mgrotel

iTrader: (3)

^i agree completely, meth allows you to tune with more timing, so if you add meth and leave the tune, it should be safer.

this one is a mystery to me

BakaN20

iTrader: (26)

Exactly, then you start adding different nozzles and the amount of meth going in, then it becomes a whole different beast in itself, lol.



Op, what kind of spark plugs is your friend running?

Here is a read, granted, it wasn't what they thought it was, but it might help you think of other possibilities to what it could be.

https://my350z.com/forum/nitrous-oxi...u-plan-on.html


As for the melted spark plug, its not happening to the other spark plugs, only the one cylinder?

Maybe he has a bad coil and its putting too much voltage through it. Anyone else, can that actually happen and cause a spark plug to melt?

streetzlegend

iTrader: (2)

Correct, also the added cooling of water ontop of the nitrous and meth, overall its a great mix. Anyway its getting a lil off topic, the OP should go with 2step colder plugs and see if its still knocking.

How are the other plugs looking? if its just a single plug on the same cylinder thats getting damaged, id say there might be a fuel issue such as a clogged or bad injector.

tollboothwilley

iTrader: (8)

friend ran a couple different types of plugs...

started out with the NGK copper V-power plugs, then tried NGK Iridium IX plugs. Same issue with both.

I wish there was a way to detect what is going on with each individual cylinder to test.

The rest of the plugs look pretty good otherwise.

mgrotel

iTrader: (3)

cylinder #1 melted for him at one point as well, a/f ratios are good

its not the plugs, some people run stock heat range plugs on a 75 shot, he is getting knock with 1-step colder on a 65 shot

streetzlegend

iTrader: (2)

Tell him to change injectors, get the one from where the cylinder is having issue, and put it in another location, see which plug shows evidence of overheating. If i was in the situation, I would test the injectors.

binder

iTrader: (8)

dude, sounds like detonation killed that plug.....i'm not reading through every last comment but that's what stood out at me instantly.

I don't think it "melted"....I think the cylinder detonated and destroyed the plug.

mgrotel

iTrader: (3)

it melted, and if it was the injector, they why in more than one cylinder?

tollboothwilley

iTrader: (8)

Ya, it happened multiple times on Cylinder #4, but it happened once or twice on Cyl #1 as well.

3* & meth injection seems like adequate timing and safety for a 100 shot.

How many guys running Nitrous are 5AT?

binder

iTrader: (8)

get some pics of this. i'd like to see what a "melted" plug looks like over one that was destroyed by detonation.

I'll bet it looks just like all the plugs i've seen destroyed from detonation.

absurdparadox

iTrader: (1)

Which plug does it look like, in this? :P

HotRodG35

iTrader: (7)

I have a 2004 G35 Coupe 5 AT and was running a vortech supercharger with 2.87 pulley (10 PSI), methanol injection and NX Express 75 HP WetShot on stock internals. I cracked piston rings with no damage to the NGK double iridium 1 step colder plugs. I have since gone to a full built long block.

As for meth injection it will not give any power increase unless the timing is advanced. I use it for a safety margin.

tollboothwilley

iTrader: (8)

The melted plugs didnt look much like any of those in the pics. That is what is weird.

It isn't the electrode that is cracking/breaking/melting. Its the arm - that the spark jumps to. In fact, the insulator looks pretty normal. Thats whats odd. I'll see if I can get a picture of it.

mgrotel

iTrader: (3)

basically the side electrode gets deformed and melts back into itself, if that makes sense
idk what the hell is going on in there

streetzlegend

iTrader: (2)

Thats the ground strap, when melted is a sign of detonation, prob caused from too much timing or not enough octane. Maybe that piston has carbon build up and is causing the knocking?

binder

iTrader: (8)

exactly!!!!


Look at the detonation picture of the spark plug. The ground strap is rounded on the end which i guess "could" look like it melted. Obviously the more detonation the further back it would be missing and rounded therefore looking like it melted.

Also, you could think about that further: what melts metal: heat. what creates heat: detonation

The detonation could be caused from a timing issue or a lean condition. If it's only on individiual cylinders i would bet it's a lean issue caused by a problem with the injector. I would definitely pull the injectors and send them to RC or DW and have them tested. That would quickly rule that out.

one thing i wouldn't do is drive that car anymore until it's figured out. It's not cheap or easy to pull these engines apart.

mgrotel

iTrader: (3)

i think you are getting detonation and preignition mixed up, they are similiar but not the same, look at that picture again, there is a difference. anyway, ill try and track down a picture of a melted one. i still find it difficult to believe its the injectors of timing, simply because its happened in more than one cylinder (injector) and there is a couple degrees of timing pulled with meth injection on a 65 shot.

is there anything else it could be???

binder

iTrader: (8)

no, i'm pretty sure i know what detonation is on plugs. I built motorcycle race engines. We diagnose engine problems with plugs since we do'nt have knock sensors and all that fun stuff on board.

Look at the ground strap on the detonation picture. See how round it is? now do that extensively with a sparkplug and it will eat that ground strap back further and further until it looks like a little melted nub of metal.

and yes, you can have more than 1 injector fail at a time. Plus, by it being an injector it doesn't really have to be the physical injector that is damaged, it means that hte injector isn't working by either mechanical or electrical. Could be something that came loose in the wiring harness or maybe the ecu has some damage causing it not to open those specific injectors which would cause it to run lean.

Going to the basics of your problem are these facts:

"melted" plug which means excessive heat
happened multiple times in different cylinders
happens when he's using nitrous (accelerant)

So you need to find out what's causing that heat.
-detonation
-fuel problem

then detonation could be:
too much timing
insufficient octane
caused by fuel prolem above


IIRC you said the car is actually knocking which would be your answer. If you didn't say that then i misread something somewhere.

you keep saying th a/f is perfect, but do you have widebands on every cylinder? even dual widebands aren't enough to show a lean condition for just1 cylinder. You said it happened on cylinder 1 and cylinder 4. Even if you have dual widebands you would only be lean on 1 cylinder per wideband which would affect it, but might not enough to show it's super lean in 1 area.

mgrotel

iTrader: (3)

look, dont get all defensive here, i was just saying you that you were referring to the preignition pic but describing it as detonation. the outside electrode on the detonation picture isnt damaged at all.

another twist to the mix. before he was just damaging plugs and there was no knocking. so because of that he got a plen spacer, meth injection, and pulled timing with a utec. then all of a sudden, it started knocking really bad. he hasnt melted a plug yet because the knocking is so bad he cant stay in the gas more than a second

streetzlegend

iTrader: (2)

Detonation, pre-ignition, dosnt matter which is happening, both can hurt the plugs. Stop ruling out the injectors and just get them checked, Dont know how long you have been messing with cars but its a given, when ever you make a modification it be spacer, meth, just anything, there is ALWAYS something random unrelated that screws up and drives you crazy since it has nothing to do with what you just installed, it dosnt fail.

So check your injectors, check your wiring, check compression n see if that cylinder or the cyls that have melted plugs reads higher (due to build up of carbon), etc...
It can even be your cooling system, inefficient cooling or mixture, causing heat bubbles on the block, etc..