6ghatch

I've never run a catch can on my H-C car but now with a newly built engine I was wondering if I would need it. I have the OEM oil separator installed, would adding a catch can do anything? Does it have to be baffled? Do you want one with a breather filter on top? How much oil do people see it collect when using it with a factory oil separator?

I've done some searching on oil catch cans but they seem mostly for forced induction or LS/VTEC's that don't have a factory oil separator.

SJR

since the SCCA requires one in IT, I have one.
1 quart capacity, with a breather. It has two input lines. One line comes from the valve cover breather hose, the other one from the PCV valve. Don't forget to plug the hole in the intake tube, and the intake manifold, where the PCV and breather used to connect.

MattD@Stoptech

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by SJR &raquo;</TD></TR><TR><TD CLASS="quote">since the SCCA requires one in IT, I have one.
1 quart capacity, with a breather. It has two input lines. One line comes from the valve cover breather hose, the other one from the PCV valve. Don't forget to plug the hole in the intake tube, and the intake manifold, where the PCV and breather used to connect.</TD></TR></TABLE>

If you don't have a vacuum connection, how does a setup like this actually work?

I have a catch-can and it usually fills up within a session or two of hard racing.

AdamITR

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by El Pollo Diablo &raquo;</TD></TR><TR><TD CLASS="quote">If you don't have a vacuum connection, how does a setup like this actually work?

I have a catch-can and it usually fills up within a session or two of hard racing.</TD></TR></TABLE>

Same here.

RexRacer19

Wouldn't both those connections be under a small amount of pressure by themselves? The PCV vents the positive pressure from the crankcase. The top of the head has a direct vent from the crankcase (oil return) thus seeing the positive pressure also. The vacuum connections just make it more efficient...right?

mstewar

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by El Pollo Diablo &raquo;</TD></TR><TR><TD CLASS="quote">

If you don't have a vacuum connection, how does a setup like this actually work?

I have a catch-can and it usually fills up within a session or two of hard racing.</TD></TR></TABLE>

i had the same question as I'm about to put one in..

how are yours setup matt and adam?

Tyson

PCV works on "positive" pressure. whatever crap that will come out of the crankcase is going to be puked out on its own, it really doesnt need to be 'pulled' out by negative pressure.

the system is designed by stock to let the engine breathe. and it normally vents out through the PCV valve into the intake manifuld, and the hose at the top of the valve cover allows fresh air in to replace the displaced air. but under hard engine use and greater pressure build up that exceeds the amount of flow through the PCV, the upper valve cover hose flow will reverse and also help release the pressure.

MattD@Stoptech

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mstewar &raquo;</TD></TR><TR><TD CLASS="quote">

i had the same question as I'm about to put one in..

how are yours setup matt and adam?</TD></TR></TABLE>

PCV valve - catch can - IM

Although the pcv will vent pressure without the pull of vacuum, i'm skeptical it will actually push a lot of the oil vapor through the oil catch can. I'd venture a guess that the person that doesn't connect to IM will see a lot less oil in their catch-can.

My valve cover was routed to the intake arm as stock till the nipple of the intake broke and I have an open breather on the valve cover.

Tyson

youre not supposed to have an 'open breather' on the valve cover. thats the whole point of a catch can, is to prevent oil from coming out of the engine.

MattD@Stoptech

Technically the point of the catch can is to seperate the suspended oil particles from the air stream and prevent them from being ingested by the engine.

I agree I shouldn't have an open breather on the valve cover, but I'm not too concerned about it.

civicrr

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Tyson &raquo;</TD></TR><TR><TD CLASS="quote">youre not supposed to have an 'open breather' on the valve cover. thats the whole point of a catch can, is to prevent oil from coming out of the engine. </TD></TR></TABLE>

I am with Tyson on this. The point of the catch can, for racing, is to prevent the oil from hitting the track.

Todd Reid

when i had a built LS B motor in my H1 car, i had the cyl valve cover vented to the catch can. i had the pcv valve vented to the catch can. no vacuum sources.

i used to run the engine about 1/2 qt over full; at the start of the day, i'd empty the catch can. at the end of a race day, i'd have about 1/4 qt of oil in it.

never had any oil problems that i know of (used that built motor for 2 years worth of racing/track events)....

before i had the built LS in there, i had a stock LS in the car. no catch can; oil breather was plumbed stock. no oil blew out of the engine anywhere...

now i have the K motor; the K motor is totally stock; i currently have it plumbed up stock without an oil catch can. it blows out zero oil from anywhere, and does not smoke at all.

todd

MattD@Stoptech

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by civicrr &raquo;</TD></TR><TR><TD CLASS="quote">I am with Tyson on this. The point of the catch can, for racing, is to prevent the oil from hitting the track. </TD></TR></TABLE>

One would have to have a hella (for the NorCal f00s) of an oil issue to be blowing oil out of the exhaust...I'm sticking to my guns.

civicrr

Well, there is also the rule in the NASA CCR that state that the lines should have catch cans or overflows.....

