HI!...Well this past FRIDAY I went out to a local racing spot to do some test runs. Well during the last pass in 3RD gear at about 4500RPM my truck started to miss badly, so I shut her down. After I got it home I ended up pulling all the plugs out and all were fine but #4 (rear p/s). It was all screwed up. The ground strap was totally melted down to almost nothing. The electrode is missing and the ceramic surrounding the electrode is de-formed. So I then did a compression check on all 8 cylinders. Average was about 180 until I got to #4 cylinder. I got "0" on it. Well I figured I burned a hole in the piston with the use of the nitrous. Almost 200,000kms and a NX 100H.P shot finished her off. Well JMC and I started to pull the engine at 2:45P.M and had it out and half torn apart on the engine stand by 7:45P.M. Not bad time wise. We pulled the P/S cylinder head and there was no hole in the #4 piston. I then looked at the head and found our problem. The exhaust valve had a huge chunk missing out of it. Not melted but a piece actually physically BROKE off. Then SUNDAY I tore down the rest of the short block. I guess this happened at the right time because this 5.4 was on it's way out. All the rod bearing are slightly scored. So were many of the crank bearings. #1 journal on the crank was severely worn with 1/16 chunks takin out of it. So yesturday my other 5.4 goes out to my engine builders to get ready for machining and assembly. The short block is being built to withstand 1000H.P (flywheel) and is being set-up for a larger (T-76) turbo. I'll be running N/A with some nitrous for the rest of THIS year though. I'm hoping to have the engine back and in the truck in about 3 weeks.

MELTED PLUG :



BROKEN EXHAUST VALVE :

 

Looks like she was running lean :

 

It's kinda good that it did blow. All the rod and main bearing were pretty worn. 200,000KMS in 6 years with "ME" driving does take it's toll lol!

 

MAIN BEARINGS :

 

This is the worst of the main bearings, #1 journal :

 

ROD bearings :

 

Excellent!

Canadians leading the charge yet again! Bravo!

Thanks for the story and the pics - very enjoyable.

Jeez - I get nervous just overclocking my pc's ;-))

Cheers!

 

This was the worst rod bearing, #3 journal :

 

The stock pistons were side loading a ton, even with the 180PSI compression.

Here is a new stock piston with the TEFLON coating on the skirts :



Here's the stock piston from my 200,000KMS 5.4 :

 

My "99" 5.4 also had a FORGED STEEL crank in it. :

 

Various engine tear down pics :

 

More :

 

Great thread, thanks for the pics!

 

Looks even better in person.

JMC

 

Considering the hard life and high miles, it does not look too bad. I agree, you are lucky the valve went first before something more expensive broke.

Just curious - how many bottles of nitrous did you put through that motor since it was new?