Well i'm about to join the forced induction side and don't want to be on the bench with other broken pistons guys.

Where is this theory formed? Is there a shorter or longer runner that makes a difference here? If there is, why do you guys think it matters, not looking for a guess, I want facts. I'm coming from a world where this manifold makes a lot of power, no leaning out of any sort. It's a box with runners, no problems.




Also, anyone think this could be a stock fuel rail problem when using large injectors and a possible low pressure area feeding that injector? Any one pop a piston with a custom rail setup, like this one for example.

Also, this guy lost number 7 and is NA..... another reason I think this could be a fuel issue (https://www.performancetrucks.net/fo...d.php?t=455347)

 

w2w did some testing , where they flipped a manifold 180 and still ran into the same issue . theories include that more air goes straight to the back of the manifold and stright into #7 and #8 but that was disproved with the flipped manifold.

other ideas are water cooling not up to par in that area of the head. and small air pockets created in the head causing hotter parts in those cylinders. with the newer ls motors having block off plates on the rear of the heads some including myself went to the older style crossover tube to try and prevent this . other ideas is to add a bit more fuel in those cylinders to help cool them a bit more.

imo it would be nice to see some more testing done in this area with a wideband on each cylinder and some hard evidence found.

 

Ive seen one piston fail with the cross over.

 

Was it #7?

 

yep. .

 

Was it forged?

 

stock on 10lbs

 

And with the Vic Jr. and naturally aspirated?

 

You beat me to the post. Was there audible knock?

 

Thunder550 had a forged piston that appeared to have tried to seize (scored really bad and started knocking) in #7. And that was running the Vic Jr. intake and aftermarket fuel rails. No good explanation of why it did it...