PLstang

Okay took the car into the shop to have some work done on it. I had some autometer gauges installed, LCA's and panhard, and a set of Brisk plugs one degree colder (needed for the Nitrous). So I got it home and set up the new Autometer tach/shift light and decided to go out and test it a little. I had set the shift light to go off at 5800 since my reflexes arent what they used to be. So I take her out and run her up a couple times. Nothing to heavy (wasn't spraying or anything). I start to head home and I notice I'm getting a back fire. A popping in the exhaust from the sound of it. I wasn't sur what was going on.

It seems to be more prevalent at lower RPM's or when you let off the gas. However, it seems to happen at anytime. I thought it may be bad gas (I had gotten some after picking the car up). I filed the tank with gas I knew to be good drove some more with the same problem. I thought well maybe it's the tune since they had been working with electrical so I reinstalled the tune. Still no good. What can it be? Could they have gapped the plugs wrong? Why wouldn't it have started earlier when I was driving it home? Could my spirited driving fowled the plugs?

i did a search and it appears that back firing (if that is indeed what it is) is caused by a rich condition in most cases. Could it be the new plugs and the tune? I'm at a lose and the shop is closed already!

Left a message for them to call in the morning. However anybopdy got any ideas?

PLstang

Okay so the car went into the shop today and they pulled the plugs. Everything was fine until we got to one plug. The electrode (I hope I got that right) was completely missing. The porcelin was fine no vissible damage to the strap, the tip was just gone. We borescoped the cylinder and it appears to be okay, so we reinstalled the old plugs. Engine fired right up no problem. I had them dyno the car agian just to check things out and everything was fine.

We called Brisk and there response was that the tip had melted away and basicly evaproated. I think i'm gonna call BS on that one. I will get some picks this afternoon and post. I have ordered some HTO plugs to install as apposed to the brisk. Just thought you guys would want to know.

As a side note the Brisk dealer here in Texas offered to replace the plugs and wanted to come by and pick up the plug that failed. He explained that he needed to send it to Europe for the home office to check. I told him he couldn't have the plug until I was satisfied that no permanent damage was done and then only after I photographed it andhe signed for it. Pretty amazing he was sure it was a detonation and thats what caused the plug electrode to "melt and evaporate" but he was willing to drive over and pick up the plug.

I'm not sure if it was a plug failure or a detenation at the moment, I didn't hear anything. However, it's enough to make me wonder. All I have so far is a guess at what happened. However,I will be checking into it a little further.

hammeron

ok, i'm no expert so i'm really just speculating here!

my guess is that the electrode was broken off when someone
was checking the gap.....they are very small and delicate....

not pointing fingers, i think it was just an honest mistake that
anyone could make, when checking the plugs with a feeler guage....

PLstang

Thanks for the input. I may be using the wrong terminology the strap wasn't broken the elctrode was missing altogether. The porcelin around it undamaged.

I just got done meeting with the Brisk rep. I must say he was very interested in resolving the issue and was willing to refund the money for the plugs and was interested in getting the plug when I was done so they could study it. He was fairly certain it wasn't his product yet he was still willing to reimburse me.

We both agreed the plug saw heavy heat. The temp it would take to melt the tip would have been excessive (tip is silver and chromiomalloy), the engine wouldn't have survived.

The Dyno after the fact showed the engine a little lean (nothing outside of tolerances) and the car had run fine with stock plugs (even spraying a couple times when we set up the system at the shop). I really am unsure what the problem is. I was planning on gettng photos of the plug and maybe an x-ray to determine where the electrode erroded to. I am also interested in finding out what Brisk discovers.

I guess I should clarify that my earlier concerns of a mass Brisk cover up were unfounded. I really just think the rep was concerned about the possible damage and wanted to make sure I knew they would take care of it. I don't know if I'll go back with Brisk plugs but I can't fault their customer service for sure.