What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

NGK Spark Plug PIREP

P

Pete G

Member
On takeoff in my RV-6 I experienced rough power at full throttle. Simultaneously, I noted a significant EGT drop on #3 cylinder to 600-700 deg range versus 1300-1400 deg on the other three cylinders. Rough power ceased with reduced throttle. Conferred with my AP who suggested a bad sparkplug or two. I swapped out all NGK BR8ES plugs for same type new plugs. No problems in five hours of flight time since change. My RV has P-MAGS on an IO-360EXP. Replaced plugs had 80 hours of use. Replaced plugs all appeared to be in good shape.
 
Spark plugs are fragile creatures. If the box they were in was dropped or worse yet the plug itself was ever dropped....they cause problems down the road. Once installed, they are relatively safe but accidentally drop a ratchet on one...and you're looking for trouble. You may have had one with an issue. I have hundreds of hours on them in my plane and thousands of track miles on NGK BR8ES's in my race car. They are great plugs....but like all others, treat them gently.

IMHO
 
I suspect this is not a typical issue. I have 700+ on NGK BR8ES plugs (dual p-Mags) and never had a problem. They get replaced every other year - mainly because they are so cheap to replace instead of clean.

Carl
 
Which part number? There are two types. One version has screw on posts and their is another one with solid posts (NGK BR8ES part number #3961). You don't want to use the screw on versions, since they can loosen and cause ignition problems.
 
Carl Froehlich said:
I suspect this is not a typical issue. I have 700+ on NGK BR8ES plugs (dual p-Mags) and never had a problem. They get replaced every other year - mainly because they are so cheap to replace instead of clean.

Carl
Click to expand...

You will want to replace them every 120 hours or so. Using the EICommander I have noticed at around the mark they start to deteriorate. It is nothing you will feel but the EIC definitely notices it.
 
Amen!

N941WR said:
You will want to replace them every 120 hours or so. Using the EICommander I have noticed at around the mark they start to deteriorate. It is nothing you will feel but the EIC definitely notices it.
Click to expand...
Pete,
I had no issues with the NGK's although I changed them every oil change. (50hrs) My favorite plugs over the years are the Autolite 386, Denso L-14U and lastly the NGK. The best of them being the Denso L-14U IMHO.
Change them often, they're cheap insurance.
V/R
Smokey
 
L-14U's are non-resistor and I find that the ignition noise can be heard quite loudly in the radio. The 386's seem to work well with Electroair and don't require adapters.

Vic
 
Good input from all, thanks. My plugs had 80 hours of use and had solid posts. Coincidentally, Sport Aviation has an article on auto plugs in this month's issue. It's Rotax oriented but probably good food for thought.
 
You DO NOT want to run non resistor plugs with Pmags. Ignition noise would be the least of your problems. As warned on the NGK site many electronic ignitions are vulnerable to RF interference thrown off by non resistor plugs and It has been my experience that Pmags are among them. The only issues Ive ever had with Pmags were self induced due to non risistor plugs.

To the OP: did you ohm your plugs before installation and after the event? I ohm and gap all my new plugs and have yet to see any deviation in many sets of NGK plugs.
 
Toobuilder said:
You DO NOT want to run non resistor plugs with Pmags. Ignition noise would be the least of your problems. As warned on the NGK site many electronic ignitions are vulnerable to RF interference thrown off by non resistor plugs and It has been my experience that Pmags are among them. The only issues Ive ever had with Pmags were self induced due to non risistor plugs.

To the OP: did you ohm your plugs before installation and after the event? I ohm and gap all my new plugs and have yet to see any deviation in many sets of NGK plugs.
Click to expand...

I'd add another vote to this. Use resistor plugs (solid caps) and proper suppression wires on all EIs. Any source of radio noise or weird EI problems I've seen in the last 20 years have been to do with bad wires, non-suppression wires or non-resistor plugs. You would not believe the bad things these can do on the bench. I wouldn't want them to happen in the air...

Never had a bad NGK plug yet- 40 years of using them personally and in every engine I've built and tuned for customers in that time professionally- thousands of plugs.

We do know of a bad batch last year so it can happen, but is a very remote possibility.
 
Can those NGK plugs be used if you have dual mags

In my RV6A with a Lyc O360 A1A increased to 200HP by Performance Aero Engines, I have always used Champion plugs which I was due to replace at the next condition inspection. They go for about $26 each. Never had any problems with them.

But I see the NGK's are a couple bucks each.

Any problem using them on engine with mags, not EI?
 
Opps

Saw this from Ross and Vic AFTER I ordered the Denso's. What wuz i thinkin??
Guess I could put them in the GO bag for emergency use only.....


rv6ejguy said:
I'd add another vote to this. Use resistor plugs (solid caps) and proper suppression wires on all EIs. Any source of radio noise or weird EI problems I've seen in the last 20 years have been to do with bad wires, non-suppression wires or non-resistor plugs. You would not believe the bad things these can do on the bench. I wouldn't want them to happen in the air...

Never had a bad NGK plug yet- 40 years of using them personally and in every engine I've built and tuned for customers in that time professionally- thousands of plugs.

We do know of a bad batch last year so it can happen, but is a very remote possibility.
Click to expand...
 
I've noticed that the Autolite 386 plugs seem to have a short reach but have not measured them....is that an problem?

PS being used on an IO-360-?? ECI engine.

Glenn
 
You must log in or register to reply here.
Back
Top