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Discussion Starter #1 (Edited)
In the past year or so I haven't been driving my 9000 much. It developed head gasket issues, so I parked it deciding if I wanted to fix it or move on to something newer/faster/more economical to DD. I've been driving a VW MK3 TDI that gets better MPG. I do a fair amount of freeway driving now, but the TDI is not as quick or a comfy as my Aero-fied 9000. I was reading around about doing the headgasket and re-discovered a post I made about when I put the engine in the car! Wow, good memories... https://www.saabcentral.com/threads/top-end-engine-noise-trying-to-get-some-ideas-before-i-tear-in.277369/.

I had forgotten some details about what I did, but remembered I had checked, chained and resealed everything on this ~95K mile engine. I didn't think to do the headgasket or check headbolts at the time...now at ~135K it shows signs of needing one. It's not bad, but not ideal, using coolant had been getting worse on warm days as I recall.

Knowing I had all the maintenance done, I decided to fix the 9K and prep it for tuning. I'll make it into a cruiser hauler car that can sit alongside my Megaquirt'd Supercharged Miata.

Anyhow, lets get to it! What do you think I should do to the head while it's off for performance gains? Dont want to go too nuts, because...well...turbo. Ordered all the parts to do the job a year or so ago when I parked it...including head studs.


Chain still looks great (as it should!) and nice inside...
head.jpg



Cylinder 1 had the issue, nice and steam cleaned. The headgasket wasn't blown but it was all deformed right near the very left side by the chain guides. There was never any noticeable coolant in the oil...and the oil pressure (blue circle) and oil return (through the chain) are right there! Coolant passages I put a green square around. This one was likely the leaky one.
I will say, this block looks burly!

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Everything is nice and big and burly looking. Cylinders look great...no ridge and even have the crosshatches on the walls. My Miata engine was the mostly the same way when I rebuilt it for the MP62 supercharger...but not quite as good.

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Head is stripped down...checked it with a straight edge...
I was surprised it was that warped .010. I still have the other head from my old engine that had the bad the lower end, and even it was warped .011.
That engine never showed signs of headgasket problems (yet), never overheated, still warped. Seems like alot of warp to me too. But anyhow... Manual says can be milled up to .5mm (0.019in).
Machine shop took off .013in. Tiny bit of cam rock but they spin evenly by hand when torqued down with the lifters out...so we're GOOD to go.


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Starting to look into the valves..take inventory of the parts and WTF!? 12 Valve Stem seals? eEuroparts is a great place to buy parts..but service is sllllllloooww. Heard they are being sold and had financial problems. Wonder what they'll do...I ordered this stuff a year or so ago when I parked the car. Elring head set comes with 12 valve stem seals, and two (got an additional) intake manifold gaskets...bah

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I'll have a few days of downtime waiting for parts. What kind of things should I do to this head? Dont think I'm going to do a full PnP or gasket match...no flow-bench...takes too much time. The casting actually looks pretty dang good! Nice and smooth for the most part already, smooth combustion chamber, no major ridges in the intake or exhaust runners...unlike some other NA heads I've seen that had obvious improvement areas. This one could be better, but not bad...nothing super obvious. Maybe I'll smooth out the ridge around the combustion chamber a bit and/or polish...maybe not. Should I?
 

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Boost negates any runner flow porting so don't waste your $. If you want to do anything extra for a turbo setup then increase boost 10-15% and retune for more fuel. I would suggest sending the cams to WPC for micro-peening on the journals and lobes. Cheap longevity mod for flat-tappet wear. You may want to look into tighter springs with higher boost as well. What spark plug are you running?
 

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I would not polish anything in the intake or combustion zones due to the amount of NA operation there is. Knock down any major flash or casting lines if you'd like. It won't really make a difference either way. The texture and runner designs are critical to proper FI mixing of the charge before it's locked off for compression. Exhaust, feel free to port and polish to encourage scavenging out the headers. The faster the exhaust can get to the turbine the less amount of spool lag you'll get from throttle up.
 

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12 valve stem seals -- maybe for the GM 6 cyl eng by mistake?

I would not touch the combustion chamber -- tis one of the things Saab did right. Unless you're making a full race motor there's nothing to change here.

Put your money in a retuned ecu, larger exhaust elbow if you must, etc. and enjoy.
 

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12 valve stem seals -- maybe for the GM 6 cyl eng by mistake?

I would not touch the combustion chamber -- tis one of the things Saab did right. Unless you're making a full race motor there's nothing to change here.

Put your money in a retuned ecu, larger exhaust elbow if you must, etc. and enjoy.
Hey Banman do you think the non-turbo block can handle boost as well or are they different specs and parts? Any known limitations to the bottom?
 

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Discussion Starter #7
Went back to it last weekend. Got the head all assembled. Didn't do much for PnP. I noticed that the exhaust manifold has an oval hole that pretty well matches my turbo. I swear I had one with a round smaller hole in the manifold matched to a larger oval hole on the turbo. I was prepared to make this hole oval and larger, but alas It's ok. I smoothed out some casting marks.

Broken stud was a turd.

broken stud.jpg

Final screw for assembly. Dont remember where I had this plug from. Found it in a wrecking yard in like...2009

plug.jpg

Swear this was a tiny round hole on one of the manifolds I've worked in my years of owning these cars

oval hole.jpg

Copper coat for a good seal. The machining marks from the factory on the block looked like...meh... they didn't care too much.
Put head studs in it, but I cant install them and set the head down over the chain guides.

copper.jpg

Boom installed! In two weeks, I'll start to put the rest of it back together.

installed.jpg


I was doing an inventory of all my wires behind the head that go to the intake manifold area. I cant find the ground wires OR my TPS plug. Was it on a separate harness that I put somewhere? Either that or it fell down somewhere and I need to go dig it out.
 

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I know you already torqued and timed the cams but if you decide to do another one send the cams to WPC and get the lobes and journals micro-peened. Flat-tappet design wears the lobes fast with today's low-zddp oil formulations. The micro-peening will make the whole drivetrain last a LOT longer and run cooler.
 
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