FWD Valve Covers

[mdb4879]

Hey all. So I'm building a motor to go in my Pulsar since the DET currently in it is knocking. Anyways, the motorset I bought is missing a couple items and one or both of the valve covers is/are included in the missing items list. I don't really want to pull parts off the motor in the car right now and I have an extra pair of FWD valve covers. Can anyone see any ill fortune in using them on a DET seeing as the intake side cover doesn't have a big top port and the exhaust side only has one nipple and neither have baffles? I was thinking of teeing off the one line and having a line go to the PCV valve and the other to the suction pipe. Any thoughts?

I also remember the FWD intake cover has a downward facing nipple on the back side of it that iirc goes to the PCV valve. Do the RWD DET covers have this as well? I can't remember. And if they don't can I just connect that to the PCV valve and send the exhaust side cover to the suction pipe? Thanks in advance.

[float_6969]

Wait, the FWD valve covers don't have baffles? If they don't, I wouldn't use them on the DET. The CA already likes to consume oil. Removing the baffles is going to make that thing eat oil like there's no tomorrow.

I vote no.

[mdb4879]

Ok, so I got to looking at the valve covers. The FWD exhaust side does have baffles, just not the extended one that has that hump the RWD DET ones do. The intake side only has the port that goes down under the intake, but not the top one. I did some digging around and found that it's the Exhaust side DET cover I have, so if using the FWD exhaust side is out of the question (remember we did determine it has baffles, just not like the DET ones, so what's the new verdict on that?) then what about using the FWD intake side with the DET exhaust side? Here's some pics of the FWD covers.

[float_6969]

Hmm, the FWD must have something different to connect the intake manifold to the cylinder head area. Does the FWD have the weird thing that sits right behind the cams and has a shorter coil pack cover? You need 2 connections to the cylinder head, one for the PCV/intake mainfold and one for connection pre-turbo.

[mdb4879]

The coilpack cover isn't necessarily shorter, but it is missing a chunk out of it for the breather separator (black block thing).



On the FWD the exhaust side went to the intake tract and the PCV valve went to the breather separator in this picture then went to the intake tract. I may be wrong, but after thinking about it this seems like a crappy PCV setup. Any positive crankcase pressure goes into the intake tract (via the exhaust side valve cover, which in this case also acts as the fresh air inlet for the crankcase), but not directly to the PCV valve where it has a vacuum source. The PCV valve goes to the intake where it mostly takes in fresh air and minimal crankcase air, so it can't evacuate the crankcase very well and leaves that to the small vacuum produced by the intake charge passing over the inlet in the intake plumbing. Am I right or wrong?



Here's how my DET is currently set up. I didn't mess with this at all when I dropped the motor in. I just left it as it was from the previous owner of the swap. (the engine bay is cleaner than that now, and will be much much cleaner when I go to drop in the new motor)



The intake and exhaust side are tied together and go to the PCV valve. The line to the suction pipe I'm not entirely sure, as I didn't feel like crawling under the car to check, but I'm fairly certain it's tee'd in with the drain from the back left of the intake side valve cover. Now realizing this, perhaps this is why my car blew so much smoke when coming off of boost. No baffles for the drain, of course, so under boost a ton of blow by was forced into the intake tract. Sound about right?

[float_6969]

Not quite. The baffle thing serves the same purpose as the "blocks" on the DET covers. On the FWD, the suction is created at the PCV valve so that anytime there is a vac in the IM, fresh air is drawn in through the exhaust side valve cover, through the head, out the baffle and into the IM. The other line that connects to the side of the intake valve cover is just a direct connection to the crankcase so that blowby has a way to get to the top of the head so it doesn't try to come up the oil drains.

The DET setup is more complicated. Under part throttle/no boost, it's the same as above; fresh air from the pre-turbo pipe comes into the exhaust side valve cover, out the intake side valve cover, through the PCV valve and into the IM. When under boost the PCV valve closes and any pressure in the crankcase goes OUT the exhaust valve cover and into the pre-turbo suction pipe.

[mdb4879]

Well, I don't think mine was ever set up right to begin with, so hopefully I'll fix that this time around. I guess I'm just going to use both RWD covers. As much as I hated to I pulled the intake cover off the DET in my car right now and replaced it with a FWD one just to move the car around.