha this is based on the old Weber Marelli P7 / P8 ECU. These go back to around 1988 and are tough as nails. We raced one for 5 seasons with non-resistor leads, non-resistor plugs and resistor caps. No problem.

 

If I were you I would use the 8’s and keep a close eye on them. Look for rounding of the central electrode. If this starts to happen switch to the 9’s and keep checking.

 

 

AMMO

[Dobuy]

 

Duratec SV, built in Dubai