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

[DrewP]

I've never taken an intake manifold off a B2x4/B2x5 engine and not had engine oil in there, either from getting blown in from the turbo or from the PCV setup.

Every time I pulled a throttle body off you could see little puddles of oil hanging out in the bottom of the plenum. I stopped worrying about it.

[KPAero]

I was going to order the gaskets I need to put a motor together and just want to confirm I have this right. With a modified timing cover, I want to get the T7 headgasket?

[Luke]

I was going to order the gaskets I need to put a motor together and just want to confirm I have this right. With a modified timing cover, I want to get the T7 headgasket?

I was with Jason when he yanked the T7 head and we noticed how thin the T7 headgasket is, its like a piece of tin foil compared to a B202, B204 etc headgasket. I was hoping someone more familiar with the modern SAABs could shed light on the durability of this gasket vs a traditional one. With the timing cover mod you'd need to use either a T5 or T7 headgasket to seal the flanges. The shape of the T5/T7 gaskets are identical, only the material and thickness is different. Also of concern is that the T7 headgasket is so thin that the clearance from the deck height of the pistons to the combustion chamber becomes very close for comfort.
Also the valves on the T7 head are concave, so you will lose compression if you use a T7 head with a thicker T5 headgasket, that may not be an issue on a turbo motors, but for those wanting to use the T7 head on a high compression 2.5 stroker-motor it would be. I would guess that thinner headgasket was a means to get back some compression lost from the concave valve heads.

[DrewP]

The dishes in C900 turbo pistons are significantly deeper than the dishes in either 9-3 or 9-5's. I have a 9-5 piston that I could measure the dish and post what the difference is. I'm quite certain they won't hit because the 9-3 and 9-5 pistons still come up flush with the surface of the deck.

The T7 multi-layer steel gaskets are very durable, no problems with them blowing out. They're 3 layers of die cut steel that lets the 3 layers slide against each other from the difference in CTE of the iron block and AL head.

I bought a NG900/9000 T5 gasket for mocking up, and planned to get a T7 MLS gasket to compare what the crushed thickness is. I think it might be an easy way to bump the CR up a little bit, but I honestly don't know.

Raul had a couple comments in his engine thread of which combination of rods, pistons, and head gasket he used to get the pistons to still align flush with the top of the deck.





9-5 piston with shallow dish on the left, 9-3 on the right (essentially flat on top with a small dimple in the center about 25mm across). T7 pistons also have the crowns hard anodized - you can see on the 9-5 piston at left that the dipshits I used to work with like to buff completely through the anodizing when they clean the carbon off during a head gasket job.









You can see what's left of the anodizing layer here:






C900 rod and piston on the left, 9-5 rod and piston on the right:

[KPAero]

Edit: Drew beat me to it, but the T7 gasket should hold up fine. Even those with big turbos and 500-600hp seem to have pretty good reliability using them.

I will get a T7 gasket and see how things look clearance wise and report back.

[DrewP]

Sweet. I'll check with my T5 gasket, I'll be at the shop this weekend.

Actually, what I'll do is put them together with no gasket, and see what the clearance is with a stock B202 bottom end, unless somebody does that too. That should be quick.

With a stock B202 you can have either or both cam gears off one tooth either way with no valve collision, it'd be good to know if that's still the case with the higher lift, longer duration T5 cams and the bigger valves.

[SwedeSport]

I am anxiously waiting for the specs. Assuming I stick my 9-3 head on a used 89t bottom end, what the actual CR is going to end up as. If I had the gasket ordered, and the timing cover mod in hands, I could almost be bolting the head on this weekend.

So long as the valve to piston clearance is sufficient, the more important issue becomes the CR.

[DrewP]

Ok.

B202:
New: 1.45mm / 0.057"
Crushed: 1.29mm / 0.050"


B204/B205/B234:
New: 1.49mm / 0.059"
Crushed: N/A


B235:
New: N/A
Crushed: 0.61mm / 0.025"




So T5 gaskets are essentially identical thickness to B202 gaskets.

The crushed gaskets are unloaded and out of the engine of course, they may crush slightly more when loaded under head bolts.

The Viggen/9-5 gaskets are substantially thinner. The B235 engines have pistons with slight dishes, though not as deep as the dishes in C900 pistons. The B204/B205 engines have essentially flat topped pistons.

[SwedeSport]

I guess the next step is to CC a t7 combustion chamber, t7 gasket and c900 (b202) piston dish? Then do the math to see where the combined CR is going to land?

[DrewP]

Yup. I have most of the stuff, but won't have a chance to get at it for a few days. I think we've got some decent metering syringes at work.

[SwedeSport]

I was planning to plop the head on with no gasket and install the chains and time it. But realized that until I score a set of the t5 cams with higher lift, none of that info would be relevant.

If I can get to the u-pull it this weekend Ill look for cams. (IIRC you (Drew) said that the 94-98 NG900 cams are the ones I want? I assume you mean off a turbo?

If I can get the cams Ill time it all up, stick some silly putty on the piston top and see what kind of clearance is there with the higher lift cams.

[Luke]

If I can get to the u-pull it this weekend Ill look for cams. (IIRC you (Drew) said that the 94-98 NG900 cams are the ones I want? I assume you mean off a turbo?

Its been a couple years since I dealt with all this stuff but I seem to remember that the 86-93 C900 turbo cams were the best of all the of- the-shelf stuff. 252 duration and 8.65mm lift. As far as I know all SAAB 16V's had 8.65 mm lift with the exception of the 85 intake?

[DrewP]

Yup, B204/B234 turbos from '94-'98 and '99 9-3's. Same 8.65mm lift as Luke states but a little less duration and different overlap Need to get the info for B202 and B212 cams into this chart that Nick has up:


http://genuinesaab.com/temp/cams.htm

[swmeatball]

I've been collecting bits to do the T7 head on a B202, it will eventually end up in the '80 99 I put a nearly dead T16v in. I put them together for fun last night just to see what it looks like, its a big greasy mess just like I'd predicted. I'm going to freshen the block (seals, bearings, and rings) and put new timing stuff in, as well as a T5 flywheel to go with the Megasquirt I've got sitting on the shelf. I'll relocate the holes for the manifold to line up with the fuel injector block and weld some stock in at the timing cover to fill up the hole, sounds like the steel T7 head gasket is the way to go? Any cam advice? I have a set from an 85 turbo, and of course the ones that came with it, any votes? I'm not trying to wring the maximumest HP out of this thing, its more about seeing how far I can get on $30 cylinder heads from the junkyard and homemade FI systems.

[swmeatball]

OK I just read Drew's post, the one immediately above mine... Not sure how I missed the cam info but I'll find the right ones.