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Carrera RSR · Joined: 08 Jan 2010 Posts: 2312 Location: Somerset, UK

I am suffering with an exhaust blow from manifold to head or manifold to turbo union but although its quite loud cold and abates when hot I cannot for the life of me locate it. The manifold has been welded between the 1st and 2nd cylinder but looks like its holding. There is no sign whatsoever of soot which is a good tell tale of location. I have looked at everything above and below and stumped. The manifold/turbo was removed last year by the PO during a head rebuild and all gaskets were replaced. I have checked the tightness all nuts on top of the manifold and the ones I can get to from below. J pipe looks solid. All gaskets look good.

I have found this http://www.924board.org/viewtopic.php?t=19349&postdays=0&postorder=asc&start=165 bit disappointed all pics have gone. I have a race engineer who has promised to look into building a new stainless manifold and exhaust this Winter so would like some advice on steering him into the design and build of the new system.

All ideas, threads and pics welcome
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1980 931 - forged pistons, Piper cam, K27/26 3257 6.10 hybrid turbo, 951 FMIC, custom intake, Mittelmotor dizzy & cam pulley, H&S exhaust, GAZ Gold, Fuch'ed, Quaife
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ideola · Joined: 01 Oct 2004 Posts: 15550 Location: Spring Lake MI

Are you certain the three bolts on the turbine-to-manifold flange are all tight? They have a tendency to back out if not safety wired.
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erstwhile owner of just about every 924 variant ever made

Carrera RSR · Joined: 08 Jan 2010 Posts: 2312 Location: Somerset, UK

Are all three bolted in from above. I can see two from above closest to the inner wing. I can't see the third which I assume is under the manifold. If its bolted in from below mine has backed out completely!! Any idea of spec and length?
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1980 931 - forged pistons, Piper cam, K27/26 3257 6.10 hybrid turbo, 951 FMIC, custom intake, Mittelmotor dizzy & cam pulley, H&S exhaust, GAZ Gold, Fuch'ed, Quaife
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Paul · Posted: Mon Jul 19, 2010 8:03 am Post subject:

M10 x 25 mm and yes it is on the bottom.
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White 87 924S "Ghost"
Silver 98 986 3.6l 320 HP "Frank N Stein"
White 01 986 "Christine"
Polar Silver 02 996TT. "Turbo"
Owned and repaired 924s since 1977
Porsche: It's not driving, it's therapy.

stevekat · Joined: 19 Jan 2008 Posts: 719 Location: Los Angeles, CA

Make sure you have the correct kind of gasket (sandwich or ring) for the type of manifold/turbo, etc. that you have. The method changed several times. Do not use both a sandwich and a ring. Also, use the collars on the turbo to manifold bolts. And yet, one does go in from the bottom.
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"Never get out of the boat. Absolutely goddamn right. Unless you are goin' all the way."

Gone to new home: '81 924T, US version, CGT Intercooler, UTCIS-PT, Euro DITC, Greddy Trust MBC, Forged Fuchs Flat Dish 6's, Factory Recaro's.

Dutch924-racer · Joined: 23 Jul 2007 Posts: 1081 Location: The Netherlands

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937 trackday car
Series 2 engine
951S turbo and intercooler
Fast road camshaft
Forge recirculation valve + boost controller

stevekat · Joined: 19 Jan 2008 Posts: 719 Location: Los Angeles, CA

Nice! Is that a part modified from the reactor at three mile island?

Looks highly engineered.
_________________
"Never get out of the boat. Absolutely goddamn right. Unless you are goin' all the way."

Gone to new home: '81 924T, US version, CGT Intercooler, UTCIS-PT, Euro DITC, Greddy Trust MBC, Forged Fuchs Flat Dish 6's, Factory Recaro's.

Carrera RSR · Joined: 08 Jan 2010 Posts: 2312 Location: Somerset, UK

I have definitely lost the lower bolt and collar. I removed one of the upper bolts and tried to fit in the lower. After 1 1/2 hours of faffing around I could not get it in due to the very limited access. Will probably need to remove oil filter, housing and oil cooler pipes to get it in. OPC can supply the bolt at £22/$30 each but the collars are no longer available.

