Why #7?
There isn't a ton of info on the board about this.....almost like a secret society of those who had to figure out how to fix the issues with "unlucky" #7.
It amazes me that this issue is such a problem that guys with forged internals are having the same problems. I would be so pissed if I put the money into a forged bottom end and then ran into these problems.
I'm not exactly handy or creative with figuring out how to fix this myself, so I went with the "I'm willing to spend $200 for the kit if it will fix the problem" method.
Ya melting 2 forged motors sucks *****. I now run a very cold plug, vent tubes, have the highest flowing injector on cyl 7, got a way more experienced tuner (Jim at speed inc) and im done with pump gas at the track. Vp 109 for me on high boost. If I blow up with all this I was just not meant to go fast.
On The Tree
Joined: Apr 2010
Posts: 152
Likes: 17
From: Saskatchewan, Canada
I had a coolant crossover on the rear of my LS1 block....and i can tell you from my experience (and i had an AFR gauge connected)...that the #7 pistons takes an asslicking of airflow, and will run hotter than the other cylinders with an LS1/LS6 style intake manifold. Edelbrock has some manifold options, although i havent tested as i've been down for almost 3 years with different setups.
Best of luck with your setup...the stock style intake manifolds are garbage for forced induction as the airflow from our boosted systems will find the farthest cylinder in which to increase flow to and cause havoc on that cylinder...it's the nature of a front mounted throttle body and intake. A top and center mounted intake manifold would do away with some of our problems....
I had a coolant crossover on the rear of my LS1 block....and i can tell you from my experience (and i had an AFR gauge connected)...that the #7 pistons takes an asslicking of airflow, and will run hotter than the other cylinders with an LS1/LS6 style intake manifold. Edelbrock has some manifold options, although i havent tested as i've been down for almost 3 years with different setups.
Best of luck with your setup...the stock style intake manifolds are garbage for forced induction as the airflow from our boosted systems will find the farthest cylinder in which to increase flow to and cause havoc on that cylinder...it's the nature of a front mounted throttle body and intake. A top and center mounted intake manifold would do away with some of our problems....
It was mentioned to me that part of the issue could be the fact that a lot of the aftermarket heads block off the coolant flow to the bottom of the #7 combustion chamber. I'm planning on addressing that issue before the motor goes back together.
9 Second Club
iTrader: (10)
Joined: Apr 2009
Posts: 1,230
Likes: 3
From: Joliet,IL and Las Vegas 50/50
fstr N U, are you saying that even with the rear ports vented that you still had the issue with #7?
At what point are you guys having this issue with the #7 cylinder? I'm getting my car tuned on e85 and hoping that going that route will help prolong the life of the motor given it's cooler properties and knock resistance. I also plan on venting the rears.
At what point are you guys having this issue with the #7 cylinder? I'm getting my car tuned on e85 and hoping that going that route will help prolong the life of the motor given it's cooler properties and knock resistance. I also plan on venting the rears.
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SO....general thought is that the rear ports need to be vented, and that the style of intake is forcing air to that cylinder. Why does it seem like everyone uses the ls1 "style" like the edelbrock pro flow and the holley then? Wouldn't the vic jr with an elbow or 4150 style tb be better for air distribution?
The people that believe the theory of the air flow and how the air is forced into the back and it slams into #7 and thats it have no idea on how airflow really works. Its not like a brick flying into the intake. Its like a liquid. As previously mentioned, the dyno tests had the intake manifold turned around. Using the previous theory, that would mean that cyl 2 would be running the leanest, but the test showed that STILL cyls 7 and 8 had the problem. So that theory isnt as conclusive as the coolant flow theory is.
Everyone has told me this, but its a crock, if that was the case, then none of our heaters would work because the heater core is usually the highest spot
On The Tree
Joined: Sep 2008
Posts: 126
Likes: 0
From: Alaska