Pjovan

Hi everyone, new Rennlist member here ! Im a passionate young mechanic who's always had a few projects to work on since the age of 14 and as time went on, I started getting more involved with the automotive field. I'm on a journey to non stop learning, with ears wide open and mind open as can be. Im in need of some help with with the timing chain guide on a 964 engine I'm currently finishing a refresh on an m64..nothing crazy. I have worked on previous 911s but this is the first 911 engine I got very technical with, any advice or pointers are greatly appreciated !

So the issue I'm having is my timing chain seems to be incorrect the way it sits in the guide. On the left bank the timing chain sits perfectly behind the timing chain guide's lip like its supposed to.

Then if you look at the right bank, you'll see the chain is sitting just on the outside towards the end of the timing chain guide. it may not seem too noticeable on the picture since the bracket wasn't fully torqued so it wasn't flush to surface. When I do torque it down and the timing chain guide is fully seated the chain ends up sitting out of the guide towards the end of it which doesn't look normal.


What could be causing this issue ?

UPDATE ***

I removed the timing chain guides and checked if the timing chain was sitting incorrect but turns out the chain sits perfect in its gear.

2. I removed the camshaft sprocket and the keeper (decided to leave it out which makes it easier in case i have to make some adjustments on the shims) and subtracted both shims one at a time, still no luck. Also from what Ive read on bentley publisher's 964 book there is usually 4 shims on the left bank and 3 shims on the right side. In my case I have 3 shims on both sides and thats how it was before disassembly. Weird thing is the timing chain sits perfect on the lower guide, I attached more images of how the chain sits after subtracting shims. Could this be due to using its original timing chain guide ?

FeralComprehension

Depending on how much intel you get here the 'engine rebuilding' forum at PParts is also a good resource.

lateforlunch

Might be a good idea to check your cam parallelism.

perelet

Your left side chain jumped off crank gear, happens pretty often when you rotate engine on stand. Take plastic guides out, rotate engine till left side is straight up and re-seat chain. Use flash light to make sure its sitting on the crank gear.

ras62

You have to have the sprockets parallel to the intermediate shaft. There is a tolerance, adjusted with shims. Google search.... 911 cam sprockets run parallel with intermediate shaft sprocket

Pjovan

That makes a lot of sense ill take a shot at that and let you know what i come up with thanks !

Pjovan

....

Pjovan

I was wondering about that but when i disassembled the engine it only had 2 thin shims and a thick one on both sides which i put back in the same orientation I will double check the measurement though doesn't hurt to do so

Pjovan

any more inputs ? just updated somethings a few members suggested to try...

Pjovan

Issue resolved. Right bank cam sprocket was supposed to be on with flat surface facing outwards.

ffc

For future reference where the sprocket alignment is concerned:

https://www.youtube.com/watch?v=YuG3...ature=youtu.be

No connection to Stomski.

Pjovan

thanks