cost of new valve guide job?
10-23-2002, 01:12 PM
#1
Track Day
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cost of new valve guide job?
I just had the 75K service on my 1989 C4 by my mechanic (who is regionally known to be highly reputable). He showed me the spark plugs that had been removed from the car and said that several showed oil residue and some caked oil on them indicating that there is some oil contamination going on. He said that the issue should be addressed at some point and that a fairly extensive job of replacing the valve guides would need to be done. Cost: between $4K-7K (55 hours labor and whatever parts are needed). Having had almost no issues with this car to date, this almost knocked me over. He said if I was going to keep the car, I should have the work done at some point. Can anyone give me some guidance here on whether this sounds right? If so, how long can I get away without spending this kind of dough? If I were to pay this kind of money, would the car then be good to go for a long time thereafter (assuming no other issues)?
thanks for your feedback
thanks for your feedback
10-23-2002, 01:57 PM
#2
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Mark,
There's a thought that 3.6L was starting to push the longterm limits of aircooling, and so increased thermal stress manifests itself in valve guide wear (another reason to remove the lower engine shielding, to aid cooling). For cost, I would have said $3K-$5K, which is in the ballpark that your mechanic quoted. If you ever go anywere near the track, I would also replace your connecting rod bolts, which can be done without cracking the engine case. Porsche went to smaller rod bolts starting with the 3.2L engines, and when stressed at high revs at the track, they can give up. Suggest Raceware or equivalent.
It doesn't sound like you need to make an emergency room trip over it, but it's an event in the future. In terms of longevity, figure it's taken 75K miles for the situation to crop up, so you'd expect at least that from a top-end rebuild, everything else being equal.
There's a thought that 3.6L was starting to push the longterm limits of aircooling, and so increased thermal stress manifests itself in valve guide wear (another reason to remove the lower engine shielding, to aid cooling). For cost, I would have said $3K-$5K, which is in the ballpark that your mechanic quoted. If you ever go anywere near the track, I would also replace your connecting rod bolts, which can be done without cracking the engine case. Porsche went to smaller rod bolts starting with the 3.2L engines, and when stressed at high revs at the track, they can give up. Suggest Raceware or equivalent.
It doesn't sound like you need to make an emergency room trip over it, but it's an event in the future. In terms of longevity, figure it's taken 75K miles for the situation to crop up, so you'd expect at least that from a top-end rebuild, everything else being equal.
10-23-2002, 03:10 PM
#3
Driver Carries No Cash
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Bill,
I've wondered about "upfixing 'der valve train" at top end rebuild time. If you're going to go through all of the labor & expense of yanking the motor and having the top end rebuilt, is it possible to go the extra yard and "build up" the valve train? Can you put RS spec cams in a stock 3.6L motor? Or this complete rocket-science that will require expensive ECU updates?
I've wondered about "upfixing 'der valve train" at top end rebuild time. If you're going to go through all of the labor & expense of yanking the motor and having the top end rebuilt, is it possible to go the extra yard and "build up" the valve train? Can you put RS spec cams in a stock 3.6L motor? Or this complete rocket-science that will require expensive ECU updates?
10-23-2002, 04:29 PM
#4
There are several cam grinds that can bolt right into a 964 and be compatible w/ the stock Motronic induction system. In order from mildest to wildest, Web Cams offerings are
Andial and other vendors will have their own equivalent grinds.
- 993 Super Sport
- 20/21
Andial and other vendors will have their own equivalent grinds.
10-23-2002, 06:39 PM
#5
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[quote]<strong> Can you put RS spec cams in a stock 3.6L motor? </strong><hr></blockquote>
The 964 Carrera RS cams are the same as those in all C2/C4 engines. The RSR may have used different cams, however. Bill V outlined some alternatives.
The 964 Carrera RS cams are the same as those in all C2/C4 engines. The RSR may have used different cams, however. Bill V outlined some alternatives.
10-23-2002, 06:43 PM
#6
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[quote]<strong>Andial and other vendors will have their own equivalent grinds.</strong><hr></blockquote>
I just looked, at Andial lists two cams on their website for the 964 3.6L: one that supports the upgrade to a 3.8L engine, and one 3.6L sport cam. If serious about upgrading cams, a call to Andial, Elgin, or Jerry Woods, for example, would be in order.
I just looked, at Andial lists two cams on their website for the 964 3.6L: one that supports the upgrade to a 3.8L engine, and one 3.6L sport cam. If serious about upgrading cams, a call to Andial, Elgin, or Jerry Woods, for example, would be in order.
