997.2 3.8 Engine Failure
05-30-2019, 08:41 AM
#886
RL Community Team
Rennlist Member
Rennlist Member
Not surprised you liked the Boxster S. My 2000 Boxster S was a better sports car than my current 2009 C2S. Just was.
Peace
Bruce in Philly
Peace
Bruce in Philly
05-30-2019, 03:08 PM
#887
Nordschleife Master
05-30-2019, 04:07 PM
#888
RL Community Team
Rennlist Member
Rennlist Member
Peace
Bruce in Philly
05-31-2019, 02:39 AM
#889
Nordschleife Master
I thought long and hard about it.... I usually don't swap cars much.... I know have a ton of work and emotion in this car now.... took it apart so many time... may do it one day. In a few years, I am moving south so the convertible top becomes more appealing. I had the hard top option with my Boxster and kept it on 6 months of the year. Maybe. The four cylinder cars have zero appeal to me.... I swore I would never own another four cylinder car.
Peace
Bruce in Philly
Peace
Bruce in Philly
How tall are you? I'm asking since I've had both Boxster and Cayman loaners from my dealer. I'm 6'3" and don't fit in either one. Way too cramped. I'd imagine I couldn't be above 6' and preferably slightly below that to find a good driving position in either one. But since you had a Boxster in the past I guess it's working out for you. I was just really surprised at how limited the driving positions were in both the Boxster and the Cayman for my height. At 6'3" I'm not exactly a deformed giant. No issues at all in the 997.
05-31-2019, 09:39 AM
#890
RL Community Team
Rennlist Member
Rennlist Member
How tall are you? I'm asking since I've had both Boxster and Cayman loaners from my dealer. I'm 6'3" and don't fit in either one. Way too cramped. I'd imagine I couldn't be above 6' and preferably slightly below that to find a good driving position in either one. But since you had a Boxster in the past I guess it's working out for you. I was just really surprised at how limited the driving positions were in both the Boxster and the Cayman for my height. At 6'3" I'm not exactly a deformed giant. No issues at all in the 997.
Peace
Bruce in Philly
06-01-2019, 02:59 PM
#891
Nordschleife Master
I thought long and hard about it.... I usually don't swap cars much.... I know have a ton of work and emotion in this car now.... took it apart so many time... may do it one day. In a few years, I am moving south so the convertible top becomes more appealing. I had the hard top option with my Boxster and kept it on 6 months of the year. Maybe. The four cylinder cars have zero appeal to me.... I swore I would never own another four cylinder car.
Peace
Bruce in Philly
Peace
Bruce in Philly
06-01-2019, 09:34 PM
#892
I considered doing a Dragon run day trip this week while I was off work. Love going up there
Flew in to Atlanta on Friday to visit Flat 6 Innovations. Very very impressive place, attention to detail, organization and cleanliness is something to be desired by a lot of other shops i have seen. I didnt want to be too intrusive taking bunch of pictures there but heres a few from one of the buildings. Jud took almost two hours to show me around and explain everything in detail. Unfortunately i missed Jake by few hours due to my Turo rental timing. We rented a pair of 2014 and 2015 Porsche Boxster S for 4 days and took it on the trip from Atlanta to visit Flat 6, then Helen GA, then Cherohala skyway in Tennessee, Tail of the Dragon in North Carolina, then visited Asheville NC and back to Atlanta to come back home last night. Total 950 miles of driving in an absolutely amazing vehicle Porsche Boxster S. I have fallen in love with the car and i totally understand now what an amazing machine is Boxster S. It handles like an absolute dream on the twisties and Tail of the dragon was the best driving experience i have ever had!!! Heres a few photos from the trip.
Girls in Blue, Guys in Orange
Girls in Blue, Guys in Orange
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PierW (04-24-2020)
06-02-2019, 02:13 AM
#893
Nordschleife Master
You are raising some interesting points... clearly you spent some time with the other cars. To be fair, I have not driven the newer Boxster/Caymen so I am not sure how the cockpits are configured. I am 6' even and found the Boxster cockpit to be perfect for me. Both tops, soft and hard, could fit me and a helmet. Obviously I am a contrarian... I found the Boxster's mechanical seats more comfortable than my 2009 C2S crazy-way auto adjustable seats. The Boxster's mechanical seat could drop down almost flat on the pan at least when compared to my C2S. The Boxster's seats where Porsche's perfectly refined model going back many many years.... why they changed them? Keep up with the posers.... enthusiasts make the brand, posers make the money.
Peace
Bruce in Philly
Peace
Bruce in Philly
06-02-2019, 06:03 PM
#894
High praise Bruce. I keep seeing a lot of 911 guys saying this now. Makes me think pursuing a 911 is divorcing your wife for that office romance.
