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If anyone out there has a left side cam from a 1984 R.o.W car I am in urgent need. According to the WSM these cams are unique to 1984 R.o.W. I will take a set if that's what you have. The cams will be stamped on the end with 211 for the RH side and 212 for the LH side. Part numbers are 928.105.212.00 and 928.105.211.00 respectively. What we thought was a bad gear turned out to be a broken cam. What's crazy is that this engine has been running for at least a year and a half with a broken cam! The timing slowly started creeping over time until the skip was significant. I've heard of people snapping the nose of the left cam but I've never heard of one that kept running for this long. Thanks to you all for any leads you can provide.
Fronkenstein
Last edited by Fronkenstein; 06-12-2018 at 10:45 PM.
Reason: add year of cams needed
Yeah I was going to call them in the AM. Particularly hard to get is an understatement considering it is peculiar to 1984 R.o.W cars. Does anyone have the actual lift and duration specs on these cams? The valve open/close data on these cams is very similar to the 78-80 cams but I don't know what the lift is.
If anyone out there has a left side cam from a 1984 R.o.W car I am in urgent need. According to the WSM these cams are unique to 1984 R.o.W. I will take a set if that's what you have. The cams will be stamped on the end with 211 for the RH side and 212 for the LH side. Part numbers are 928.105.212.00 and 928.105.211.00 respectively. What we thought was a bad gear turned out to be a broken cam. What's crazy is that this engine has been running for at least a year and a half with a broken cam! The timing slowly started creeping over time until the skip was significant. I've heard of people snapping the nose of the left cam but I've never heard of one that kept running for this long. Thanks to you all for any leads you can provide.
Fronkenstein
Sorry to her this. Just curious - in what manner is it broken? Do you have any pictures? What were the running symptoms?
Had my left bank cam snout crack less than 6 months after I bought the car. The noise sounded like a rod bearing. Took me about 9 months to find a replacement cam, that's why when a set of m28/21 heads and cams came up for sale I jumped on it just so I had spares. If you're going to keep the car you may want to do the same. Also try reaching out to Roger, he has friends all over the world. It might cost you a premium but it will be worth it.
Posted on the UK 928 group - also the German group.
__________________
Does it have the "Do It Yourself" manual transmission, or the superior "Fully Equipped by Porsche" Automatic Transmission? George Layton March 2014
928 Owners are ".....a secret sect of quietly assured Porsche pragmatists who in near anonymity appreciate the prodigious, easy going prowess of the 928."
Sorry to her this. Just curious - in what manner is it broken? Do you have any pictures? What were the running symptoms?
No pictures yet because we haven't pulled the cam tower. The symptoms over 18 months were chasing two issues. First issue was poor running due to a fuel distributor issue. Then after that was solved I had intermittent performance issues. Apparently the cam gear was moving back and forth and sometimes she would run awesome and then not so awesome. Then the problem became worse to the point if I pulled a plug wire on the left bank it made little change to the running of the car. It really didn't matter which plug from 5-8. Also my AFR gauges showed that the right bank was running lean when I adjusted the mixture to get the left up around 13. It was always 3-4 points unbalanced and IR showed a 100 degree difference from RH to LH header temp. All of this pointed to either a fuel delivery issue, unlikely but we tested it, or a timing issue. It was a systemic LH bank issue. So we popped the covers and saw that the LH cam gear was running out of round. We loosened the belt and unbolted the cam gear and to my dismay the snout was wobbling around held in by the distributor. I will pull the distributor later and post pictures, but it isn't going to show much more than a broken cam.
I know exactly why this happened. When I purchased this from a recycle yard, LKQ, it was received with two issues, old coolant still present because they didn't pull the rear lower drain plugs. That required 21 TIG repairs to both heads surfaces. The second issue and the one that caused this mayhem is that the LH bank cam gear was out of round by 5mm! I called LKQ and told them they sent me a potentially broken engine. I negotiated to keep it for $750 including the shipping. I figured at very least I would have 3/4 of an M28/22. When I disassembled the engine the cam was intact with no apparent damage - right. So we refreshed the bearings and put it back together and she ran AWESOME. Then over time the micro line crack the was caused by the impact finally broke in half. Fortunately the long gear bolt and distributor kept it stable for at least 18 months and the engine didn't self-destruct. The way I see it I am very lucky.
Thanks to Mr Merlin for being a sounding board helping me to return my focus to a timing issue rather than fuel delivery.
Clearly I got very lucky. Notice the wear on the keyway and how close we came to losing contact with the cam itself.
Wow
Ouch
Hanging on!
Just barely caught. We were minutes from a disaster
Something clearly wrong here. I need to check the collar from another assembly. I find it hard to believe that this is wear. It appears to have been machined, but then again...
06-12-2018, 06:34 PM
Urgent need of an M28/22 left cam :(
George Layton March 2014
