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Registered
Join Date: Feb 2014
Location: Louisville, KY
Posts: 10
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Cam chain sprocket
Started rebuilding down my 1987 930 engine and found when I removed the cam covers someone has been in here before. The left side has the old style chain tensioner (requiring crows foot to remove) and the right side is the newer version. Is there any problem with having this set-up this way? When this change was do, did they need to change something else?
 
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12-29-2019, 04:21 PM
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Banned
Join Date: Oct 2019
Location: St.Pete
Posts: 90
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There might be a problem with the cam type specs, you need to firstly id the cams to see what are specs on them for correct timing info.
Nick. |
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12-29-2019, 07:28 PM
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Join Date: Nov 2000
Location: kcmo
Posts: 1,069
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Have you ever seen this engine run. I'm not liking it but if it works. Looks like somebody cut some corners. I wonder what else they did. Maybe MM. rebuilt it.
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12-29-2019, 07:29 PM
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I believe Porsche started using the bolt to secure the cam starting with the 1984 Carreras. the cam profile is the same as the 1978-83 911 SC cam. Both cams could be SC grind but one cam wnt bad and was replace with the later Carrera cam.
Rahl |
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12-29-2019, 07:46 PM
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Stranger on the Internet
Join Date: Apr 2004
Location: Bradenton, FL
Posts: 3,244
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You have camshafts that are definitely not the original configuration. As sixbanger says, wonder what else they did.
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Patrick E. Keefe 78 SC |
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12-29-2019, 08:10 PM
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Join Date: Feb 2014
Location: Louisville, KY
Posts: 10
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Thanks for the replies. The engine was running in the car, but it backfired constanly when you let off any amount of gas. Not sure if that could be from the wrong cam though. I guess my only choose is pull them out and check them.
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12-30-2019, 05:25 PM
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Do you know if you still have the, I think it's called "decell valve"? It is the gold colored saucer looking part. It helps to prevent the popping on deceleration. It could also be that you are running a little rich.
Rahl |
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12-30-2019, 07:01 PM
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Join Date: Oct 2006
Location: MYR S.C.
Posts: 17,321
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my bet is the left side cam got damaged and they replaced it with an earlier cam.
I had it happen to me when some coking came lose from the turbo and blocked one of the oil holes in the cam housing. it messes up a cam lobe and rocker. just find a used set of SC cams or get some new cams. you could easily measure the cam lobes on each cam to see if they have the same lift. my bet is they are not the same profile. backfiring can be lots of things. exhaust air leaks, the exhaust he is running. ditch the decal valve.
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86 930 94kmiles [_  _] RUNNING:[__] NOT RUNNING: ____77 911S widebody: SOLD88 BMW 325is 200K+ SOLD 03 BMW 330CI 220K:: [_ _] RUNNING: [__] NOT RUNNING:01 suburban 330K:: [_ _] RUNNING: [__] NOT RUNNING:RACE CAR:: sold |
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12-31-2019, 03:01 AM
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Join Date: Mar 2005
Location: Phoenix, AZ
Posts: 2,852
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To the OP -- did you get this resolved yet?
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Chris Carroll TurboKraft, Inc. Tel. 480.969.0911 email: info@turbokraft.com http://www.facebook.com/TurboKraft - http://www.instagram.com/TurboKraft |
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01-08-2020, 07:49 AM
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Join Date: Oct 2006
Location: MYR S.C.
Posts: 17,321
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I have a left side stock 930 cam if you want it.
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86 930 94kmiles [_ _] RUNNING:[__] NOT RUNNING: ____77 911S widebody: SOLD88 BMW 325is 200K+ SOLD 03 BMW 330CI 220K:: [_ _] RUNNING: [__] NOT RUNNING:01 suburban 330K:: [_ _] RUNNING: [__] NOT RUNNING:RACE CAR:: sold |
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01-08-2020, 09:26 AM
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1976 Porsche 930
