Water leaking when poured over combustion chamber
#1
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This is probably a stupid question and i'm sure I know the answer but I need to ask first. If a valve job is done properly and you pour water on the combustion chambers with a spark plug in NO water should leak by the intake and exhaust valves regardless if the water is there 1 second, 1 minute, 10 minutes, 3 hours, 24 hours or what not? Am I right or wrong? This is what i'm dealing with. I've got 1 intake runner on each head leaking and on one head I have 2 exhaust ports leaking one you can see on the left on the right it's kinda hard to see. Before I poured water I went to a dark room and shined a led light into each runner/exhaust port and those leaking I could see a faint bit of light around the valve in a couple tiny spots
![](http://i12.photobucket.com/albums/a248/Red04StangGT/DSC00015.jpg)
![](http://i12.photobucket.com/albums/a248/Red04StangGT/DSC00018.jpg)
![](http://i12.photobucket.com/albums/a248/Red04StangGT/DSC00015.jpg)
![](http://i12.photobucket.com/albums/a248/Red04StangGT/DSC00018.jpg)
![](http://i12.photobucket.com/albums/a248/Red04StangGT/DSC00017.jpg)
Last edited by AutomagicLS1; 02-14-2010 at 02:43 AM.
#5
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Were the valves lapped after the machine work was done? You could hand lap the ones that are leaking to see if they seat afterwards.
It's not unusual for the valves/seats to leak a slight amount when checked cold, which is why compression and leakdown tests are more accurate when run hot.
Seems like there could be something wrong here. You could remove the spring on the problem cylinders and visually inspect the valves/seats. By slowly turning the valve while shining your LED light, you might figure out if anything is out of round, or if you perhaps have a valve that is not concentric to the seat, etc.
It's not unusual for the valves/seats to leak a slight amount when checked cold, which is why compression and leakdown tests are more accurate when run hot.
Seems like there could be something wrong here. You could remove the spring on the problem cylinders and visually inspect the valves/seats. By slowly turning the valve while shining your LED light, you might figure out if anything is out of round, or if you perhaps have a valve that is not concentric to the seat, etc.
#6
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This is probably a stupid question and i'm sure I know the answer but I need to ask first. If a valve job is done properly and you pour water on the combustion chambers with a spark plug in NO water should leak by the intake and exhaust valves regardless if the water is there 1 second, 1 minute, 10 minutes, 3 hours, 24 hours or what not? Am I right or wrong? This is what i'm dealing with. I've got 1 intake runner on each head leaking and on one head I have 2 exhaust ports leaking one you can see on the left on the right it's kinda hard to see. Before I poured water I went to a dark room and shined a led light into each runner/exhaust port and those leaking I could see a faint bit of light around the valve in a couple tiny spots
how long are your vaves actually on the seat? not very long. not long enough for the cylinder pressure to overcome the valve to seat seal to cause any problems. i filled my runners up with water on my GEN I heads and they leaked within the first 10 seconds. just enough to wet the surface of the chamber, but nothing major. they run fine on the engine with a great cranking compression test and a great leak down test results. if they were my heads, i wouldnt worry about them.
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if they are fully assembles, tap the valve with a rubber malled acouple of times. somtimes it just needs to get a couple pieces of dust out. also deisle fuel is recommened more than water.
#15
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At 53 I know my engines. I already stated what was wrong with the heads but you guys are so much smarter than me but you ignored it. The valve guides and seats were shot because of the wrong rocker arms. I know the guy and his car, we converse each week.
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You were wrong, and he was letting you know, and probably was not aware of your sarcasm. Millions of morons roam these forums giving false information, and he might of thought you were one of them. No harm, no foul.
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What the hell do head bolts have to do with a freakin valve job????....what kind of voodoo engine building are yall practicing out there on the intrawebzzz????