Catch cans and crank pressure
#76
I used the fitting with and without the flat washer that the cam tower allen plug used. Never had any issues with it seating fully. You used the exact same fitting I used from Summit?
#77
Rennlist Member
Thread Starter
I too have considered this many times but I have one big concern. We know from the 928 that the crank can push oil up through the return chutes and load up the heads. This can supposedly cause problems by leaving too little in the sump. The 944 8V has positive pressure in the cam tower (thus the relatively common problem of blowing out cam tower gaskets). This could help push the oil back to the sump. Could not relieving this pressure cause problems, and possbly flood the catch can and/ or the intake?
On the other hand it could alleviate the problem with the cam tower gaskets.
On the other hand it could alleviate the problem with the cam tower gaskets.
By the way, when I tested the pressure in my crankcase via the dipstick tube I was surprised to get only 3psi or less even at 17psi of boost. At WOT the pressure in the crankcase seems to increase linearly with RPMS...
#78
Drifting
Join Date: Aug 2009
Location: Bangkok, Thailand, Milpitas, CA & Weeki Wachee, FL
Posts: 2,239
Likes: 0
Received 2 Likes
on
1 Post
Ted: Thanks for the updated information we were thinking along the same lines. I have a 1/3 psi SS check valve with compression fittings. I was going to ask you what pressures you were recording in the Cam tower but Tom just posted. I am shocked at only 3 psi but that is at 17 psi of boost. I wonder how much worse at 21-23? I did not have any issues below 20 psi. I have just received an incredible new catch can from Mishimoto. I am going to working on this issue very soon with Tom. I am currently waiting on my new turbo and custom pedestal. When it comes in I am going to install everything at once. I wish I could post pictures but this app still not working and nobody wants to fix the issue.
#79
Rennlist Member
Thread Starter
Ted: Thanks for the updated information we were thinking along the same lines. I have a 1/3 psi SS check valve with compression fittings. I was going to ask you what pressures you were recording in the Cam tower but Tom just posted. I am shocked at only 3 psi but that is at 17 psi of boost. I wonder how much worse at 21-23? I did not have any issues below 20 psi. I have just received an incredible new catch can from Mishimoto. I am going to working on this issue very soon with Tom. I am currently waiting on my new turbo and custom pedestal. When it comes in I am going to install everything at once. I wish I could post pictures but this app still not working and nobody wants to fix the issue.
Since you are changing the turbo I assume you'll just open up the top hole on the AOS and be done with it. No need for T's and check valves that way. The only possible upside to my approach is that the system will function exactly like the stock configuration with a closed catch can (i.e., small hole on top of the AOS fed through a closed catch can to the J-boot, bigger side port spinning oil back to the pan) -- the only time it will behave differently is when the crankcase pressure goes positive. When it goes positive, the check valve will open and the pressure will vent out the AOS side port, through the same closed catch can, and to the J-boot.
Incidentally, the drain port that connects to the turbo mount uses the same 18x.1.5 threads as the cam tower. So if one wanted to get fancy, you could use that AN adapter to plumb up a fancy line from the AOS side port, to a T, and down to the mount... I'm planning a slightly more shade tree approach -- will post pictures of the mock up.
#80
Drifting
Hey Tom,
I'm having the exact same issue. I measured the crankcase pressure from the dip stick tube because I was getting some oil leakage from the turbo oil drain 0-ring after replacing because of slight leaking, only to see same! I get around 4psi at 12psi. That's quite a bit of pressure. I then removed the oil cap, zip tied a breathable cover, and got 1psi with NO oil leaking from the O-ring. I'm either installing LR AOS upgrade with their catch can - crankcase breather or copying you.
Any update as to your remedy?
G
I'm having the exact same issue. I measured the crankcase pressure from the dip stick tube because I was getting some oil leakage from the turbo oil drain 0-ring after replacing because of slight leaking, only to see same! I get around 4psi at 12psi. That's quite a bit of pressure. I then removed the oil cap, zip tied a breathable cover, and got 1psi with NO oil leaking from the O-ring. I'm either installing LR AOS upgrade with their catch can - crankcase breather or copying you.
Any update as to your remedy?
G
See post 8 for Teddy's pressure -- 8psi. That's why I was expecting more, but of course my motor has only 25k miles or so, so may have less blow by than an older motor. Or maybe my crankcase isn't as well sealed elsewhere. Hard to draw any useful conclusions based on that number.
Since you are changing the turbo I assume you'll just open up the top hole on the AOS and be done with it. No need for T's and check valves that way. The only possible upside to my approach is that the system will function exactly like the stock configuration with a closed catch can (i.e., small hole on top of the AOS fed through a closed catch can to the J-boot, bigger side port spinning oil back to the pan) -- the only time it will behave differently is when the crankcase pressure goes positive. When it goes positive, the check valve will open and the pressure will vent out the AOS side port, through the same closed catch can, and to the J-boot.
Incidentally, the drain port that connects to the turbo mount uses the same 18x.1.5 threads as the cam tower. So if one wanted to get fancy, you could use that AN adapter to plumb up a fancy line from the AOS side port, to a T, and down to the mount... I'm planning a slightly more shade tree approach -- will post pictures of the mock up.
