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Stranger on the Internet
Join Date: Apr 2004
Location: Bradenton, FL
Posts: 3,244
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Cam Timing SC
Hi all:
I have DC-15 cams in my 3.0. These are essentially SC cams. Regardless, is there a way to check cam timing with the engine in the car? I can likely gat to #4 OK, but the 1-2-3 side is hellish. I'm wondering lately if the cams are timed a bit off. TIA Pat
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Patrick E. Keefe 78 SC |
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12-29-2020, 07:52 AM
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Join Date: Oct 2008
Location: Nash County, NC.
Posts: 8,518
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Just pull the top valve covers and set TDC Z1 Install dial gauge on 1; rotator 360 and record reading.
Set up dial indicator on #4 and turn 360 degrees back to Z1. Record and compare If there is a major difference, you should pull motor and set on table for ease of work. Bruce |
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12-29-2020, 12:07 PM
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Join Date: Sep 2005
Location: Northern Virginia
Posts: 1,794
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Hey, Pat, what symptoms are you experiencing that suggests a cam timing problem? A failed or failing tensioner can mess up engine timing. That's easy enough to check before moving on to verifying cam timing with the dial indicator.
Nix
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'82 SC Targa '83 SC Cabriolet |
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12-30-2020, 02:31 PM
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Stranger on the Internet
Join Date: Apr 2004
Location: Bradenton, FL
Posts: 3,244
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Car seems to misfire and run badly in general, in different RPM ranges. The trouble is in lower RPM ranges, like up to 4000. Engine pulls pretty well above 4000. One day it's OK, the next day, not so much. I still seemingly don't have the EFI properly dialed in yet. My AFR's skip around quite a bit, which I can't explain to my own satisfaction. My leak down numbers are all very good, like within a few percent, IIRC. The valves are adjusted per spec. Something is going on; I just don't know what, and I am usually pretty good at troubleshooting. I have some sort of intermittent issue, it seems.
But I think the cam timing is a reach. I need to find someone here in Bradenton with a dyno to get this sorted. BTW, I have hydraulic Carrera tensioners, along with new chains and ramps.
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Patrick E. Keefe 78 SC |
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12-30-2020, 05:10 PM
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Location: Northern Virginia
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I've experienced the failure of both types of tensioners. With the later, pressure-fed Carrera tensioner failure, the engine was a fresh rebuild and the tensioner was brand new, but failed to pressure up at low RPMs.
The apparent symptom was a loud growly sound at low engine RPMs from the right bank and the timing just slight moving around when I checked it with a timing light. At anything above 2,000 RPMs or so the noise would go away -- I guess because the tensioner filled up from the higher oil pressure. Anyway, another fresh tensioner solved the problem. Still a pain, though. Good luck on getting your engine sorted. Nix
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'82 SC Targa '83 SC Cabriolet |
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12-31-2020, 04:32 AM
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Join Date: Jul 2001
Location: mt. vernon Wa. USA
Posts: 8,727
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Pat,
What ECU are you using? Are you datalogging? regards, al
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12-31-2020, 06:35 AM
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Cam timing measurements......
Pat,
Use a mechanical or solid chain tensioners when doing cam timing to obtain consistent readings. There is a significant difference between mechanical and hydraulic tensioners values. Tony Last edited by boyt911sc; 01-02-2021 at 06:18 AM.. |
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01-02-2021, 05:29 AM
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