Head work, anybody heard of this????

[nipper]

Yeah But...

The groove apears to be just part of the equation. You have to increase the CR and retard the timing to take advantage of the supposed improvement. That's what I gathered from my brief reading of the stuff.

Right? It's not just the groove it is what modifications you can do along with it?

Sounds too good to be true, maybe, but I'll reserve judgment. I am dubious. Nipper cracked me up! I really appreciate his posts on this I'm sayin Yeah what he said.

 

You see then that makes the entire test moot. To be valid you change only one thing. On an I head anything helps it is so ineffecient.

 

Also (yes im a stickler) you needed several runs of the unmodified engines, at least three, then three of the modified engine (though i think five is the standard i dont remember) to certify the improvements as valid.

 

nipper

[SuperSubaru]

You see then that makes the entire test moot. To be valid you change only one thing. On an I head anything helps it is so ineffecient.

 

Also (yes im a stickler) you needed several runs of the unmodified engines, at least three, then three of the modified engine (though i think five is the standard i dont remember) to certify the improvements as valid.

 

nipper

 

If I did one run or thirty runs, I saw a slight difference in HC and NOx, but when added together - they cancelled each other out. And the slight difference was within experimental error anyway. Had I seen something more significant, I would have ran with it and investigated further. I already know if I adjust the timing, things will change, I could have done that without cutting the head.

 

I took one engine one head, ran it. Removed the head (takes a little bit of time) ground a groove, and reinstalled it, and ran again. It's not worth my time to continue.

 

One side note - Oxygen numbers dropped measurably, so something was happening inside that was different, but at the end, it didn't matter.

 

I was cautiously optimistic, but now I have proof. Subaru 2.5L need head gaskets replaced often - if some of you wish to try it for yourselves, stop by your mechanic with a dremel during the operation and try for yourself.