06-15-2019, 02:51 AM
#895
FYI Jake has been pumping out more content on Rennvission [youtube]. Thanks boss
Question if possible; I've seen and read a lot of your material. But have not seen this question answered..
Do you work with an extended warranty company upon an engine failure or major discovery [vehicle under coverage]?
One reason I bought a warranty was in the event of failure or a path to failure case scenario. ie bore scoring etc
In my example, have a policy with Fidelity. God forbid issue - I'd want you to fix my car.. because I l-o-v-e it (video reference)
Question if possible; I've seen and read a lot of your material. But have not seen this question answered..
Do you work with an extended warranty company upon an engine failure or major discovery [vehicle under coverage]?
One reason I bought a warranty was in the event of failure or a path to failure case scenario. ie bore scoring etc
In my example, have a policy with Fidelity. God forbid issue - I'd want you to fix my car.. because I l-o-v-e it (video reference)
06-15-2019, 03:51 AM
#896
Three Wheelin'
Ok that was a long read.. 
Interesting thing to me looking at the pics of the pistons,, looks a LOT like what we used to see (late 70's early 80's) on big bore 2 strokes used to trail ride.
They lasted forever on the motocross tracks, but when trail riding, where RPM's were harder to keep higher, they would "stick" pistons,
especially the ones with early forged ones. If you lugged them, they would fail the same way. One phenom that I've seen is the if aluminum
gets hot enough to start getting plastic it can significantly shrink when it cools. We "fixed" part of the problem by jetting appropriately.
The other thing was that it turned out that some mix oils were a bit hydroscopic and would absorb water.. We found that sticking with
castor-nitro at the time rather than the (then new) Semi and full synthetic mix oils when trail riding was a better choice, again a temperature thing.
FWIW check out the issues they have had with Ecotec and Eco-boost motors,, some real issues with pistons/rings in their DI motors..
Similar to early 996 engines,, just a few too many bugs.. Because a mid 2000 ecotec non turbo is making almost the same HP per liter as a 996 C2/C4
PS: thats for the guys who do this for a living and still participate here,, helps the guys like me that do their own work.. A LOT>>
Interesting thing to me looking at the pics of the pistons,, looks a LOT like what we used to see (late 70's early 80's) on big bore 2 strokes used to trail ride.
They lasted forever on the motocross tracks, but when trail riding, where RPM's were harder to keep higher, they would "stick" pistons,
especially the ones with early forged ones. If you lugged them, they would fail the same way. One phenom that I've seen is the if aluminum
gets hot enough to start getting plastic it can significantly shrink when it cools. We "fixed" part of the problem by jetting appropriately.
The other thing was that it turned out that some mix oils were a bit hydroscopic and would absorb water.. We found that sticking with
castor-nitro at the time rather than the (then new) Semi and full synthetic mix oils when trail riding was a better choice, again a temperature thing.
FWIW check out the issues they have had with Ecotec and Eco-boost motors,, some real issues with pistons/rings in their DI motors..
Similar to early 996 engines,, just a few too many bugs.. Because a mid 2000 ecotec non turbo is making almost the same HP per liter as a 996 C2/C4
PS: thats for the guys who do this for a living and still participate here,, helps the guys like me that do their own work.. A LOT>>
06-15-2019, 07:40 AM
#897
Former Vendor
Do you work with an extended warranty company upon an engine failure or major discovery [vehicle under coverage]?
One reason I bought a warranty was in the event of failure or a path to failure case scenario. ie bore scoring etc
One reason I bought a warranty was in the event of failure or a path to failure case scenario. ie bore scoring etc
The last time I attempted to do this was 2008. I won’t even consider it. If someone has an extended warranty I refuse to even diagnose the issues with the engine, or touch the car.
06-15-2019, 10:52 AM
#898
Burning Brakes
Thanks for that Charles, we too are in the thousands of Nikasil cylinder replacements and build on average 4 engines/week while supplying many more blocks with new cylinders Worldwide.
Most of my text above is relating to the differences in the failed 9A1 engines we have worked on and I agree with your general findings with the Lokasil blocks.
The first hard iron coated pistons didn't score bores because the surface was hard enough to resist the released silicon particles penetrating the surface (and the particle size was smaller).
Later engines had larger silicon particle sizes (which reduced ovality creep) but impinged on the now plastic coated pistons resulting in bore scoring.
The 9A1 has Alusil (as very successful previously in 944/968 engines) but a different piston coating that is not quite as hard as the originals but much better than plastic!
By not changing the block height or cylinder spacing when increasing capacity from 2.5 to 2.7, 3.2, 3.4, 3.6 and then 3.8, Porsche did compromise the rod length to stroke ratio - but they work Ok if the cylinders survive.
