Timing chain guides are one of those parts that has gone through a lot of updates. If you put an early guide next to one you can buy today, you would be surprised by the amount of changes.
Black and Brown Timing Chain Guides
There are two types of timing chain guides. A black one and a brown one, they have different part numbers.
In total, you will need 5 black guides and 1 brown guide. Today we are only loading 4 guides into the engine block, 3 black, and the one brown. The difference between the two guides is the overall heigh. The Brown guide is skinnier than the black guide.
There is only one spot for the brown guide and that is on the lower right-hand side of the engine. The right side is when you are facing the pulley side of the engine, otherwise the passenger side. If you were to use all brown guides the chain would be looser than intended and could cause a chain slap.
Installing the timing chain guides
Using the special bolts from Porsche, part number, 901-105-226-03, one hole of the timing chain guide is a support side and one hole is a locking one. The way you place the guides is with the longer pointier side facing into the crank. Starting with the support side, make sure to add the 10x16mm copper washer to the bolt, and place the chain over the guide.
For the locking side of the timing chain guide, you need to start the bolt, and then using a pry bar, you need to support the guide as you do it up. You will feel the locking clip on the bolt. Keep pressure on the guide to keep it in the center of the engine housing.
If you feel or see that the guide is off to one side and has been pushed over by the bolt, dont’ worry. Just undo it and reposition your pry bar. Torque down the specialty bolt to 35 Newton meters when you have everything lined up. Visually confirm the positions of the timing chain guides and make sure the chain rides on them nicely.
We like to run the timing chains smoothly as we turn over the engine to install the pistons and cylinders. To help the chains run smoothly and not bind up or fall into the engine block, we put the camshaft drive gears into the chains.
After this lesson you should feel confident that you have the right guide in the right place, your torque is perfect, and your guides are running in the center of the housing.
Up next in your air-cooled engine build
The next part we install is the front pulley. This is a very short lesson, and the head studs are next after that.
If you missed the earlier parts of this build, go back to the beginning. How to save your magnesium engine case.