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Join Date: Jul 2008
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968 Head Gasket job
I am looking at doing the head gasket on my 968, I have done it on a 944 but am looking for both estimate on time as well as any hints on working with DOHC head
Dan daniel.freedman @ Lmco.com |
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Join Date: Jun 2006
Location: O.C. CA
Posts: 4,587
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all the parts you need are here
contact pete at rsbarn for tech assistance - all they do is 968s |
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Mark everything real well for the cam timing in relation to the cam gear and the back of the cam gear cover. Read up on how the cam timing is adjusted after a head gasket change and that should motivate you to mark it so well that you can for go that part of the procedure. It's a pain in the ass to adjust and do it right.
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1994 968 "Totaled during practice for GBRS / PCA 2009 Race season" 1989 944 Track car replacement. Complete with 968 running gear. 1988 911 Carrera "Friday / Weekend Driver" 1988 944 Daily Driver now. 1973 911S "In storage" |
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since new belts are being installed at the time of a head gasket (never reuse belts) the cams need to be reset, so marking them, while helping in reassembly, will not preserve timing
to do it really right, you need dial indicators and a special tool - i had my cams timed and it made a significant improvement over stock timing - stock was "close" but not perfect - the workshop manual does not specify how to time them though - it only gives you the procedure that gets you "close" - runs fine that way, but better when really dialed in again, pete can fill you in more on this - he is one of a very few who actually know how to do it - most shops don't know how or don't even know that you can |
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Typical numbnuts reply from someone long on wind but short on practical knowledge and experience, and yet who acts with compulsion to answer every conceivable thread or comment regarding 968's. Exactly why I ceased particpating in the 968Forums he hosts.
If you're a hands-on guy, the job is not that complicated. It's a weekend job. Trickiest aspect of the whole engine, in my opinion AND EXPERIENCE, is reassembling the camshafts and Variocam, and this only because the Variocam unit is a bit of a pain to hold together while installing the chain. Again, not that complicated, and there are excellent DIY articles available on the web. Dial indicator? Sheesh! Been bending too many dimes between your butt-cheeks, anal-retentive jerk! Porsche did an excellent job making these engines DIY-friendly without a lot of special tools, though no doubt there are always going to be things that help one arrive closer to perfection. As with any head R&R, I would recommend at a minimum taking the head to a good shop to be cleaned, particularly the mating surface to the block. And if it were my head, I'd also have it rebuilt, ported & polished, just on a "WTF, I'm here, might as well do it" basis. Last edited by rdhayward; 07-31-2008 at 12:47 PM.. |
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sorry you feel that way
having seen the difference, and having gotten the feedback from others who also have, there is very real "practical experience" on this - mine was off almost 5 degrees from the factory - ran ok - ran better when it was right obviously you have not had the benefit of experiencing the difference when it is done "right", and only the experience of doing it "good enough" - if i had to guess it was at least 5hp and a noticeable torque difference at 2500 even the workshop manual tells you to use dial indicators to set the cams (see page 15-3) yes, you can slap it together - yes, it will run - you might get lucky and get it bang on - you might not - you won't know without the tools you can pound a nail with a 2 lb sledgehammer too call pete - he'll be happy to fill you in |
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Make a good health scribe line in both the gear and the cover. Mine was dyno’d a year or so before I changed the head gasket and a few months after the R&R, no problems it was on the same dyno and during the same month of the year since it was a local PCA outing. Difference wasn’t really noticeable a little better afterwards since I cleaned out the intake manifold most likely.
Can do the dial indicator thing just encase. I forgot to mention the most important step. Turn off your cell phone and don’t let anyone near you during the torque of the bolts in the head. It is really easy to get out of sequence if you get a lot of phone calls. Should mark off on photo copy of the spec sheet just to make sure you get them all.
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1994 968 "Totaled during practice for GBRS / PCA 2009 Race season" 1989 944 Track car replacement. Complete with 968 running gear. 1988 911 Carrera "Friday / Weekend Driver" 1988 944 Daily Driver now. 1973 911S "In storage" |
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Tags |
968 , head , top end rebuild |