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Old 12-28-2004, 08:51 AM
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SCOBRAC SCOBRAC is offline
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Join Date: Jan 2002
Location: Northern California, CA
Cobra Make, Engine: -Sold- Contemporary 427S/C # CCX-3152 1966 427 Med Rise Side Oiler, 8v 3.54:1 Salisbury IRS, Koni's.. (Now I'm riding Harleys)
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With 4000 documented miles you are well beyond typical break in. You mention oil use. How much are you using? Oil use and low compression suggests rings or cylinder wall issues.

If you warm up the car and do a compression check again do a second check after a squirt or two of 30wt oil (any kind really). If your rings / cylinder walls are not mating well you will see a pretty big improvement. If not it is likely a piston chamber miscalculation.

I had a 428 that sat for four years with contamination in #2 cylinder. (the engine in my car when I bought it) When I pulled compression I got 180-195 in all cylinders but #2 which was 160.
I pulled the head and found the cylinder pretty chewed up where the piston sat in a pool of fuel for a very long time. It used a quart of oil every 1000 miles.

The tricky thing about low cylinder pressure is you may not have been breaking in the cylinder walls as you would have with higher pressure. Another thing to consider is improperly adjusted valves. If you somehow got (all) your mechanical lifters set to a point they are not allowing the valves to completely close for their full duration, as opposed to .022"-.025" hot, You could create a condtion in which cylinder pressures are low, you are not allowing rings to seat and as a result you are using oil...


Good luck,
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A man that is young in years, may be old in hours, if he have lost no time. But that happeneth rarely. Generally, youth is like the first cogitations, not so wise as the second. For there is a youth in thoughts, as well as in ages... Sir Francis Bacon (1561-1626)
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