[shinysun]

Hello,

Due to the leak from the front oil seal, I am thinking about pan e-vac system.

A question is that

Should I delete or block the stock breathers on the both head covers with the system?

I understand the breathers are needed for the circulation of PCV system , however with the pan e-vac system, seems don't need the breathers because the vacuum is not that strong.

Any idea on it?

[jessrayo]

Originally Posted by shinysun

Hello,

Due to the leak from the front oil seal, I am thinking about pan e-vac system.

A question is that

Should I delete or block the stock breathers on the both head covers with the system?

I understand the breathers are needed for the circulation of PCV system , however with the pan e-vac system, seems don't need the breathers because the vacuum is not that strong.

Any idea on it?

I assume you have forced induction on your car by posting this in this forum. I suggest you do a compression test on your cylinders because when the front seal goes that is the first sign you broke a piston.... at least it was for me.

[Elite Engineering]

First, the LT engines have no breathers. They have a cleanside separation system, but tell us more about your build. You want full time evacuation and never breathers.

[parish8]

For more serious builds I prefer a simple breather/catch can set up and change the oil more often. I am running a 5/8" hose from each valve cover to a mighymouse race catch can. I recently leaned you can replace the stock low tension crank seal with a normal crank seal from an ls3.

[LanceMagnum]

Anyone have the part # for that LS3 seal? Any particular year that applies here?

I'm planning on replacing that seal proactively when I do my install.

[shinysun]

Originally Posted by jessrayo

I assume you have forced induction on your car by posting this in this forum. I suggest you do a compression test on your cylinders because when the front seal goes that is the first sign you broke a piston.... at least it was for me.

Yap, I concerned about it at first, but the dyno number is the same as before, so just I am planning to check it later.

[shinysun]

Originally Posted by LanceMagnum

Anyone have the part # for that LS3 seal? Any particular year that applies here?

I'm planning on replacing that seal proactively when I do my install.

Front Cover Seal(12585673)

I ordered this one. Partsguy said it is.

[shinysun]

Originally Posted by Elite Engineering

First, the LT engines have no breathers. They have a cleanside separation system, but tell us more about your build. You want full time evacuation and never breathers.

I mean them. They are connecting the intake hose, so seems similar function as the breathers.

My plan is that just put the cleanside separators on the each head and connect them to exhaust ventilation pipes through the checkvalves.

Thank you,

[shinysun]

Originally Posted by parish8

For more serious builds I prefer a simple breather/catch can set up and change the oil more often. I am running a 5/8" hose from each valve cover to a mighymouse race catch can. I recently leaned you can replace the stock low tension crank seal with a normal crank seal from an ls3.

looks good and clean!

[aka Reckless]

Same as Parish.....most of the 6th Gens we are putting blowers on are getting breather style cans. Too much crankcase pressure causing leaks.

[Elite Engineering]

Only pulling suction on the crankcase at all times never allowing pressure ever build is proper crankcase evacuation. Defeating the cross flow flushing and actual evacuation of an engine results in leaving much of the damaging combustion by-products to settle and mix with the engine greatly increasing wear. NO Professional Motorsports "vents" with breathers as they know better than to sacrifice the engine. Also, venting results in ring flutter and compounds blow-by. Anyone venting could be sacrificing the durability of their engine.

[Goohead]

Originally Posted by shinysun

Front Cover Seal(12585673)

I ordered this one. Partsguy said it is.

Hey can anyone confirm the GM OEM LS3 front oil seal is a coil springless design? I got one from acdelco which is a national seal that seems to be.

I always thought the coil spring oil seals last longer

[exxit]

Originally Posted by Elite Engineering

Only pulling suction on the crankcase at all times never allowing pressure ever build is proper crankcase evacuation. Defeating the cross flow flushing and actual evacuation of an engine results in leaving much of the damaging combustion by-products to settle and mix with the engine greatly increasing wear. NO Professional Motorsports "vents" with breathers as they know better than to sacrifice the engine. Also, venting results in ring flutter and compounds blow-by. Anyone venting could be sacrificing the durability of their engine.

It seems like there is a clear divide between the high HP guys and Elite Eng's statements.

I haven't pulled the trigger on a catch can just yet, but the car is parked for now anyway. I have time to decide where to go.

Most high HP builds i've seen on the 6gen are running catch cans with breathers... Are there really that many performance shops that are not "real" by elite's statement? Anyone care to drop some counter knowledge other than "that's the way they do it?"

[parish8]

i am not sure how their set up works. if it allows a large amount of venting at wot, can handle boost and pulls a cross ventilation when under vacuum then sure it would be better than breathers only.

most people like me pushing a decent amount of boost change their oil often and don't really drive all that much so oil contamination isn't an issue. i am not sure about the ring flutter comment.