Good evening,
I have a car that is getting the better of me.First engine had extensive work
done to it but machine shop installed a cylinder liner poorly resulting in
premature head gasket failure at the sealing surface between number 3 and 4
cylinder. Had to start again with a new block.
New engine was all gone though and re-bored (used oversize County pistons),
Payen head gasket (with correct sealing ring built into head gasket) and ARP
hardware. This "new engine" blew head gasket again with under 500 miles on
engine.
Engine did not over heat (has newly re-cored radiator, new thermostat and new
water pump), ignition timing is only 30 degrees total advance, premium gas,
9.5:1 compression, roller rockers, improved cam, ect...... Removed head, its
flat, block is flat. Head gasket is blown out right between cylinders 3 and 4
and just starting to go between cylinders 1 and 2. Recess in block is a
uniform .027" below the deck of the block on all four cylinder recesses.
Engine originally called for 46 ft/lb torque for head studs, I figured with
good ARP head bolts and nuts I could torque to 52 ft/lb cold with oil on the
threads. Measuring old fire ring crush surface versus new gasket it appeared
to crush about .010".
One posting I saw out of England was someone had used a set of .030" or .040"
pistons that had not been radiused and the edges of the piston crown ended up
touching the head gasket sealing ring causing it to fail head gaskets
prematurely. Another posting regarding repeat 1500 head gasket failure
suggested decking the block and bringing the recess down to .015" below the
deck of the block, others say remove the recess all together.
Has anyone experienced this before? My key question is what should be the
proper recess below the block? What would anyone suggest as head torque (cold
or hot and what lubricant to be used with hardware)?
thanks for your time,
Pat Mannion
Santa Cruz CA
_______________________________________________
fot@autox.team.net
http://www.fot-racing.com
Donate: http://www.team.net/donate.html
Archive: http://www.team.net/archive
Forums: http://www.team.net/forums
Unsubscribe:
http://autox.team.net/mailman/options/fot/patrickmannion1@netzero.net
____________________________________________________________
Official Obama 2012 Site
In 2008 we changed the world. Let's do it again. Join the campaign now.
http://thirdpartyoffers.netzero.net/TGL3241/4e13ec321829022e236st02vuc
_______________________________________________
fot@autox.team.net
http://www.fot-racing.com
Donate: http://www.team.net/donate.html
Archive: http://www.team.net/archive
Forums: http://www.team.net/forums
|