Some clarification: In my post earlier, the quotes indicate the actual words of the article, as best I can see them anyway.
A possible correction here: in paraphrasing it, I assumed the Editors' use of the term "oil squirters" referred to the injectors (after all, these are oil burners) because of the following statement in the article: "Since oil squirters cool the piston, no oil spray from the squirters meant that the top of the piston overheated." This led me to think the Editor is referring to the injectors.
I did not even consider the possibility the Editor was referring to piston underspray.
But that still doesn't make sense. Any oil used as underspray would be supplied via the crankshaft and need to get past tiny bearing clearances and all - correct? Or are there separate squirters that use a different oil supply that could be blocked? Something still doesn't make sense to me, so I am open to explanations.
So, I apologize if I caused any confusion - but I still think there is more going on that the writer allowed for.

Marc - It may very well be G&J is the correct name. My enhancement software is great, but is only as good as my eyes.

(Mimochodem, piotrsko, mluvim cesky. Cerna y bila vlajka je mi rad, ackolif Ceska vlajka je mi rad lip.)

 

Ooops, not sure how the double post happened!

 

What does the caption say under the piston?


Bad injector causes a cold cylinder, and like said above you can run like that for a long time... i put on 2,000 miles!




I welded up my oil squirters the other day, i also see it very hard for them to get clogged, but i don't see a reason for the guy to lie.

My guess is after time and so much heat expansion and contraction in these motors (especially performance orientated) the pistons just crack. As always high EGT's are the enemy and I'm sure play a huge roll in how long your motor goes before cracks appear. Most of my pistons have small cracks... I know the guy who owned it before me liked to get on it.

 

Picture caption:
Here's an example of a piston(?) that has been burned and melted(?), which probably means a bad injector or _____-______ EGT(?) readings(?). If the piston is just ______ without the star-shaped burn(?) pattern, then it's probably a cylinder _____ or oiling(?) issue.

I think this is correct, anyway! I am taking a stab at some of the words here.

 

The "burnt piston" was piston #5 which is on the passenger-side bank that's not monitored by a standard-installation EGT gauge ...but even if the burnt piston had been on the driver-side bank ...an over-fueling injector can elevate the CGT in a single cylinder to over 1,350*F ...and since the EGT probe averages over 4 cylinders ...the EGT gauge will still indicate an apparent "safe" reading.

A clogged "piston squirter" is also a distinct possibility ...I read about a 5.9L Cummins tear down due to a burnt piston ...and a small speck of foil like is used to seal some brands of oil jugs ...was found to have clogged the piston squirter ...and shortly thereafter I noticed the 1 gallon jugs of Rotella that I use stopped using foil seals ...but in any case filling the center of an oil filter is a risk which is easily avoided by using a small funnel to fill the filter from its outer holes!

I'm guessing that the reference to "cheap oil filters" clogging the piston squirters meant the oil filters degraded to the point of shedding debris into the oil supply?

Towing heavy with a chip is always dangerous ...but if plain old "over fueling" from a chip was the cause I'd expect to see piston #8 as the one most likely burnt ...followed in likelihood by pistons # 7, #2, and #1 ...and here's a quote from an old thread about a burnt #8 piston...

..."Here's a "triple whammy effect" theory as to why piston #8 is the one most vulnerable to burnout.

1) Cylinder #'s 1, 2, 7, & 8 receive less airflow during their intake strokes than do cylinder #'s 3, 4, 5, & 6 due to the taper in the intake plenums. I've drawn this conclusion from my engine model, and from several reports on "dusted engines" which clearly showed that most of the dusting damage occurred in the center 4 cylinders. BTW your #2 piston which also shows some damage is one of the outer 4 pistons which receive less airflow!

2) Cylinder #'s 8 & 6 are in the process of filling at the same time, i.e., during the same 1/2 crankshaft revolution, and they both fill from the same intake plenum, and that means #8 gets even less airflow than do the other outside cylinders.

3) Cylinder #8 has the injector with the fuel cackle issue, and it seems to me this "water hammer" effect that causes the knocking noise from the #8 injector might mean the ICP and therefore the fuel rate is a little higher for #8?

Regarding whammy 2), cylinder #'s 7 & 3 are also in the process of filling at the same time, i.e., during the same 1/2 crankshaft revolution, from the same plenum, BUT, they fill from OPPOSITE ends of the same intake plenum (passenger side), whereas cylinder #'s 8 & 6 fill at the same time from the SAME end of the intake plenum (drivers side), and that means #8 gets less airflow than do any of the other 8 cylinders!

Combining the least amount of airflow with perhaps the most fuel would certainly make #8 the most problem prone! I'd sure like someone to start a pole (which I don't know how to do) and see if #8 has caused significantly more issues than a random sampling of 1/8 would suggest if all cylinders failed equally.

"It is also compounded by the fact that the rear most cylinder manifold tubes are the hottest. So the #8 starts out as a potential problem, and only gets worse with the firing order and what Gene spoke of with how the intake plenum lends itself to poor air flow to the outer cylinders. The front cylinders are only saved by the fact the exhaust goes back on the manifolds and carries that heat there." Tenn"...

Here's what you're up against when you tow with a chip ...your EGT is given by this equation...

EGT = [(1.2)(MAT)] + [{(FWHP)(MAT+460)(329)}/{(RPM)(AAP+BP)(TERF)(VE)}] + [(100)] *F

...where MAT=Manifold Air Temperature *F, FWHP=Flywheel Horsepower hp, RPM=Crankshaft revs/min, AAP=Atmospheric Air Pressure psia, BP=Boost Pressure psig, TERF=Thermodynamic Efficiency Reduction Factor, VE=Volumetric Efficiency ...and if anyone's interested in doing some calculations ...for RPM=2,600 and BP=17 psig use TERF=0.95 and VE=0.822 ...and for RPM=2,800 and BP=21 psig use TERF=0.92 and VE=0.80.

This equation says that to minimize your EGT when towing grades use the lowest possible FWHP setting on your chip ...and use a lower gear to increase the RPM ...and remember that even though increasing the BP increases the airflow which reduces the EGT ...increasing the BP also increases the turbo outlet temperature which increases the MAT which increases the EGT.

And I'll end with another quote from post #30 on this thread... https://www.ford-trucks.com/forums/9...rcooler-2.html ..."So by just removing the "rubber baffle" at the top ...the OP saw a 50*F decrease in EGT when running empty on the highway and not even stressing the engine like he would when towing ...where I saw larger decreases in EGT using the total "Genedad2" mod!"...

 

I just got my copy.

Jason Sands did an excellent job answering the guys question.


Diane

 

kinda contradictive....

 

I agree.
Also recently confirmed (by accident of course).
I replaced my injectors this past weekend and the engine ran great....for a while. Apparently I must have dislodged the retainer clip on the #7 solenoid when I was re-installing the valve cover. After about 40 miles the plug came loose and I drove around on 7 cylinders for about a day. Plugged it back in and everything was fine.

 

I thought so too, good info.

 

We have told people for years when they call and ask why are my egt's so high(even stock). To help decrease EGT's while towing bump up the RMP's while towing. For example, when you downshift before a grade this puts the truck in a lower gear, increases the RPM's and immediately your EGT's will become more managable.

Jody's tow tunes have this already built in.



Diane

 

has anybody heard of breaking the top edge off a piston on startup? my 2000 7.3 with 219,000 miles did that when i went out to start it one morning.