coldfire

iTrader: (1)

I just finished installing my new RB header yesterday. my question is, now that the header is on, i can see that the EGR passages (i think they are EGR, the two openings on the bottom of the housing) are exposed. is there any need to block these off?
i should mention that i have already taken off and blocked my EGR valve on the top of the block.

thanks,

Jager

iTrader: (10)

I thought the EGR was on top of the block? I'm not sure where you're going. When I did my header install I just removed the ACV, blocked off the two lines. Installed that 02 sensor extention and went on my merry way.

Maybe I don't know what you're talking about?

coldfire

iTrader: (1)

i'll try to get a pic of it later, but basically i can see 2 passages at the bottom of the housing (2 holes). normally they went into the exhaust manifold (if you look at the stock gasket, there are holes for these), but now they aren't covered by the header, so they are just open.

i blocked off the EGR VALVE at the top of the block, but i think these holes are the actual inlet passages for the valve. i'm just wondering if it is ok to leave them exposed.

i hope that makes sense?

HAILERS

The last time I looked your series car does not have a EGR, therefore no EGR passages. The holes at the bottom are where the air from the airpump/ACV goes after leaving the ACV. See the Fuel section of your series FSM.

My5ABaby

iTrader: (7)

Edit: nevermind, I was looking at the wrong FSM

coldfire

iTrader: (1)

yes, i have a Series 5 car, but my actual shortblock engine is an S4 (irons, housings, internals). sorry, i should have mentioned that explicitly.

i forgot about the ACV...i imagine on the S4 engine there are holes for those also?

basically i just need to know if i need to block anything off...
the EGR VALVE is blocked off, and the S5 ACV is still on the car.

HAILERS

Ok, I'm not quite right in my first post. Right about S5 having no EGR. A little WRONG about the two holes below the exaust ports.

Only one should be open to the exaust because of the way the exaust manifold gasket is made. The one on the rear (fairly sure, not positive) is a passage to the EGR on top of the enging. BUT if you already have a blockoff plate over the EGR area, then no worry. It will lead nowhere.

Remember the EGR when you took it off? One very large hole and two small holes. Small holes lead to the intake passages, large hole to the hole on the rear rotor at the bottom. If there is a plate covering the large and two small holes you have to do nothing to the small holes at the exaust port area. Make sense? Yes.

The ACV feeds two holes in the exaust diffusers. Those holes are inside the exaust ports and not visible so I know your not looking at those.

If you have a S5 intake manifold on I'm really not sure that you have a passage from the ACV (the spoked checkvalve) to the exaust ports anymore. If you have a S4 intake on then no problem.

coldfire

iTrader: (1)

ok, thanks for the reply.
i think the header flange actually blocks off all the mentioned passages. for some reason i thought it didn't. i saw two holes on the bottom of the SIDE housing, but i don't think they lead anywhere (they are not passages). i sort of overestimated how large the stock exhaust manifold is.

i think you are right about the ACV passage. you are refering to the "port air" passage? i have that jb-welded on the S5 LIM, and i'm assuming that is what you are reffering to.

anyways, it should all be good now. thanks for the replys.

HAILERS

I think you have a non turbo six port motor.

On the front and rear side housings there are three holes. The upper two are for intake. The smaller and not so round hole (oval) below those two, is a passage for the ACV air.

Those two lower oval holes go straight down to the bottom of the side housings, then lead into a hold in each ROTOR housing and from there to a hole in the exaust diffusers and the ACV goes into the exaust. Called Port Air like you said.

The intake manifold for a series five is different than the series four as far as ACV air. On a series four the ACV air goes past that spoked checkvalve and goes to the end of the intake manifold and feeds those two OVAL holes mentioned above.

At least on a series four this is one very good reason not to switch the front with the rear rotor housing. The acv passages at the bottom of the rotor housings will not pass air to the Port Air if you swap front and rear rotor housings and it makes emissions testing, well a test of wills.

The two holes your talking about are covered with the INTAKE manifold, right? I'm doing this out of curiosity. I know your pleased with what you have already done.