LS1 weak #7 cylinder
Thread Starter
Drifting
Joined: Aug 2007
Posts: 1,495
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From: Homer Glen IL
Thanks. I usually ask the wider audience in this forum. I fugure the tech guys cross over. The number 7 cylinder has a reputaton for ring/piston failure (according to what I have read). It appears to the be the first point of failure. I am just trying to understand why (if it is in fact true).
Team Owner
Joined: May 2006
Posts: 21,473
Likes: 356
From: Palmdale, Ca----- 2009 Cyber Gray 4LT A6 F55 452 RWHP 422 RWTQ- RIP 1998 C5 734 RWHP & 585 RWTQ-----
Thanks. I usually ask the wider audience in this forum. I fugure the tech guys cross over. The number 7 cylinder has a reputaton for ring/piston failure (according to what I have read). It appears to the be the first point of failure. I am just trying to understand why (if it is in fact true).
It is always best to tune a vehicle with a wideband O2 sensor closest to the #7 cylinder before the catalytic converter and right after the header collector. This gives you the best overall AFR readings and if it is good on the readings then the rest is going to be healthy too!
When you buy fuel injectors (flow matched inj's) it is always best to put the one with the slightly more flow in the #7 and #8 cylinders. When they go lean(more air than fuel), the cylinder detonates and can blow the ring or make it pin/Knock around in the bore.
This happened to mine under Boost, the cold winter morning offered more than the #7 could handle and I lost my ring - If you forge the motor parts - rings, rods, pistons etc - then tune accordingly you'll have a motor that last quite a long time
and ys you can do it with a stock motor too!Thanks,Matt
Team Owner
Joined: May 2006
Posts: 21,473
Likes: 356
From: Palmdale, Ca----- 2009 Cyber Gray 4LT A6 F55 452 RWHP 422 RWTQ- RIP 1998 C5 734 RWHP & 585 RWTQ-----
#7 is the furthest away from the air intake and can be starved for air, if not properly tuned it can lead to failure.
This pretty much goes for all motors with the cylinder furthest away - it's not like people are driving around and the #7 ring falls out
But when you mod, like H/C, LT's,Supercharger etc it is wise to make sure there is proper fueling etc.
Thanks,Matt
This pretty much goes for all motors with the cylinder furthest away - it's not like people are driving around and the #7 ring falls out
But when you mod, like H/C, LT's,Supercharger etc it is wise to make sure there is proper fueling etc.
Thanks,Matt
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