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U can time bank one in the car with the basic hold down tool. U can not get the factory style adjustment tool in there. The oil pump can be put in loose before u put the valve cover on or u can drop the motor a little and pull it back with a ratchet strap
@dougn , the valves on Bank 1 were exactly in the Cyl 1 TDC position, but I am sure they were 'helped' along to that point as the chances of that naturally happening when the cam broke are pretty low. I plan on doing a leak-down tonight to see if I have any bent valves.
In fact, the cams are out at the moment so all of the valves are at rest (closed).
thats obviously the concern now. you could easily see any marks on the pistons with one of those 40 dollar cameras off amazon. if they all look closed, that's a good sign i'd guess
DeJeeper, thank you, that is exactly what I was looking for...not a "yes" but a "yes"+ little gotcha details to look out for. BTW it is really fun to follow along with you on your incognito GT3 project thread. Thanks for that.
dougn, borescope was the very first thing I grabbed after I had the plugs out, and I didn't see any marks at all. However, the pistons are brand new and very shiny, so unlike on older pistons where the crown is covered in a layer of carbon, the touch points don't register with as much visible contrast. The leakdown will probably tell the tale, especially since I can compare to cyls 4-6 as known good (another great Porschetech3 idea).
There was a failed variocam actuator thread about 3 months ago where the op posted some good pics and tips. Basically set up the variocam, chain and cams correctly, lift into place. Bolt down the actuator and 2 caps, along with the hold downs. Put the cam lock tool on and verify both cams r correct and continue to put it back togther. U cant exactly lock the came gear down per proceedure. I put the tensioner in with the cam locked and hold downs installed, set the gear and then pulled the tensioner again. Then i slid the scavange pump in losely, removed hold downs, installed cam cover, then worked the pump into place. I did not slide the motor rearward.
@hatchetf15 Yes, I definitely plan on talking with LN, they've been great throughout the rebuild, supporting the block machining and another mishap I had along the way. I know they offer a IMS reconditioning service but am somewhat surprised that they don't appear to pin or weld the small sprockets either (maybe I'm wrong). That was one of the cues that I took as to why I didn't do mine. That, plus watching other rebuilds through the process where they didn't do theirs either. I'd sure be curious to hear how many out there did indeed stabilize the small sprockets during the rebuild process. I saw the Flat6 video talking through the issue and showing their weld fix, so they obviously do it.
Leak down test results for cylinders 1-3 to see if I've got a bent valve or not. Thoughts appreciated about my observations. The leak down numbers seem low (good) to me.
Cyl 1: 4% (inlet 50 psig/cyl 48 psig)
Cyl 2: 1% (inlet 50/cyl 49.5)
Cyl 3: 1.6% (inlet 50/cyl 49.2)
Cyl 6: 1% (inlet 50/cyl 49.5) Reference from Bank 2
For all tests, I listened at the oil filler tube, tailpipes and throttle body. I only ever heard air hissing sound at the oil filler tube.
Never any sound at the coolant reservoir cap either.
I moved the pistons to three different positions to see how consistent the readings were, pretty much the same no matter where the piston is in the bore. One of the advantages to doing a leak-down with the cams out...the valves are always closed.
Borescope photos of all four valve pockets in piston #1, the one with the highest leakdown %:
Intakes:
Exhausts:
Last edited by ChuckUFarley; 07-21-2021 at 12:48 AM.
Reason: typo
There was a failed variocam actuator thread about 3 months ago where the op posted some good pics and tips. Basically set up the variocam, chain and cams correctly, lift into place. Bolt down the actuator and 2 caps, along with the hold downs. Put the cam lock tool on and verify both cams r correct and continue to put it back togther. U cant exactly lock the came gear down per proceedure. I put the tensioner in with the cam locked and hold downs installed, set the gear and then pulled the tensioner again. Then i slid the scavange pump in losely, removed hold downs, installed cam cover, then worked the pump into place. I did not slide the motor rearward.
hope this helps.
@De Jeeper Quick question...you mentioned that the standard factory tool for adjusting the timing doesn't fit when the engine is in the car, and I agree as I tried it last night. When you mentioned using the "basic" cam locking tool, were you referring to:
This one, P253:
Or this one:
I only have this one...which doesn't fit when the engine is in the car as you noted:
The 5 chain cam lockout tool isn't precise enough to set the cam timing on a 5 chain engine. You really need to use the one above with the red ***** to correctly set the cam timing.
The 5 chain cam lockout tool isn't precise enough to set the cam timing on a 5 chain engine. You really need to use the one above with the red ***** to correctly set the cam timing.
Thanks Charles, that's what I used during the build when the engine was out and it was easy to use and seemed precise.
How about this one? I don't hear of people using it very often, but seems like it would also fit in the necessary location with the engine in:
By the way, you, George, Stephen, whoever "LBH" is, and the rest of your crew at LN are great! Thank you for what you do for our community!
07-19-2021, 03:24 PM
