Exhaust Manifold nightmare - anyone have a jig?

Hi folks Apologies for the brand new account, i locked myself out of my other one, but the mods are clearly down due to the corona crisis as the request to unlock it hasn't been done yet. Anyway, what else does one do on lock down other than get cracking on jobs you've got outstanding on the 996? :hand: After heating up gently and allowing to cool, soaking with plus gas every day for 2 weeks, the upshot being for me is i now have 7 of the 12 studs snapped in the head (4 flush) 4 came out and 1 is still stuck with a rounded off head. Winner! I'm a lucky boy in that i have a 2 post lift in the garage and access to a time-served mechanical engineer of a father in law to help take on the task of drilling. Rather than buy the outrageously expensive stomski jig, i wonder if anyone has one that they could sell me? Or indeed I'm happy to rent it and cover postage and some beer tokens. Also, any tips on the depth to drill to on the header bolts, plus tips on how to get the exhaust flange studs out (grinding and smacking with the tapping stick not working) then i'd be very grateful! I guess i need to take the cat clamps off and remove the whole lot to drill these out? Thanks in advance for any help

I've not done it yet (although I know there is a small blow there on my car) but the studs in the cat look like a tough job. I saw a thread where someone had just cut the flange on the cat itself parallel to the stud. This released the pressure on the press fit stud and allowed them to be removed easily. Makes sense and seems unlikely to cause any damage to the cat - although maybe wise to use washers under the head of the replacement bolts.

Maybe get a specialist in from your area? In the motor trade there are various "bolt and injector" removal men they will come to your home and sort you out.

Hi sorry to hear that - i had this on mine last summer when 6 snapped/twisted off on my NS manifold. 2 were flush with the head My ex-OPC Tech had the car on a lift and had a friend of his in to weld a short section of rod with a nut onto each one. the heat helped as well I guess - they came out easily after that. I am planning to have the OS changed as well just in case as they aren't getting any younger ! Might be a different route if you have a handy welder near you instead? HTH and good luck :thumb:

I did this over Christmas and posted a long thread about it. In all honesty I'd stop now and get a jig from someone or make a jig out of an old manifold. I had nuts welded on and had an array of tools and basically nothing really helped. Drilling, tapping is the way to go but you'll want the jig.

Just borrow a jig, a few on here have them. Or buy one, you'll get 75% of the cash back when you sell it again on ebay afterwards.

http://911uk.com/viewtopic.php?t=134686 Give Mistercorn a shout

Mine is out with somebody at the moment, I'll see when I can get it back. MC

Thanks mate, that would be excellent. I'm just off J22 of the M1, so i'm pretty close to you if/ when you do get it back. As some have suggested, I really do think drilling is the way to go! If i can't find someone with the jig in the next week or two, i'll do as suggested and buy one, then either sell it on or do a rental service on here to earn the pennies back.

Is there a reason why these bolts are not replaced when eventually removed, with stainless studs and brass nuts in the old-fashioned way? Stuart

Some people do, but usually replacing with ss bolts is sufficient.

Just get the best bolts available and they will last for many, many years, I looked at my bolts the other day and they are in as new condition and I fitted stainless bolts around 7 years ago.

I'll be going with something much more durable. I know Titanium studs with nuts are an option too. SS probably just be fine if regularly checked. I will add, "release and grease" to my annual service items list! For those experts out there, can you give me any idea of the drilling depth? I believe the head bolts are M8 x 28? So all 6 of them will be drilled to 28mm plus the depth of the gauge?

28mm less the thickness of the flange on the exh manifold plus the thickness of the jig /arbor guide. I'd use a depth gauge on the ones you got out and check the depth of the drilling so you know the tolerance you've got to play with.

Any links to the stainless bolts? Ive just refitted mine with a brand new set from Porsche but id rather future proof if i can. And yes it was a complete pain in the balls