B16, B18, B20
By NickH
#306114 Hi,

I have a B18A1 that has a major leak somewhere in around the PVC box on the back of the motor. The motor has a 1998 B18B1 head that has the PVC valve built into the valve cover, can i take that black box out of the back of the A1 motor and replace it with a freeze plug?

Thanks in advance.

Nick
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By bartman201
#306149
NickH wrote:Hi,

I have a B18A1 that has a major leak somewhere in around the PVC box on the back of the motor. The motor has a 1998 B18B1 head that has the PVC valve built into the valve cover, can i take that black box out of the back of the A1 motor and replace it with a freeze plug?

Thanks in advance.

Nick


you can do it, but i will not recommend it.
By bks84
#306175 yes, as long as theres a valve present it should be fine.
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By SkunkDcivic
#306188 I believe the black box is the the crank case breather so I'd run a catch can if you remove it
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By bartman201
#306193
SkunkDcivic wrote:I believe the black box is the the crank case breather so I'd run a catch can if you remove it


You're correct
By NickH
#306201 Yea i was going to just replace it with a freeze plug, I hope that the older block vents the crankcase up to the valve cover PCV valve.
By bks84
#306207
NickH wrote:Yea i was going to just replace it with a freeze plug, I hope that the older block vents the crankcase up to the valve cover PCV valve.


If you compare a 90-83 A1 to a 94+ b1 you'll notice there's no box, no other means of "catching" anything. Its all done through that lil valve, you'll be good as gold.
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By suspendedHatch
#306319 DO NOT ATTEMPT TO PLUG THAT. Replace the O-ring on the bottom of the black box. It isn't threaded, it just pops out, though you'll have to unbolt it and some other things to get it to come out.

Also replace the PCV valve in it unless they are both the hollow style. Replace the PCV valve on the intake manifold as well.

Honda uses an already inadequate crankcase breather system. Plugging it will cost you power, cause you to waste oil, cause you to fail emissions visual inspection, cause your spark plug wires to blow out of the motor, and force oil past your valve cover gasket.

A proper catch-can setup with an enlarged valve cover port is recommended for off highway race vehicles (particularly forced induction), but on a moderately modified street car it's pretty ridiculous especially for the amount of money you'll spend to do it properly.