Yesterday the shorter bolts arrived for the tappet chest, the standard ones are 35mm long but due to a slight machining issue on the prototype some areas where it bolts down are around 3-4mm lower than they should be. Thankfully it doesn't affect any areas where the height is critical so I can just bolt it down with shorter bolts, after checking that they won't bottom out of course.
Tappet chest all bolted in and bolts torqued to 10Nm, starting from the middle and working out.
Camshafts and variocam actuator fitted. I'm not changing the pads on this as they look OK and they won't be in for long.
The tension was taken off the actuator using a piece of M5 left hand threaded rod and some nuts. At some point they changed from using a right handed thread to a left hand thread on these, so you can find either on the cars.
Caps and variocam actuator all torqued up to 10Nm, camshaft drive sprocket refitted. Final timing will be done when the cover is installed.
Now cleaning up the cover. I'll get some sealant ordered ready to refit it.
Joined: 07 Oct 2016 Posts: 1065
Posted: Tue Apr 30, 2019 8:16 am Post subject:
There was a Wheeler Dealers in the US (sorry can't remember which) where they added material to worn cam lobes by welding. Seemed highly dubious to me, apart from anything else, the material of the cams is critical to avoid wear.
Weld is pretty tough stuff, much harder than standard unhardened steel. And I suppose if you then weld and quench, you could make it pot hard, then temper back to the toughness you require, especially if you can weld with an EN steel that is made for hardening.
All in, it's probably a very cheaper solution than manufacturing new cams.
Yes I agree and probably fine on a 'more basic car' but I would never use this on a Porsche! The real issue is that you don't know how hard the new finish is (they didn't seem to test it at all.) _________________ Mike
2003 996.2 C2 Coupe Arctic Silver
Joined: 08 Nov 2018 Posts: 441
Posted: Tue Apr 30, 2019 9:07 am Post subject:
First class stuff mc _________________ #modified996mk1
MisterCorn Long Beach
Joined: 08 Jan 2011 Posts: 6941 Location: Nottingham, England
Joined: 21 Mar 2015 Posts: 6485 Location: Brighton
Posted: Wed May 01, 2019 7:11 pm Post subject:
I don't like to butt in with obvious points but just to be on the safe side ..
If you have altered the position of the vario cam unit .. removed it etc then dry fit the cam cover and make sure the solenoid is central in the cam cover hole .. i've seen them shifted to one side before and it causes leaks .. mechanic should have removed cover and adjusted it but hadn't .
There is a left and a right handed thread tool for locking these down .. i had assumed they were always like this but im afraid i just follow instructions so don't really know if it was the same at one point .
When you wind the 13mm nut back on the ims .. put a bit of sealant under it .. just in case the small seal gets damaged this will stop any further leaks .
Shaft play and its up down .. in / out and spin.. at least that's how i do it but its pretty obvious when there is wear _________________ .
After some discussion, it was thought a good idea to add in the rev ranges and rev checking like on the later cars. This is being done in the instrument cluster so it is independent of the ECU being used. There are six ranges set up, which can be set for any desired RPM value. The system counts the number of ignition events in each range and stores the number along with the time in seconds that the event occurred at.
New o-ring and outer seal have arrived, along with the two sealing washers for the tensioners. I will also be fitting new viton o-rings for the tensioners but these are coming from another source and haven't arrived yet.
Cover removed from the IMS bearing, all looks nice and clean inside, but no sign of any grease as expected.
Cover put back in place after fitting the new o-ring to the shaft.
Bolts all cleaned up and refitted with some Loctite thread sealant on them.
Centre nut refitted, again with Loctite thread sealant.
Joined: 08 Nov 2018 Posts: 441
Posted: Tue May 07, 2019 9:30 am Post subject:
So did you pack the bearing with grease or what is the idea there?
Also on a random 1, is there much to removing the front wings? I’m guessing it’s only a matter of bolts along the top, probably 1 down at the sill and 1 behind the bumper? _________________ #modified996mk1
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