Why so bloody expensive - rebuild
11-29-2010, 10:41 AM
#61
Race Car
At a 150K you probably have some valve guide wear - and you most certainly have layshaft bearing wear (and showing copper)
That said - I've seen Carrera engines go 300K miles without opening up.
Anything over 80K and you should probably replace the lower end bearings and seals. It just makes sense if you are that far along (assuming you have the top end to do) I'd also recommend replacing head studs. The 3.0 have suffered this - and age and cycle wise the 3.2's are getting to that magical time frame.
And of course - if you go into the bottom end - replace the 3.2 connecting rod bolts,
That said - I've seen Carrera engines go 300K miles without opening up.
Anything over 80K and you should probably replace the lower end bearings and seals. It just makes sense if you are that far along (assuming you have the top end to do) I'd also recommend replacing head studs. The 3.0 have suffered this - and age and cycle wise the 3.2's are getting to that magical time frame.
And of course - if you go into the bottom end - replace the 3.2 connecting rod bolts,
11-29-2010, 11:42 AM
#62
Rennlist Member
At a 150K you probably have some valve guide wear - and you most certainly have layshaft bearing wear (and showing copper)
That said - I've seen Carrera engines go 300K miles without opening up.
Anything over 80K and you should probably replace the lower end bearings and seals. It just makes sense if you are that far along (assuming you have the top end to do) I'd also recommend replacing head studs. The 3.0 have suffered this - and age and cycle wise the 3.2's are getting to that magical time frame.
And of course - if you go into the bottom end - replace the 3.2 connecting rod bolts,
That said - I've seen Carrera engines go 300K miles without opening up.
Anything over 80K and you should probably replace the lower end bearings and seals. It just makes sense if you are that far along (assuming you have the top end to do) I'd also recommend replacing head studs. The 3.0 have suffered this - and age and cycle wise the 3.2's are getting to that magical time frame.
And of course - if you go into the bottom end - replace the 3.2 connecting rod bolts,
Again, to reinforce what Doug keeps harping on.....errr....pointing out
, you don't HAVE to do all of these. But, a prudent person WOULD. This has nothing to do with 3.4, 3.2, high compression, low compression, turbo, NA, street or race. To clutchmonkey: research will show you that many of these go a long time before needing any attention.
11-29-2010, 12:44 PM
#63
I haddah Google dat
Rennlist Member
Rennlist Member
Yup. ARP rod bolt$, and machine the rod$. $tandard for rebild$. Haha, it's only money. Some guys offset bore the rod small end, and stay with standard size bearings. Cost, you know.
11-29-2010, 08:05 PM
#65
Just for reference here is a UK build sheet from my top end that was done late 2008 - i supplied the 3k GBP worth of Mahle 3.4 P&C, as well as a KEP lightweight clutch housing. Bear in mind, the case was not opened, however the rod bolts and bearings were replaced - all prices in GBP
11-29-2010, 08:19 PM
#67
11-29-2010, 10:03 PM
#70
I haddah Google dat
Rennlist Member
Rennlist Member
I'm not making a political statement, but a 17.5% tax would put the Kabosh on all Porsche projects for me.
I saw that and a little bit o pee come out. How can you people live with that??? It's the work of the Devil himself.
I saw that and a little bit o pee come out. How can you people live with that??? It's the work of the Devil himself.
11-29-2010, 10:12 PM
#71
Rennlist Member
We're over 10% in many CA localities now. The fact that most of us evade it when buying from out of state doesn't mean it's not on the books, and you are liable.
Granted, it's only on on products. So far. When they can finally tax services.............. (Which I think is being done in parts/all of other states.)
Granted, it's only on on products. So far. When they can finally tax services.............. (Which I think is being done in parts/all of other states.)
11-29-2010, 10:20 PM
#72
RL Technical Advisor
Thankfully, Oregon has no sales taxes and even in this financial climate, any such suggestions from the mouths of elected officials is terminally toxic to their careers.
