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Andrew Smith

NGK BP6ES or BP5ES?

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I understand the generally preferred plug for TR5/6s is the NGK BP6ES, but note the BP5ES is specifically for use in lead free head - VUX's head is gas-flowed and unleaded.

Anyone using the BP5ES and notice any benefits over the BP6ES?

Cheers, Andrew

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Andrew,

I used BP6ES and noticed the two plugs 5 & 6 were running blacker than 1-4.  I checked the mixture and butterfly opening to no avail then I fitted 5 & 6 with BP5ES  (hotter) now I get a better colour match over all plugs. Probably due to reduced air flow down to the end of the original inlet plenum.

So my answer is both!

Alan

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5s will be ok for anything but race use

used em for yonks, as said, better colour than colder plugs in normal drive

 

Alan says

Probably due to reduced air flow down to the end of the original inlet plenum.

 

..this is why ye all need a small KnN type filter at end oft log

as a RR session  yonks ago showed, rear cyl was not same trace on screen as other plugs

 

try the 3 or 4 pronged type

quite a few say they run better, me own seems to  after I got right grade

meb,e something t,doo wid spark coming out of end,not being hidden by electrode!!

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I’m trying the tripple electrode Bosch w7dtc this year after quite a bit of research.

i do have spares in stock Andrew if you’d like a set :-)

steve

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I bought a couple of bp5es to go in numbers 5&6 but still not got round to doing it, also nearly bought a set of the Bosch ones Steve has mentioned but my concern was gapping them correctly as I think they come as 40th but I may be wrong with that.

Let us all know how you get on with them Steve.

Edited by Kevo_6

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Over the years I've  tried both BP5ES and BP6ES plugs but had problems with fouling and hard starting after a few hundred miles . After a fair bit of research I switched to NGK BUR 6ET   triple electrode plugs and the fouling and starting problems have gone away. 

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Those are both hot plugs, and the BP6ES works well in the U.S. market applications, grey colour on my stock TR250 engine long ago. When I tried them with my CP spec engine with Weber DCOEs they ran white. So I've been using BP7ES since the 1900s. These get changed out at 30K miles whether they need it or not. Apart from LUCAS P.I. equipped TR5/6 fast road engines I'm told the 7s are the favourites.

From what I've seen on this forum the P.I. cars do better with hotter plugs. The above issue about #s 5&6 is a recurring theme too. Some have fattened the plenum to 4" in an effort to correct this.

 

Cheers,

Tom

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24 minutes ago, Tom Fremont said:

Those are both hot plugs, and the BP6ES works well in the U.S. market applications, grey colour on my stock TR250 engine long ago. When I tried them with my CP spec engine with Weber DCOEs they ran white. So I've been using BP7ES since the 1900s. These get changed out at 30K miles whether they need it or not. Apart from LUCAS P.I. equipped TR5/6 fast road engines I'm told the 7s are the favourites.

From what I've seen on this forum the P.I. cars do better with hotter plugs. The above issue about #s 5&6 is a recurring theme too. Some have fattened the plenum to 4" in an effort to correct this.

 

Cheers,

Tom

Hi Tom, what compression ratio are you running on the Weber engined car. Is it a Stage 2 type head?

Cheers Daz

 

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49 minutes ago, DRD said:

Hi Tom, what compression ratio are you running on the Weber engined car. Is it a Stage 2 type head?

Cheers Daz

 

Hi Daz,

I'm not versed on " Stage XYZ " heads, but one of my BP7ES equipped engines with CP cam has 9.5:1 c/r and the other has 10.7:1 with high lift ( 0.504" ) / 282 degree duration cam. Heads are both Racetorations produce ( caveat emptor! ).

The [ dated ] information I have is that the 7s correlated to Champion N9Y and the 6s correlated to Champion N12Y, specified for TR5/6 P.I. and TR250/6 carb respectively,  by TRIUMPH. So my experience amounts to " going by the book ".

 

Cheers,

Tom

Edited by Tom Fremont

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Tom - a Stage 2 head is basically gas flowed and ported with slightly larger valves. Mine is approx a CR of 9.75.

Daz

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My memory may be fooling me, but I think BP5es would equate to an N12Y,  a BP6es (being a bit colder) would probably be an N9Y.

your BP7’s would be cooler still, so an N7 in Champion

...... Andy 

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I ran stock '250s from 1976 to 2004 using Champion N12Y, Autolite 55 and by 1990 NGK BP6ES, all giving the same colour. I used Bosch once or twice but don't remember the model; I would have cited N12Y Champion as a cross reference.

 

The proper correlation between NGK and Champion is the question, and at the end of the day the colour ought to govern the choice.

 

Tom

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Thanks for the feedback folks, very useful.

Steve - thanks for the offer, although I'll wait until you've tried them and see what you think.

Cheers, Andrew

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Hi

If you use the function to fit your car on the NGK web site mine comes up with NGK 6637 BPR6EIX IX Iridium Plug (which I have and are a bit sooty).

I there a guide to what all the numbers etc mean?  I am easily confused ;-)

 

Rich

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6 hours ago, AarhusTr6 said:

 

I there a guide to what all the numbers etc mean?  I am easily confused ;-)

 

I have used this one for a while, there are probably others, hope it helps

..... Andy 

 

 

986BE260-9090-4FCE-8035-9A2D58ABF80B.jpeg

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not wanting to ruin the NGK debate...but is no one using Bosch?  I am driving 4-point WR78X. Someone once noted such 4-point plugs are a better fit for an engine such as ours...

Jochem

 

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Looks good Andy, all I need do now is understand whats best for my engine :-)

Rich

 

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