Head gasket blowout

Alas, another torched head and block. Somebody somewhare has got to have some insight as to why this is happening. I'm fresh out of ideas on how to prevent it. New gasket, properly torqued, one run, didn't even burn the tip on the plug, and pow, block and head to the machinist! All ideas are welcome.

 

Assuming you have the stainless wires pressed into the grooves in your heads, make sure the receiving grooves in your sleeves are wide enough to allow the copper gasket in without holding the head up off the deck. I don't have one in front of me right now, but I believe the grooves should be about .100 inch wide. Also, when torqueing, I snug everything down with a speedhandle first, then torque only the 5 upper row nuts (my block is 110 ft lbs). Then torque the inner studs, re-torque the 5 upper studs again, and lastly the bottom row (8 nuts) to a lower value (90 ft lbs). This puts extra torque on the upper portion of the head, where the hemi is weakest. If you are still having trouble, you have to check that the deck and the head are flat, and that all O-ring wires and sleeves are protruding the same amount. We had to go away from the stainless O-ring wires and machine the head for solid inserts.

 

I agree with Ken. That is how we torque are heads. It you torque your heads the normal way if will lift the top of the head off the block.
Comp. and Timming ?

 

Make sure all of your sleeves are above the block the same height.

 

Thanks for the input. The block is a BAE billet purchased new from BAE. The heads have been reworked by BAE and should(?)have the rings and grooves matching. That is something we'll check. The head is going back to BAE to be repaired. As to the torque sequence, the procedure outlined by Ken Sitko is the way we do it, with the exception of 135 ft-lbs. We'll have a post mortem on the head in a few days. We're using Clark gaskets. Anyone using another brand and having them blow out? Just wondering if a different manufacturer of gasket might help.......

 

The brand of head gaskets hasn't really been an issue for me, but then we only run a roots blower. By the way, I measured the grooves in our sleeves and found that they are only .070 to .080 wide, not .100 as mentioned earlier.

 

Sounds expensive and not a lot of fun. Brings up a lot of questions. Is it the same cyl as before. Timing and comp as already mentioned. Are the fuel hoses new. Maybe a flapper in a hose. Is this a new combination or do you know that the fuel system is in goodshape. Are the plug wires separated and in good shape. the headgasket may be the result not the cause. Happy to chat with you if you want for what it is worth. My work number is 604-291-7300. On the westcoast

 

Gasket blowout has hit us on cyl's 1, 7, and 8. Always the end of the head. Timing is proper, hoses are new, fuel system as correct as can be. My thoughts are leaning toward cylinder mis-alignment with the head. Sadly Jackie Stidham endured the same problem at Houston as us, just different cylinder. So I feel confident that ideas put forth on this forum will help more alky racers than just us!

 

quit looking, you won't find it. i told your driver if he and the "cartell" didn't get diesel prices down, i was going to jinx his season. when prices go down, car will be fine.

 

If the sleeve groves and oring height are ok you have a tuneup problem more than likely. The reason it is always an end cyl. is because you don't have the same clamping power on the ends as the ctr. cyls. They will usually lift the head and blow first.