What is the best way to pressure test head gaskets with water pump off?
04-27-2014, 02:03 PM
#1
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What is the best way to pressure test head gaskets with water pump off? I am getting ready to put car back together but before I reinstall supercharger, I want to make sure the head gaskets are ok. What do you think would be the easiest thing to do? I really don't want to risk getting the new Opti wet either.
04-27-2014, 10:31 PM
#2
mhslax6 -
QUOTE: " What is the best way to pressure test head gaskets with water pump off? "
With the heads ON and the studs torqued (you are using studs, right?), and the valve covers OFF and spark plugs OUT, rotate your engine so <pick your favorite cylinder> is at the TDC (on the compression stroke); then using a screw-in adapter, apply compressed air into that cylinder via the threaded spark plug hole. If you hear no air flow, then your cylinder's valves and head gasket are all sealing properly for that cylinder. If you get air flow, then you have an issue. Air flow thru the intake = Intake valve. Air flow out the exhaust manifold = Exhaust valve. Anywhere else = head gasket.
Rotate your crank 90 degrees, then move on to the next cylinder in the firing order.
Have fun!
BTW - This is the very method I used to determine that Cylinder #1 and Cylinder #8 were both leaking - at the same spot on the Felpro Head Gaskets. (I was able to see bubbles at my radiator cap, but you'll just need to listen, as your cooling system is not functional.)
FYI - Some people say that if you use head studs, then you don't need the $80 apiece Mr Gasket MLS Head Gaskets for boosted applications on an LT1 - they say you can get away with a standard Felpro - but my engine disagrees.
Good luck!
QUOTE: " What is the best way to pressure test head gaskets with water pump off? "
With the heads ON and the studs torqued (you are using studs, right?), and the valve covers OFF and spark plugs OUT, rotate your engine so <pick your favorite cylinder> is at the TDC (on the compression stroke); then using a screw-in adapter, apply compressed air into that cylinder via the threaded spark plug hole. If you hear no air flow, then your cylinder's valves and head gasket are all sealing properly for that cylinder. If you get air flow, then you have an issue. Air flow thru the intake = Intake valve. Air flow out the exhaust manifold = Exhaust valve. Anywhere else = head gasket.
Rotate your crank 90 degrees, then move on to the next cylinder in the firing order.
Have fun!
BTW - This is the very method I used to determine that Cylinder #1 and Cylinder #8 were both leaking - at the same spot on the Felpro Head Gaskets. (I was able to see bubbles at my radiator cap, but you'll just need to listen, as your cooling system is not functional.)
FYI - Some people say that if you use head studs, then you don't need the $80 apiece Mr Gasket MLS Head Gaskets for boosted applications on an LT1 - they say you can get away with a standard Felpro - but my engine disagrees.
Good luck!
04-28-2014, 11:16 AM
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mhslax6 -
QUOTE: " What is the best way to pressure test head gaskets with water pump off? "
With the heads ON and the studs torqued (you are using studs, right?), and the valve covers OFF and spark plugs OUT, rotate your engine so <pick your favorite cylinder> is at the TDC (on the compression stroke); then using a screw-in adapter, apply compressed air into that cylinder via the threaded spark plug hole. If you hear no air flow, then your cylinder's valves and head gasket are all sealing properly for that cylinder. If you get air flow, then you have an issue. Air flow thru the intake = Intake valve. Air flow out the exhaust manifold = Exhaust valve. Anywhere else = head gasket.
Rotate your crank 90 degrees, then move on to the next cylinder in the firing order.
Have fun!
BTW - This is the very method I used to determine that Cylinder #1 and Cylinder #8 were both leaking - at the same spot on the Felpro Head Gaskets. (I was able to see bubbles at my radiator cap, but you'll just need to listen, as your cooling system is not functional.)
FYI - Some people say that if you use head studs, then you don't need the $80 apiece Mr Gasket MLS Head Gaskets for boosted applications on an LT1 - they say you can get away with a standard Felpro - but my engine disagrees.
Good luck!
QUOTE: " What is the best way to pressure test head gaskets with water pump off? "
With the heads ON and the studs torqued (you are using studs, right?), and the valve covers OFF and spark plugs OUT, rotate your engine so <pick your favorite cylinder> is at the TDC (on the compression stroke); then using a screw-in adapter, apply compressed air into that cylinder via the threaded spark plug hole. If you hear no air flow, then your cylinder's valves and head gasket are all sealing properly for that cylinder. If you get air flow, then you have an issue. Air flow thru the intake = Intake valve. Air flow out the exhaust manifold = Exhaust valve. Anywhere else = head gasket.
Rotate your crank 90 degrees, then move on to the next cylinder in the firing order.
Have fun!
BTW - This is the very method I used to determine that Cylinder #1 and Cylinder #8 were both leaking - at the same spot on the Felpro Head Gaskets. (I was able to see bubbles at my radiator cap, but you'll just need to listen, as your cooling system is not functional.)
FYI - Some people say that if you use head studs, then you don't need the $80 apiece Mr Gasket MLS Head Gaskets for boosted applications on an LT1 - they say you can get away with a standard Felpro - but my engine disagrees.
Good luck!
I run 1074's on my afr headed 383 at 20psi. My motor is 12 years old. And this last year was the first time I pulled it out because of a head gasket issue. When I get it back together hopefully I can get consistent 8.80's out of it.
04-29-2014, 01:52 PM
#5
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Has the block been decked and the heads milled true? If so, slap that **** together and forget about it. If they haven't, both surfaces should be checked to see if they are true.
05-04-2014, 09:17 AM
#6
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Will it hurt if I pressurize the cooling system with air to 14-15 lbs? If the system is sealed and the head gaskets are good won't it just hold pressure and if there is a bad gasket, the air will leak?