Leaking L98 Aluminum heads
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Leaking L98 Aluminum heads
Hey, lets see if you guys can figure this one out.I have a set of L98 113 Aluminun heads fresh from machine shop, surfaced 0.20,new springs,lock,retainers,keepers,cut for bigger springs .600 lift,and Pc seals.This heads I put on a carbed 355,decked 0.10(i know its flat) solid cam,etc.. The problem is I cant get them to seal! Ive tore the motor apart twice to replace head gaskets and the are still sucking oil from the lifter valley(I noticed this when I took it apart the first time) You can see a trail of oil from the drainback holed in the head to around the out board cylinders(just the four corner cylinders) Ive run about 10 gals of gas through it(its 0n a engine run stand) and its breaking in fine,no oil in water,no smoke,sounds real good,but between the head and gasket you can see oil bubbling out. Arp head bolts torqued to 75ftlb.I bought felpro blue stipe gaskets(didnt think i need the silicone ones,the guy at Jegs said they should seal fine(they dont) So, I dont even want to tear it apart again,but maybe I should have bought the $60 gaskets. Is there something wrong with the heads,Cheverolet have a TSB on the heads? I dont know,just looking for another opinion,Thanks!!
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Hey, lets see if you guys can figure this one out.I have a set of L98 113 Aluminun heads fresh from machine shop, surfaced 0.20,new springs,lock,retainers,keepers,cut for bigger springs .600 lift,and Pc seals.This heads I put on a carbed 355,decked 0.10(i know its flat) solid cam,etc.. The problem is I cant get them to seal! Ive tore the motor apart twice to replace head gaskets and the are still sucking oil from the lifter valley(I noticed this when I took it apart the first time) You can see a trail of oil from the drainback holed in the head to around the out board cylinders(just the four corner cylinders) Ive run about 10 gals of gas through it(its 0n a engine run stand) and its breaking in fine,no oil in water,no smoke,sounds real good,but between the head and gasket you can see oil bubbling out. Arp head bolts torqued to 75ftlb.I bought felpro blue stipe gaskets(didnt think i need the silicone ones,the guy at Jegs said they should seal fine(they dont) So, I dont even want to tear it apart again,but maybe I should have bought the $60 gaskets. Is there something wrong with the heads,Cheverolet have a TSB on the heads? I dont know,just looking for another opinion,Thanks!!
You took .200" (between 3/16 & 1/4 inch) off the surface of the heads? Why? That seems way excessive. I don't know if you can physically/safely take that much off the heads but if you did then you must be running one hell of a compression ratio! If thats true and you also took .100" off the block deck then the intake ports and coolant passages of the heads will be .300" lower than those on the intake manifold if it wasn't also modified/lowered. If the intake manifold wasn't modified then your going to have a huge mismatch between the intake and heads which will lead to leakage and poor air/fuel flow. Are you also loosing coolant? Any coolant in the oil?
Maybe you meant .020" off the heads and .010" off the deck or ?
Mike
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GM went through the hassle of making a head gasket just for this head. Part # is 12557236. Perhaps it's worth a try? They worked for me just fine, and my ZZ heads are surfaced a bit too.
http://www.gmpartsdirect.com/perform...CATID=697.html
http://www.gmpartsdirect.com/perform...CATID=697.html
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