Hi, I want to get a breather for my 3800sc I just don't want to pay 40+ bucks, I saw a pic somewhere where somebody drilled out the oil fill cap, and put a small breather filter in it, anybody do this?

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86 Fiero GTX project soon to tear up the street, My build thread! 3800sc, interior, wheels and more! https://www.fiero.nl/forum/Forum1/HTML/089483.html

Found what I was looking for, here's the link. Nice way to save 30 bucks! http://www.ls1truck.com/for...ap-breather-how.html

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86 Fiero GTX project soon to tear up the street, My build thread! 3800sc, interior, wheels and more! https://www.fiero.nl/forum/Forum1/HTML/089483.html

I don't recomend doign that..

the 3800's have a good PCV system. The breather makes a nasty mess..

Try this: http://www.grandprixforums....-breather-44478.html

Well I'm not running an EGR system either, I just would rather not have my intake coated in oil.

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86 Fiero GTX project soon to tear up the street, My build thread! 3800sc, interior, wheels and more! https://www.fiero.nl/forum/Forum1/HTML/089483.html

You could make a catch can. It doesn't have to be the expensive aftermarket ones. I made one out of a Ragu jar once with a cut up used fuel filter and an old one-way check valve from the brake booster. It worked great but looked red neck.

I have one in my garage collecting dust that you can have for 15.00 shipped. I bought it from ZZP several years back, but decided to use the stock PCV system.

quote Originally posted by Hudini: ... I made one out of a Ragu jar once with a cut up used fuel filter and an old one-way check valve from the brake booster. It worked great but looked red neck.

LOL...YA think....Betta RedNeckOnize

A pcv will not dirty your intake....

quote Originally posted by Purple86GT: I don't recomend doign that.. the 3800's have a good PCV system. The breather makes a nasty mess.. Try this: http://www.grandprixforums....-breather-44478.html

Good joke..The PCV system on the 3800 is god awful...

That's what I was thinking, nearly every swap I've seen has one.

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86 Fiero GTX project soon to tear up the street, My build thread! 3800sc, interior, wheels and more! https://www.fiero.nl/forum/Forum1/HTML/089483.html

My 3800SC uses a breather for the PCV air INTAKE withthe stock PCV valve to vent the crankcase gasses. When I removed my supercharger after 2 years to do the intercooler install the LIM was very clean. When the EGR valve system is not used(as in my setup) there is no carbon buildup in the intake. Using a PCV should not dirty up anything and will keep crankcase pressures within limits.
BTW, nice job on the DIY low cost breather. As a crankcase air intake it should work fine.

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" THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Powerlog manifold, Northstar TB, LS1 MAF, 3" Flotech Afterburner Exhaust, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, HP Tuners VCM Suite.
"THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "

A properly working PCV system on any engine performs 2 primary functions:

1) It draws a slight negative pressure inside the crankcase which improves engine sealing.

2) It evacuates moisture from the crankcase (by changing the air constantly) which improves lubrication (by keeping the oil dry) and extends engine life.

Simply running a breather with no PCV won't accomplish either of the two aforementioned tasks. In order to be able to use a PCV valve, you must have a way for filtered fresh air to get back into the engine (ie: either a passage that has access to filtered air coming into the throttle body or an open element filter that has access to fresh ambient air).

Stock, the 3800 Series 2 engines have the breather passage built-in to the intake and throttle body. But if you are running a turbo, you'll need to block this passage otherwise boost pressure could be pushed into the crankcase (which you don't want to happen). If you are running a SC and aftermarket intercooler that blocks the breather passage, you'll need to make modifications to complete the breather passage to the TB or add a breather filter on (or in place of) your oil fill cap. (Series 3 SC and NA engines have a breather passage that exits out the top of the upper intake/blower housing).

You can run a catch-can, but it must have a breather filter on it. Truth be told, you don't actually need a catch-can. I'm not running one. Instead, I'm running a fill cap extension from a Series 3 engine and a breather cap on top of that. The Series 3 extension points the breather straight up and high enough I have very little to no oil escaping, even under high G's acceleration (despite the fact the breather is on the rear valve cover). Guys not running such an extension that uses the straight-up angle may find oil wanting to "climb" out their breather cap which will make a mess.

