The Alchemist

iTrader: (19)

I think it's important even at stock NA levels. Live and learn I say. Horsepower is directly related to cylinder pressure. The more cylinder pressure results in more heat. More heat isn't good, especially if it's localized to one area.

We all watch our coolant temp, but it's at the front of the driver's side head, but what if we were able to see what the back of the head was reading and it was 30, 40 even 50 degrees hotter?

You read about lots of NA guys losing #7 ringland, it tells you something.

willizm

iTrader: (10)

Very well put. I'm always concerned about my temps and they read pretty decent now, but that temp is probably not the same in the rear. I'll be looking to vent the rears before spring now.

5w20

iTrader: (21)

put a sensor with a sending unit on the other head. they are cast exactly the same, theres just a plug on the passenger rear.

wouldn't that give you the reading that you are after?

JRENIGAR

iTrader: (37)

How hard would it be to rig up a temp sender and guage on a car that has the ls6 rear tubes, then run it on the dyno or a good WOT run and compare the two temps???

willizm

iTrader: (10)

It shouldn't be hard at all since the provisions are on the back of the head. Might have to make an extension for the wiring harness.

Fbodyjunkie06

iTrader: (10)

First off glad to hear that it was what you thought to begin with and what I had figured happened too. Got too hot back there from being a little rich and too much boost, (steam vents probably played their part too) and lifted the ring land and what you found in your intake was that ring land material.

Like you said secondly, steam vents should be there all the time. Especially boosted. I really like that KUP set-up it just looks bad *** like everything KUP does.

In general if you were going to rig up something to measure the heat of the rear cylinders and go through the time and trouble why not just rig up steam vents themselves and be done with it? Or use the stock ones? **** I'm wondering if my car even has them now.

lsxmalibu

iTrader: (50)

rear temp on my motor is only about 10-15 degress hotter than the front. the drivers side head i use the stock sensor, the pass side i use an autometer temp gauge. on my 1/4 mile runs, ive never seen the temp on the rear port go over 180-190.

White.Lightning

iTrader: (53)

Another thought is to put a temp sender in the rear part of the head. Then log it with the front of the head temps using HPTuners. You can then graph the changes over time, under boost, etc and see what is really happening.

357i

iTrader: (4)

How much boost were you running when this happened?

The Alchemist

iTrader: (19)

Too much...

I do beleive that I have some logs showing 200kpa at 6800rpm .

I know, I know.... way too much on a stock shortblock... but hey, what fun is it being conservative.

357i

iTrader: (4)

and I am worried about 9.8psi haha
AFR at WOT?

TWS

iTrader: (63)

On every pre '01 car that I have upgraded to an LS6 intake manifold, I always retain those original crossover pipes. Just dremel the ridges smooth on the bottom of the LS6 intake to allow clearance. I see people taking those off when they upgrade from an LS1 manifold and I just facepalm. They are spending extra money buying extra parts (the later model crossover) in order to down grade the coolant distribution.

The Alchemist

iTrader: (19)

It was waaay rich, 10.2-10.6:1, and timing was only 13 degrees of timing.

Some people have said that too rich can be just as bad as too lean, why I'm not really sure. When I started tuning, I added a lot of extra fuel to make sure I didn't go lean, and I then started slowly pulling fuel out. When I first started running, it was bottoming out the wideband at less than 10.0:1 and I actually fouled a sensor.

357i

iTrader: (4)

I'm doing the same thing, my AFR's are around 9.7 with timing at 14. Well, good luck, hope the cyl is able to be bored!

koolrayz

iTrader: (26)

It looks to me like the rich condition is what blew that piston. The raw fuel gets in between the rings and ignites breaking the piston. Post those pictures on the bullet and you will hear the same thing.

The Alchemist

iTrader: (19)

I'm not doubting you at all. I just didn't know the answer. I think part of my tuning issue was the initial throttle tip-in into boost / PE it would go way rich, sub 10.0:1 and come back up to 10.4 on it's way to 10.6-10.7:1 through the rpm band. Not sure if that's typical or not, but I'm confident that when the motor goes back together I'll be on my way to a happy / healthy running motor.

dschmittie1

iTrader: (64)

On my car my autometer gauge in the back of the passanger head reads a good 10 degrees hotter than the factory gauge does

Fbodyjunkie06

iTrader: (10)

Ray hit it on the head. Too much fuel will weaken the rings and then when it does what ray described above it lifts and breaks off.

When I had my car on safe mode my AFR would be 11.1-11.2. Normal mode was 11.4-11.6. Kill mode was 11.9-12.2. 15psi 50/50 93&110 14-16* timing.

RooRnZ28

iTrader: (14)

Do the rear steam ports come blocked on factory LS6 intake cars? (01/02's?)

dschmittie1

iTrader: (64)

^^yes^^