DragStuff

Posted: **Wed Mar 14, 2007 4:06 pm**

Hey there John, I have finally managed to get some decent plug pics and would like your comments on them?
Can I mail these to you? or is there an easier way?
Cheerz

Posted: **Wed Mar 14, 2007 5:24 pm**

You can email them to me Tom - admin@dragstuff.com

Posted: **Tue Mar 20, 2007 11:34 pm**

I am having trouble spotting the "timing line" on my spark plugs. The side of the ground strap is too clean/grey to see anything real discernible, so I am turning to you guys.

These plugs are from a inline 6 bmw motor (24v) with a Holset truck turbo running 11 psi of boost. Because of the 10.0:1 compression and 4v/cyl I am running ~8 degrees advance at 10.5 psi of boost.

These are NGK BKR7E plugs (1 step colder):

I know the first image shows rich idle - I had issues with cold start/idle but I have resolved it. But in the second picture you can see how I cannot see the timing line on the ground strap, unless I am looking wrong.

Jon

Posted: **Wed Mar 21, 2007 7:44 am**

It's not super clear but looks like it's about here where I put the red line at

Posted: **Wed Mar 21, 2007 8:52 am**

So the timing is acceptable?

Posted: **Wed Mar 21, 2007 9:00 am**

Urinemachine wrote:So the timing is acceptable?

I've always heard that you want the line that John drew right in the middle of the bend on the ground strap, so I would say that looks pretty close.

Posted: **Wed Mar 21, 2007 9:30 am**

Urinemachine wrote:So the timing is acceptable?

It's not excessive I don't believe. Probably wouldn't want to put much more in it than you already have. At this point you might want to check all of them and see if they're about the same before you add even a degree.

Posted: **Wed Mar 21, 2007 9:49 am**

Beyond wrote:
Urinemachine wrote:So the timing is acceptable?
It's not excessive I don't believe. Probably wouldn't want to put much more in it than you already have. At this point you might want to check all of them and see if they're about the same before you add even a degree.

8 degrees sounds quite reasonable for a 10:1 motor I think. They are all the same really. Does the ground strap look normal? All of the images I see on the net (which look like they're mostly from pushrod motors) are a brown color or something while mine is like a grey color. It looks like plugs pulled from my other stock BMW, but I don't know if it should look different.

Posted: **Fri Jun 15, 2007 1:39 pm**

Hi guys...so glad to find a forum that discusses nitroused plugs.

Already spoke to John a bit about this so I'll just quote the emails so far...

Nitrous_1.3 wrote:I realize that you guys are all running high power engines that are well beyond the scope of my little 1.3 liter but I was wondering if you may have some insight into my plug. The car is a Suzuki Swith with a 1.3L engine. Nitrous is a wet system 55 shot (n2o jet 0.032 and fuel 0.017) activated at 3500RPM through to 7200RPM. I do have an aftermarket ignition (Mallory Hyfire). Mods are filter/headder/exhaust. Timing is set at stock...I didn't back it off for the 55 shot but once I get into the larger ones (plan is to end up spraying 125) it will definetly happen. There are no funky cam gears to change timing there either. Fuel is Sunocco 94 with no octane boosters. AF gauge (one wire...no $$ for wideband just yet) is showing rich through the entire run. I see what may be some peppering on the insulator and I believe the ground strap colour is from the Cadmium burning off. Plug is an NGK BP7ES (one range cooler than stock). The picutre is a 3-4 pull. Unfortunately I wasn't able to pull the plugs out right away because the car needed to be driven home. If its absolutely necessary I do have another new set I could do it with. Any insight you may have would be greatly appreciated.

Here's the pic...

And here's John's response...

