replacing the timing chain 3.2

[Rols 912]

Hi,
I am about to replace my chain with a masterlink timing chain. Id appreciate any help/tips on doing so.

Sprockets are in good condition.

Thanks to those that help!

[Flat6pac]

The question has to be why.
If the chains are so shot that the tensioners dont take all the slack out the engine is pretty worn out so chains are not going to save it.
You ll have to reset your timing which is out of wack with the chains streched to the need to replacement
Several hours of work, especially on a Carrera

[Rols 912]

Not that.

Just reading Wayne's book and appears to be a good time to do it while the engine is out of the car and getting a refurb (lines / hardware /sensors etc). Not splitting the case though.

[88911coupe]

Be careful about replacing the chain only since it can break off the teeth of the sprocket if the old chain has worn down the "valleys" What happens in the new chain ends up riding higher up on the teeth since it's not worn like the old chain was. There are some threads on this which are a little scary. Just FYI...

[BReyes]

Welcome.

What has been done to the car before? How about just changing the oil (and driving ), not pulling the motor?

You have a good question. And plus you say the motor is out. You can clean and clean somemore. Anything rubber, and ICV, fuel lines, entire car's hydraulic oil lines, clutch, axles. Which are a few pretty pennies at dealership. With above and hardware reanodized, detail couple paint items and the tin, yada yada, oh yeah it will be like new. Actually right now your motor is good or you need more than chains, actually just a top end rebuild, worst case complete rebuild.

If you are going to do all the service/rebuild yes, you can strip it to long block and ship to an engine builder with justifiable high expectations and likely get good results. Guys on this forum will help you if you are tearing into it now and seeking sources for tools to get it down to the case and beyond with also good results.

Let us know when you are done (read tired) cleaning. Oh yeah did I ask about the car/build.

Goodluck.

Regards,



p.s. Did it burn/leak oil. A leak down is important to tell you to do the top end rebuild replacing valve guides and some valve, presuming any head stud issues are for prevention.

[dtw]

Unless you have a specific reason for replacing cam timing chains, leave them alone. They are not really a 'while you're in there' replacement item. Plus, replacement of just the chains without replacing the inner & outer sprockets can result in some seriously bad juju, as discussed above. Use the $ elsewhere.

[Determined]

Split the case and do a rebuild.

Alex

[2.70Racer]

Rols 912,
Most of the advice given has been reasonably good.
Putting new chain onto worn-out sprockets is a no-no.
I've have a considerable number of years experience working with chain and sprocket driven machinery.
Something I learned quickly is roller chains "stretch". They begin to "stretch" from the moment they are placed into service until they are replaced.
As a result of the chain "stretch" sprockets can be worn.
The amount of wear is dependent upon the load, the amount of stretch, and of course lubrication.
Roller chain drives that are ignored for prolonged periods of time are the most likely to wear sprockets beyond any usable life and will infact quickly wear a new chain.
That said, sprockets must be inspected and compared to new sprockets.
In many applications the chains and loads are very conservative.
This type application may not wear sprockets as quickly as heavier loads and in some cases under designed drives.
Bottom line here, inspect the cam sprockets and with a bright flash light, inspect the drive sprockets.
There are many photos on this site of worn and reusable sprockets.
Carefully check the good and bad photo's against your engine.
As posted by many here, replace the worn sprockets.
However, unworn sprockets do not deserve the labor and cost to replace.
Be critical of what you see, take a few pictures and post them if you are unsure.
I did a top end job on my race car about five years ago. I installed new timing chains. The sprockets on the 100,000 mile motor were in good shape and were not replaced.
Today after maybe fifty weekends on the track, the engine runs terrific.

Inspect, inspect, inspect. If you aren't sure take the cam sprockets to an experienced Porsche tech and compare them to new sprockets.

[Rols 912]

Thanks everyone.

Not keen to rebuild Bernard. I have just finished a rebuild on a 356 and it cost enough to see me out for the year!

The 3.2 is going in my fully restored 912 of all things. Going to use it as a "reliable" daily driver with air cond. Leakdown came up trumps.

I might take you up Doug on posting some pictures of the sprockets to see what you all think.?

Re. cleaning the case - I used brake and carb cleaner - worked an absolute treat!

Cheers

Roland

[2.70Racer]

Nice looking hotrod!