Marc3.4V6

iTrader: (1)

Mods in sig. Had engine rebuilt about 30+ k ago and the issues still never cease. I had a headgasket failure about 20k miles ago when i decided to change the plugs from autolite 106's (builder's choice) to ngk tr-55 v-power with copper core and nickle tips. I finally decided to pull a few plugs and they had a fair amount of black carbon buildup and smelled of fuel. I figured I was running rich, so I bought an aldl cable and datalogged and nothing seems obvious. I did clear a few codes and readjusted the tps and decided to just change the plugs because maybe they just fouled. I decided to try autolites, but was unsure of which. Due to the extreme difficulty of changing them with shorty headers (these are worse than manifolds I think), I''m considering a platinum or double platinum because I don't want to change these again for a very long time. I read a lot of you guys like the 104 but that's a colder heat range and I think with my mild engine I should stick with the stock heat range, what do you think?

I have JBA shorties, the only way I was even able to change them is because I was doing headgaskets and everything was off, had to drop the headers down to do it....is this even possible with them on? My Y-pipe is welded on, dropping the headers is more complicated that usual on my car. I never bought a shorty spark plug socket, does it help?

Rob94hawk

iTrader: (1)

NGK TR55-IX Iridium is what I have.

quik95lt1

iTrader: (7)

dont waste your money on iridium plugs they are a gimmick...........long as your compression ratio is under 11.3 or so run the stock heat range 106 or TR5.........a NGK V Power Plug or Autolite Plug will work just fine...........i run 4$ autolite racing copper plugs in my LT1 and a 3$ NGK V Power Plug in my daily LS2 GTO and they run perfect for many miles...........ive experemented with iridium, four tip, e3, platnium, kryptonite blah blah...........they are all jokes...........only time ive ever ran an iridium was on a high boost application LS motor because it was blowing the spark out.......

Gojira94

iTrader: (4)

Riddle me this... my long-held understanding on heat range and gaps is that the bump between HR 5 & 6 on aluminum headed SBC is right at 11.0:1. And the gap is closed .004 for every 50 crank HP above stock. So, as an example, 443CHP @11.2:1 would be a HR6 plug at .037"

Experience is more valuable than theory, IMHO so I'd like to hear what your experimentation would say to the above setup.

Marc3.4V6

iTrader: (1)

So you guys recommend no platinum at all, just copper core and copper tip?

jlpz

iTrader: (8)

Just get yourself a set of AC delcos..

quik95lt1

iTrader: (7)

basically you want to run the most gap you can without blowing out the spark and causing a misfire......this depends on many things from Static Compression ratio to intake charge velocities and how they enter the chamber to ignition strength and fuel characteristics........the bigger the gap the more flame front but the more chance you have of blowing it out..........i run mine at .037 and i make well north of 443fwhp yet if i open them up to .040 or so the car will start to misfire under heavy load.....

as for heat range you can go by compression to get you in the ball park but the best way is to run it and read the plug...........if im ever tossed up i go a heat range colder and run it.......if the plug reads cold i step up to the warmner range..........cold plugs will foul.......warm plugs will detonate and case issues.......

draggin97s10

iTrader: (2)

I would also like to know!

Rob94hawk

iTrader: (1)

And did it work?

Marc3.4V6

iTrader: (1)

My datalog shows possible low fuel delivery (just checked and pump pressure is under spec pressure), and I am getting a **** ton of knock, anytime I touch the gas, could that be causing plugs to foul?

That's an idea, still not sure about platinum tips or not, though it sounds like just plain copper is the way to go, but how long does that type of plug last before needing changed?

jlpz

iTrader: (8)

I've had great performance with my delcos my is 100% stock for now and those plugs last to a few thousand miles, In racing environment people change the Plugs more often than street drivers. TR55 copper core. That's all you need for high performance..IMHO

robsquikz28

iTrader: (246)

I used 104s for awhile in on spray. But ngks I found to be best

Marc3.4V6

iTrader: (1)

I decided in the NGK G-Power platinum tip for longevity. I just hope that they don't foul again.

quik95lt1

iTrader: (7)

yea thats why i ran them lol


if you are fouling plugs the tune is wrong.........fix the tune dont band aid it with a high dollar plug that will foul anyway

Rob94hawk

iTrader: (1)

So you pretty much concluded that not only do they work, but they work well in a high horsepower situation. Doesn't sound like a gimmick to me.

I bought my NGK irridiums a long time ago because I still had the stock cast iron manifolds which as you know are a PITA to change plugs and wanted a plug that will have decent longevity. Now that I have headers it's much easier but I will keep them cause my compression is almost 11.5.

quik95lt1

iTrader: (7)

no ive concluded that they are useless unless needed due to extremely high cylinder pressures with fuel that is extremely difficult to light off ........the application they were used in was seeing 24lbs+ boost from a set of twin turbos running a 120+ octane fuel......for a stock car or even as i have PROVED in my naturally aspirated motor I have come to the conclusion that they are useless and a waste of money........unless of course you have a very poor tune in your car and it is running rich.......they are a bit more resistant to fouling however if that is the case fix the tune instead of band aid'ing the problem......

let me give you another example.......im running 14.2:1 CR with a very efficent top end and im lighting off 114 octane fuel..........with the msd 7 ign im running a copper plug works just fine and gives me a great amount of flame front........an iridium plug did ABSOLUTLY ZERO for me by way of power or long gevity because the tune is correct....

if you want to run them go right ahead and do so......its your $90 for spark plugs not mine lol

Marc3.4V6

iTrader: (1)

That's what I'm afraid of. The plug is only $3 though. I'm having other problems with a lot of (possible false) knock and some bad oil consumption. Will something like a dyno tune clear stuff up? Heres a datamaster file of my pos running (I only just recently cleared a TPS and A/C code, but tps is still off a little):

http://hotfile.com/dl/131916283/a66019e/run3.uni.html

http://hotfile.com/dl/131916342/b9ec...drive.uni.html

Rob94hawk

iTrader: (1)

Like I said before, didn't buy them thinking it was going to gain me anything. I was just looking for a plug that would last and I wouldn't have to go through the stress of changing the plugs on a stock engine and have to constantly lay accross the engine trying to get to plug #8 with cast iron manifolds.

I definetly see where you are coming from and you have more experience with this situation than I do. But, I bought them along time ago, never used them so I'll stick with them. If they give me problems with my new engine setup then I'll change them. Thanx for the heads up.

quik95lt1

iTrader: (7)

bad oil consumption probably isn't atune issue unless you have alot of ring flutter from detonation........but even then i dont know if id classify the oil burning as "bad".............if you have an oil consumption issue id start looking at mechanical parts.........possibly valve seals..........do a test blow air into the cylinders with a compressor get a SMALL AMOUNT lol of bubble blowing soap and put it near the tip of the valve seal and see if you can see some bubbles..............if not it could possibly be a ring issue if the car was excessivly rich from day one you could've washed down the walls and the rings never sat............you NEED to get a wideband O2 on the motor the narrow bands will not tell you jack.....

Marc3.4V6

iTrader: (1)

When talking about clearing things up on the dyno I was referring to the knock.

As far as oil consumption, on 5w30 synthetic (it was on sale) I was topping it off once a week, it seemed to burn more or less a quart on 35 miles a day. I had previously been running 10w40 with results not being much better.

I've been looking around and apparently I missed the boat on the OBD-1 dyno tuning for the LT1, if shops/tuners in my area ever did them, they don't anymore, and apparently they take longer to tune correctly so it costs a bit more.