Valve Timing

[lib]

Hi All

I have a 1997 Boxster 2.5 man trans. RoW.

I have the Cyl. head off bank 1 and the chain to this bank has moved from the camshaft gear.

The question is how do I find when piston number 1 is on the compression stroke and not on the exhaust stroke without taking the cam cover off bank 2.

Would I check for piston #4 coming on to compression or is it piston #6 coming on to compression that would indicate that piston #1 is on the exhaust stroke which would line up on the crankshaft pulley.

I hope I have been able to explain clearly?

Many thanks Lionel

[JFP in PA]

Unfortunately, this is not going to be as simple as you think. Because of the twin cam design and variable valve timing Porsche used, you need to index the cams to each other as well simultaneously the crankshaft position (what the factory calls “allocating” the cams). In order to do this correctly, and not destroy your engine (a real possibility if you get it wrong), you need some special fixtures set and then lock the cams in the correct positions in relation to the crank:

This can be done with the engine in the car and the cam covers on, by pulling the green plugs out of the cam covers the attaching the fixture, or it can be done with the cover off as well:

While the process is not difficult with the correct tools, it is time consuming; so you need to do some research, or obtain access to the 13 volume set of the OEM manuals for the procedures.......

Edited May 15, 2010 by JFP in PA

[Wayne R. Dempsey]

That indeed is a neat timing tool kit, but not all of the tools in there are 100% necessary unless you're a shop You can get away without some of them. I'll go over the tools here:

P255 holds the cams from falling out when you take out the cam covers, but you can also use P253 to do the same thing.

P256 holds the cams in place after you release the two cam holders that hold them in place - useful if you're working on the engine with it still in the car, but if the engine is on the stand, simply rotate the engine upwards to prevent them from falling out

P258 crankshaft lock. Simply use a 5/16th drill bit and save yourself some money

P253 is the only tool that I think is pretty necessary, but you can also index the camshafts at the end by their markings. I don't have a good photo of this up on the web right now, but I will in the next week or so...

JFP is right - the process is not very difficult (not like an air cooled 911 motor), but the potential to mess things up is high if you don't have the proper tools or knowledge.

-Wayne

[lib]

That indeed is a neat timing tool kit, but not all of the tools in there are 100% necessary unless you're a shop You can get away without some of them. I'll go over the tools here:

P255 holds the cams from falling out when you take out the cam covers, but you can also use P253 to do the same thing.

P256 holds the cams in place after you release the two cam holders that hold them in place - useful if you're working on the engine with it still in the car, but if the engine is on the stand, simply rotate the engine upwards to prevent them from falling out

P258 crankshaft lock. Simply use a 5/16th drill bit and save yourself some money

P253 is the only tool that I think is pretty necessary, but you can also index the camshafts at the end by their markings. I don't have a good photo of this up on the web right now, but I will in the next week or so...

JFP is right - the process is not very difficult (not like an air cooled 911 motor), but the potential to mess things up is high if you don't have the proper tools or knowledge.

-Wayne

HI.

Thanks JFP and Wayne

Thats very useful stuff I will remove the green plug and cautiously try and make progress.

Thanks very much

Regards Lionel

[Wayne R. Dempsey]

Follow my instructions here, and they should help you out tremendously:

http://www.pelicanparts.com/techarticles/Boxster_Tech/16-ENGINE-Camshaft_Swap_and_Chain_Tensioner/16-ENGINE-Camshaft_Swap_and_Chain_Tensioner.htm

It's not too difficult if you have the right information in hand.

-Wayne