View Poll Results: Have you ever lost #7???
Yes
81
29.45%
No
194
70.55%
Voters: 275. You may not vote on this poll
How many of you guys have lost number 7....
02-20-2006, 10:30 PM
#24
Keep the tune rich, especially on a forced induction motor. #7 is the last injector to recieve fuel. I tune all forced iduction cars to 11.0:1 on the street. All n/a cars to 12.5. The difference in a/f has very little effect on HP. When I was making 500 rwhp the change for 10.6 (dynojets load, was 11.0 on the street) leaning it out to 11.2 on the dyno netted me a whopping 11 rwhp.
02-21-2006, 05:53 AM
#26
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I don't think its a rail issue, I think its an intake issue. #7 is the last cylinder on the plenum. I think something along the lines of the air rushing into the plenum and hitting the back wall creates a slightly higher air pressure zone which gives #7 a touch more air than the other cylinders.
02-21-2006, 06:26 AM
#27
This makes me wonder about my motor. #7 has this weird ticking sound that isn't valvetrain related as I've pulled the valve cover, pulled the pushrods ect and even switched things around to see if it moves. I still have the factory 26lb injectors and I'm wondering if it's time to swap out to some 30lb injectors as I know I'm pushing them pretty hard.
02-21-2006, 08:15 AM
#28
The #7 problem is the only thing that's holding me back from putting spray on my car. Although I have no issues, so many people have, that it worries me, esp. with anything other then a direct port setup... if that cyl is getting more air, then it's getting more nitrous then the rest too if that's the case.
There's a reason why alot of the race car guys are swapping over to the edlebrock/single plane intakes, I think even distribution is probably one of them.
There's a reason why alot of the race car guys are swapping over to the edlebrock/single plane intakes, I think even distribution is probably one of them.
02-21-2006, 03:42 PM
#29
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My stock bottom end cam only + 100 shot car lost #7 on a first gear punch NA. I'm pretty sure the ringland was busted and didn't realize it. Sunavabitch came apart that day though! 
02-22-2006, 12:53 AM
#31
95% of it is in the tune and not having fuel distribution right. It can be made to live though, after hit ATVracers car with the shot all year, on a basic rebuild shortblock with shelf pistons, motor came out looking BRAND NEW, not a spec of carbon on the pistons, no marring nada
Phil, what exactly caused all the detonation in your last motor? Ive never seen it that pronounced and heavy on all 8 on a LS1 before, mainly #7
The #7 thing, is a intake design issue
Phil, what exactly caused all the detonation in your last motor? Ive never seen it that pronounced and heavy on all 8 on a LS1 before, mainly #7
The #7 thing, is a intake design issue
03-12-2006, 09:35 AM
#32
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The intake issue is why the sucessful stock eliminator racers run an aftermarket ecu.
They map the motor on the dyno with a egt in each cylinder and adjust accordingly.
There are definate differences in cylinder to cylinder distribution.
They map the motor on the dyno with a egt in each cylinder and adjust accordingly.
There are definate differences in cylinder to cylinder distribution.
04-18-2006, 10:02 PM
#34
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#7 I just lost #7 Saturday on my 4th run at Gainesville. Ran good and pulled all the way threw. Looked up behind me and alot of white smoke. Pulled around to get my slip. It was missing. No noise, good oil pressure, temp normal. Even drove it home. Took it apart yesterday. #7 piston edge burnt off and exposing the ring. Motor all bolt on. See sig. WTF
04-18-2006, 10:48 PM
#35
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I thought I blew #7. While pulling the heads I found suspicious scratches in the #7 cylinder. I pulled the motor expecting to find cracked ring lands, but I found carbon buildup scratching the cylinder instead. A hone and re ring got me going.
04-19-2006, 02:26 PM
#37
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Sorry guys, im wondering what a #7 ringland is? 
, I dont know all the engine technical english yet. Just finished my LS1 install inn my Camaro 67 and fired it up now, now i was just curious to find out what the weaknesses of this engine is.
, I dont know all the engine technical english yet. Just finished my LS1 install inn my Camaro 67 and fired it up now, now i was just curious to find out what the weaknesses of this engine is.
04-19-2006, 03:10 PM
#38
On the piston sides you have the slots for the rings. The ringland is that lil section of the top of the piston that hangs over the top ring. What happens is that lil overhanging part of piston over the top ring can break off or melt off or something to that effect.
04-19-2006, 04:06 PM
#39
Got a stock number 7 a few years ago, patriot heads, 224 112 XER cam, LTs, LS6 intake and a 150 shot (NX MAF kit). Car ran great, even the last pass of the night (10.40 @ 130), started it up the next morning and it started knocking pulling it off the trailer. Broke part of the top ring land off, then the piece came off and got in between the piston and head, bent the rod and cracked the sleeve/block also 
04-19-2006, 04:58 PM
#40
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Originally Posted by Fireball
I don't think its a rail issue, I think its an intake issue. #7 is the last cylinder on the plenum. I think something along the lines of the air rushing into the plenum and hitting the back wall creates a slightly higher air pressure zone which gives #7 a touch more air than the other cylinders.
is this the official answer?? does this happen to other engines also.??