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Old 10-05-2015, 03:39 PM   #1
austinp02
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Default What are you using to cap off crankcase breather in your hybrid build?

Hey guys, title says it. Looking for what people are using to cap off the secondary breather on the ej257 block for hybrid builds. Are you using rubber caps and a hose clamp? Freeze plugs? Tapping it for a gallery plug? Pulling it out and welding it? Sticking a small animal in it?

I've searched a lot and haven't found much on this. Plenty of arguments on if it should be capped, or how to route it into the existing pcv system or valve covers, but not much on the method folks are using to actually cap/block it off. I've seen others asking this question without a clear answer as well. Hopefully this thread can help them too.

To be clear, this is not a discussion on whether or not this is the proper way to do the build, there are plenty of other threads on that. Please take those thoughts over to one of those.

Thanks in advance!
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Old 10-05-2015, 03:59 PM   #2
maciek
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I have done most of the options. Freeze plug with correct diameter (sucks it you tap it in too far)...or tap it and screw in a bolt (viable with fully disassembled case halves)...or install a rubber cap with a hose clamp on the fitting (quick and easy, but cap will crack eventually).
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Old 10-05-2015, 05:14 PM   #3
austinp02
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Interesting. I would like to keep the pipe intact if possible as I may swap over to STI heads eventually and do a full swap, so the rubber cap (or something similar) is the most appealing. What's a guestimation on "eventually" for it breaking down?

The block is also assembled so I don't really want to split it again either if at all possible. Don't want to ghetto it, but also looking for the path of least resistance.
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Old 10-05-2015, 05:16 PM   #4
Zombie Panda
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Quote:
Originally Posted by maciek View Post
I have done most of the options. Freeze plug with correct diameter (sucks it you tap it in too far)...or tap it and screw in a bolt (viable with fully disassembled case halves)...or install a rubber cap with a hose clamp on the fitting (quick and easy, but cap will crack eventually).
I did this method using a silicone cap. When/if this motor gets rebuilt, and is apart, it will either get welded or tapped and plugged.
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Old 10-05-2015, 09:38 PM   #5
mtnmarc
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My builder told me not to cap it as it would create excess crankcase pressure.

I tee'd it to my air/oil separator.
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Old 10-06-2015, 08:23 AM   #6
austinp02
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Quote:
Originally Posted by mtnmarc View Post
My builder told me not to cap it as it would create excess crankcase pressure.

I tee'd it to my air/oil separator.
Do people even read before posting anymore?
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Old 10-06-2015, 08:29 AM   #7
austinp02
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Quote:
Originally Posted by Zombie Panda View Post
I did this method using a silicone cap. When/if this motor gets rebuilt, and is apart, it will either get welded or tapped and plugged.
Thanks for the input. Any particular reason you are going away from the silicone? Just happy with the performance in its capped state and want to make it more permanent or have you had issues with the silicone cap?

Also curious if you are happy with it, what method you used for your build. Thicker gaskets? Machined heads? Stock heads with regular sti gasket?

I have had my combustion chambers matched (just got back from the machine shop) and will be using oem sti gaskets. Curious how other similar builds are faring when capped.
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Old 10-06-2015, 09:58 AM   #8
fan boy
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Clamp a short piece of hose with a bolt. Those rubber caps always seem to crack and leak after a short time.
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Old 10-12-2015, 09:57 PM   #9
scoobyrex123
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^ thats what ive used for a while now lol still holding strong.
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Old 05-20-2020, 10:16 AM   #10
Sir Dangles
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I jammed a medium-sized gerbil into mine and have had no issues.

All jokes aside, this thread hit the spot so I'm bumping for continued relevance.
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