LOKASIL beyond 50,000 miles.
02-16-2010, 12:58 PM
#1
Burning Brakes
Thread Starter
LOKASIL beyond 50,000 miles.
Has anyone seen anything about Lokasil bores becoming OVAL on the 3.6 ? This can't be right.
"The cylinder walls in the 3.2 were modified over the 2.7 (which was bored out from the 2.5) to maintain a decent thickness, but the 3.4 and 3.6 are simply bored out further from the 3.2 to obtain the right capacity. This results in a reduced wall thickness and a thinner LOKASIL liner – a cylinder lining system fitted to all Porsche water cooled engines (except the GT3 unit which uses NIKASIL). The metal matrix of the LOKASIL is not perfect and over time they can fracture, and the bores almost inevitably become oval beyond 50,000 miles." Total 911 issue 41.
Close-up of the localized Lokasil liner in the M96/M97 block; later revised 3.6 block shown with reinforced webbing.
Chris
2002 C2 CAB
GT3 Wheels.
"The cylinder walls in the 3.2 were modified over the 2.7 (which was bored out from the 2.5) to maintain a decent thickness, but the 3.4 and 3.6 are simply bored out further from the 3.2 to obtain the right capacity. This results in a reduced wall thickness and a thinner LOKASIL liner – a cylinder lining system fitted to all Porsche water cooled engines (except the GT3 unit which uses NIKASIL). The metal matrix of the LOKASIL is not perfect and over time they can fracture, and the bores almost inevitably become oval beyond 50,000 miles." Total 911 issue 41.
Close-up of the localized Lokasil liner in the M96/M97 block; later revised 3.6 block shown with reinforced webbing.
Chris
2002 C2 CAB
GT3 Wheels.
02-16-2010, 01:14 PM
#2
RL Community Team
Rennlist Member
Rennlist Member
That's a very well written statement by that author: "almost inevitably" -- I'd tend to believe anything that guy comes up with. 
On the other hand, maybe one day our media will actually provide statistically significant objective evidence that supports their dramatic conclusions; until then, it's sell, sell, sell.
On the other hand, maybe one day our media will actually provide statistically significant objective evidence that supports their dramatic conclusions; until then, it's sell, sell, sell.
02-16-2010, 05:33 PM
#5
Race Director
I would question that simply bored out to make a 3.6l from a 3.4l. The liners are inserts and do not have all that much wall thickness. IOWs, there's not a lot of extra wall thickness to machine away before the special cylinder liner material is, well, gone.
Even if the liners are bored out, the insert material is consistent in its make up through the entire liner's wall thickness. The liner material serves as a very low friction long wearing cylinder material and is not responsible for adding much to the cylinder's structural strength. The responsibilty for that is with the cast aluminum that flows into the rather porous liner material and surrounds the liner material during the block casting process.
Regardless, there are enough 3.6l engines around that if the bores were going oval I think we would have heard about it by now.
What's the matter? IMS bearing failure, porous blocks, D-chunk failure in cylinders, sucking AOSs, cracked heads, internal freeze plug failure, cam chain breakage, rod bolt failure and so on not enough to worry about. Now you need oval bores too?
BTW, my 02 Boxster 2.7l engine has over 228K miles on its original engine. I suspect bores have gone past oval now and are square... Yet engine still runs good and oil consumption (now up to a quart every 5000 miles) still reasonable.
Sincerely,
Macster.
Even if the liners are bored out, the insert material is consistent in its make up through the entire liner's wall thickness. The liner material serves as a very low friction long wearing cylinder material and is not responsible for adding much to the cylinder's structural strength. The responsibilty for that is with the cast aluminum that flows into the rather porous liner material and surrounds the liner material during the block casting process.
Regardless, there are enough 3.6l engines around that if the bores were going oval I think we would have heard about it by now.
What's the matter? IMS bearing failure, porous blocks, D-chunk failure in cylinders, sucking AOSs, cracked heads, internal freeze plug failure, cam chain breakage, rod bolt failure and so on not enough to worry about. Now you need oval bores too?
BTW, my 02 Boxster 2.7l engine has over 228K miles on its original engine. I suspect bores have gone past oval now and are square... Yet engine still runs good and oil consumption (now up to a quart every 5000 miles) still reasonable.
Sincerely,
Macster.
02-16-2010, 05:54 PM
#6
Race Director
Here's a pic that shows the other end of the cylinders, the business end....
This engine out of an older 996 that suffered IMS bearing failure. Engine salvagable.
I checked for a lip at the top and bottom of the cylinders. None. Tech told me these cylinders are very long wearing with of course proper oil servicing.
Sincerely,
Macster.
This engine out of an older 996 that suffered IMS bearing failure. Engine salvagable.
I checked for a lip at the top and bottom of the cylinders. None. Tech told me these cylinders are very long wearing with of course proper oil servicing.
