Cayman R - Rebuilding Engine Info

[CanAm]

I recently heard something about Porsche engines needing to be "rebuilt" after about 120 hours of track use (I guess about 50 to 100 track days), at a cost of about $10K. Does that sound right?

[Casey914]

You need to be more clear... Are you referring to your Cayman? That is a lot different than a very high compression race engine.

[CanAm]

You need to be more clear... Are you referring to your Cayman? That is a lot different than a very high compression race engine.

Yes, specifically for our Cayman R. Thanks for the question.

[VaSteve]

Yes. Your're using it up at an incredible rate.

[Patrick3000]

Get rid of it quick, you really want a GT3 anyway ;)

[CanAm]

Get rid of it quick, you really want a GT3 anyway ;)

Problem is that the 991 GT3 won't be available until next year. :)

[BlackTalon]

Don't know where you heard that, but chances are you did not understand the context. Race motors typically need to be rebuilt every 20-150 hours for cup cars, etc. -- depending on level of compression, tune, etc. But this does not apply to street cars.

Oh, and good luck rebuilding the Cayman motor (or any 6 cyl Porsche motor ever built) for only $10k unless you are DIYing a bit of the labor.

(BTW, is this really just a troll post?)

[CanAm]

Don't know where you heard that, but chances are you did not understand the context. Race motors typically need to be rebuilt every 20-150 hours for cup cars, etc. -- depending on level of compression, tune, etc. But this does not apply to street cars.

Oh, and good luck rebuilding the Cayman motor (or any 6 cyl Porsche motor ever built) for only $10k unless you are DIYing a bit of the labor.

(BTW, is this really just a troll post?)

Not a troll post, heard the comment from a reputable source, but it's hard for me to believe that a street car engine would need to be rebuilt that often, so I thought I better ask here. Other than looking at number of track hours, are there any symptoms (leaks, noises, etc.) that would indicate when a rebuild is needed?

[VaSteve]

Both those would be a good indicator.

[BlackTalon]

For a street car, don't go by track hours.

It will either suffer compression loss due to wear, such as worn valve guides, wear on piston rings/ cylinders, etc., or it will suffer a catastrophic failure. For the former look for increased oil consumption, and bad leakdown/ compression test values. For the latter, look for a big hole in the case, parts strewn down the main straight and cars that were once planted on your tail now planted on the tire walls.

[Casey914]

I think the likelyhood of missing a shift is far greater than wearing out the engine. Those engines run for an entire season + in Grand-am...

[CanAm]

Both those would be a good indicator.

For a street car, don't go by track hours.

It will either suffer compression loss due to wear, such as worn valve guides, wear on piston rings/ cylinders, etc., or it will suffer a catastrophic failure. For the former look for increased oil consumption, and bad leakdown/ compression test values. For the latter, look for a big hole in the case, parts strewn down the main straight and cars that were once planted on your tail now planted on the tire walls.

Thanks, I'll monitor for signs of anything odd (which I do anyway), and will do the normal servicing, but will otherwise assume the car's OK.

[racer]

I imagine if you want to "win", then having a fresh engine is important. IIRC, cup car (993+ newer) benefit from rebuilds in the 20-50-100hr use ranges.

Unless its a 944 motor, can't imagine too many Porsche motors can get rebuilt for $10K these days, unless there is a lot of D-I-Y effort involved.

[Jase007]

If nothing's broke (big IF) 356/912 race motor can get refreshed for < $10k.

Comes apart every ~40 hours ... no matter what. :)

[}{arlequin]

if things break, they get rebuilt.

cost will be dependent on the market price of whatever broke

[tbernard]

Isn't it just cheaper to find a donor motor for these cars, rather then rebuilding?

[Trak Ratt]

^ some times but as the cars get older their donor cars do to. Not a lot of Rs around yet either.

[Lupin..the..3rd]

Thanks, I'll monitor for signs of anything odd (which I do anyway), and will do the normal servicing, but will otherwise assume the car's OK.
The key to prolonging the funtime is maintenance. For example, your owners manual may call for 12,000 mile oil changes, but that is assuming 12,000 miles of commuting to work and going to the grocery store. If you attempt to put 12,000 track miles on the same oil, your engine will be worn out in no time. You need a maintenance schedule that matches your usage pattern. All your fluids must be changed a lot more frequently on any car that sees significant track time.

[Dr K]

If nothing's broke (big IF) 356/912 race motor can get refreshed for < $10k.

Comes apart every ~40 hours ... no matter what. :)

I assume that's not a Furman 4-cam...

[CanAm]

The key to prolonging the funtime is maintenance. For example, your owners manual may call for 12,000 mile oil changes, but that is assuming 12,000 miles of commuting to work and going to the grocery store. If you attempt to put 12,000 track miles on the same oil, your engine will be worn out in no time. You need a maintenance schedule that matches your usage pattern. All your fluids must be changed a lot more frequently on any car that sees significant track time.

I think the standard oil change interval for the CR is 10K miles. Assuming half of the miles on the car are track miles, about how often would you change the oil?

[LPM911]

I think the standard oil change interval for the CR is 10K miles. Assuming half of the miles on the car are track miles, about how often would you change the oil?

Every couple of events.

