Sprockets

iTrader: (6)

Quite often I'll notice something about my car, then do a search on H-T, only to find people responding to questions with worst case doomsday scenarios that leave me with a sick feeling.

I have an Endyn style catch can setup, as well as a hose running from the valve cover to a breather the same size as ones that are on Moroso catch cans. This seems to be a tried and true method for crankcase ventilation in turbo Hondas, and aside from the smell, also seems to have worked well for me.

Today, while getting my car inspected, the mechanic happened to notice a gurgling sound coming from the valve cover breather. I've noticed this before, and plan to add a second catch can. Where the hose dips down, a bit of oil accumulated over time. So, he takes the oil cap off and commented on the air coming out as being a sign of a tired engine, too much crankcase pressure, and blowby getting past the rings. I know that some air coming out is normal, but is the amount of air going to be higher in a built engine? The reason I ask this is because many people weld additional valve cover vents on the front of the valve cover, or even use the Z10 oil cap with the -12an vent. How do I know for sure if this is normal blowby?

dasher

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by USE2B16A &raquo;</TD></TR><TR><TD CLASS="quote"> How do I know for sure if this is normal blowby?</TD></TR></TABLE>

Leak down test.

Built engines should have slightly greater blow-by because an engine builder has to take into account extra heat causing more expansion under highly stressful loads in boosted applications. An engine builder uses a greater piston-wall clearance and uses a wider gap when building a boosted or nitrous prepped engine and this will lead to greater blow-by even out of boost.

It is quite normal for a "built" engine to have air coming out of the oil cap when you remove it. Your mechanic needs to keep in mind 2 things:

1) Air will naturally try to escape the easiest way possible. So when you remove the oil cap it will come pouring out of it almost exclusively instead of fighting their way up your catchcan lines, past the baffle, and through the filter on the catchcan.

1) You no longer have the regular PCV line going to your intake manifold like a stock honda does. When you are idling the intake manifold sees a high amount of vacuum which would normally assist in removal of blowby in a stock PCV setup. Since you have disconnected this line and run an open breather arrangement all the blowby is going to escape through the open oil cap orifice.

You engine is most likely fine and your mechanic isn't understanding your complete setup... but if their is an unusually high amount of air escaping or you are paranoid then you can always do a leak down test.

Sprockets

iTrader: (6)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by dasher &raquo;</TD></TR><TR><TD CLASS="quote">Built engines should have slightly greater blow-by because an engine builder has to take into account extra heat causing more expansion under highly stressful loads in boosted applications. An engine builder uses a greater piston-wall clearance and uses a wider gap when building a boosted or nitrous prepped engine and this will lead to greater blow-by even out of boost.</TD></TR></TABLE>

Thanks, Dasher. This is what I thought, and wanted to confirm. I mentioned this to him, and he said it shouldn't matter because the rings are spring loaded, which didn't make sense.

dasher

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by USE2B16A &raquo;</TD></TR><TR><TD CLASS="quote">Thanks, Dasher. This is what I thought, and wanted to confirm. I mentioned this to him, and he said it shouldn't matter because the rings are spring loaded, which didn't make sense. </TD></TR></TABLE>

yikes, he apparently has never had to gap piston rings. Time to find a new mechanic.

C M S

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

yikes, he apparently has never had to gap piston rings. Time to find a new mechanic.</TD></TR></TABLE>

Sprockets

iTrader: (6)

LOL, he's not my mechanic. This was for state inspection. I passed!

dasher

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by USE2B16A &raquo;</TD></TR><TR><TD CLASS="quote">LOL, he's not my mechanic. This was for state inspection. I passed! </TD></TR></TABLE>

Apparently he is not even that great of an inspector; being that he let a car with an open breather PCV pass... or maybe he was a friend.

Sprockets

iTrader: (6)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by dasher &raquo;</TD></TR><TR><TD CLASS="quote">... or maybe he was a friend.</TD></TR></TABLE>

No, just a friendly inspector. Last year I put the pcv valve on top of the catch can, and routed the valve cover hose to the pre-turbo intake. I took a chance and left it alone this year, and he didn't care.