964 C4 light refurb
#556
Rennlist Member
Thread Starter
I'm lucky to have only ever done it engine-out. I showed the tool to a Porsche mechanic and he said he still prefers the feeler gauge but many struggle with it because they can't recheck the gap.
#557
Having the skill and making the time to remove your engine isn't luck. :-) Great thread BTW.
#558
Burning Brakes
John,
Can you confirm the following as true;
Cyl 1 and 4 lash are set correct.
When at TDC cyl #1 (cyl #4 also is at TDC at this time) and the dot stamp of both cams therefore is pointing UP.
1st 360 degree turn s/b 1.26mm left cam, 2nd 360 degree turn s/b 1.26mm right cam.
This now puts you back at TDC cyl #1 and both dots on cams pointing up.
Can you confirm the following as true;
Cyl 1 and 4 lash are set correct.
When at TDC cyl #1 (cyl #4 also is at TDC at this time) and the dot stamp of both cams therefore is pointing UP.
1st 360 degree turn s/b 1.26mm left cam, 2nd 360 degree turn s/b 1.26mm right cam.
This now puts you back at TDC cyl #1 and both dots on cams pointing up.
#559
Rennlist Member
Thread Starter
I received a PM re the service cover I'm using.
It's available from Pelican. It's a Colgan custom rear service cover http://www.pelicanparts.com/cgi-bin/...+service+cover
Please note that the cover isn't perfect. The pad for the air con compressor is on the wrong side and I felt the need to put some cloths under the elastic part that clips on the fenders
It's available from Pelican. It's a Colgan custom rear service cover http://www.pelicanparts.com/cgi-bin/...+service+cover
Please note that the cover isn't perfect. The pad for the air con compressor is on the wrong side and I felt the need to put some cloths under the elastic part that clips on the fenders
#560
Rennlist Member
Thread Starter
John,
Can you confirm the following as true;
Cyl 1 and 4 lash are set correct.
When at TDC cyl #1 (cyl #4 also is at TDC at this time) and the dot stamp of both cams therefore is pointing UP.
1st 360 degree turn s/b 1.26mm left cam, 2nd 360 degree turn s/b 1.26mm right cam.
This now puts you back at TDC cyl #1 and both dots on cams pointing up.
Can you confirm the following as true;
Cyl 1 and 4 lash are set correct.
When at TDC cyl #1 (cyl #4 also is at TDC at this time) and the dot stamp of both cams therefore is pointing UP.
1st 360 degree turn s/b 1.26mm left cam, 2nd 360 degree turn s/b 1.26mm right cam.
This now puts you back at TDC cyl #1 and both dots on cams pointing up.
Update: I didn't get to the above before I left for Japan. I downed tools for a period at the OPC that did the rebuild's request while they worked out their response to the leak(s). Now that I have that response (reading between the lines they want to split the case themselves, to see whether I can prove fault) I have a definitive position to act on. I've declined their offer, as there's no commitment and I don't want to be given a pile of parts back.
So next up is the final strip down. What will I find?
Last edited by John McM; 04-26-2017 at 08:33 AM.
#561
Rennlist Member
Thread Starter
I arrived back from Japan and started into the teardown the same day.
The first hurdle came with the four bolts holding the chain bracket. It's a tight fit around the heads and the Bahco 12 point 10mm socket wouldn't fit. It was 14.4mm wide so off to the tool shop. A Toptul 6 point socket at 13.9mm sorted that out.
The first hurdle came with the four bolts holding the chain bracket. It's a tight fit around the heads and the Bahco 12 point 10mm socket wouldn't fit. It was 14.4mm wide so off to the tool shop. A Toptul 6 point socket at 13.9mm sorted that out.
#562
Rennlist Member
Thread Starter
With the guards off and the tensioners removed it was easy to take off the sprockets. As per the workshop manual directions I carefully checked the thrust washer and number of shims.
Unfortunately they were not installed correctly. The shims and thrust washers were in the wrong order and one thrust washer had the wrong orientation. I have no idea if that is an issue or not.
Unfortunately they were not installed correctly. The shims and thrust washers were in the wrong order and one thrust washer had the wrong orientation. I have no idea if that is an issue or not.
#563
Rennlist Member
Thread Starter
With the sprockets and shims off I removed the left hand cam cover. There's an interesting blob of sealant on the cover. Is this going to be repeated on the nose bearing? That could be the cause of my leak.
#564
Rennlist Member
Thread Starter
I decided to remove all of the tappets and camshaft on the left bank.
The tappets required a lot of socket extensions to get the hex key in the right place.
The camshaft is in perfect condition. Two of the tappets have minor pitting. I'll get them checked.
The tappets required a lot of socket extensions to get the hex key in the right place.
The camshaft is in perfect condition. Two of the tappets have minor pitting. I'll get them checked.
#566
Rennlist Member
Thread Starter
Originally Posted by C4inLA
Is that what's left of paper gasket or was that a sealant coated to paper gasket? They call the bevel a groove makes me feel better it's documented, thanks.
#567
Rennlist Member
Thread Starter
With the rockers removed it's relatively easy to remove the camshafts, then undoing a fair few bolts allows the cam tower to be removed, revealing the cylinder heads and valve train.
#568
Rennlist Member
Thread Starter
Undoing the head studs allows the heads to be removed. The first sight of the pistons is fun but the joy is tempered by the sight of two chips where the early year heads have been machined to accept a sealing ring. If I had that decision again I would have left the heads as per original. At least they appear to be sealing ok.
#569
Burning Brakes
Interesting .. wonder if machining jig/lath caused that? Seems to had good seal. So, the orange sealant between cam and heads is not really adhesive makes cam tower come of easy?
#570
Rennlist Member
Thread Starter
Originally Posted by C4inLA
Interesting .. wonder if machining jig/lath caused that? Seems to had good seal. So, the orange sealant between cam and heads is not really adhesive makes cam tower come of easy?
As for the cam towers the 574 application is a bit over the top and it gave a bit of resistance. A lot of studs meant it had to come off almost perfectly vertically.