[s-cars] //S4cylinder, almost again!

[audijim at comcast.net]

I agree, a lean condition could kill a plug...among other things! I seem to kill engines! Thanks a lot bro! :) I only killed one, and I'm not taking credit for it either! LOL! I try to communicate my problems to the list, so anyone else who has a similar problem will either remember that this happened before or know what it is when its happening to them. You don't hear much about Haps project anymore , do you?! I'll chalk it up to your second theory of "other people don't report their problems" I do not have any data logging, for the most part, I felt it wasn't needed since Bob has been running this set-up for ever. Maybe I have an Audi-god generated black cloud with this S4? I have a tubular header I'm getting ready to build (on the back burner....way back) to incorporate slip joints and individual sensors on each runner. I like over kill and redundancy :)
 -------------- Original message ----------------------
From: "Taka Mizutani" <t44tqtro at gmail.com>
> Sounds like you really, really built your engine right this time around.....
> lean condition could kill your plugs as would a loose plug.
> 
> My mechanic told me about how a loose plug could pretty easily lose it's
> electrode, I'm not a mechanic so I can't explain exactly
> what happens, but from your work experience, I would imagine you know what
> you're talking about.
> 
> I don't know, the reason why I asked is because you seem to kill engines and
> have problems a lot more than some other people.
> Either that, or the other people don't report their problems.
> 
> Do you have a wideband O2 and data logging? That would probably help with
> diagnosis if you could datalog your actual failure next
> time around.
> 
> If you really want to get exotic, wideband O2 in each manifold runner so you
> can monitor all 5 cylinders individually, but that's pretty
> overkill.
> 
> I can't explain how the electrode went from cylinder to cylinder in my old
> A4- it happened, there were bits of electrode in two different
> cylinders, there was scoring in 3 cylinders on the tops of the pistons as
> well as all over the head. This happened because a plug
> got loose (f'ing Don Rosen techs suck) with the plugs not being torqued down
> properly and the temp climbed, blew the plug to pieces.
> Maybe this is the same thermal shock which you mention, this is very similar
> to what my mechanic described from his Bosch school.
> 
> BTW, how much boost are you running and what is your compression ratio? Just
> curious. Obviously, high boost will stress the plugs a
> lot more.
> 
> Taka
> 
> 
> On 11/19/06, audijim at comcast.net <audijim at comcast.net> wrote:
> >
> > Taka, yes I have. What are you trying to say? The original Lehmann engine
> > that this car came with was a problem from the time I drove it home. It was
> > F'd up and I knew it. I bought it cheap and it had everything I wanted it to
> > have. My rebuild engine spun a #5 rod bearing. I'm still scratching my head
> > on that one. I can only try to say that I had a bad bearing to start with. I
> > used BG assembly lube and triple checked everything from the crank bearing
> > on up. My newest AAN is still going strong, less the bullet I recently
> > dodged. My current set-up is KS main bearings with the Lehmann crank, ARP
> > main studs, Pauter machine rods with Clevit 77 bearings, ARP rod bolts, ARP
> > head studs on ported head, RS2 EM/Turbo/Ex Cam/MAF/Injectors/Cam gear/Water
> > pump/T-belt and Uncle Bob's current software w/ V-map. As Tim eluded to my
> > driving technique of running my foot to the floor while under 2000 rpm and
> > "teaching" a customer of his how to drive his S-car, I think he is way off
> > in my situation.
> >
> > I talked to Uncle Bob over the weekend and he stated that this has happend
> > to him a few times. He also said that he sent the plug back to Bosch for an
> > explanation. They told him is was do to thermal shock. Should I read that as
> > detonation? Why would that happen at easy throttle highway speeds (65 mph)
> > and then slowing for a toll and downshifting?
> >
> > What if this plug was dropped prior to me recieving it and installing it?
> > In aviation, if I dropped a reciprocating aircraft engine spark plug, it is
> > considerd "junk" at that point and should never be installed onto an engine.
> > The same applies to turbine engine ignitor plugs, I was at a Champoin
> > Aviation seminar years ago and they showed us examples of what happends when
> > you drop a spark plug. The "shock" of being dropped caused fine cracking of
> > the ceramic material around the electrode. The electrode started to arc to
> > the body of the plug before it reached the tip. This caused excessive heat
> > and blew the plug apart and the aircarft lost a cylinder in flight. Could
> > this be what happend to my #1 cylinder on Friday?
> >
> > How does an electrode get from one cylinder to another on your A4?
> >
> >