Since you are changing the turbo I assume you'll just open up the top hole on the AOS and be done with it. No need for T's and check valves that way. The only possible upside to my approach is that the system will function exactly like the stock configuration with a closed catch can (i.e., small hole on top of the AOS fed through a closed catch can to the J-boot, bigger side port spinning oil back to the pan) -- the only time it will behave differently is when the crankcase pressure goes positive. When it goes positive, the check valve will open and the pressure will vent out the AOS side port, through the same closed catch can, and to the J-boot.
Incidentally, the drain port that connects to the turbo mount uses the same 18x.1.5 threads as the cam tower. So if one wanted to get fancy, you could use that AN adapter to plumb up a fancy line from the AOS side port, to a T, and down to the mount... I'm planning a slightly more shade tree approach -- will post pictures of the mock up.
#81
Drifting
Join Date: Aug 2009
Location: Bangkok, Thailand, Milpitas, CA & Weeki Wachee, FL
Posts: 2,239
Likes: 0
Received 2 Likes
on
1 Post
Hey Tom, I'm having the exact same issue. I measured the crankcase pressure from the dip stick tube because I was getting some oil leakage from the turbo oil drain 0-ring after replacing because of slight leaking, only to see same! I get around 4psi at 12psi. That's quite a bit of pressure. I then removed the oil cap, zip tied a breathable cover, and got 1psi with NO oil leaking from the O-ring. I'm either installing LR AOS upgrade with their catch can - crankcase breather or copying you. Any update as to your remedy? G
#82
Burning Brakes
#83
Drifting
Join Date: Aug 2009
Location: Bangkok, Thailand, Milpitas, CA & Weeki Wachee, FL
Posts: 2,239
Likes: 0
Received 2 Likes
on
1 Post
I tried but the IPhone App is hosed and it is not my Phone. I just got a new 6 plus and installed everything from scratch. Still can't upload pics, I get this "Parse" error. I posted to the 951 FB page if you want to see.
#85
Drifting
#86
Rennlist Member
Thread Starter
Hey Tom,
I'm having the exact same issue. I measured the crankcase pressure from the dip stick tube because I was getting some oil leakage from the turbo oil drain 0-ring after replacing because of slight leaking, only to see same! I get around 4psi at 12psi. That's quite a bit of pressure. I then removed the oil cap, zip tied a breathable cover, and got 1psi with NO oil leaking from the O-ring. I'm either installing LR AOS upgrade with their catch can - crankcase breather or copying you.
Any update as to your remedy?
G
I'm having the exact same issue. I measured the crankcase pressure from the dip stick tube because I was getting some oil leakage from the turbo oil drain 0-ring after replacing because of slight leaking, only to see same! I get around 4psi at 12psi. That's quite a bit of pressure. I then removed the oil cap, zip tied a breathable cover, and got 1psi with NO oil leaking from the O-ring. I'm either installing LR AOS upgrade with their catch can - crankcase breather or copying you.
Any update as to your remedy?
G
#87
Rennlist Member
Join Date: Mar 2004
Location: France
Posts: 428
Likes: 0
Received 0 Likes
on
0 Posts
#88
Drifting
Tom,
I'll post our remedy likely next week. Have a few things to sort, but likely solved the issue with few additional parts. Mario designed an easy fix that I'll share once proven correct. I can send you a PM if interested.
G
I'll post our remedy likely next week. Have a few things to sort, but likely solved the issue with few additional parts. Mario designed an easy fix that I'll share once proven correct. I can send you a PM if interested.
G
I've been on a little detour lately but will pick it up shortly. My thought is shown in these two picture. If you cut the crimp collar off the hose/pipe that runs from the AOS side port to the drain, you can repurpose the hose and pipe to make up a T. The T in this picture is just a 3-way 5/8' T. The brass check valve comes from McMaster (stays closed unless pressure in the AOS side port, then vents it to the can). The original AOS top hose will also go to the same can. The can will go to the J-boot (to preserve any micro-vacuum the J-boot might supply to the AOS). Unless/until the crankcase has positive pressure, the system will work exactly like stock. Once the crankcase/AOS sees .3psi or more, the check valve opens and the pressure vents to the can/j-boot. All thoughts welcome -- this is just a mock up on an old motor for now...
#89
Drifting
Join Date: Aug 2009
Location: Bangkok, Thailand, Milpitas, CA & Weeki Wachee, FL
Posts: 2,239
Likes: 0
Received 2 Likes
on
1 Post
Finally had some time to upload pics from my Iphone to the laptop and post to here. Honestly can't believe the powers that be at RL can't solve such an easy issue as making uploads work on the app. Anyway, here is the Mishimoto Billet Baffled and filtered Catch Can. It is a true work of art and also has amazing packaging. I also included a picture of the 1/3 psi SS check valve. It is hard to see in the pictures but the two zip lock bags are Banjo bolt to -10 AN adaptors.
#90
Addict
Lifetime Rennlist
Member
Lifetime Rennlist
Member