Post a pic of the spark plug electrodes. Any have broken porcelein? Is the porcelein tan (it should be) or white (bad sign). Are the electrodes burned down?

I posted some comments here:


Cracked Piston & Head

Finally some good news! Took the head & a picture of the piston into Merv Gray today (guys who built my engine) and they said that a forgein object is the result of this, and sure enough we filed a bit off the no. 4 head swirl & put it under the microscope. Does turn out it was the slag from my sh*tty arc welding!
Must have had such a suck & poor penetration from the job that it sucked a bit off and into the chamber.
There is no damage to the head apart from the chunk, no valve/seat damage or notching in the ports thank god!

Its a relief that it is the weld and not so much detonation, & also i can get just 1 piston & the head is salvageable. They are going to run a weld in the notch and grind it down. Im going to pull the engine tommrow arvo & if im lucky mite even get it going by thursday/friday...

This time i am going to live by the rule 'do it right, do it once'

Dave

Why did the manifold need welding repairs in the first place?

The one that i was sent by Greg (vixen) was an A15 polution manifold and had those two ports in the back of the manifold for some vaccuum crap im guessing. As i did not have the 'bit' that went on there, what better way than to cover it up...

Dave

Oh one question, is TIG welding that hard as it looks? It uses tungston yeah? Why is this better on alloy than MIG etc..?

Dave,Dave,Dave,Dave,Dave
If i read your last thread right you used an arc welder to weld up an aluminium manifold?????
Arc is for steel only thats why a piece came adrift and entered your engine.
At least its not to bad and i hope you get it going without to much expence.GREG