NOTE: If your engine is worn out and has a lot of blow-by, you may need a catch-can as excessive crankcase pressure may push liquid oil out of any breather cap extension configuration you are using.

A properly functioning PCV valve is a one-way check valve that also meters flow. It prevents boost pressure from entering the crankcase and it prevents an excessive amount of crankcase "vapor" flow from being ingested by the engine. A poorly performing PCV valve may not block boost pressure flow from the intake into the crankcase and it could also allow too much crankcase vapor flow from the crankcase into the engine's intake.

The way the M90 blower is designed, the PCV valve only sees vacuum and it never sees boost. On turbo applications or applications using an external supercharger, the PCV valve will be subjected to boost pressure (which is fine, so long as you are using a quality, properly functioning PCV valve).

-ryan

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OVERKILL IS UNDERRATED

Custom GM OBD1 & OBD2 Tuning | Engine Conversions & more | www.gmtuners.com

[This message has been edited by Darth Fiero (edited 10-03-2012).]

Okay here's one for you, thanks for the info btw. I still have the pcv valve in my blower, and the engine is stock besides EGR removal, and sensor relocating. So what other parts are there to the PCV system? And I did buy a breather btw couldn't pass it up.

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86 Fiero GTX project soon to tear up the street, My build thread! 3800sc, interior, wheels and more! https://www.fiero.nl/forum/Forum1/HTML/089483.html

quote Originally posted by IanT720: Hi, I want to get a breather for my 3800sc I just don't want to pay 40+ bucks, I saw a pic somewhere where somebody drilled out the oil fill cap, and put a small breather filter in it, anybody do this?

Like this?



I am not sure why, I cant remember, I didnt keep it that way...

[This message has been edited by BV MotorSports (edited 10-03-2012).]

quote Originally posted by IanT720: Okay here's one for you, thanks for the info btw. I still have the pcv valve in my blower, and the engine is stock besides EGR removal, and sensor relocating. So what other parts are there to the PCV system? And I did buy a breather btw couldn't pass it up.

Besides the PCV valve itself and the passages between it, the intake manifold (manifold vacuum source), and the crankcase; on a stock engine, you have a passage that leads from a crankcase source (usually the lifter valley via a cylinder head passage) to the throttle body.

On a supercharged engine, there is a spring that installs over the PCV valve under the metal cover. Under the PCV valve, there is an o-ring and a plastic insert (the insert installs down into the blower housing). I believe this plastic insert acts as some kind of oil separator.

quote Originally posted by Dennis LaGrua: Using a PCV should not dirty up anything and will keep crankcase pressures within limits.

Ok, I gotta ask...what can happen if the crankcase pressures are outside the limits...say that you put the oil filler cap on instead of the air breather cap thus blocking the flow of air into the block while the PCV valve is set up and working fine? I ask because this happened to me on my 4.9 swap. I forgot to modify the oil filler cap as I had planned and once the engine got up to running temp, it would make a belt squeal sound coming from the oil pan area. I couldn't find the cause right away so the engine ran for a total of aprox 2hrs this way. When I figured out what was causing it, I took the oil filler cap off and could hear the inrush of air into the engine. Possible damage?

quote Originally posted by Reallybig: Ok, I gotta ask...what can happen if the crankcase pressures are outside the limits...say that you put the oil filler cap on instead of the air breather cap thus blocking the flow of air into the block while the PCV valve is set up and working fine? I ask because this happened to me on my 4.9 swap. I forgot to modify the oil filler cap as I had planned and once the engine got up to running temp, it would make a belt squeal sound coming from the oil pan area. I couldn't find the cause right away so the engine ran for a total of aprox 2hrs this way. When I figured out what was causing it, I took the oil filler cap off and could hear the inrush of air into the engine. Possible damage?

I can answer this. If you are running a PCV valve and there is no venting of the crankcase (either via a breather cap or breather passage that has access to atmosphere), two possible things can happen:

1) Excessive vacuum can build in the crankcase which could "suck in" seals, gaskets, or possibly (in extreme cases) collapse the oil pan or other stamped metal parts.

2) If the engine has piston ring sealing issues (ie: lots of "blow-by"), without a breather, excessive pressure can build up in the crankcase which can blow out gaskets and seals.

Not good in either case.

-ryan