Whats the cure for lean #7
08-29-2009, 09:11 PM
#11
Couple of guys swapped the intake around and feed it from a charge pipe coming from inside the car from the a/w I/C and still had problems with #7. The water jacket problem is a combo of the water getting hot before it reaches #7 and 7 firing after 5. All other cylinder do not fire directly after each other like 5 and 7, so they have a little more time to dissipate heat.
08-29-2009, 09:20 PM
#12
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I always put the fattest injector in #7 and the next fattest in #5. I have been told that won't help but, I disagree. If you can richen and cool those 2 cylinders--why not do it.
Jeff
Jeff
08-30-2009, 11:16 AM
#13
My injectors i bought from FiveO.com all there injectors they say are flow matched, but im not sure which ones flows more...... I'm gona need bigger ones when I turn the boost up more with the forged internals guess i could always get a custom set of injectors with number 7 flowing a little more.... and have the tuner tune a bit fat also
Not sure about the crossover tube my heads are stock and have never been removed, but i don't remember seeing any back there when i did my trans swap
The pistons I'm getting are wiesco 5.3s there not the coated ones with the smaller ring..... They should be able to handle more heat right? Has anyone burned up a number 7 forged piston?
Not sure about the crossover tube my heads are stock and have never been removed, but i don't remember seeing any back there when i did my trans swap
The pistons I'm getting are wiesco 5.3s there not the coated ones with the smaller ring..... They should be able to handle more heat right? Has anyone burned up a number 7 forged piston?
08-30-2009, 12:01 PM
#14
Yeh, I have read on here that the intake causes more air to enter the #7 cylinder making it go lean. Others have said it is because the #7 runs hotter do to the fact that there is no crossover in the back for the coolant. Just to be safe you can get a flow matched set if injectors and put the one that flows the most in the #7 cylinder. ...
It is not the intake. Several on ls1tech have reversed the intake is race setups and still loose #7. The problem is the firing order and #7 not being cooled as efficiently as the other cylinders. A slightly better flowing injector in #7 helps. Others have changed the firing order and had good success.
08-30-2009, 02:28 PM
#17
If your issue is a lean problem, you can add a mechinal injection point for that one hole. You need a nozzle some very small jetting, fuel noid, some osrt of controller, simple hobbs switch or a wot switch. Then you can add all the extra fuel you need at wot with out effecting your driving tune.
08-31-2009, 04:41 PM
#19
So I take it nobody has burned up a number 7 forged?????? dont know if i makes a difference what coolant im running i use prestone 50/50 green... 160 tstat and my cooling fans are set at 188degrees
I just firgured its a lean prob from what ive been hearing
If your issue is a lean problem, you can add a mechinal injection point for that one hole. You need a nozzle some very small jetting, fuel noid, some osrt of controller, simple hobbs switch or a wot switch. Then you can add all the extra fuel you need at wot with out effecting your driving tune.
