Quote:
Originally Posted by maytag
While I'm waiting on parts, I've been studying-up on the procedure.
I found this video tutorial, which seems to be very comprehensive. IMS Retrofit & Procedure Overview – IMS Retrofit
However it leaves me with a couple of questions I hope y'all can help me with:
1. At about 1:52 in the video, they say "if locking camshafts on left and right cylinder head is desired, a specially modified camshaft locking tool is required". Does that mean it's OPTIONAL to lock left & right side? What am I missing here?
2. Is it absolutely necessary to remove the A/C compressor to do this job, as described at 2:22? I haven't heard anybody else say they've done this? Will I have to vent the system then?
3. Somebody explain to the dummy here (me) why it's necessary at all, to remove all of the tensioners and lock the cams? Is there really that much tension on the chains that they'd pull the shaft out of alignment with the bearing / bore when you remove that bearing? Is that what's going-on here? I mean, why I can't just pop the one out and the next one back in, the way all the rednecks on the other youtube videos do it?
Hit me, will ya? but don't be too harsh. :-)
thanks in advance. |
OK, let’s start with the obvious: They are working with a 996 engine out of the car; so left and right are reversed. Because of the type of cam locking tool they are using, this is a three chain motor, which is more susceptible to jumping time than a five chain motor, so more care is advisable, and they are locking the cams on both sides. Realistically, if you are doing a five chain in a Boxster, you only need to lock the passenger’s side cam. Because the “off side” head on the M96 will line up the cams differently than the passenger’s side on a Boxster, you would need to modify the cam holding tool for that side on a three chain retrofit .
Because the 996 is a three chain, they are going full “belt and suspenders” to eliminate any chance of jumping time, including removing the chain tensioner under the AC compressor. If this was a five chain, this precautionary step is not required.