J series-Breather Setup

EastMT said:
Is there any speculation about the amount of boost and the size of the lines? IE up to W PSI of boost 10AN lines are good and X-Y PSI 12AN lines are adequate? Over Z PSI you must have an ??AN line?
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I went with -12 lines since I have excessive crank case pressure and was blowing oil everywhere. I didn't want to go smaller and still have a problem so -12 is what I ordered. My guess would be -10 lines would be more than enough as long as you have 3 lines. I boost my car to 14 pounds and still no oil coming out of the breather or anywhere else on the engine.

 
The crankcase ventilation is next on my list for a boosted J35 engine, so this came at a good time for me. Thank you for the specific info and pics. It will make my build so much easier. Glad to see you fabricated your own system, also.

 
JM PRO said:
I agree.

I was looking for something specific and couldn't find anything to my liking so I built one.
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Any issues with oil splash getting into the breather, or length of the lines + uphill run makes it drain right back?

 
Rockwood said:
Any issues with oil splash getting into the breather, or length of the lines + uphill run makes it drain right back?
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Definitely  a concern but after nearly a season I still have a dry filter on the breather box. 2 of the lines run downhill to the breather box and the 3rd drains back to engine. I also run more oil in my engine than recommended. I like seeing oil on my dipstick and add an additional 1/2 quart.  Engine is raked at roughly 6 degrees forward.

 
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If I jack the front of the car up and fill the car to manuf. Recommended  amount the oil level is perfect. When I take it off the jack I will barely register any oil on the dipstick. I tried adding length to my dipstick but there is no room in the pan. I add an extra half quart to get to the first hole or to show low on the dipstick.

 
EastMT said:
Thanks for posting some very good pictures. What is the diameter and height of your breather can? Does the return line go into the bottom of the valve cover? How many miles were on the motor you had the cylinders cleaned up? 
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Moroso sells a catch can with inlets for a single line, 2 lines, -10 or -12 etc.

Summit or Jegs sells it.

 
I am going to be running two of these. One for each side due to limited space around my engine. One -10 line to each one.

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ChasingSand said:
I am going to be running two of these. One for each side due to limited space around my engine. One -10 line to each one.

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I had a radiator overflow of similar design from Latest Rage.  Kept cracking where the mount was welded to the canister.  @Sausage450r welded it a couple of times before I gave up and went with something different.  Not sure if this is beefier, but with oil, I'd be concerned.

Maybe the no bracket model:

MB17-2510_321x705.jpg


With a DIY steel mount made of tubing the same ID as the OD of the canister, plus some 1.75x.0.120 DOM to clamp it to the frame.  Would let you mount it at any angle instead of just perpendicular to whatever tube it's clamped to.

 
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My issue with most of those Catch breather cans is they are not set up to drain any collected oil back into the engine. There is a 1/8th or 1/4 NPT on the bottom of those breathers so you could run a line, just not a large breather line.

 
JM PRO said:
My issue with most of those Catch breather cans is they are not set up to drain any collected oil back into the engine. There is a 1/8th or 1/4 NPT on the bottom of those breathers so you could run a line, just not a large breather line.
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Do you usually end up with a lot of oil in yours? 

 
Also, look for a breather cannister with the largest air cleaner opening or mouth. The smaller the choke points the more pressure will be seen at that point.

 
ChasingSand said:
Do you usually end up with a lot of oil in yours? 
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My breather drains back to the engine so I have no idea if oil is making it up to the canister. If you would have seen the amount of oil I was puking before you could understand why I didn't want to take any chances. It made a mess and I thought I was going to catch on fire when the oil covered the entire side of the engine including the exhaust header. My boys got on the radio and were screaming fire, I jumped out of the car so fast and acted like Ricky Bobby and started running around the race track ....lol

 
JM PRO said:
My issue with most of those Catch breather cans is they are not set up to drain any collected oil back into the engine. There is a 1/8th or 1/4 NPT on the bottom of those breathers so you could run a line, just not a large breather line.
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I wouldn't want to drain back to engine. 

Ever look at a oil fill cap after sitting overnight?

Condensation etc builds up when car sits, that goes back into your motor.

 
JM PRO said:
My breather drains back to the engine so I have no idea if oil is making it up to the canister. If you would have seen the amount of oil I was puking before you could understand why I didn't want to take any chances. It made a mess and I thought I was going to catch on fire when the oil covered the entire side of the engine including the exhaust header. My boys got on the radio and were screaming fire, I jumped out of the car so fast and acted like Ricky Bobby and started running around the race track ....lol
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Where was the oil puking from? Also what seals were leaking?

 
lincster said:
I wouldn't want to drain back to engine. 

Ever look at a oil fill cap after sitting overnight?

Condensation etc builds up when car sits, that goes back into your motor.
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very good point and a genuine concern.

 
I run a turbo Honda, I virtually have zero blow by.  Why are you having so much blow by?  On my Subie, it meant an engine build was in the future.  I currently only have a breather, no catch can.

 
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