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Spark plug Indexing, Should the plugs face the intake or the exhaust valves?
For those who don't understand, spark plug indexing is facing the spark plug for the most gain in power. its said to give 2% more power. BUT, i get conflicting reports of what way to face the plugs.
I hear the ground strap should face towards the intake to act as protection for the flame kernel. I am just performing this on my new motor.
It appears motorcycle performance part stores are a good source for 12mm washers
I have never owned a car with an engine that was as temperamental as the N14
Does indexing with washers make up for the little bit of compression lost by spacing the plug out further? And what about rimfire plugs or whatever Brisk are. They say you get about the same amount of gain with just changing the plugs and not having to mess about.
Seems like a lot of effort for dubious reward. I don't think 2% in a road car is statistically significant.
I do think that indexing spark plugs may be important for certain applications but a road car is not one of the them. You're going to get a slight reduction in the rate of misfire but this is the type of small gain that equates thousandths of a second on a race track.
Given my personal experience experimenting with 8 various brands and models of spark plugs and their varying performances and how sensitive these engines are to misfires when tuned, I think indexing is just one of those thing one does for a holistic & professional result. Not sure what "rabbit hole" infers or why one would even write it but, IMO some are rather happier having their head in the sand rather than pursue excellence. If protecting the source of something very very critical as in ignition and the resultant suppression of misfires, then why would one NOT do it.
As for my car, misfires are a huge issue especially at the track.
Further, misfire and a resultant multitude of issue incl detonation & raw fuel dumping into the exhaust can lead to significant additional problems incl burnt pistons and valves.
I agree not needed for the average road going engine but....., not all here are doing that with their Mini.
The "rabbit hole" that I speak off is the "proper" orientation of the plug. Everyone seems to have a differing opinion of what is best.
It would be great to read some peer-reviewed articles on the subject for engines that have similar characteristics to the N14/N18, mainly boosted direct injected applications. (I realize that this is the 1st generation forum)
If you are having huge issues with misfires then I'd start looking elsewhere. I'm curious to know what your EGTs when the misfires and denotations are most problematic.
No need to look elsewhere as it has always been the plugs. I did not realize this was 1st Gen forum as I have a N14 motor car. EGT always seemed to be up 1700 under full song.
Indexing is easy enough; mark a vacuum line that I use to install plugs and orient the open end 1/3 turn away from the intake valves then snug them up.
Again, not for the average motor but running 25 psi of boost has caused problem when it comes to the secondary ignition or is spark plugs part of the primary ign. system
Spark plugs with one electrode should be indexed to have the open side pointed at the exhaust valve or on multi exhaust valve engines in the center of the exhaust valves. Engines with indexed plugs do make more power.
You can use multi electrode plugs and not have to index plugs. We have found that the Brisk LGS-Ts work the best and are worth 2-3 horse power in most engines. Correctly indexed plugs are very close in power but takes more work and having to buy more plugs to find ones that will index correctly in each cylinder.
As for the N14 blowing out spark at high boost. Have you reduced the gap? We were having a misfire problem and gapped the plugs down to .025 and the problem was solved.
Interesting and thanks for the info; I have used 2 different models of the Brisk silvers conventional ground strap. Both melted within 4k miles but the performance was good.
Have you run these in tuned cars running 25psi of boost? How did they do?
I do gap my plugs down to .019-022 which definitely help with misfires.
One can use indexing washers to control orientation but it is a PIA when the motor is together vs the head on the bench.
I will give these a try for sure.
What heat range or part number Brisk were you using. If your melting the electrodes then the heat range is wrong. I can get you the right ones. Just need to know what you've tried already.
I used the QR12LS & QR08S
Here I indexed my plugs using a washer kit purchased for motorcycles.
I always had decent results with the NGK 1422 that come gaped down to .022.
I really feel the Brisks make better power.
I just need a dyno in my garage next to the mower and power washer.HA
Cool but is that Gen 1 stiff? N14 runs 12 mm vs 14 mm SP threads. Also running 25-30 psi of boost. Blowing out plugs happens.
Don't get me wrong as I love Brisk.
New motor with meth will hopefully allow me to run the mad silver!!!!
Spark plug Indexing, Should the plugs face the intake or the exhaust valves?
For those who don't understand, spark plug indexing is facing the spark plug for the most gain in power. its said to give 2% more power. BUT, i get conflicting reports of what way to face the plugs.
04-22-2016, 02:32 AM
