Author: Bigblockbird March 30, 2008 at 19:21:10 from 67.142.130.11 in reply to: engine vapour posted by glen on March 30, 2008 at 10:52:28
How much run time on the engine? Do you have head bolts or studs?
How are you venting the block?
Generally the only source of vapor on the breathers is an internal coolant leak such as a head gasket or head stud or bolt not sealing properly.
Are you getting just a little moisture or something resembling white grease?
I assume since you said "crate motor" it was fully assembled. That is pretty big inches so is it a Street engine or full drag engine?
If it is a street car you should be running a PCV valve, a lot of people think they are a smog device but that is not the case, they are needed to vent the engine adequately at lower RPM's.
A couple of push in breathers without a PCV valve won't cut it on the street, no positive suction to clear the crankcase. My crankcase vents to my collectors on my race car but doesn't do a great job at low speed or idle, it would never be enough on the street.
Often people fail to put a thread sealer on the head studs or bolts where they go into the through tapped bolt holes into the water jacket. This is the most common source of moisture in the crankcase. The highest point of escape for the steam or vapor is at the breathers so the source can even be from down deep in the block.
Head studs are notorious for leaking coolant since they are not tightened into the block like a head bolt, the nut is torqued not the stud.
You really should go back and re-torque your heads after a few heat cycles of the engine, especially if you have aluminum heads.
Hope this gives you some ideas.
John
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