460 engine failure 800 miles street use

I'm in agreement is that the blown hose was a result of the head gasket letting go not causing it. The temp gauge on the head (stick on) shows the head never got hotter than 210 degrees. I shut down the motor when the hose blew and had it towed home.So, with the 30 lb injectors causing 1-5 cylinders to foul (too much fuel for SD)(you can see this on the picture then what caused cyliners 6-8 to run lean (head misaligned initially?) proof in the dowels stuck in the head...I don't know as I've seen dowels stuck in many heads I've pulled apart on perfectly good motors (jusrt freshing up)!

02 wires crossed.   Left bank was right bank..  so the one reading lean was at full duty cycle and the one reading rich was at min duty cycle.   That or the injector harness swapped sides.  Same result. If referencing the soot no head gasket seal, low compression, slow fuel burn. Lots of soot.

kim wrote:02 wires crossed.   Left bank was right bank..  so the one reading lean was at full duty cycle and the one reading rich was at min duty cycle.   That or the injector harness swapped sides.  Same result.  If referencing the soot no head gasket seal, low compression, slow fuel burn.  Lots of soot.

That sounds like someone changed the firing order wires of the injectors. If the injector firing order and the ignition firing order don't match ... SO WHAT ... don't change them to match. That screws-up to O2 readings and control within the ECM from side to side.

Thats how it can happen. Truck isnt SEFI any how... its batch fire left or right...

Speed density is batch fire correct and it only has one o2 sensor in 1989. As far as the harness goes, there is only one way it can go together...one is loing and one is short.

I was just offering a hypothetical way it might happen to rich/lean the banks. I think the soot is merely the result of the blown head gasket and the resulting low compression.

kim wrote:Thats how it can happen.   Truck isnt SEFI any how... its batch fire left or right...

I see that a lot when using a mass air small block injection system on a big block.

800 miles fine and then blown head gasket that bad?  Original picture of head gasket is of a gasket put on backwards. The coolant passage on the side has to be at the back and one at front blocked. If reversed coolant comes out of block into front of head and right out to the intake without circulating across head. Certainly would not show as overheated at front of head in that case, but coolant in head would be a lot hotter.

So looks like we are into the internet guess game. Simple question was the passage on the side of gasket installed to the front or rear? Original picture is to the front and wrong.

My guess is gasket installed backwards and got away with it running 30 lb injectors in a stock setup calling for 24lb meaning you where running rich. Either 7 and 8 wires started cross firing or you got some bad gas and was enough to push it over the edge.  

If shop put on gasket backwards you have a point, otherwise would be whatever the warranty is. I will tell you most shops will not warranty an engine if you take it apart as you have. When it fails should have towed it to the shop if under warranty. Good luck.

The gasket pictures show the bottom view and the top view both left side facing front...If it was installed backwards, the shop will definately be responsiible...I am heading there this morning for the showdown and will keep everyone advised. Thank you again for all your help.

mgawat wrote:The gasket pictures show the bottom view and the top view both left side facing front...If it was installed backwards, the shop will definately be responsiible...I am heading there this morning for the showdown and will keep everyone advised. Thank you again for all your help.

Realize that they are not required to fix or be responsible for anything, (no matter what the warranty), after you disassembled it.
Try and reason with them; don't go there with a hard case attitude. This is not a time for that.

We disassembled it per the machine shop instructions so they were involved every step of the way. The head gasket was NOT installed backwards because we matched up a new one to the old one and everything is exactly as it should be (blocked in the front and open in the back). The theory the machine shop had it that there may possibly be something off with the time advance curve in the SD computer itself or a problem in the new distributor causing the same problem. They thought predetonation was the culprit. I'm confused at to why only 3 cylinders were affected in the whole motor (all the rest were carboned up due to too much fuel and no enough air).This motor takes the place of exactly the same build 7 years ago. The old motor broke the camshaft teeth and the distributor teeth beyond repair. The SD computer is the same exact one. The only other difference between the old motor build and the new one were the installation of 30lb injectors to try to get more pick up out of the new motor.

Like Randy said, you took it apart. Good luck. Even though they are at fault. It will be a BIG headache getting anything out of them. Probably cheeaper to chalk it up to lessons learned than take them to court......
For a civil case suit around here, the lawyer retainer fee is $5,000.

Just salvage the ole girl. Plenty of good help here as well as reasonable parts.

Best wishes.
Al

7 and 8 fire in sequence.  Cheap wires can induce a spark in 8 way before you want it.  If inductive induced detonation was the cause then once the gasket was blown between 7 and 8. The intake charge gets all messed up with cross feed pressures etc.  Can then sequence out other cylinders due to lean conditions.  Just the issue with being excessivly rich can cause the rings to wash out and let oil get into combustion chamber.  Oil contaminated fuel detonates at a very low pressure.

When using an OEM computer calibrated for THAT same vehicle, do not increase the injector size but, simply get an ADJUSTABLE fuel pressure regulator to increase pressure a bit and therefore a richer air/fuel ratio at Wide Open Throttle.

No need to even do that if everything else is as OEM delivered because it is about 4% to 7% rich from the factory ...  I suspect it is not as it was delivered new.

how does an adjustable fuel regulator get mounted to a triangle plate as comes with an oem fuel regulator?

Problem with these threads is all the important information needs to be pulled out of the poster. Wastes a lot of time and of course the OP gets annoyed.

Now that we established the head gasket was on right looking at the big burn out between 7 & 8 would say is safe that the spark plug wires were touching and was cross talk. Is easy enough to verify. Look at the wires for any burn marks. Failure started at 7 & 8 and was just progressing to 5 IMO.

They sell adjustable fuel pressure regulators that bolt to the stock fuel rail. Running a 30# injector on something calibrated for a 24# injector will not work. That is a 20% increase in fuel. Engine must have been pig rich.

mgawat wrote:how does an adjustable fuel regulator get mounted to a triangle plate as comes with an oem fuel regulator?

Three bolts

the aftermarket adjustable fuel regulators I've seen come with a nipple not a plate and I can't see where there is any nipple associated with the OEM ones. Also;.l 7 and 8 spark plug wires were completely seperated and have no burn marks on them.

I melted up a sbc head and burnt the gasket EXACTLY how you did years ago as a novice on an aggressive NOS tune. Car was pulling like f__k before it no pulled no more. lol. Lean and too much advance as was previously said. Good luck with the reassembly.

The other head was ready to let go also and rods showed predotanation signs on the bearings...Pretty much convinced faulty ECM did this

mgawat wrote:the aftermarket adjustable fuel regulators I've seen come with a nipple not a plate and I can't see where there is any nipple associated with the OEM ones. Also;.l 7 and 8 spark plug wires were completely seperated and have no burn marks on them.

Then you haven't seen enough of them. I know that BBK sells one and there are others.

One of these?

thank you...what is the manufacturer and number ?

Lastly, How does one install a fuel gauge into the stock fuel rail circa 1995 7.5?

Most simply use the shrader valve on the fuel rail. Otherwise you have to put a T in the delivery side before the fuel rail, wich involves cutting the stock braided steel Teflon lined fuel line. Using AN adapters and a T and then another AN adapter to factory rail.