Scot

i think it is more s2000 related, but my car without a catch can looks like it is blowing up after taking turn one at Road atlanta and also coming into 17 (i think) at VIR north...and coming through turn 9 at summit........ hard turns and some braking and i have a BBQ.

6ghatch

This is about the best info I could find on the topic.

https://honda-tech.com/zerothread?id=331750

RexRacer19

I can't see where having the catch can hooked to the PCV on one end and back to the manifold makes any sense. The catch can is vented, so that means you are changing the vacuum condition in the manifold.

In the stock system, both the PCV and the valve cover connections are pressurized from the crankcase. By adding vacuum to both points (as the stock configuration does) you would be drawing more oil from the engine and back into the manifold. A catch can attached to both the PCV and the valve cover effectively removes the vacuum from the equation and it seems logical that less oil would come from the engine...good right?

Just my $.02

stormy

The PCV system should remianed closed

In higher level teams that run a dry sump sytem they use the 3rd or 4th pumpline to pull to a non returnable catch can thereby maintaining the vacum and removing all oil from returning

One of my friends uses this with a 2in 2out barb and swears by it

RexRacer19

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by stormy &raquo;</TD></TR><TR><TD CLASS="quote">The PCV system should remianed closed

</TD></TR></TABLE>

Why?

.RJ

Thats a stupid idea. That thing doesnt have anywhere near the capacity you would need to be an effective catch can.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by stormy &raquo;</TD></TR><TR><TD CLASS="quote">One of my friends uses this with a 2in 2out barb and swears by it

</TD></TR></TABLE>

Grip

from what ive seen and used the oil catch tank should be placed inline from the pcv to the intake manifold to catch oil before it re-enters the manifold and engine again...kinda like this:

pcv------oil catchtank--------intake manifold

thats how mine is setup and it catches oil...i left the valve cover hose connected to the intake arm.

i had mine setup like this for a day and my car ran like crap:

valve cover---oil catch tank------pcv

i blocked off the intake manifold vacumn fitting

when you think about it the manifold is pulling air through the pcv and the intake is pulling air from the valve cover..if you put a cath tank inline from the valve cover to the pcv..what wil be pulling air from either of them?..my car smoked alot and ran like crap until i switched it to my current setup..now it catches oil just fine and ive noticed my throttle body/intake arm arent pulling oil into them either ..just my .02

slammed_93_hatch

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by RexRacer19 &raquo;</TD></TR><TR><TD CLASS="quote">

Why?

</TD></TR></TABLE>

read this

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 6ghatch &raquo;</TD></TR><TR><TD CLASS="quote">This is about the best info I could find on the topic.

https://honda-tech.com/zerothread?id=331750</TD></TR></TABLE>

i think im gona pick up this one its 50 bucks and comes with the hardware

RexRacer19

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Grip &raquo;</TD></TR><TR><TD CLASS="quote">when you think about it the manifold is pulling air through the pcv and the intake is pulling air from the valve cover..if you put a cath tank inline from the valve cover to the pcv..what wil be pulling air from either of them</TD></TR></TABLE>

The crankcase produces the positive pressure for both...

I makes no sense to me how your car would run like crap with this configuration.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by slammed_93_hatch &raquo;</TD></TR><TR><TD CLASS="quote">

read this


</TD></TR></TABLE>

I read that before. It seems like a bunch of overcomplicated ricer crap to me. These guys are trying to keep oil out of thier intakes AND remain emissions compliant. I don't think we are worried about that with a race car setup. Nobody has yet given a sound explanation of why the vacuum system needs to remain in place on a race car...

slammed_93_hatch

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by RexRacer19 &raquo;</TD></TR><TR><TD CLASS="quote">
I read that before. It seems like a bunch of overcomplicated ricer crap to me. These guys are trying to keep oil out of thier intakes AND remain emissions compliant. I don't think we are worried about that with a race car setup. Nobody has yet given a sound explanation of why the vacuum system needs to remain in place on a race car...</TD></TR></TABLE>


basiclly replace the "black box" with the catch can, and it will catch the oil.

Dan GSR

with proper ventalation, you will notice a power gain