head gasket leaking

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Postby jb88ci » Mon Aug 15, 2005 9:08 pm

Hey all, i'm trying to test run one of my engines. i decarboned it, cleaned the points, set the timing and put in new head and base gaskets. The SOB is spewing fluid from the head gasket. It's a new gasket and is intalled with the wide band up. Anyone using forma gasket or hi time gasket sealer?

I'm an AME but not a two stroke guy.....any suggestions on whether it's ok to seal this gasket?
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Postby Guest » Mon Aug 15, 2005 9:54 pm

What torque value did you use ?
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Postby Lazair_guest_please_registerjb88 » Mon Aug 15, 2005 10:22 pm

torqued to 220 inch pounds, diametrically opposed pattern.
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Postby Guest » Mon Aug 15, 2005 11:28 pm

It is normal to get some leakage and oil weeping from the Head/Base/Case gaskets as well as the compression releases. As an example a severely flooded engine may present fuel bubbles emerging from between head and cylinder as the crank is slowly rotated on the compression stroke. Check for cracks in head (especially around sparkplug hole) and incorrect gasket placement (centering-orientation). Remove the head to verify gasket placement. Check that case studs are centered in cylinder holes prior to re-installation of head (cylinder alignment). Retorque head in small increments (30-40 in/lbs at a time) up to the ultimate value of 210-220 in/lbs. Re-torque the head after 5-10hrs and check every 25-50hrs.
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Postby Chappy » Mon Aug 15, 2005 11:46 pm

I'm assuming this is a 185:

Repeated retorqueing of the head without replacing the head gasket will over crush the gasket under the head bolts and over stress the head. It usually manifests itself by bending, and eventually cracking, the cylinder head right along the cooling fins and right through the spark plug hole. Please refer to Lazair Technical Update 8.8. Your cylinder head may be bent but not yet cracked.

Cylinder heads have also been known to crack in the same manner if an engine has ever experienced a very sudden cooling, as in landing in water, etc.

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Postby Guest » Tue Aug 16, 2005 12:36 pm

I would not use sealer. Engines not meant to have that obviously. Check gasket orientation. Experiment with a few things first. Loosen and re-torque in stages, swap heads and gaskets between the engines (align used gaskets carefully), replace the suspect gasket, finally replace the head and gasket. Some slight leakage from the gaskets is normal. The engines are not designed to be 100% air tight. Severe blow-by isn't normal either obviously. You may not have a problem at all then again you may have a warped head or bad gasket. Try the easy stuff first then the expensive stuff.

It may be possible that heads are warped or cracked by sudden shock cooling (engine out) in extremely cold climates. Heads have been reported to mysteriously fail (crack) in cold climates with an abrupt reduction from sustained full power. Heads have failed for no apparent reason also.

Note: heads go on certain way. Scooped out side of head towards carb side of engine.
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Postby ozzie » Tue Aug 16, 2005 5:12 pm

alloy head? get a sheet of glass (old window will do) tape a sheet of 400 grit wet and dry oxide paper onto it add a little kerosene and place the head on it and rub it in a figure 8 motion for a couple of minutes have a look at the face and check that is sanded evenly it will show any hi low areas if the head has warped. once you are satisfied that it is flat change the paper to a higher grit 1000 and polish out the scratches. you can do this to the barrell as well i think you will find after doing this your problem will dissapear. don't worry about changing the compression ratio you are taking minimal amounts off here. remember keep it lubed with kero whist doing this. it only takes a couple of thou warp to get leaks when the material gets hot. ozzie B)
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Postby jb88ci » Tue Aug 30, 2005 8:29 am

Well, it was a head gasket problem. I must have not torqued it evenly when i first installed it. She's fine now. Lesson learned.
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Postby Shannon » Fri Sep 09, 2005 11:51 am

Let me guess. You torqued the head in small increments and it quit leaking ??

This is my earlier post where I forgot to sign-in.

It is normal to get some leakage and oil weeping from the Head/Base/Case gaskets as well as the compression releases. As an example a severely flooded engine may present fuel bubbles emerging from between head and cylinder as the crank is slowly rotated on the compression stroke. Check for cracks in head (especially around sparkplug hole) and incorrect gasket placement (centering-orientation). Remove the head to verify gasket placement. Check that case studs are centered in cylinder holes prior to re-installation of head (cylinder alignment). Retorque head in small increments (30-40 in/lbs at a time) up to the ultimate value of 210-220 in/lbs. Re-torque the head after 5-10hrs and check every 25-50hrs.
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Postby jb88ci » Fri Sep 09, 2005 3:31 pm

yep, did just that......i now need to adjust the timing slightly. She's kicking back, pulling the starter cord out of my hand....
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