2 piece 9-5 manifold - useful for using t-7 head?

[Luke]

I was scrounging around in a junkyard the other day and noticed the 9-5 (that are starting to come into the u pull-its in huge numbers) uses a 2 piece manifold - it looked like separated and contained just the injector ports really, so I spent a little time pulling it apart so I could see what was going on inside, basically its just sandwiched between the head and the plenum. The nice thing is in that short distance it transitions from the funky T7 shaped port with the injector shroud to a very simple almost dead rectangular port.
Im thinking that this might be useful for the guys (like seth, drew etc) planning to use a T-7 head on a B202. My thought is to build a very basic manifold from welded tube els from this to a set of DCOE flanges and run ITB's on the nice flowing T7 head. mmmm, yummy.

Part Number 5 in the below drawing:


Also the injectors are really weird on T7, whats the deal with them?

[DrewP]

Damn, you stole my thunder! I was ramping up to start a thread about these.

I was digging around our parts supply and found one of the lower intake manifolds.


I wrote a bunch below about what you have to do to use this, but in summary:

YOU WANT ONE OF THESE.

If you find one, get it with the rail and the injectors.

I haven't checked to make sure it actually clears the hood, as it adds about 2 inches (vertically) to the manifold height, so it might be close against a hood that hasn't had the stiffening web cut out of it already.








The bolt pattern for the inlet manifold is identical for all the intake manifolds, there is some modification needed, but looks like it will be much more straightforward than chopping and welding on the flanges and is what I'm planning to do to preserve the injector placement and angle and port mating geometry.

You just need the long bolts that clamp the stack.








I looked into it some and from what I can tell the two piece manifolds came on:

'99 9-5's (ALL, 2.3L and Euro 2.0L cars) (technically they were on MY98 9-5's that the European market got as well)
'99-'02 Viggens (ALL)
Possibly '00-'01 9-5 Aero's with B235R engine - not sure about this one.

The part number is either:

9185844 or
4774477


The accompanying gaskets are on this parts diagram:








There are some modifications you need to do.

The early cars came with the 2 piece manifold so that there is actually a water jacket that floods the lower manifold, probably for emissions reasons. You have to weld the port that allows water into the upper manifold shut, by closing off this passage. You can see the water jacket channels in the side that faces the head.

The little rectangle I'm pointing to in the 2nd photo is the passage that has to be closed.

The little pocket to the left of my finger is where the coolant temp sensor on the C900 manifold pokes through between cyls 2 & 3. You need to drill that pocket to allow coolant to flow into the sensor, or re-locate the sensor to the upper rad hose or the t-stat end of the cylinder head (like where the 9-5 sensor is already).











The ports don't line up perfectly, but with a little material added in by welding and then ground back out the transition is definitely do-able.

The C900 runners come in a little low, but it shouldn't be any different than matching runners together from anything else, and as Luke pointed out the runner side of this flange has rectangular ports.





You also preserve the C900 fuel rail and injector mounting points, so you could actually run two sets of injectors and rails if you wanted to.


Now, my favorite part about this is you can now use the 9-5 style fuel rail, which has some really nice advantages.

The rail inlet and outlet use GM style quick disconnect fittings already that just click on, and there are already adapters you can buy to install Aeroquip style hose with metal GM clip fittings.

You can also now easily get a 3.5 BAR fuel pressure regulator that pops right into the rail.

You also get a fuel pressure check port that taps right into the rail, it's also a GM style fitting with a little tapered seat, almost any fuel pressure guage set comes with this attachment, which is really convenient. It's got a little one-way schraeder valve built into it, it's under the little black screw-on cap in the center of the rail.


You also get the 9-5 injectors, which are like 38lb/hr or something like that already, T5 will play real nice with them already, and they'll support something like 325 whp easy before you max them out.

[airsweden]

We're all on the same page. Seth and I were just checking some of these out at Chris' shop tonight.

[Luke]

Nice write up Drew. Looks like adapting the std c900 manifold to this thing is basically similar to adapting straight to the cylinder head but it alleviates the injector shroud mismatch (which is defintely part of the complication)
I think the easiest route would be to weldup and redrill the bolt pattern on the C900 manifold to move to manifold 5/16" up or so. Then with only some minor porting to create a transition from the oval shape to a rectangle in the c900 manifold you'd be set. The only question at that point is hood clearance!

[DrewP]

I actually hadn't thought if welding over the bolt holes and lowering them a bit, but the more I think about it the more I like it. Looks like a real easy way to drop the manifold on - I'll bolt one one to my mockup engine on Monday and see how the hood clears and get a photo posted, I think it will just make it.

[Luke]

Now that I've been looking I've seen at least 4 of these in u-pull-its over the past few weeks, so if anyone really needs one to play with I can probably pull some next time Im there. I expect the cost would fall under "intake manifold" so maybe $25 or so.