Sincerely,
Macster.
Trending Topics
02-17-2010, 09:02 AM
#8
Burning Brakes
Thread Starter
Macster:
Now that is what I want to hear, an “engine has over 228K miles”! I sold my 3.4 996 with 60k and picked up a 3.6 996 back in September. So, what kind of routine maintenance schedule did you use on you 02 Boxster to get over 200k.
Chris
2002 C2 CAB
GT3 Wheels.
Now that is what I want to hear, an “engine has over 228K miles”! I sold my 3.4 996 with 60k and picked up a 3.6 996 back in September. So, what kind of routine maintenance schedule did you use on you 02 Boxster to get over 200k.
Chris
2002 C2 CAB
GT3 Wheels.
02-17-2010, 09:09 AM
#9
Burning Brakes
I have yet to tear down an M96 that had 6 totally round and totally straight cylinders, no matter the displacement. The center cylinders are usually distorted the most, especially near the top of the bore.
Not all 3.6 crankcases are the same, later units are more reinforced.
Not all 3.6 crankcases are the same, later units are more reinforced.
02-17-2010, 09:28 AM
#10
Drifting
Go to this site and read section 2 of their buyers guide.
http://www.hartech.org/buyers.html
It has an extensive write up on the M96 engines and a detailed analysis of failures including the problem of liners going oval. An interesting read.
http://www.hartech.org/buyers.html
It has an extensive write up on the M96 engines and a detailed analysis of failures including the problem of liners going oval. An interesting read.
02-17-2010, 09:45 AM
#11
Rennlist Member
I would question that simply bored out to make a 3.6l from a 3.4l. The liners are inserts and do not have all that much wall thickness. IOWs, there's not a lot of extra wall thickness to machine away before the special cylinder liner material is, well, gone.
Even if the liners are bored out, the insert material is consistent in its make up through the entire liner's wall thickness. The liner material serves as a very low friction long wearing cylinder material and is not responsible for adding much to the cylinder's structural strength. The responsibilty for that is with the cast aluminum that flows into the rather porous liner material and surrounds the liner material during the block casting process.
Regardless, there are enough 3.6l engines around that if the bores were going oval I think we would have heard about it by now.
What's the matter? IMS bearing failure, porous blocks, D-chunk failure in cylinders, sucking AOSs, cracked heads, internal freeze plug failure, cam chain breakage, rod bolt failure and so on not enough to worry about. Now you need oval bores too?
BTW, my 02 Boxster 2.7l engine has over 228K miles on its original engine. I suspect bores have gone past oval now and are square... Yet engine still runs good and oil consumption (now up to a quart every 5000 miles) still reasonable.
Sincerely,
Macster.
Even if the liners are bored out, the insert material is consistent in its make up through the entire liner's wall thickness. The liner material serves as a very low friction long wearing cylinder material and is not responsible for adding much to the cylinder's structural strength. The responsibilty for that is with the cast aluminum that flows into the rather porous liner material and surrounds the liner material during the block casting process.
Regardless, there are enough 3.6l engines around that if the bores were going oval I think we would have heard about it by now.
What's the matter? IMS bearing failure, porous blocks, D-chunk failure in cylinders, sucking AOSs, cracked heads, internal freeze plug failure, cam chain breakage, rod bolt failure and so on not enough to worry about. Now you need oval bores too?
BTW, my 02 Boxster 2.7l engine has over 228K miles on its original engine. I suspect bores have gone past oval now and are square... Yet engine still runs good and oil consumption (now up to a quart every 5000 miles) still reasonable.
Sincerely,
Macster.
02-17-2010, 01:55 PM
#12
Go to this site and read section 2 of their buyers guide.
http://www.hartech.org/buyers.html
It has an extensive write up on the M96 engines and a detailed analysis of failures including the problem of liners going oval. An interesting read.
http://www.hartech.org/buyers.html
It has an extensive write up on the M96 engines and a detailed analysis of failures including the problem of liners going oval. An interesting read.
"Before we start detailing faults and solutions it is important to us to put the incidences of failures reported mainly on the Internet or brought to us for repair – into perspective. We do not know exact National or Worldwide figures but it is very clear to us that most cars have been performing very well with no problems at all for many thousands of miles.
No one contributes to an Internet site to explain why and how their car never went wrong and worked just fine – nor do they seem to praise supplying dealers or service and repair centres when nothing goes wrong. So it is easy to read into the complaints that do occur that there is a huge problem – which there is not.
We think that the problem really comes about because the cost of repairs (if things do go wrong) is quite high and in some circumstances – higher than previous models – so for some owners it becomes too expensive and hence the complaints we all read about."
That is about as clear a introduction to this discussion as I have read.
Thanks for the link.
02-17-2010, 03:48 PM
#13
Race Director
Glad I have something of value to contribute. Can't pay back those that have helped me in the past but maybe can pay forward.
Not selling anything.
