Spark plug failures

mikeinatruck · Post by **mikeinatruck** » Thu Sep 30, 2010 9:20 pm

I have always sworn by NGK spark plugs, and up to now I have not really had any problems but for some reason my V8 seems to love to eat them! I have a 3.5 efi flapper and have been using BPR6ES plugs but when I start up some of them refuse to fire, finger test and one header pipe is still cold. I still had a set of carb V8 plugs laying about so have been experimenting by changing them as they fail, I am now putting in BP5ES, and they fire fine as soon as I restart.

Anyone have any ideas why its eating plugs

SuperV8 · Post by **SuperV8** » Fri Oct 01, 2010 9:46 am

Do/have you had any missfires?

I tried starting mine but i had wrongly put in the wrong crank angles for megasquirt so it was popping and banging and never ran. Finally found my mistake but it still wouldn't start, turned out to be knackered plugs.

Tom.

ian.stewart · Post by **ian.stewart** » Fri Oct 01, 2010 10:02 am

If for any reason the plugs are wetting up, this tends to kill the plugs on RV8s

mikeinatruck · Post by **mikeinatruck** » Fri Oct 01, 2010 9:48 pm

When I take out the offending plug it is indeed wet, I never get the problem on the number 5 plugs, so slightly hotter, maybe its just one of those quirky Rover things...

stevieturbo · Post by **stevieturbo** » Sun Oct 03, 2010 7:58 pm

ian.stewart wrote:If for any reason the plugs are wetting up, this tends to kill the plugs on

Any engine.

fuel soaked plugs = bin.

RoverP6B · Post by **RoverP6B** » Mon Oct 04, 2010 8:10 am

My original 3.5 in my P6B ran with a 10.5 : 1 CR. I always used Champion plugs except on one occasion when I trialled NGK plugs. For my engine they just didn't work well, so out they came and Champions went back in.

I now have a 4.6 in my P6B which runs with an 8.37 : 1 CR. Champion plugs are in this engine too, and for a total of 25 years that I have been with my Rover, not a single spark plug failure with Champion.

Ron.

kokkolanpoika · Post by **kokkolanpoika** » Thu Oct 07, 2010 3:08 pm

I have got similar proplem with NGK plugs in my old rover stage 3 4,6 engine.. In worst case i can drive 20km and 3 plugs are dead.. I change 3 set of plugs in ~500km. Then i start to use Bosch and no proplem anymore..

stevieturbo · Post by **stevieturbo** » Thu Oct 07, 2010 6:06 pm

Very rarely would I use anything but NGK. Denso would come second. Never had any problems

bobtail84 · Post by **bobtail84** » Thu Oct 07, 2010 7:49 pm

I must admit that I use NGK bp6es and they last... well about a year then I change them. At £1.65 each it's not too much of a problem.

Jeff

davehoos · Post by **davehoos** » Sun Oct 10, 2010 11:04 am

australian spec is BP5ES for leaded fuel--better than 95 octane
unleaded 91 octane BP6ES.im guessing to stop pinking.
champion-bosch are similar and ive been recomended to use euro denso as they make most other brands.

im told that plugs in euro have had changes so that the same number on the plug is to suit modern fuel.IE you dont fit colder plug when using unleaded as the plug is already colder.

My 86 range flapper often refused to start cold.swap the set of plugs and fires up.with the temp sender unpluged it flooded.

my disco had BP4ES super bosch and denso plugs-when i picked it up and fowl missfire that took time to clear.on occasion it refused to fire..it was fitted with 82 thermostat with hole drilled.
92 standard flow stat fitted temp gauge wonders between 3/4 and 1/2.
temp sender unpluged it runs perfect.new sender didnt fix issues.

DaveEFI · Post by **DaveEFI** » Sun Oct 10, 2010 11:23 am

I do remember my first RV8 in a '69 P6 suffered badly from plug fouling 'till BL changed the spec to an extended nose type. Both Champion. But when NGK came to this country I changed to them and never looked back.

I've got a MS and EDIS on my SD1 EFI - is there a better than standard plug for this combination?

davehoos · Post by **davehoos** » Mon Oct 11, 2010 12:02 pm

P76 V8 had problems with oil fowl when new.
several different champion plugs are listedfor this engine..
BP5HS is ngk listed.

then as a fix the 48-53 GM-holden FJ plug is listed by leyland.[also stag]
I found some old stock AC plugs and they was magic at a few cents each..
BP-4 is ngk listed is listed for holden.

http://fefcholden.org.au/forum/index.ph ... pic=4774.0
if you have a read here you see the cross reference charts dont work.

champion cat lists L92YC 0.6 or L87YC 0.7 P76.
holden FJ listed J18YC or J11C

mikeinatruck · Post by **mikeinatruck** » Wed Oct 27, 2010 6:58 am

Changed over to BP5ES that I had left over from my old carb engine and they seem much better, I do use the better 97 RON fuel though so maybe that was part of the problem.