11-29-2010, 10:31 PM
#73
Addict
Rennlist Member
Rennlist Member
Really didn't know when I posted this was going to get this much response. As a relative newbie then, let me ask this question as a follow up. Why would I need a bottom end rebuild? What things go wrong? Obviously, broken parts - rings, connecting rods etc. But, in general, at what point is it just wear and how do you know? My car has 150,000 on the clock, pulls strong and does not smoke. It really doesn't even leak. As a convertible, and given its general condition, I don't think it has ever been on a track either. How many more miles do I have assuming I never track it and take care of it (as I do all my cars).
As the owner it is your call as to when you need to go the full meal deal.
In 2003, when my car had 116,000 miles, the valve guides were toast. My shop told me that I should expect to pay about $3,500 (plus the cost to purchase/replace any out of spec valves) for renewing the valve guides. While we were in there, I replaced the clutch as it was worn to the rivets.
I did not replace any bearings nor spilt the case. I am now at 146,000 miles with no worries.
I will add that I have a magnesium cased 2.4 L 911T engine that is (mostly)mildly stressed. If I needed to split the case, I would most likely face the cost of line boring and case adjustments which signifcantly add to the rebuild cost. For the later Aluminium engine block, the need for this is less certain.
According to others, most of the cost is the top end. Unless there are significant machine costs, the splitting of the case and replacing the bearings does not add "significant" money to the job but gives you a longer time before you need to revisit the rebuild.
If you need to replace the P&C's, you are looking at a meaningful chunk of change as well.
To get a better feel for this work, you need to know what is the problem you need to cure, what, if any, upgrades you want to make, and what is your budget. Using this knowledge, you can speak to local pros or price out the parts and machine work. This will give you a sense of the cost and you can decide where you want to go.
As in all things, your car, your money, your choice.
11-30-2010, 02:39 AM
#74
Three Wheelin'
This is an interesting thread and good to hear everyone's thoughts on the subject.
As someone in the industry who has to tell customers how much a 911 top-end rebuild is these days, I am used to hearing how ridiculous it is, and in some ways it is.
A big part of the reason the price is so high these days is the prices of the parts has gone up so much in the last 5 or so years (anyone priced out 24 993-type fully threaded head studs lately?) Don't get me started on 915 transmission parts . . . .
Of course the other part is the labor component and yes most reputable Porsche shops charge a seemingly high labor rate, especially here in CA, but I think that you get what you pay for. You get years of experience and expertise, and most good places will stand behind their work. The other part of the cost is of course due to the extremely high overhead: high rent/equipment prices, ongoing training for the technicians, workers comp, insurance, and all the environmental regs/rules we have to deal with here in CA., but that is life.
On the flip side at many shops you can often get invaluable advice and technical help at no cost. I personally spend several hours every week dispensing free advice, even to people I know will never spend a dime at my shop. It is all about the passion for these cars and wanting to keep them all happy and on the road. Be sure to thank guys like Steve Weiner and Pete Zimmermann who spend countless hours on message boards like these and share their decades of experience with these cars (both have probably forgotten more than I will ever know!)
How many lawyers/doctors/dentists do you know give their professional advice for free. Hell, we won't charge you if you miss an appointment either!
I have nothing but respect for the guys who go for it themselves. If you have mechanical skill and ability, and clean, neat, and organized, and have access to the tools and manuals necessary, and more importantly have time and patience, I think you could rebuild a 911 engine and have it run well, and have fun doing it and gain a real sense of accomplishment. But, to be honest, come resale time, a receipt from a good shop would probably serve you better as previously mentioned.
As for top-end vs full split case rebuild, I think the issues with the mag cases are well documented (send the case to Ollie's and you'll be fine, but be prepared to spend some money). The later AL case engines have a very solid bottom and often times do not need to come apart. Remember, a "top end" on these engines includes pistons and cylinders if necessary, and also rod bearings. Through-bolt O-ring oil leaks are a common issue on the 3.6 engines, but you can in theory replace them 1 at a time without completely splitting the case . . .