[swmeatball]

I'm a little unclear on which cars the T7 head can be found on, I pulled one of a 1999 9-5, which I think is a T7? The local U-pull just got a 2001 9-5 Aero and a 2000 9-5 base, they'd both be T-7's no?

edit:

The car that still had anything under the hood had the single piece manifold. I didn't grab the head because I ran out of time and it'd started raining, hopefully it'll be there still next week.

[DrewP]

All 9-5's have T7 engine management, but not all of them have the two piece intake manifold. It's very obvious by just looking at it if it does or not.

From my post above which models should have the two-piece inlet manifold:

'99 9-5's (ALL, 2.3L and Euro 2.0L cars) (technically they were on MY98 9-5's that the European market got as well)
'99-'02 Viggens (ALL)
Possibly '00-'01 9-5 Aero's with B235R engine - not sure about this one.

The part number is either:

9185844 or
4774477

[KPAero]

I got a t7 head with the 2 piece manifold and spent some time taking a look at it today and ended up a bit confused. The passages that drew pointed out seamed to be carrying oil? It also doesn't look like it comes from the head, so it must flow in from up by where the throttle body attaches. (The passage goes all the way up there) And from what I can tell, the reason for the oil flowing through the manifold is for the injectors. There is a jacket around part of each injector that gets fed. I've never seen that before, and I'm wondering if I'm looking at how this works correctly. Has anyone looked at these more and have any insights? From the looks of the aluminum it has had oil in these areas for quite some time. I can get some pictures up tomorrow too.

[Crazyswede]

Very unlikely to be oil passages given their size and the operating pressure of hot oil. Most likely coolant passages intended to help bring the engine up to temperature faster. The 99's used to have a piece that fit into the intake manifold that circulated coolant through it.

I got a t7 head with the 2 piece manifold and spent some time taking a look at it today and ended up a bit confused. The passages that drew pointed out seamed to be carrying oil? It also doesn't look like it comes from the head, so it must flow in from up by where the throttle body attaches. (The passage goes all the way up there) And from what I can tell, the reason for the oil flowing through the manifold is for the injectors. There is a jacket around part of each injector that gets fed. I've never seen that before, and I'm wondering if I'm looking at how this works correctly. Has anyone looked at these more and have any insights? From the looks of the aluminum it has had oil in these areas for quite some time. I can get some pictures up tomorrow too.

[KPAero]

I thought it seamed odd, but I've never really worked on a 9-5 and wasn't sure. The head was just pulled off a car that was running fine until it was recently junked for other non-engine related stuff, and there was definitely oil sitting in there when I pulled things apart. Here are some pictures of what I'm talking about.

You can see where the passages would be and the head appears to be oil stained.

Here is where the passage starts.

You can see where the passage flows into this area around the injectors/

And the gray section in between the bottom two seals is where they get flooded by whatever fluid is in there.

[Luke]

The weird thing is, the channels in that thing definatly match up to the water jacket, but I pulled two of these out of junkyards last year and I remember noticing the exact same thing with the oil up in there, on both of them!... wondering if a chronic weepy headgasket lets oil into the coolant near the top of the head somewhere and without any circulation in that area (and being at the high point) it just floats up there and stays? Just a possible theory.....

[Crazyswede]

Well I was wrong one time before so it could be oil. It just seems like a bad idea to put oil into that area given that a leak will result in oil being burned in the engine.

[DrewP]

I think I see what's happening - the three freeze plugs in the head actually block off the coolant flowing to the intake - those passages are air spaces, there shouldn't be coolant in there, but if the freeze plugs weep a little it will collect in there and have nowhere to go. Those heads have the coolant temp sensors threaded into the end of the thermostat area, where the upper hose comes out, so there is no need for coolant flow there.

Weird that there are vents into the injector seal seats, I never noticed that. Must just be an expansion thing, so it doesn't blow out the intake mani gasket from it being sealed?

[Luke]

I think I see what's happening - the three freeze plugs in the head actually block off the coolant flowing to the intake - those passages are air spaces, there shouldn't be coolant in there, but if the freeze plugs weep a little it will collect in there and have nowhere to go. Those heads have the coolant temp sensors threaded into the end of the thermostat area, where the upper hose comes out, so there is no need for coolant flow there.

Weird that there are vents into the injector seal seats, I never noticed that. Must just be an expansion thing, so it doesn't blow out the intake mani gasket from it being sealed?

oh weird, now looking at the pic of the head that pascal posted I see the freeze plugs, I didnt notice those when I was yanking some of these spacers out to play with, but I wasnt looking that closely at the head.

So where is the oil feeding in from, must be a line into the manifold?
Weird stuff....