Sincerely,
Macster.
02-17-2010, 04:10 PM
#14
Race Director
Just regular (every 5K miles) oil/filter changes and other filters/fluids serviced at regular intervals.
There are exceptions of course, we've all read reports of them, but generally catastrophic engine failures are rare.
What usually takes an older higher mileage car off the road is neglect which over time turns into a huge repair bill to catch up on what the car needs. Keep the car clean and waxed and looking nice. Makes it easier to justify spending money on servicing if the car looks good.
Another reason an older higher mileage car ends up off the road is a failure of an subsystem (like the cooling system) which takes out an otherwise perfectly good engine. A slow coolant leak which can suddenly lead to an overheated and possibly warped or cracked head, for instance. Then one's looking at throwing thousands at an older car, a high mileage engine, vs. putting that money towards a new or newer car purchase.
Then too some luck plays a role. As a car ages and gathers miles accidents claim a fair number. An older higher mileage car can with not much damage be declared a total loss.
Give a cold engine a moment of idling to gather a bit of warmth and ensure good oil flow, drive car easy -- low to medium low loads and rpms below 3K or thereabouts -- until engine has time to get fully up to operating temperature -- which based on my experience with the in-dash temp gage which is at best a crude indicator of the engine's actual coolant temperature requires the in-dash temp gage be at "180" or thereabouts for some minutes.
Once up to temperature then just drive the car. The more time you spend driving the engine at redline the more this shortens the engine's life but moderately high engine speeds with good oil (and a perfectly working coolant system) is relatively harmless to the engine. (I can't tell you in what deserted parts of the country at what speeds in what heat I've driven my Boxster for miles and miles and miles with no apparent harm -- but I can tell you that even high rpms at high speeds and high (100+) temps did not seem to phase the engine.)
As a side note, the Boxster may appear to be looked down upon as not a "real" Porsche but but it has as its heart and soul the heart and soul of a real road car and the abilty to cruise as fast as you dare for as long as you dare. You will run out of courage, road, gas, or luck before the car quits on you.
Before you shut off the engine give it a moment of idling to shed some heat, especially if you've just come off the freeway or from the track.
I try to drive the car every other day or so. I have two cars and sort of split the driving between them. For some times I have owned just the Boxster though and being my only car serves as grocery getter, commuter, grand tourer and just fun car.
Sincerely,
Macster.
There are exceptions of course, we've all read reports of them, but generally catastrophic engine failures are rare.
What usually takes an older higher mileage car off the road is neglect which over time turns into a huge repair bill to catch up on what the car needs. Keep the car clean and waxed and looking nice. Makes it easier to justify spending money on servicing if the car looks good.
Another reason an older higher mileage car ends up off the road is a failure of an subsystem (like the cooling system) which takes out an otherwise perfectly good engine. A slow coolant leak which can suddenly lead to an overheated and possibly warped or cracked head, for instance. Then one's looking at throwing thousands at an older car, a high mileage engine, vs. putting that money towards a new or newer car purchase.
Then too some luck plays a role. As a car ages and gathers miles accidents claim a fair number. An older higher mileage car can with not much damage be declared a total loss.
Give a cold engine a moment of idling to gather a bit of warmth and ensure good oil flow, drive car easy -- low to medium low loads and rpms below 3K or thereabouts -- until engine has time to get fully up to operating temperature -- which based on my experience with the in-dash temp gage which is at best a crude indicator of the engine's actual coolant temperature requires the in-dash temp gage be at "180" or thereabouts for some minutes.
Once up to temperature then just drive the car. The more time you spend driving the engine at redline the more this shortens the engine's life but moderately high engine speeds with good oil (and a perfectly working coolant system) is relatively harmless to the engine. (I can't tell you in what deserted parts of the country at what speeds in what heat I've driven my Boxster for miles and miles and miles with no apparent harm -- but I can tell you that even high rpms at high speeds and high (100+) temps did not seem to phase the engine.)
As a side note, the Boxster may appear to be looked down upon as not a "real" Porsche but but it has as its heart and soul the heart and soul of a real road car and the abilty to cruise as fast as you dare for as long as you dare. You will run out of courage, road, gas, or luck before the car quits on you.
Before you shut off the engine give it a moment of idling to shed some heat, especially if you've just come off the freeway or from the track.
I try to drive the car every other day or so. I have two cars and sort of split the driving between them. For some times I have owned just the Boxster though and being my only car serves as grocery getter, commuter, grand tourer and just fun car.
Sincerely,
Macster.
02-17-2010, 04:32 PM
#15
Burning Brakes
I agree..
Many engines that have come here to be upgraded have done so in perfectly good operating condition and it appeared that the lack of cylinder concentricity really didn't impact them very much.
Many engines that have come here to be upgraded have done so in perfectly good operating condition and it appeared that the lack of cylinder concentricity really didn't impact them very much.