PSIG

BTW, for your buddy, I'd have to see the plugs to do a proper analysis, but it sounds like he's over-advanced. All power adders require ignition timing control for both best power and to prevent damage. If he's spraying heavy (and it sounds like it), he must have proper timing retard as part of the program.

The plugs should be 2 or 3 steps colder (start with the coldest plugs you can get that won't foul immediately), the porcelain should be light to medium gray/brown (gasoline fuel), and the timing heat mark should be at the bend in the ground electrode. All this can't be seen unless he does a clean shutoff from WOT in the traps. Get a tow back to the pits or pull the plugs in the return lane pullout without restarting the engine. Standard plug-reading stuff.

David

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-=≡ If it was easy everyone would do it ≡=-

cahorne

BINGO.. Car is back together and ready for the track. No burnt valves just a pinched ring on #5. New piston and ring set as well as a fresh set of rod bearings and good as new. I did go back with an 8 heat range even though the "so called E85 experts" claim the -7 is safe on a small nitrous shot. I think they are masking the hotter heat range with extra fuel. My plugs looked great with the same tune on the 1/8 mile passes but the 1/4 just allowed more heat. Should be fine now with the -8 and two steps smaller on the nitrous jet on the corners.

I also loosened the converter a bit and opened up the plenum quite a bit on the Vic Jr intake so I am anxious to see how it responds.

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6.19 @112 1/8 mile; 9.73@138 1/4 mile Texas Motorplex Fun Ford weekend 2012
NEW COMBO: 5 Speed is gone. 4R70W with BE controller.E85, solid roller 13:1 compression.

PSIG

Gotta open those cold ring gaps. If #5 butted, then the rest are touching or damn close to zero gap when hot. Don't forget, ring gapping isn't to make the smallest gap, it's to make enough when hot. Go big. If you position your ring gaps properly, your ring gap can be a bit too big and still not lose cylinder pressure. Don't fear the gap. Of course, you should be fine now with re-tuning, but there's no reason to risk butting with tight gaps.

David

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-=≡ If it was easy everyone would do it ≡=-

cahorne

This was not a ring gap problem. Pinching the land was a result of heat in the chamber, burned plug strap and detonation not end gapps butting together. The ring gaps were .028 and .030. With only a 125 shot that is more than adequate. I still had 200 psi of cranking pressure with this cam. The problem was E85/-7 heat range plug and nitrous at an aggressive tune. Had I went with -8 plugs I know I would have been fine. I have read the plugs many times and checked AFR many times so I know the tune was a little too close to run on the 1/4 (usually run 1/8) with that hot a plug I just screwed up and it cost me. It happens all the time I just had to pay for it and learn a lesson no big deal.

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6.19 @112 1/8 mile; 9.73@138 1/4 mile Texas Motorplex Fun Ford weekend 2012
NEW COMBO: 5 Speed is gone. 4R70W with BE controller.E85, solid roller 13:1 compression.

PSIG

My misunderstanding - bartlett said "I bet ya pulled a ring land up on a piston.." and you said "BINGO..". If instead you pinched or crushed a land - then yes, that's different.

David

__________________
-=≡ If it was easy everyone would do it ≡=-

cahorne

No problem. It was a pinched land..

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6.19 @112 1/8 mile; 9.73@138 1/4 mile Texas Motorplex Fun Ford weekend 2012
NEW COMBO: 5 Speed is gone. 4R70W with BE controller.E85, solid roller 13:1 compression.

cahorne

UPDATES:

Took the car out last weekend. 6.11 @112.98. 60 ft was a 1.35. I am happy. The track was cold and I think the car has a little more in it. Glad the engine is back in and ready for the season. Probably hit one more test and tune before the March 10 open. Good luck to everyone this year.

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6.19 @112 1/8 mile; 9.73@138 1/4 mile Texas Motorplex Fun Ford weekend 2012
NEW COMBO: 5 Speed is gone. 4R70W with BE controller.E85, solid roller 13:1 compression.

69fastback

Nice times. I'm right behind you with a 6.23. I just made a cam change, and tightened up the converter, and I hope to be right there with you.

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1969 Mustang
11.18@122 - motor
9.92@134 - 71 jet