The piston offset is odd - right one side and wrong the other until the 3.6/8 engines, then the same both sides and then back to right and wrong in the Gen 2 9A1. We don't see this as a major issue though.
It would be good if anyone over there has a scored (really a seized) Gen 2 9A1 block and can measure the bores very accurately (with a bore comparator) near the seized one and next to it at different positions and heights and compare notes with ours - all of which had the same shrinkage.
Best regards,
Baz
Most of my text above is relating to the differences in the failed 9A1 engines we have worked on and I agree with your general findings with the Lokasil blocks.
The first hard iron coated pistons didn't score bores because the surface was hard enough to resist the released silicon particles penetrating the surface (and the particle size was smaller).
Later engines had larger silicon particle sizes (which reduced ovality creep) but impinged on the now plastic coated pistons resulting in bore scoring.
The 9A1 has Alusil (as very successful previously in 944/968 engines) but a different piston coating that is not quite as hard as the originals but much better than plastic!
By not changing the block height or cylinder spacing when increasing capacity from 2.5 to 2.7, 3.2, 3.4, 3.6 and then 3.8, Porsche did compromise the rod length to stroke ratio - but they work Ok if the cylinders survive.
The piston offset is odd - right one side and wrong the other until the 3.6/8 engines, then the same both sides and then back to right and wrong in the Gen 2 9A1. We don't see this as a major issue though.
It would be good if anyone over there has a scored (really a seized) Gen 2 9A1 block and can measure the bores very accurately (with a bore comparator) near the seized one and next to it at different positions and heights and compare notes with ours - all of which had the same shrinkage.
Best regards,
Baz
Baz,
I thought the M96-M97 engines had pin offset differences left to right bank, but you are saying that that was rectified for those, then the offset differences reappeared in the Gen 2 engines. Correct ?
On the OPs discovery of a failed belt tensioner (not applying tension) that could have been in that state for some time, I would think it possible that under repeated hard launches or other engine workout demands, the water pump pulley could slip significantly, resulting in less water flow for moments at a time. This could result in some hot spots. When the engine speed was brought back down, traction could be regained, and water flow and hence overall temperature kept in check.
With a hard launch in a straight line, the power steering demands are low, alternator demands low, AC most likely off, but water pump demands high and surging.
A complete stop of the belt would throw it off, and hence no power steering and charge light coming on.
06-16-2019, 07:37 AM
#899
The big end of the rod is falling below the centre line on bank 2 under thrust loads but rising on bank 1 so how the offset works depends upon the ability to rotate the piston assembly positions when changing from bank 2 to bank 1 pistons.
The piston crown on the 996 up to and including the 3.4's is a different shape on the inlet and exhaust sides and so since the inlets is on the top of both banks and the exhaust on the bottom you cannot rotate the pistons 180 degrees on assembly between banks but they have to be fitted the same way around which makes one side with the offset right (if there is actually a right and wrong) and the other side wrong.
The same difference in piston crown shape applies to the Gen 2 engines.
However the 3.4 Cayman S, 3.6 and 3.8 pistons have the crown shape the same on both inlet and exhaust sides so they can be fitted in either way around and therefore are marked so the same offset applies to the thrust faces.
It looks as if Porsche might have tried to correct it for the Cayman S, 3.6 and 3,8 models but found it made no practical difference and so reverted to the original assymetric crown layout for the Gen 2.
Baz
The piston crown on the 996 up to and including the 3.4's is a different shape on the inlet and exhaust sides and so since the inlets is on the top of both banks and the exhaust on the bottom you cannot rotate the pistons 180 degrees on assembly between banks but they have to be fitted the same way around which makes one side with the offset right (if there is actually a right and wrong) and the other side wrong.
The same difference in piston crown shape applies to the Gen 2 engines.
However the 3.4 Cayman S, 3.6 and 3.8 pistons have the crown shape the same on both inlet and exhaust sides so they can be fitted in either way around and therefore are marked so the same offset applies to the thrust faces.
It looks as if Porsche might have tried to correct it for the Cayman S, 3.6 and 3,8 models but found it made no practical difference and so reverted to the original assymetric crown layout for the Gen 2.
Baz
06-16-2019, 10:31 AM
#900
Addict
Rennlist Member
Rennlist Member
Awesome thread. FlatSix does great work and provides a much needed service to Porsche owners.
Does anyone else think that these design flaws would be the end of any other car company?
99% of other car brand owners could never afford to fix these issues?
Does anyone else think that these design flaws would be the end of any other car company?
99% of other car brand owners could never afford to fix these issues?