911 Rod

You look like you have a handle on it!

Marc Masterson

Awesome Thread..Looking forward to the progress.

Hey Imre..just noticing in pictures/diagram the exhaust seems to change direction many times seems kinda inefficient am i missing somethin? the old SC i had was pretty direct.

Imo000

Marc, I'm guessing the need for catalytic convrters made the system longer and more complex.

Took the passanger side cams out tonight and all the chain pads look normal. The chain actuator betwen the two cams is very soft. Much softer than the other side. Might have been an issue too. There was also a small piece of plastic in the IMS tensioner hole. Tried looking in with a borescope but can't see enough. The only place the plastic could come, I think, is the IMS chain ramp and tensioner pad. Looks like the case needs to be split. Still reading up on this.

Cosmo Kramer

When you say some compression on driver side are you thinking it might be low? With the cams in time on that side should be normal unless something else is up.

I must say you are progressing nicely!

Imo000

Rod dropped by tonight so he had a look at the chain pads and found the one that broke. Somehow I missed it last night. It came from the passanger side. About quarter of the top pad is gone. This somehow made it's way to the back and got cought in the other bank's chain. So with some luck, the case might not have go be split. Then we did a leakdown test on the passanger head (the cams are already out since last night). There is constant 12% leak from all cylinders and they are all at the exhaust valves. One was 70% but after tapping the two valves it went down to 10%. We think this is because of carbon on the seats. The previous owner must have driven the car with a failed cam actuator or tensioner. Next couple days I'll try a quick lapping of of the exhaust valves with the head on the car to see if the leakdown numbers improve. If they do, the problem is carbon at the exhaust valve seats.

Speedyellow993

+1 on the B&B.

They are pretty loud and drone on the highway but 3/4 to WOT... They sound great!!!

GL

justinsrx7

This is a very cool project. I always wanted to do a project like this and although I am mechanically minded, I have never done engine work and would not know what I was looking for. I'm very impressed with and jealous of your abilities Imre!

Imo000

The bent ones. Exhaust ports look clean.

Speedyellow993

Wow...those look pretty bent!! Do you want them? Don't throw them away. I'll buy you Tims coffee for the bent valves?

Al

Imo000

Sorry, I'm keeping them, have a collection of faild parts already from other projects. Blown headgasket from the boosted 928, a chipped and cracked valve from my DD TDI, shreaded 928 timing belts and faild water pumps. I only keep the worst ones and these are keepers for sure.

Tool the tensioner pads off tonight. The faile one came off on it's own and the one form the other side snapped when I was pulling on it. It was not far away from failing too. The bottom pads look mint, compared to the top ones. $20 part that took out an entire engine.

aviography

So, how are you going to ensure everything is lined up when you reassemble with the new parts?

I've read there are kits to lock the cam gear and other parts of the engine in place while the IMS bearing is changed out, will you be getting these special tools?

Pretty scary a little thing like that can take out the engine, just like the IMSB!

Imo000

There are some good write ups on how to make some of these lo king tools, using common materials. At first these engines look complicated but once you start digging into it, its not that much different than most DOHC with varuable timing.

Tomas993

...and what Justin said - no skills (or maybe, just no experience) but watching and hearing all the details is very interesting.

I could be a helper at no cost for someone who just needs an extra hand or two...

Imo000

No progress in the last few days. Went with the family in a short vacation. Tomorrow afternoon it will go on the engine stand and will pull the other head off too.

Imo000

Engine is all stripped, passanger head is off, no sign of burnt vavles so probalby just a good lapping will get them to seal again . Lots of carbon on this bank. The air oil seperator looks gone, maybe the PO was driving it like that for a while. Next step is to pull all the good valves and have a look at the valve seats. So far only 6 bent exhaust valves. Starter has a lot of play and will be rebuilt and will have the alternator looked at by a professional too.