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Discussion Starter #1
i tend to drag on when i tell stories so bare with me....thanks..632 14* BIG CHIEF, CFE INTAKE, 2 EDELBROCK FOGGERS, 13.5 : 1, 3 STAGE DRY SUMP. alright well i havent had the car to the track in 2 yrs.. finally got cert updated to 7.50 and got the motor all nestled in the car... go out for the first weekend and did 1 motor hit and then 3 1/8 squirts on 1 gun.. then 1 1/8 on 2 guns...then 2 hits out the back door on 2 guns.the two out the back door were 8.06 and 7.99--8.06 pass was 1.284 60'...5.19 @ 139.1...6.69 1000'...8.064 @ 167.29 ..7.99 pass was 1.280 60'....5.15 @ 140 660'...6.62 1000'...7.99 @ 168.04. ok with that being said after the last pass i never started it again... loaded it up in the trailer in the morning and went home... later that week i fired it up at home and noticed the vacuum pump canister is producing smoke right on the start up..not bad but enough to notice ( usually it never hased smoke till it warmed up) so i decided to do a leak down and all cylinders were 12-16% leak down... #8 was 60% (oops) whats weird is it only shows that % 10* before and after TDC... everywhere else throughout the stroke it shows 20%...i have yet to tear into it yet.. tracks are closed around here anyways so im in no hurry to tear the car apart but would like to get a idea what it is before i get into it... we think it might be a slightly pinched ring... ( it does not smoke out the exhaust at all just canister ) i read through that lengthy "what causes lifted ring lands" thread and maybe thought that could be it... im not sure... tune up according to plugs is on the right direction on all cylinders except 6 and 8... those to plugs looked pig fat... it had nice blue flames all the way down though 2 ft out the fenders...1st gun 28n 24f..2nd gun 32n 28f..30 base timing..10* out first gun..8* more when 2nd gun comes on 1.3 out.... 8* launch retard for 1.1 to get off the line...5 3/4 # fuel pressure ...29.5 10.w 2950# going down track... 1.69 1st gear ...4.10 out back.. im off one gear cause im on the limiter for 1 second before the traps... anyways sorry , just looking for some input what could be wrong with slug #8 thanks guys
 

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Did you ever pedal the car?? I've hurt #8 on my combo after 3 passes several times from getting back on the throttle after smokin the tires
 

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Those tunes sound rich also. I know when I went to a 32 jet I had a 6 jet spread at 5lbs of fuel
 

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First round fodder...
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rich and possibly riding the timing window as well.........if its down for the winter i'd drop #8 and check the ringlands (you got time). depending on the chamber work on the 14* heads they are on the edge at 12* on 2. add the fuel issue and your gonna get friendly with your piston manf.......in my opinion.......
 

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Discussion Starter #6
nope never pedaled.... i went from under the car headers 355 sbc that screamed... to a 632 fender exit exhaust with mufflers ... not quite used to the sound of the new engine since its quiet inside now... but i was on the rev limiter for 1 second according to the racepak...i never even thought to glance at the end of the run in the data....... and yes i know its rich... but from what ive read ... to rich can lift ring lands.... with that being said.. would a lifted ring land cause the 60% leak down and then tighten back up 10* after tdc to 20%??
 

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Discussion Starter #7
chambers arent softened yet... that was this on the to do for this winter list
 

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Sounds rich to me and to much timing.My 14* headed 615" at 13:1 with softened chambers run 21* with a 30n/20f at 5 pds.tune up.NO2 fuel. I think you need to find some patience and get the first kit right before hitting the secound kit.Smaller steps are way less costly.Good luck.
 

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Being on the rev limitor can/will cause hurt ring lands VERY fast!!!!
 

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RED ROCKET
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would a lifted ring land cause the 60% leak down and then tighten back up 10* after tdc to 20%??
lifted lands can pinch rings...6 spreads is what i run to keep it happy...and i would knock a few degrees out with your heads for sure.
 

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First round fodder...
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the rev limiter deal is just part of the problem. 20% leak is not bad but you don't know what you have at this point. your pulling the heads to get work done, pull the piston and verify what you have before making decisions on tune-up. you have all winter to contemplate and research what you have and what you can do. relax....
 

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Sounds like your on the right track.. Based on the averages, the tune could use a little work. You have to correct the issue causing it to hit the rev limit. That is hard on the engine. Also as stated I would look at getting the chambers softened as well.

The head gasket thickness, plug type, fuel, cam, rear gear, and so on can all play a part in your results.. A little fine tuning and you'll be in great shape.. Thanks, SJ
 
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