[BoulderBronco]

Just as I thought. A nice hole in the piston. Good news is it apears as though the cylinder wall is unscathed. I am going to pull it completly out tomorrow and take a closer look. I think I am just going to rebuild it myself. Save me some $$.
Hole in piston

Closer

And closer

Engine still in there

Wider view of my space

My workspace between my Dads Broncos

 

[The Yak]

That sucks. It looks like pre-ignition was the culprit.

Hopefully there isn't any serious damage elsewhere in the motor. Good luck on the remove, rebuild, and installation.

Later.....

 

[[email protected]]

Looks like my family isn't the only one that is Bronco crazy...

Good luck with the fix, man...I hope it works out!

Bill

 

[gearrat]

that bites good luck on the rebuild

 

[Chris85xlt]

let me guess... the number 8 cylinder (driver side, rear of motor)?

if it is, ur having some oil blow by. if u look at the PVC valve on the passenger side valve cover, follow the hose up and it plugs into the back of the upper intake manifold. what is happening is the oil blow by will travel up that hose to the manifold then it dumps oil right into the #8 cylinder port. this will cause pre-ignition and carbon build up. this is a common problem with earlier truck motors. i think in 95 they fixed it but not sure. to fix the problem re-locate the fitting to the side of the upper intake manifold where the blow by oil is spread more evenly.

edit- i just realized u have a 351 motor so it might be different. find out where the passenger side PVC valve hose goes to and see if it can dump oil into the cylinder u burned. if it does, it might be a good idea to re-locate it.

good luck

 

[SMOOTH]

This is what I found when I tore into my engine last year.

(Sorry to hyjack your thread)

 

[jerry 1 a b]

I can't tell very well, but is that a crack in the crank shaft?

 

[SMOOTH]

yup