John wrote:From what I can see on your plug, it appears you might be able to add
another degree, maybe two of timing. The timing mark can move further out
towards the bend. I don't see any signs of detonation on the porcelain at
this point, but it might need some better fuel with the extra timing. Might
want to only go 1 degree at a time extra. Now on the fuel we need to look
down in side the plug, I can't see that from your pic. I would say it's
burning fine at idle and part throttle and that your using a plenty hot
enough plug as there are no fuel deposits on the top half. The color of
the plug base doesn't show much fuel either, so my guess is you're either a
bit lean or pretty darn close on the fuel mixture.. Disregard your A/F
meter, if it's not a wideband it can't measure what we're looking for
anyway. That plug is not showing that it's fat at all, but if we could see
down inside that would tell more. At this point I'd say put a little more
fuel in it if and when you advance the timing any.

Here's a closeup of the same plug showing what I had though was some peppering....

And my latest questions...

I put a close up of the plug in there with arrows pointing to what I thought was marks from detonation. You don't think thats a problem? It was the first thing that made me think there was something wrong

. I don't have a pic of down inside the plug...but I can tell you it was as white as the rest of the insulator. There was no ring to speak of. Thanks again.

Posted: **Fri Jun 15, 2007 2:41 pm**

Looks more like some oil specs that are in the process of getting burnt off. Just to be on the safe side you might want to burn some better fuel in it. If you can't see any color down inside at the bottom of the porcelain it needs more fuel.

Posted: **Sat Jun 16, 2007 2:11 am**

I'll have to see about the better fuel. Best we have here is Sunoco94. Maybe some sort of octane booster will help. I do plan on upping the fuel pressure a touch to help though. Plans call for a Mastermind and 100-125hp shot so I want it to be perfect. I mean hey...its a Swift...nobody will see it coming

.

Posted: **Mon Jun 18, 2007 5:07 pm**

Went out again today. Everything is the same as last time but I ran the nitrous a few more times than last. Pulled the plugs and the next pics are of the #4 (farthest from the TB) plug. This one is the worst as far as the black on the insulator. I cut the threads off for you guys to get a better look at the fuel line. Its readily apparent now....

So are the specs caused by the new plug burning in? I'm hearing no knocking whatsoever and timing is retarded 1 degree for the 55 shot. Car pulls smoothly when its on and there is no surging or anything that would let me think there is something off. Engine temperature goes up on the bottle, as expected, but doesn't reach any alarming level. I checked the fuel pressure the other day and everything is in good order. What do you guys think? I really appreciate the answers on here guys...other forums have been telling me that plug reading is hogwash on new cars running unleaded fuel....

Posted: **Mon Jun 18, 2007 8:45 pm**

Ouch, that doesn't look good. Those specs appear to be aluminum which is probably due to severe detonation. Yes, the cadmium on the ground strap is burning off, but I don't think that's what's on the porcelain. If you can look at them in the sunlight that will help tell what the specs are, but from what I see it doesn't look good.

The fuel ring at the base shows it's got lots of fuel in it, but it's burning off so much towards the electrode those must be pretty hot plugs. What heat range are they? If they are as hot as I think they are, that might be causing the detonation. Did you put more timing in it or change the fuel?

Did you change the tuneup from those last pictures? I wouldn't run it like that again without pulling some timing and getting some higher octane fuel. Very likely need to put some colder plugs in it also.

Posted: **Mon Jun 18, 2007 9:10 pm**

Tune hasn't changed from the last pictures. I'll pull a bit more timing from it and see what happens. I'm running 94 octane fuel...is there an additive worth buying? Its the highest octane fuel I can get here. Plugs are one heat range colder...I have to special order anything colder than these (NGKBPR7ES) ones. Other cars like mine have run 75HP shots with this heat range with no issues. I'm starting to think there is some underlying problem that I haven't found yet. Might be time to put the car on the dyno wideband and see what's happening inside. Thanks for the input.

Posted: **Mon Jun 18, 2007 9:33 pm**

I think you ought to use a colder plug at least one heat range cooler and take a couple degrees out of it before your next test. Maybe you can find some BPR8ES, but ideally something without the extended tip that BPR7ES has. An extended tip plug isn't good in a nitrous motor.

I don't think most additives raise octane levels much, but haven't really spent any time researching that.

DragStuff

PLUG READING FOR A NITROUS MOTOR

How to upload plug pics??