Head bolt torque for hi compression engine? - Engine & Transmission

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Bob 13902
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After rebuild with high compression pistons and other HP upgrades, head gasket leak after 5,000 miles from cylinder 2 to water jacket. Does anybody know if head torque should be increased with hi compression engine?

Upon head removal torque was ~80 ftlb (slightly less than spec). No uneveness between cylinder sleeves or outside or block rail and head was milled flat prior to install so no obvious reason for why leaked other than maybe the torque needs to be higher. Head gasket was the Delta Motorsports product.

Jensen Healey
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Contact JAE for ARP torque angle studs and instructions.

http://www.jaeparts.com

Dakota123
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Also make sure that the gasket fits properly. The one I received from the club store sat askew on the head, and I ended up trimming bolt and dowel holes slightly to make sure the cylinder sealing rings were perfectly centered.

Jim Ketcham
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Make sure cylinder liner nip is correct. Especially between adjacent cylinders.

Jensen Healey
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The liners should stand .005" above the block. As Jim points out in a previous post, they can be shimmed at the bottom after removal if needed.

Jim Ketcham
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I believe the nip spec is .004-.006" liner over block and .001" between adjacent liners.

Bob 13902
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thanks. i was in spec when I installed the liners and they still look good. Planning to go with the JAE ARP stud nut upgrade kit and higher torques. Hopefully that is the trick!

gmgiltd
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I am running 12.1 to 1 compression ratio in a 2.2 ltr and was advised to retorque the head after 500 miles or half a dozen heat/cool cycles - no leaks in the last 25 years.
Gordon