The big issue (which of course has been an issue for a long time) that we are seeing a lot of the last few years on SCs and 3.2s (and even a couple 964s!) is broken head studs, especially on relatively lower mileage cars that sit a lot (rust spots form on the studs, creating stress risers). This can happen on engines that otherwise are healthy and do not use a lot of oil, and otherwise could have gone a lot longer without a top-end rebuild. Check the torque of the head nuts every time you have the valve covers off for a valve adjust, and look out for oil leaks between the heads and cylinders when you are underneath the car (a sure sign of a broken exhaust stud/compression loss). You can also sometimes hear the compression loss if you snap the throttle or accelerate hard (if so don't drive the car much till you can fix it, you risk damage to the cylinder head to cylinder sealing surfaces due to bouncing and a more costly rebuild).
Anyway good thread and I am glad that even though this is a DIY-focused board there are plenty of guys here who appreciate the hard work we do!
As someone in the industry who has to tell customers how much a 911 top-end rebuild is these days, I am used to hearing how ridiculous it is, and in some ways it is.
A big part of the reason the price is so high these days is the prices of the parts has gone up so much in the last 5 or so years (anyone priced out 24 993-type fully threaded head studs lately?) Don't get me started on 915 transmission parts . . . .
Of course the other part is the labor component and yes most reputable Porsche shops charge a seemingly high labor rate, especially here in CA, but I think that you get what you pay for. You get years of experience and expertise, and most good places will stand behind their work. The other part of the cost is of course due to the extremely high overhead: high rent/equipment prices, ongoing training for the technicians, workers comp, insurance, and all the environmental regs/rules we have to deal with here in CA., but that is life.
On the flip side at many shops you can often get invaluable advice and technical help at no cost. I personally spend several hours every week dispensing free advice, even to people I know will never spend a dime at my shop. It is all about the passion for these cars and wanting to keep them all happy and on the road. Be sure to thank guys like Steve Weiner and Pete Zimmermann who spend countless hours on message boards like these and share their decades of experience with these cars (both have probably forgotten more than I will ever know!)
How many lawyers/doctors/dentists do you know give their professional advice for free. Hell, we won't charge you if you miss an appointment either!
I have nothing but respect for the guys who go for it themselves. If you have mechanical skill and ability, and clean, neat, and organized, and have access to the tools and manuals necessary, and more importantly have time and patience, I think you could rebuild a 911 engine and have it run well, and have fun doing it and gain a real sense of accomplishment. But, to be honest, come resale time, a receipt from a good shop would probably serve you better as previously mentioned.
As for top-end vs full split case rebuild, I think the issues with the mag cases are well documented (send the case to Ollie's and you'll be fine, but be prepared to spend some money). The later AL case engines have a very solid bottom and often times do not need to come apart. Remember, a "top end" on these engines includes pistons and cylinders if necessary, and also rod bearings. Through-bolt O-ring oil leaks are a common issue on the 3.6 engines, but you can in theory replace them 1 at a time without completely splitting the case . . .
The big issue (which of course has been an issue for a long time) that we are seeing a lot of the last few years on SCs and 3.2s (and even a couple 964s!) is broken head studs, especially on relatively lower mileage cars that sit a lot (rust spots form on the studs, creating stress risers). This can happen on engines that otherwise are healthy and do not use a lot of oil, and otherwise could have gone a lot longer without a top-end rebuild. Check the torque of the head nuts every time you have the valve covers off for a valve adjust, and look out for oil leaks between the heads and cylinders when you are underneath the car (a sure sign of a broken exhaust stud/compression loss). You can also sometimes hear the compression loss if you snap the throttle or accelerate hard (if so don't drive the car much till you can fix it, you risk damage to the cylinder head to cylinder sealing surfaces due to bouncing and a more costly rebuild).
Anyway good thread and I am glad that even though this is a DIY-focused board there are plenty of guys here who appreciate the hard work we do!
11-30-2010, 03:26 AM
#75
