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Originally Posted by mikefocke
that says a replacement engine will be less reliable than an original?
An original of what model year? Versus a replacement engine from what build year?
A late '99 versus a replacement newly built in 2007?
A '02 versus a replacement in 2008?
While the replacement engine will have the design deficiencies of its generation, so would many of the engines it is replacing.
So why do you make this sweeping statement?
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I base this statement on the interface I have had with customers and core engines that have been torn down with each mode of failure examined so they could be added to our data base, hopefully to create trends that will be useful down the road helping everyone.
When the factory reconditions an engine, their methods are similar to what was done with the 99model engines that had sleeves installed, but they don't do this on every cylinder!!! This is a pic of a sleeve that failed in a factory reconditioned engine with only 30K miles on it.
Once the sleeve dislodged the next occurrence was what is depicted in the below pic takemn from the opposite side of the cylinder.
Today most of my calls are coming from those that have reconditioned engines and some of the customers don't even know the engine is reconditioned until it is sent to us, because they bought the car used with little history. It seems that the problematic OE engines have already failed and those that are still on the road were the "Best" of the bunch, some going 150K+.
I only know what we experience from the phone ringing and emails as well as what we are finiding at tear down time and currently the reconditioned engines are the highest failing units, at least with cylinder failures. Lots of these giys don't want another reconditioned engine (in fears of a future recurrence of the same failure) so that may be the reason why we get the job instead of Porsche and may be the reason why the rash of these has occurred lately..
Thats part of the mystery that intrigues me with these engines.
I'll now go over Bruce's post
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There is no data nor logic to support the notion that running the engine hard will lower the chance of engine failure.
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Actually there is, or at least there will be soon. I have gathered a ton of info from how the engines were driven that we have received for work and how they failed. This is part of the trend setting process that will help us see why these things occur and that will help to avoid them.
To date, none of the engines we have seen have died during any type of racing or hard driving, in fact most of them that failed had NEVER been driven that way! Of the 8 cores I have sourced in the past 2 months all but one of them died while being driven at less than 50 MPH!
I take advantage of the time I have on the phone with customers and want to learn what happened with the engine, I even have forms they fill out to describe how the car was treated, maintained and driven since they have owned it. Coupling this with what we find inside is quite interesting and it seems that even given the same set of driving parameters from several different cars and drivers we see that sometimes the same cylinders fail the same way.
It's too early to say this is an absolute as 2-3 more years of interface and investigation will be needed to do that, but I KNOWthat understanding what happens, why it happens and when it happens is a critical aspect of true development. I also need this information to pass on to my clients who buy the engines, determining shift points, driving styles and maintenance scheduling. I have thrown away all the Porsche directives for the updated engines-
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In fact, the opposite is quite true.
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Won't argue there... At least with the majority of engines, but this engine is different and quite misunderstood.
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Think about it. The IMS fails under stress. Is the engine experiencing stress more or less at idle or at 7000 rpms.
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I have not seen or heard of any IMS failures in any of the competition classes, or haven't heard of failures at DE/AX events. Thus far not a single IMS failure we have seen has come from high speed driving. I did buy some cores that had failed IMS, but they were from salvage yards with no history.
It's hard to say at which rev point the IMS is under the most stress. The way the vario cam works the IMS is loaded and unloaded at different revs more and less with varying stresses continually.
It is my hypothesis that the variocam stresses are experienced multiple times in lower speed driving as the vehicle goes up and down through the gears and breaks through the rev range and atuation point of vario cam. This means the loading and unloading of the arrangement is stressing the IMS more frequently at some speeds than others,. At high speed the vario cam is actuated and remains actuated, it is loaded and stays that way so at high speeds with high revs the loading and unloading that works on the IMS bearing may actuially be less than at lower speeds and in traffic.
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Lets stay rational on this topic, huh?
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I think we are... Look at the posts on forums about when engines have failed. See how many people in those threads were at high revs or were driving in a spirited fashion when they experienced a failure, compared to those that were just driving.
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If I had a used Box, I would have a warranty. That is me.
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Its good insurance for sure.. I am working with a couple of warranty companies to create Boxster packages for the entire car that could be applied after one of ourupgrades, or maybe just individually for those that want some security.
Now, I'll close by stating that I don't want to ruffle any feathers here on these topics, I only know what we have experienced and thats more than any other group outside of Porsche thus far. In the beginning it made no sense to me when failures occurred, paying attention and documenting the failures is the only way to seek-out the true issues, understand them and solve them.
If cars are driven and respected as a Porsche should be on a daily basis it seems there are very few issues... That doesn't mean that people should TRY to break their car like I do the test car, but they should not be afriad to see 6,500 RPM at least once a week and 5,000 RPM at least once a day!
I have a broken X-51/ 996 engine here now.. It has a broken crankshaft, but had 12,000 track miles on it! The crank broke because of a LWF install and the removal of the haronic dampening of the dual mass flywheel as well as an imbalance issue due to the flywheel not being balance indexed to the engine, since it was installed with the engine assembled. I'll be updating the site with these pictures and more in the next couple of weeks.
2013 Porsche Boxster S
Hybrid Mode
