Found fix for #7 piston problem

[zeake]

Naw the 9th piston gets bolted on to the block. Its independent. He only uses it for going in reverse. That way he doesnt blow hot exhaust fumes out the intake manifold.
Looks like this

That was good.

[CHEVROLADE]

I think allen is just joking.

hes got to be,whos going to put one forged piston

[Sleaper]

I think allen is just joking.

I know he's joking but I do believe that there are people not aware that this is a common issue. That was the reason for the explaination. I guess I forgot to put the REAL reason that #7 fails.......IT's THE TUNE!!

[pl4yboy]

I heard Allen's tunes break trannys. No one buy from him!




jk.

[Chevy-Art]

This has happened in many different applications, FI, N20 & N/A, with different intakes, stock, LS6, Vic's... and fuel systems, return or returnless. The arguments are as follows:

1) #7 is the farthest back and due to block design doesn't have adequate coolant circulation since there are block offs unlike earlier years that had cross overs.
2) Returnless fuel systems can have trash build up in the fuel rails/injectors since there is not an inline filter and no way to return the trash to the tank.
3) The stock intake design doesn't allow for even air distribution, especially in heavily modified applications, which cause #7 to run lean and not show on a wideband.


These are the main arguments or theories. The problem is failure has occured when some of these are not present. For example, someone is running an aftermarket intake or upgraded fuel system and they still lose #7.
Nothing has been absolutely, 100% proven to be the causing factor that I have read. IMO, I think that it's probably a combination of some of the above issues and not just one in particular. In addition, the factory clearances are set up tighter than what you would normally run in a highly modified set up which just adds another possibilty of reason for failure.

If you have never heard of this being an issue, now you have!

I heard of it just never knew what it was.

[Sleaper]

I heard of it just never knew what it was.

I know!! That's the million dollar question!!!! The real reason for typing up that long post was for some of he newer people on the site who may not know the common problems and weak points when you start modifying. I wasn't directing it towards any one person.

[Chevy-Art]

I didn't take it that way. I am glad to finally know what it is. Thanks Art...

[gmctruckmotorsports]

I didn't know about the #7 piston failure til it happened to me but I do know my 02 sensors were bad, one side was dead and the other was really weak.

[CHEVROLADE]

so in other words the design of the ls blocks are crap,cause 7 piston will always fail?well that sux if it cant be fixed

[ff_jeff]

so in other words the design of the ls blocks are crap,cause 7 piston will always fail?well that sux if it cant be fixed

wrx's have a similar problem with the #3 piston. These problems may not be completely cured, Having forged internals will eliminate most of the problem.
I know the thought behind the Subaru piston failure was linked to the heat from the turbo. Maybe there is a similar situation with the LS motors. I know that the belief is less air flow. But maybe its extra heat, or a weakness to.