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Old 10-12-2017, 11:22 AM   #12
seningen
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Join Date: Jul 2008
Location: austin
Posts: 824
Quote:
Originally Posted by thstone View Post
Yes, you read it right: Should I replace my entire engine as preventative maintenance?

Before you start typing, read on...

I race my Boxster extensively and drive it to/from the race tracks. The race tracks vary from 1 hour to 6+ hours (each way) from my house.

Racing experience suggests that 2.5L engines last about 60-80 hours on the track (which is a lot of time at 5000-7000 rpm). This rough estimate of engine life is highly variable with some engines failing earlier and some lasting much longer. Its impossible to know how long any individual engine will last. So there is no way to know if I have 2 hours left or 25 hours left.

My current engine has 75 hours of racing time and I already have a replacement engine sitting in my workshop.

The effort and minor costs to DIY the replacement swap is within my time available, tools (including a four-post lift at my house), and skill set.

The downside of experiencing an engine failure at the track is the time, effort, and general PITA to transport me and the car home. I could ride with the tow truck driver but for a long drive (more than 2 hrs), I'd probably rent a car locally and drive myself home. I have AAA 200 mile towing but the furthest tracks would exceed that limit and potentially I could be looking at a $600 bill to have the car towed home. While that might sound like a lot, that level of expense is already built into my racing budget so it wouldn't create any financial strain. But with that being said, I certainly could find a better use for $600 than paying a tow truck.

In general, I tend to follow the "if it ain't broke don't fix it" theory but not exclusively.

So, do I replace the engine now to preemptively avoid an engine failure or just drive/race it until it fails?

Now start typing...

Assuming you have an off season -- I'd replace it. But, you are replacing with a unknown time bomb if its a junkyard used engine.

Then take the now in-car "used" engine -- and do a rebuild of it so that you have a back-up just in case. I haven't checked in awhile -- but it's probably $2k in parts to rebuild (depending on how crazy you get)

What have you experienced in the past as failures? Bearings? Rod bolts? lifters?
There are only a couple special tools you need to rebuild the engine specific to the Boxster. The only tricky part is getting the blind piston circlips in. you can make a homemade tool for that -- or buy Porsches.

Mike
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Drivers: '15 Panamera Hybrid (wife's), ' 01 996 GT2, 00 Boxster S, '96 993 Çab/Tip (wife's)
Race Cars: '75 911 RSR Replica & '99 Spec Boxster
mike@lonestarrpm.com
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