Quote:

---

I would definetly have those two injectors look at, maybe have all eight flowed by the same company

---

Quote:

---

Quote:

---

I would definetly have those two injectors look at, maybe have all eight flowed by the same company

---

There is a history of this problem with this engine. Last year I had the same thing happen; burned number 8 piston. I was using Bosch 160 lb/hr injectors and I sent them out and had them tested... they tested good and flowed within 1% of each other. Even so, I replaced all eight injectors when I rebuilt the engine. I now have a brand new set of Injector Dynamics 225 lb/hr injectors and that's what I ran on the dyno. I could have them tested but I'll bet there's nothing wrong with them, just as there was nothing wrong with the Bosch 160's. Given that I have had the same thing happen twice with two entirely different set of injectors, I am inclined to look elsewhere.

---

This is proving to be a challenge, how about something in the heads, maybe a thin spot in the combustion chambers I've burnt up pistons on the dyno also, due to unequal fuel distribution on a tunnel ram My bad, I had a loose power valve plug Good LUCK some of these things(problems) can be very frustrating and maddening, but you can find it

Quote:

---

Quote:

---

Quote:

---

I would definetly have those two injectors look at, maybe have all eight flowed by the same company

---

There is a history of this problem with this engine. Last year I had the same thing happen; burned number 8 piston. I was using Bosch 160 lb/hr injectors and I sent them out and had them tested... they tested good and flowed within 1% of each other. Even so, I replaced all eight injectors when I rebuilt the engine. I now have a brand new set of Injector Dynamics 225 lb/hr injectors and that's what I ran on the dyno. I could have them tested but I'll bet there's nothing wrong with them, just as there was nothing wrong with the Bosch 160's. Given that I have had the same thing happen twice with two entirely different set of injectors, I am inclined to look elsewhere.

---

This is proving to be a challenge, how about something in the heads, maybe a thin spot in the combustion chambers I've burnt up pistons on the dyno also, due to unequal fuel distribution on a tunnel ram My bad, I had a loose power valve plug Good LUCK some of these things(problems) can be very frustrating and maddening, but you can find it

---

Thanks Cab. I appreciate all the feedback you guys are giving me. You guys are asking all the right questions. Unfortunately the answer to this one is elusive. I will keep plugging away and I know I will figure it out eventually. Maybe I should have a priest come over and sprinkle some holy water on it!

Quote:

---

Is this a siamese bore block? If so, was the deck/gasket/head drilled for steam bleed off?
Ringland issues can be caused by a few different things. Blown/ turbo motors with ringland issues are almost always to rich. Liquid fuel gets into the space (usually close to the intake valve) and burns or breaks the piston. Nitrous motors will do this to, but oil control is usually involved.
I would suggest making sure the deck area is drilled as I mentioned before, knock your A/F ratios back into the mid to high 12s and keep your timing in a realistic zone. To much breaks things, not enough melts things.
Another poster asked about sparkplugs. Use the coldest plug you can get away with. Trim back the electrode strap. The shorter the strap the cooler the strap will be. Keep your plug gaps tight(.020- .025). If you blow out the spark under boost, fuel will puddle in the lower portion of the piston and the ringlands will be damaged at the 6:00 position of the piston.

---

This is a Keith Black block and I believe it has the steam bleed off holes. Before I hurt the engine on the dyno I had the cylinder heads off and took a pic (passenger side), you can see the little steam holes between the cylinders. I have cometic head gaskets and they have slits where those holes are. A/f ratio on the last dyno pull when we hurt the pistons was 11.7 and ignition timing was 25 degrees on that pull with 7 lbs of boost. Spark plug I was running was NGK R5671-A9 which is a pretty cold plug.

Quote:

---

Prior to the damage, what have past plug readings had to say about the mixture? Do they look leaner than the others? Does the ECU you are using have individual cylinder fuel trims?

---

Quote:

---

How in the world does water get into the heads?.....

---

Quote:

---

Quote:

---

How in the world does water get into the heads?.....

---

There are two main water passages, one at each end of the block. The water enters the head from rear passage, flows through the head, then back into the block through the front passage. In the pic I posted you can tell the main water passages (see the holes that have traces of black sealer around them).

---

How do you figure the water enters the head at the
rear and goes back into the block at the front....
coolant enters the total block and goes up into the
heads then out the front of the heads to the thermostats
hose... it dont go back into the block

Quote:

---

Actually, thats not right. A big block has two waterpump holes at each side of the block(r&l). Water does flow into the block from the lower hole, around the cylinders,(and normally thru holes in the deck to the heads in small quantities) to the back of the block, where it enters the head and than flows back to the front water passage, into the front of the block. The front water passage in the block is separate/divided from the inlet waterflow. Remember, a big block has the t-stat housing on the pump, not the intake.
The picure shows the upper small holes in the deck, but on a siamese block, air gets trapped in the hourglass shape on the lower deck because the air cant escape between the cylinder bores. Your gaskets will have holes in them, and my guess would be that your heads have holes there also. It may be as simple as drilling a few 1/4"holes in the deck to get rid of this problem.
The timing you report seems awfully low. Do you have a real small cam?

---

Your correct on the 4 holes in the block...my error

Quote:

---

Actually, thats not right. A big block has two waterpump holes at each side of the block(r&l). Water does flow into the block from the lower hole, around the cylinders,(and normally thru holes in the deck to the heads in small quantities) to the back of the block, where it enters the head and than flows back to the front water passage, into the front of the block. The front water passage in the block is separate/divided from the inlet waterflow. Remember, a big block has the t-stat housing on the pump, not the intake.
The picure shows the upper small holes in the deck, but on a siamese block, air gets trapped in the hourglass shape on the lower deck because the air cant escape between the cylinder bores. Your gaskets will have holes in them, and my guess would be that your heads have holes there also. It may be as simple as drilling a few 1/4"holes in the deck to get rid of this problem.
The timing you report seems awfully low. Do you have a real small cam?

---

My heads are Indy 440-1's and yes they do have the lower holes (see pic, see the two lower holes shaped like arrows).

My cam is very small. Intake duration is 224 degrees at .050 and lift is .541 and Lobe Sep Angle is 116. The ignition timing is so low because this was the first time we put boost in the motor and we wanted to start very conservative on the timing and a/f and then creep up on the tune to make more power. On that pull we only put 7 lbs of boost in the engine and it only made 707 hp at the wheels. Figure it would have gotten closer to 800 whp on that boost if we could have run more timing and leaner a/f... but as I said we only got the one pull in on boost and burned those two pistons.