Jump to content

Spark plugs probably again


Recommended Posts

My plugs are out do to trying to trace a misfire (suspect leads) the plugs which are NGK BP6ES have only done about 150 miles. A friend of mine in the motor trade said replace the plugs as there may be a faulty one and they are relatively cheap. But keep away from Champion plugs as they are not what they used to be.

 

My question is are there any better plugs than the NGK I could use maybe some of the newer type that have no gap to adjust.

 

I would appreciate any advice that members could give me.

 

Regards John.

Link to post
Share on other sites

Hi John

have you had a look at http://www.sparkplug...NGK_PN/BP6ES-11

 

Possible spark plugs:

 

  • NGK: BP6ES-11
  • Accel: 114
  • AC Delco: R42XLS
  • Autolite: 63
  • Beck Arnley: 176-5090
  • Bosch: WR6DC
  • Bosch: WR7DC
  • Champion: RN9YC
  • Champion: RN11YC4
  • Denso: W20EP-U11
  • Denso: W20EX-U11
  • Mighty: M4GR22
  • Mighty: M4GR32
  • Mopar: 4106117
  • Motorcraft: AGS22C
  • Splitfire: SM006C
  • Valley Forge: 32R

 

Details about your spark plug:

 

  • Type: AUTOM.
  • Thread size: 14mm (0.55118 inches)
  • Hex size: 0,81 inches (20.574 mm)
  • Reach: 0,75 inches (19.05 mm)
  • Seat type: GASKET
  • Projected tip: YES

 

And if your engine is modified for performance, you may need a cooler heat range plug.

 

Regards

Ian

Edited by cvtrian
Link to post
Share on other sites

NGKs, especially nearly new ones do not seem to be able to stand a fuel soaking (something the PI system seems to be good at delivering) and just stop working. Strangely, well-used ones appear to be able to take it, the problem being how to get them to the well-used state!

 

I like the Bosch triple electrode ones myself and have had very good results with them in various Triumphs over the last 20 years.

 

Nick

Link to post
Share on other sites

I've never had a bad Champion spark plug, yet over on your side of the pond it seems that they don't have the best of reputations..I wonder if they are shipping y'all 'seconds'.

RN12YC... favorite for my TR6

Link to post
Share on other sites

I fitted the Bosch Multi electrode ones Super 4 no. 507, last year and have found them to be excellent.

Link to post
Share on other sites

Haven't had a problem with NGK BP7ES in circa 100K miles with Webers on my '250. Pre-emptively changed at ~ 10K miles, never lose their gap ( 0.030" on mine ) nor require cleaning. Blue Streak points and LUCAS Sport Coil.

 

Odd bit about fuel soaking - hard to believe I haven't perpetrated that offence in so many miles, even counting calibration trials.

Link to post
Share on other sites

One of the things about the multi-electrode plugs is that they last a very long time (that is the original reason for the design). In my household we have two Triumphs, running triple electrode plugs, a diesel and a Ford Focus 1.6 petrol. Before the Focus we had a succession of Golf GTIs which also have triple electrode plugs - so I'm used to plugs lasting for ages (VW say 25 k miles) and don't check them as often as I should it seems. Tonight the management complained that the Focus seemed a bit sick, so I took it up the road and had to agree. We've had it a while and although I've changed the oil and filters a few times I've left the plugs alone. So I looked at them this evening.....

 

Yep, these NGKs have done sterling service, but they're just about dead now....... pretty impressive ignition system that will reliably fire a near 2mm plug gap! Closing the plug gaps back up to the regulation 1mm has transformed the car - but I will buy some new ones. Triple electrode preferably ;)

 

Nick

post-7915-0-57622300-1337804305_thumb.jpg

post-7915-0-57622300-1337804305_thumb.jpg

Link to post
Share on other sites

Thanks for the advice guys I think I will clean the NGKS and give them another try with a new set of leads.

 

If I still have a misfire I will give the Bosch multis a try

 

Regards John.

Link to post
Share on other sites

I checked my plugs last weekend after 3K miles and although gaps were ok only 1 and 2 were biscuit coloured, 3 and 4 were dark toast colour and 5 and 6 looked a bit sooty.

The existing plugs are BP5ES in 1 to 4 and BP6ES in 5 and 6. I am thinking of trying new 5's in 1and 2, new 6's in 3 and 4 and if available BP7ES in 5 and 6. Hiopefully as the plugs will run hotter I will achieve perfection!

 

Anyone tried this route??

Link to post
Share on other sites

Nick

That plug is worn out chap,new ones asap ;)

 

 

Yes..... so are the other three! New ones will be fitted tomorrow evening. Closing the the gaps has done the trick temporarily.

 

Mike,

 

I'd think that balancing the throttle linkage properly (not especially easy) will solve your problem. If the linkage is out of balance the MU gets an approximately averaged vacuum reading from all 6 cylinders and fuels accordingly. All cylinders get the same amount of fuel, but the pair of throttles opening most will allow those two cylinders will get more air and run leaner (1 & 2), the throttles opening least will cause the those two cylinders to run richest (5 & 6) and the remaining pair somewhere in between. There is no particular reason why any would be actually correct.

 

I don't think mixing heat range plugs will solve the problem, or even mask it.

 

Cheers

Nick

Link to post
Share on other sites

The only thing is I would end up going back to Malcolm at Prestige as he set up the under throttle linkage as well as replacing the MU and injectors!

 

For the cost of a couple of plugs I will give it a try. I know a few others have used BP6ES on cyls 5&6. I also wonder if the single K&N trumpet filter at the end of the flex hose is giving 1&2 a few extra gasps of air

Edited by jemgee
Link to post
Share on other sites

Out of idle curiosity, wouldn't linkage settings affect just the idle conditions?

 

 

The PI TBs are supposed to give total closure at idle with idle air being supplied by the bypass bleed screw. The linkage has to be adjusted to pick up all three pairs evenly. This varies from moderately tricky to impossible dependent on the linkage type and condition.

 

It will have most effect small throttle openings where the differences are a larger proportion of the total opening. This is where you spend most time in normal driving as the TBs are very big.

 

Freshly reconditioned TBs often don't seal fully at idle as they need a bit of carbon build-up to fill the gaps. This does not help the setting up process, so it pould need doing again after some miles.

 

Nick

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...

Important Information

Please familiarise yourself with our Terms and Conditions. By using this site, you agree to the following: Terms of Use.