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Discussion Starter · #1 ·
Hey guys...starting a new thread since my old one gets views but no questions answered. I'm about to rebolt my exhaust manifold to the block, and I don't want to have to redo this again (just did it a few months ago). My question is...does the gasket go on a specific way? I have this one from eeuroparts : link...except that both sides are covered in a sort of white puffy coating. So there's no real difference between sides, except that on one side the edges of the holes are sharp, and on the other they are a bit rounded. Any one have any insight?
 

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Whenever I have assembled something with rounded edges they have always gone face first into the flow of a fluid (air is a fluid) for reduced turbulance (however slight it may be) so I would put the rounded edges towards the block.
 

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Discussion Starter · #5 ·
How do you tell one side from the other? It appears to be a metal sheet covered with a puffy white material... identical on both sides except for the stamping?
 

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I don't want to insult you, but did you check that there is no wrapping on the gasket? When I rebuilt a go-kart racing engine the new gaskets came with like a teflon (??? some white shit) coating. Turned out that it was some film to prevent the gasket from getting nicked and oxidizing (lead gasket)
-Cm
 

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Discussion Starter · #7 ·
Yeah, definitely not a film or anything, at least with the one linked from eeuro. I pulled apart the old one to check...it's the white coating, thin metal, graphite, thin metal, white coating. Incidentally, after trying to fit the gasket both ways I discovered that due to the way the top center hole is punched, it will actually only fit on in one direction.

Doesn't matter though because the stupid bottom stud under the PS pump stripped right out when I tried to torque it to spec, even with the addition of some JBweld in the threads. So now I'm basically at the point where I think the whole head needs pulled, it'll need welded and then machined and rethreaded. So basically FML. Hard.

What all do I need parts wise to pull the head? New gasket, new head bolts...anything else I should do while I'm in there...(Timing chain etc)

The car only has 96 and change on it. No sludging issues or anything as I pulled the pan earlier this summer while doing my suspension. Blah.
 

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I don't really think you need to do all that for a single stripped manifold stud. Pretty sure one of mine is in similar condition, or at least close to it. In my case I haven't really had any issues with it. I guess if you have the time though...
 

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You have an turbo engine, right? 900 se. I dont know about the turbo's, but the other engines had a problem in the 80s. The exhaust manifold would come loose all the time. Solution from SAAB's side was to put longer studs on the head (about an inch) so it should be something like this= washer, long metal "tube", maybe a washer again, and finally the nut. This solved the problem.
 

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Discussion Starter · #10 ·
Yeah, it's a turbo'ed 900 se. I definitely can't leave it like this, as it's leaking exhaust out of the that corner heavily. You can hear it. I sound like a honda with a fart can, except the farts are coming out of the engine bay. It's not like I really want to pull this head to fix one damn bolt. I definitely don't have that much free time on my hands and what I do I'd rather be spending warm, rather than freezing my ass off in the Pittsburgh cold.

El, my manifold has the longer bolts with those spacers/heat expansion tubes with the washers and the whole dealy already. The problem is that stud under the PS pump broke off a while back, and during this summer I discovered it in the course of pulling my turbo due to it breaking a stud at the exhaust clamp. My father and I drilled the stud out and retapped it for 3/8s, unfortunately the tap must have wobbled or the drill wasn't perfectly straight or something. The new stud threaded in nice and tight, but when torqued pulled out. I'm afraid to drill it out any larger because I have no idea what the tolerances on everything are near there.
 

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How about Helicoil, or something similar? It's hell to put Helicoil in, if it's a tight space. But if you had room enough to drill it out and retap it, you might be able to put H.coil in? Autozone sells kits with the inserts tool and everything. 25 to 30 dollar I think. The torque for a M8 bolt is around 25 nm, which feels like almoust nothing, on a normal handwrench. I normaly probably tighten a M8 with 35 nm. But in your case to avoid breaking it again (if you put H.coil in) I would torque it exactly what the book says.
 

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My dad just replaced my manny gasket. Bought the gasket + turbo gasket + set of exhaust studs off eeuro. I can ask him which way he did it... maybe.
 

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Discussion Starter · #13 ·
Any input would be good Aikmanson. El, we're looking into the helicoil right now, I've never installed one and am not familiar with how it works at all...will update when I have some more info
 

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Helicoil works sometimes, and not others. I've had mixed success with it at a couple bike shops I've worked at. We keep some around for cheap customers who would rather fix a worn out part than replace it. For something like the head that gets hot, I have no idea, but I've heard other people did the same and it seemed to hold. Depends on how much metal is left in there to grab to. Otherwise it would require a bigger bolt.

Basically it makes up for threads being gone, and replaces them by binding to what is left in the hole.
 

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There's nothing wrong with helicoils, and sometimes the "cheap customer" may be the wise one. Better to repair something easily than replace it needlessly. But maybe there's no space for that viewpoint in brainless modern society.

Super, the "gist" is that you drill out the stripped part with a larger bore, tap it, and screw in the coil which is threaded inside the same as the original stud or bolt.

I don't know the NG900 well but I know the exhaust is in front of the car. If you cant get a hand drill in the front, it might be easeir to take out the radiator to get space than to pull the head to retap it.
 

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Discussion Starter · #16 · (Edited)
My concern here is that this hole was already drilled at tapped out to fit 3/8s once already...I have no idea what the clearances/tolerances are like with relation to the exhaust valves and all that nonsense. Basically I've talked to the machine shop that just decked the manifold per Harvey's suggestion, and they said their suggestions were to do the following: Try a 7/16ths fine tap first...if that doesnt work, try the helicoil kit. If that doesn't work, pull the head and they will insert a steel sleeve rather than risk welding it, as apparently that can warp the aluminum fairly easily.

Off hand does anyone know the specs for the stock studs? m8 x 1.25?

If I've gotta remove the manifold from all the bolts I have torqued the gasket is f'ed, right?

What's the proper torque for these? Harvey suggested between 25-29 ft/lbs so I set my torque wrench to 27 ft/lbs...I'm seeing on the platonoff site however that he torqued his to 18.5?

I probably can't have the one shitty bolt torqued to 18.5 while the rest are at 27, right? Seems to me that would encourage warping and another blow out of the manifold...
 

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When you ruin a light alloy tread for a sparkplug, and repair it with Helicoil. It can be really good, because now you have a stainless steel tread, instead of a soft alloy one. WV type 1, was an engine that this happen a lot to. Because you are fumbling around with 2 fingers in a deep dark hole on an aircooled engine. Long time after I stopped doing services on these engines I heard about the "rubber hose trick". Anyway, I think H.Coil is a great "head saver".
 

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18,5ft/lbs is around 25 Nm, and I guess that's what SAAB recomend. In the "real world" (when you are in hurry) where you tighten most M8 bolts with a regular wrench, you probably end up around 35 Nm. I did some measurements with a torque wrench that could measure "loosening torque", and I ended up around 35 Nm, with the good old 'feel". 35 Nm is around 25ft/lbs. If your repaired tread can't survive 25ft/lbs, I think it was no good anyway, and would not last long. I would go for 25ft/lbs, and torque all bolts with that.
 
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