[Trak Ratt]

That's what I do (and it's a lot more oil than your lump). Also cut open the oil filter, check the magnetic drain plug. If suspicious or a lot of miles put a mag in the bottom of the oil pan.

I did this over the weekend on my dead race car engine. Found a few bits for my efforts in the pan and some on the plug. But none in the filter.

[Vicegrip]

I recently heard something about Porsche engines needing to be "rebuilt" after about 120 hours of track use (I guess about 50 to 100 track days), at a cost of about $10K. Does that sound right?No, laughable both in frequency and cost with one too high and the other too low. (Unless you are as said by 007 racing a 356/912 motor and having it built by a paid pro.)

Thanks, I'll monitor for signs of anything odd (which I do anyway), and will do the normal servicing, but will otherwise assume the car's OK.Why assume? Automotive oil analysis is common in racing circles. You can’t just look at your oil and say the motor is OK or not. If you can see someting wrong with the oil fill your motor is already in bad shape. If you have not heard about this already I am suprised one of the many you have driven with has not mentioned this important testing tool. http://www.blackstone-labs.com/?gclid=CNuz58L9-LICFYaDQgodLXEAmA

I think the standard oil change interval for the CR is 10K miles. Assuming half of the miles on the car are track miles, about how often would you change the oil? See above. Why guess at something that has many variables? Test and test often until you get a plot line and change according to the test results. Once you have a plot line you can ajust the change timing to the use profile. This is one area where you just might be able to use analysis to improve results.
Many assume that track miles are harder on the oil than street miles. Perhaps so perhaps not. I say it depends on the initial conditions. As an example 100 street miles, 5 miles a day short trip is far harder on the oil than 100 miles at the track fro a modern water cooled car. Water and fuel builds up in the short trip cycle oil during starts and cold running and the motor never gets hot enough to cook the moisture and unburned fuel out. Most modern water cooled motors don't thermaly stress the oil as hard as the old school air-cooled motors do so what might be a reasonable change cycle for a track built 2.4L MFI fed 911 is a total waste of time and money on a crock-r

[vranko]

Every couple of events.
x2 That's what I try to do. I also change the gear oil every 6 months. PS fluid also gets flushed frequently since it's often trying to evacuate itself from the car :shock: :bang::bang:

[spiffyjiff]

Every couple of events.

yep

Also cut open the oil filter, check the magnetic drain plug. If suspicious or a lot of miles put a mag in the bottom of the oil pan.

and yep.

Why assume? Automotive oil analysis is common in racing circles. You can’t just look at your oil and say the motor is OK or not. If you can see someting wrong with the oil fill your motor is already in bad shape. If you have not heard about this already I am suprised one of the many you have driven with has not mentioned this important testing tool. http://www.blackstone-labs.com/?gclid=CNuz58L9-LICFYaDQgodLXEAmA...Test and test often until you get a plot line and change according to the test results. Once you have a plot line you can ajust the change timing to the use profile. This is one area where you just might be able to use analysis to improve results.

annnd yep.

i am on my 6th analysis from blackstone. yes, of course my motor could grenade at any time for a variety of reasons but for the exception of a small lead spike a couple changes ago, everything on the reports is reassuring that at least nothing is glaringly out of the ordinary. i have been changing every couple thousand miles/couple events but from the reports it looks like i could even go longer betw changes (but i will prob not, for superstitious' sake!).

and isnt it about time for BMAN to chime in to this thread?? isnt it time to rebuild his motor?? ;)

[CanAm]

Thanks guys, as always, for all of the info and advice. This forum continues to be a vital resource for me and I'm sure many others.

Sounds like I definitely need to do the Blackstone testing. I feel bad that the previous oil changes likely haven't been frequent enough, but I guess at this point the best action is to get it right going forward.

When I started this track thing, I had no idea how much would be involved as far as taking care of the car - and the cost!

[Ryan]

My GT3 before I got rid of it had 33k miles in 3 years, 20k of which was track. Changed the oil twice, never the trans fluid, and no other fluids. Ran like a champ.

[Trak Ratt]

my gt3 before i got rid of it had 33k miles in 3 years, 20k of which was track. Changed the oil twice, never the trans fluid, and no other fluids. Ran like a champ all during the lease.ftfub-o

[Lupin..the..3rd]

Sounds like I definitely need to do the Blackstone testing. I feel bad that the previous oil changes likely haven't been frequent enough, but I guess at this point the best action is to get it right going forward.
Do the blackstone analysis in conjunction with your next oil change, so that you sample the old oil as its draining out. It will be interesting to see what the analysis reveals on oil that has seen so many track hours...

[ausgeflippt951]

120h sounds ridiculously frequent from my fairly limited experience. Our Formula Atlantic motors (highly stressed 1.6L revving to 11k and making 260hp) were rebuilt every 800 hrs as a preventative measure. Our F1 motors (97 Jordan and Benettons) needed to be rebuilt every hrs. And if memory serves our Judd V10s were rebuilt every 500hrs.

I'll have to double check on those numbers; it's been a while.

[BlackTalon]

Porsche Cup Car motors are something like 50 hrs unless detuned for longevity.

[Vicegrip]

From what I have been reading all you need to do is lower your shift points to extend the rebuild cycle.