Re: Odd spark plug behavour
I've never experienced anything like that. It is very interesting though. Is there a different shape to the electrode between the two styles of plug?
Re: Odd spark plug behavour
datalog the knock volts/ cyl retards to see if there are different results.
listen to the knock sensor?
https://uprev.com/documentation/Knoc...n%20Device.pdf
EDIT to add new link to the PDF.... https://drive.google.com/file/d/1sfW...ew?usp=sharing
Plus
https://www.amazon.com/FiiO-A1-Porta...01LYYKP29?th=1 (rather than the fiio e5)
also, an alternative circuit.... ive used this one on my Honda CR-V to listen to knock. I can hear the gearshift moving around in the transmission with the engine off with this circuit below.
(KS pin/wire) ------------ (.1uF capacitor) -- (100k ohm resistor) ------ (mic jack tip)
(engine ground) ------------------------------------------------------------(mic jack base)
that way you can hear if the CEL turn on is real knock or some other phenomenon.
Brian
Re: Odd spark plug behavour
Quote:
Originally Posted by
cordes
I've never experienced anything like that. It is very interesting though. Is there a different shape to the electrode between the two styles of plug?
Yes the irdium plug has a narrow electrode
Re: Odd spark plug behavour
thats strange.... the NGK 97382 is a GR4IX.... 4 heat range is hotter than the RN12YC from what i can gather.... I would think it would knock more....
i assume all the cam/distributor timing is set correctly.
I dont generally get CEL flash for anything but really high boost but my 2.5 is a Ghead.
Brian
Re: Odd spark plug behavour
Quote:
Originally Posted by
Aries_Turbo
thats strange.... the NGK 97382 is a GR4IX.... 4 heat range is hotter than the RN12YC from what i can gather.... I would think it would knock more....
i assume all the cam/distributor timing is set correctly.
I dont generally get CEL flash for anything but really high boost but my 2.5 is a Ghead.
Brian
I believe the timing and cam are fine but I will check when things quiet down a bit here at home. Where can I check the heat ratings on the plugs vs others? I searched but did not find this cross reference. NGK does recommend the BPR4ES and GR41X for our application.
Re: Odd spark plug behavour
i saw this chart floating around the internet.
https://forums.pelicanparts.com/uplo...1393302384.jpg
not sure how accurate it is. I run BPR6ES
Brian
Re: Odd spark plug behavour
Another data point Miles, I run BR8ES (non-projected tip) in my CSX (2.5 G Head) because the porcelain doesn't break as easily from knock as the projected tip plugs do. Same plugs Reeves uses in his OMNI with no issues (9.99 second-proven spark plugs...lol).
Re: Odd spark plug behavour
ive ran that plug too from time to time... I had a strange low load miss though when i first tried that plug with my g-head 2.5.... it wanted more timing.
Brian
Re: Odd spark plug behavour
Thanks Guys
Plugs are cheap so I will try 'em
Re: Odd spark plug behavour
do you have the support bracket/bar that attaches to the head and neck of the 2 piece intake in place?
that bar stops false knock readings from happening
that's why it's there .. it's not a support but rather it eliminates an echo in the manifold that the knock sensor can hear..
Re: Odd spark plug behavour
Thanks Johny, yes I do have this but perhaps I should test it is tight The NGK GR4IX does fix the issue
Re: Odd spark plug behavour
OK update time.
I changed the fuel o Exxon 91 as Jamie suggested Costco 91 had quality issues as noted by others. The bottom line .... about the same.
This car is my summer daily.
Spark plug trials as follows 2.5 TII CB. ported head/S60/FMIC/3" SV/3" Exhaust/ SMEC/MPFlash with BB stage II (stock injectors/2 bar/ 12 psi max boost.) All was tested on cold engine and ran to work of 25-50 miles each on country roads and highway.
-Stock like Autolite 65, lots of knock even under vacuum conditions
-Warren suggestion BR8ES. Could not get this to knock which was a positive, the engine was very sluggish to build power but A/F number looked fine.
-Brian's suggestion BPR6ES This was a very responsive plug with snappy engine, worked near perfect except for knock on large hills under load.
-Miles' favourite GR41X This was a very responsive plug with snappy engine and never knocked with many attempts..
My thought on this. I wonder if the incoming charge is able to cool the small iridium tip down to prevent predetonation on the next engine compression cycle.
Re: Odd spark plug behavour
havent looked at all disclaimer... do they make a GR6IX?
for big power on things like honda k series they run a BR8EIX or something like that. I figure on a medium boost TM, 6 heat range will be fine and wont be sluggish like the BPR8ES snowmobile plug.....
Brian
Re: Odd spark plug behavour
did some digging. looks like they make a BPR6EIX NGK 6637 that should work fine. 14mm thread, .75 reach.
for a less projected option, BKR6EIX NGK 3764 should work.
the B means 14mm thread, 13/16" hex and the BK means 14mm thread, 5/8" hex, 6 is the heat range, E means 19mm/.75" reach and IX is performance Iridium
the GR4IX.... G = projected, 13/16" hex, 19mm reach, 14mm thread
both B, BK plugs can be had in a 5 heat range as well.
Brian
Re: Odd spark plug behavour
Hi Brian,
I had a quick look but thank you for taking to time to figure this out. I was hoping to find the iridium in a 6 heat range, and you figured it out for me!
Re: Odd spark plug behavour
you're welcome. twas fun to poke around and decipher the plug numbers.
Brian
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Re: Odd spark plug behavour
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Here are those plugs.
the electrode and insulator sticks up the same height on the BPR6EIX and BKR6EIX but the BKR shrouds the insulator closer with the metal plug body.
I think ill try the BPR for now considering im already running BPR6ES
Brian
Re: Odd spark plug behavour
Darn you beat me to the punch!:clap:
Re: Odd spark plug behavour
Wow. You guys have got me itching to try out some new plugs. I have some br9es plugs in most of my cars with now if I'm not mistaken. It seems like that is way too cold for the daily drivers I have.