Anyone know why the collars are needed and a shorter bolt not be used? Anyone have any collars for sale or indeed bolts as well?
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1980 931 - forged pistons, Piper cam, K27/26 3257 6.10 hybrid turbo, 951 FMIC, custom intake, Mittelmotor dizzy & cam pulley, H&S exhaust, GAZ Gold, Fuch'ed, Quaife
Now www.924board.org/viewtopic.php?t=34690
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stevekat · Joined: 19 Jan 2008 Posts: 719 Location: Los Angeles, CA

I think you can get at this from below with a couple of extensions and/or swivel sockets. Might want to loosen all bolts and tighten to evenly apply pressure.
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"Never get out of the boat. Absolutely goddamn right. Unless you are goin' all the way."

Gone to new home: '81 924T, US version, CGT Intercooler, UTCIS-PT, Euro DITC, Greddy Trust MBC, Forged Fuchs Flat Dish 6's, Factory Recaro's.

zimm · Joined: 18 Oct 2006 Posts: 62 Location: Hereford, UK.

give me the collar dimensions (so i dont have to strip mine to find out), and i can have some made and waiting for you when you come to pick those wheels up.

wouldnt think they'll cost much, and there's a decent machineshop round the corner i use for lots of little jobs.

I imagine they're required becuaes of the temperatures involved.

TTFN
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6 bikes, 9 cars, 1 van.... the more you have the less they work.

Rasta Monsta · Joined: 12 Jul 2006 Posts: 11733 Location: PacNW

stevekat · Joined: 19 Jan 2008 Posts: 719 Location: Los Angeles, CA

I was able to re-seal mine, as it used to close when the joint got hot, so it was very minor and only at start up. He may have to separate it (drop turbo) but getting that pulled together flat, as much as possible, in any situ might be best.
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"Never get out of the boat. Absolutely goddamn right. Unless you are goin' all the way."

Gone to new home: '81 924T, US version, CGT Intercooler, UTCIS-PT, Euro DITC, Greddy Trust MBC, Forged Fuchs Flat Dish 6's, Factory Recaro's.

Carrera RSR · Joined: 08 Jan 2010 Posts: 2312 Location: Somerset, UK

Any one manage to refit the lower bolt without unbolting or removing anything? Tried to do it on my back whist car was on stands. After an hour or more of trying I got the bolt in the hole but was unable to get purchase on the threads.

Will try to get the car on a ramp this weekend, any advice?
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1980 931 - forged pistons, Piper cam, K27/26 3257 6.10 hybrid turbo, 951 FMIC, custom intake, Mittelmotor dizzy & cam pulley, H&S exhaust, GAZ Gold, Fuch'ed, Quaife
Now www.924board.org/viewtopic.php?t=34690
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Cedric · Joined: 27 Aug 2004 Posts: 2834 Location: Sweden

Thats a pita bolt, not the first time it losens up on a 931, although mines seems to hold on

. If you use short bolts and no sleeve the bolt will overstrech when the manifold gets hot and expands. This will make the bolt losen up in no time. you could also see the waist on the oem bolts which also makes for streching. So proper torque and sleeves/bolts are really worth it on hot spots like this.
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1980 924 Turbo
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stevekat · Joined: 19 Jan 2008 Posts: 719 Location: Los Angeles, CA

I watched one of my techs get in there and tighten it up, however the bolt never came all the way out. It involved an extension or two, and possibly a universal and/or a universal built onto a socket. These are very effective as they require less height in that tight space to get the universal feature. Sears for sure sells them.
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"Never get out of the boat. Absolutely goddamn right. Unless you are goin' all the way."

Gone to new home: '81 924T, US version, CGT Intercooler, UTCIS-PT, Euro DITC, Greddy Trust MBC, Forged Fuchs Flat Dish 6's, Factory Recaro's.