I sold a truck i loved cause one of the cylinders was burning oil bad. In fact the head was pulled and it was encrusted with dried up cakey oil residue, with a freshw et coat of oil on top of that. I was literally scrapping a layer of encrusted oil out of the chamber and off the piston. Didnt feel like paying for it to be fixed so it was sold. It had a very pronounced audible rattle/ping on acceleration that even 93/100 octane did not cure before the head was pulled. The combustion chamber was decreased a significant amount over time. Timing was pulled higher octane used, ping ping ping! Everything you can imagine was tried before pulling the head. It also fouled the plug within a few hundred miles. Damn ford #6 cylinders!

 

This is very true and theoretically would eliminate any problem with premature detonation.
But while were here, you know how we all like those LT4 KM's since they allow a tad more timing advance, hence power,{to an extent}, but the LT4 KM is originally intended for the dual sensor arraingement on the LT4 and is not designed to be used with a single sensor set-up used on the LT1 F-body's. Then the price of gas gets in the way and we decide to use the 87 octane, since it's cheaper, but while pumping it we remind ourselves not to punch it or we may cause damage from un-sensed knock - therefore not sufficient timing retard. But then the bad-*** stang revs it up at the light and we forget all about that sensor / KM situation and bingo, we bang on those pistons and rings. The KM designed for the LT4, but used with the LT1 arrangement, will generally still retard the timing enough to keep from breaking a ring, or worse, but continued use of this part coupled with lower octane fuel will eventually cause damage whether it winds up blowing a piston or ring or not. So later down the road, when we have our wallet in good shape and are using 93 gas, we are running along at WOT and 'BAM'. Nothing in the data log shows a reason for the catastrophic {considering} failure of the bottom end. But, although not excessive, that minor premature detonation over time eventually took it's toll.
I agree with your post and am really just replying with this information to remind everyone who uses an LT4 KM in an LT1 F-body that it is a shortcut to timing advance that can yeild a small amount of added power, but if used with low octane fuel, can be a costly situation.
Sorry, I guess this should have gone in a thread concerning LT4 KM's instead of 'octane rating of oil' and stuff, but maybe it will help someone. I removed my LT4 module in favor of using LT1_Edit to control the PCM reaction to the knock sensor signal. Anyone want an LT4 KM? {use with caution}

 

I am fairly certain when I say that I do not believe oil in the combustion chamber will cause early detonation, based solely on the fact that oil is there. If there is carbon buildup over time, or hot spots are created, then these are a plausible/hypothetical reason that you could get some pre-ignition. As it has been said, a fouled plug and other related problems will likely develop and be noticed prior to the motor starting to ping.

However, an excessive amount of oil in the cylinder WILL cause other immediate, noticeable problems. Stumbling, missing, etc.

In essence, it is the difference between a ping and your car running like crap. This is all IMO, but it makes perfect sense to me.

PS - To the above poster - Mike 96 ws6 - Hell yea I want an LT4 KM!! I always run premium anyhow

 

I partly dissagree with the "immediate, noticeable problems. Stumbling, missing, etc" part since carbon deposits resulting from burned motor oil will start to accumulate instantly, and will increasingly become massive enough to produce enough of a residual ignition source to possibly created a premature ignition situation, and while this is taking place, the spark plug can keep funtioning, although not at full potential, for a very long time without completely failing. The O2 sensors on our cars will likely fail to preform correctly because of the harmful content of the burned-oil exhaust gases before a complete failure of ignition occurs due to spark plug fouling. During the time it takes the cylinder/ piston ect. to cease to perform it's funtion, which is when the noticable problem begins, {miss}, there is a wide window of possibility for the hot carbon deposits to do their thing, and if the fouled plug is replaced with a fresh one, and no means of cleaning the carbon out of the chamber is preformed, that creates an even greater possibility for this motor damaging situation to occur.


And we have a winner. I sent you a PM. If you want the module then I'll need a reply to that PM with a shipping address. And seeing as how you always run premium fuel, you will likely gain a small amount of power with the module without harming anything.
Have fun!!!

 

Got this from an aviation piston manufacturer....




"The lubricating oil may be a source of octane reducing fuel contamination. Excessively worn piston rings may allow enough oil into the combustion chamber to dilute the fuel/air mixture. The dilution will reduce the octane rating of the fuel and can lead to detonation and engine damage. While this scenario is not entirely typical of the engine that uses large amounts of oil because of worn or broken piston rings, it is possible for this situation to occur"

 

Oil will help to promote detonation. Just go on mustang sites and ask people how they feel about the first self contained procharger units that were leaking oil through pin holes into the intake track

 

Now can we let this thread die a peacful death?

 

It's all good. Nobody got shot either.