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Discussion Starter #1
For the high horsepower guys, what does yall's catch can look like after X number of pulls?

I drained my catch can for the 1st time since my new longblock, there was ~1.5qt of fluid(mostly oil).
~20 pulls(including dyno tuning pulls), 400mi breakin, 2 oil changes.
33-42psi boost.

2x -10 valve cover vents
1x -12 block vent
FE (large) catch can, 2 breathers.

I've been told this is normal.
 

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Do your valve covers have baffles in them? 1.5qts seems slightly high to me.
Just for reference I usually drive 500 miles between oil changes and definitely more than 20 pulls between 18-38psi. I have 2x-10 lines and I probably get 6-10oz at most.

How loose is the motor built do you know?
 

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Discussion Starter #3
Do your valve covers have baffles in them? 1.5qts seems slightly high to me.
Just for reference I usually drive 500 miles between oil changes and definitely more than 20 pulls between 18-38psi. I have 2x-10 lines and I probably get 6-10oz at most.

How loose is the motor built do you know?
They're baffled.

"Loose" according to my builder. They said my amount is normal, and they see even more on cars running without the block vent and/or small catch cans.
 

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I believe its normal, my built Grand National used to do the same, from the high psi of turbo boost, the oil gets excavated in larger amount, positive pressure in the crank case. Basically a massive suction , it will pull oil with the pressurized air.
is/does some part of your catch can pressure being vented ? or is it getting some of it back into the air intake ? compressor inlet , is what i mean? if not, it may be something to look into and re route and have less oil in the catch can.
 

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Discussion Starter #5
I believe its normal, my built Grand National used to do the same, from the high psi of turbo boost, the oil gets excavated in larger amount, positive pressure in the crank case. Basically a massive suction , it will pull oil with the pressurized air.
is/does some part of your catch can pressure being vented ? or is it getting some of it back into the air intake ? compressor inlet , is what i mean? if not, it may be something to look into and re route and have less oil in the catch can.
My catch can just has 2 large VTA breathers, you can see it in my sig.
I considered creating a vacuum line to the intake/inlet, from the can. But i'm not ok with the risk of pulling oily/eth mix into the intake. I'll just deal with draining it every 4-5 pulls.
 

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Crazy, I don't get that much in a year.

Steve
 

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Discussion Starter #8
Crazy, I don't get that much in a year.

Steve
number of passes? I race it every weekend, those 20 passes happened in like 2wks.
 

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Your builder went too wide on ring gap, too loose on bore size for the pistons he used, or the rings haven't seated AT ALL (which is very unusual on a 2JZ unless something else is super fucked) or all three.
 

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Not sure what a pass is? I do a lot of 20-150mph pulls on the highway. I have maybe 2 table spoons of water/condensation in my catchcan when I drain it every 3-6 months.

Steve
 
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Discussion Starter #11
Your builder went too wide on ring gap, too loose on bore size for the pistons he used, or the rings haven't seated AT ALL (which is very unusual on a 2JZ unless something else is super fucked) or all three.
He did say they were going to build my motor loose. This kind of blow-by seems consistent with all their local builds, none have had issues though. Just annoying having to monitor oil level so closely. It isn't burning it, I know that much.

My 6870 kicked the bucket during Friday's race. Soo now my concerns have shifted a bit lol
 

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Did you remove the baffles from under the valvecover? If you did, it would pick up more oil vapor than usual.

Other than that, definitely a loosely built motor or the rings might have not sealed and it could be do you improper machining/assembly. Some machine shops like to treat a 2JZ and make the clearances like a BBC.
 

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He did say they were going to build my motor loose. This kind of blow-by seems consistent with all their local builds, none have had issues though. Just annoying having to monitor oil level so closely. It isn't burning it, I know that much.

My 6870 kicked the bucket during Friday's race. Soo now my concerns have shifted a bit lol
My I ask how much abuse/usage your 6870 had and what went wrong with it? I have a new GTX3582R Gen1 I was gonna use on my upcoming build but was thinking of selling it for a 6870.
 

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Discussion Starter #14 (Edited)
My I ask how much abuse/usage your 6870 had and what went wrong with it? I have a new GTX3582R Gen1 I was gonna use on my upcoming build but was thinking of selling it for a 6870.
~30 passes under 30psi
~15 passes between 30 & 40psi
Only used 2step & anti-lag for dyno testing & motor break-in.
<5k miles

Compressor wheel snapped/broke off.

This is my 2nd premature Precision failure, on different cars. I bought a Garrett G42-1450.
No more Precision for me.
 

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Yeesh. That's way more than I've experienced. Even my race car doesn't see that much oil in the can. I usually don't need to drain the can at the end of a track day. It's usually just out of good habit. And trust me there's a lot of full throttle there. I find the blowby excessive but if that's how they built it, then that sucks.

Have you done a leak down? I'd be interested to see the numbers on the crank. 5 bucks you put compressed air on a cylinder and it sounds like a trumpet lol
 
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~30 passes under 30psi
~15 passes between 30 & 40psi
Only used 2step & anti-lag for dyno testing & motor break-in.
<5k miles

Compressor wheel snapped/broke off.

This is my 2nd premature Precision failure, on different cars. I bought a Garrett G42-1450.
No more Precision for me.
Wow that's a pretty big failure. I'd be pissed with that usage and outcome. I always thought the Precision failures were more myth than reality.
 

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Do your valve covers have baffles in them? 1.5qts seems slightly high to me.
Just for reference I usually drive 500 miles between oil changes and definitely more than 20 pulls between 18-38psi. I have 2x-10 lines and I probably get 6-10oz at most.

How loose is the motor built do you know?
Here's what I use for a catch can on my 2jz motor but then it's in a Genesis coupe chassis I do run it hard and I haven't checked how much blow bye ive gotten since the build of my 2jz and pushing 600hp @22 with a 14lb spring the goal after the diff swap is 1400hp .
 

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Here's what I use for a catch can on my 2jz motor but then it's in a Genesis coupe chassis I do run it hard and I haven't checked how much blow bye ive gotten since the build of my 2jz and pushing 600hp @22 with a 14lb spring the goal after the diff swap is 1400hp .
What's your throttle body setup?
 

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Here's what I use for a catch can on my 2jz motor but then it's in a Genesis coupe chassis I do run it hard and I haven't checked how much blow bye ive gotten since the build of my 2jz and pushing 600hp @22 with a 14lb spring the goal after the diff swap is 1400hp .
The stock ports are not nearly enough. You'll see when it starts leaking at the front or the back or the top at the front. lol Get some weld on 10AN going when you can. Trust me.
 

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Brotato, I suspect you're gonna like that G42. I thought about getting one just for shits and giggles to see what I could really push out of my 1j, and how high it would rev and still make power, but... for one, it's pretty much impossible to put that sort of power down on our filthy desert roads, and two, I suspect it'd make enough torque to break the transmission, and possibly the diff. Last thing I want is more things to break haha.

But seriously, I have one of their G25's, and the way that little tiny thing pulls, I can only imagine the G42...
 
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