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351C Plug Blowby?

G Guest
I have chased this problem for over a week now. On a new rebuild of a 70 351C I am getting one of two issues. Either a massive header leak or leaky spark plug? The comp ratio is 10.7:1 and I am using a mild cam. When first starting the car it blows a small amount of black smoke from the cylinder head area. There is obviously a gasket leak around the headers but also evidence of leaking by black deposit on the boots of the plug wires. Plugs are champion RFY12 torqued to 15 ft/lbs. Any ideas???
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M mikep01 (Guest)
hello, to locate an exhust leak, use a length of hose, one end close to ypur ear an the other probing the area wher the leak exists. if it a header leak, what kind of gasgets are ypo using. i have had the best luck with the thick white header gasgets, for get the name. take a cote both sides of the gasget with copper sealant. tighten the bolt, run till norm op temp or a short drive. nest day retighten bolts cold. i also recomend stage 8 bolt. after that they shouldnt leak again.
bosswrenchbosswrenchMember
Sounds like the rocker cover gasket is seeping oil onto the headers andeverything eose in the area. Oil smokes when the headers & head castings get hot. A slight tightening may work if the gasket is still good, but I suspect you'll have to take the cover off, clean it & the head surface, then replace it with a new rocker gasket.
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