clubrcr

I am not a mechanic, but I have had several cup cars, both water cooled and air cooled. In selling previuos cars, I have done a lot of research into the leakdown and what it really tells you. In my opinion, there are two items to consider; First if the compression numbers are in line across all the cylinders, then the leakdown really doesn't tell you much. That should be obvious from the post about the bhp numbers being higher on an older motor than a newer one. The other item and a very important one is the use of the motor. If a motor isn't used a lot, and sits for a long period of time, the leakdown numbers are going to be higher. If the motor is not hot when the leakdown is performed. the numbers are going to be higher. Many mechanics don't want to heat the motor up because it is easier for them to do it on a cold motor. The numbers are going to be different. I had a 993 Supercup that sat in my garage for three months, the mechanic did a leakdown for a potential buyer. The numbers were higher than the average. We took the car to the track that weekend and the leakdown numbers came down to regular acceptable numbers. I have also heard that the 996 Cup do leakdown with higher numbers, but from my research, the leakdown is not as important as the compression.

jrgordonsenior

Thanks for your imput Jim. I enjoyed your PCA article.

Compression was good at 183-187. The mechanic who took the leakdown said he took the manifolds off to get to the plugs, so you know it wasn't that warm when he took the readings. I'm going to run it a bit on their dyno, look at the HP numbers, and then re-test for leakdown if I like the dyno numbers. All this testing is getting expensive.....

Darren

You can't really compare the "normal" leak down numbers (<5%?) of a street car to an all out race motor like in the CC. By the time most motors have their rings seat, the cup car motor needs a rebuild. So clearances on internal components are all different when they are built. And the leakdown test is sort of like using a pyrometer to check tire temps in the pits, i.e. it might be close to the real reading, but it doesn't tell you exactly what is happening at temp.

clubrcr

Thanks, Patti Mascone was very nice to use me in the article.

As far as al this getting to be expensive, I agree. You can spend a ton of money and go out on the track and have a problem on your first test session. You have to remember these are race motors and with all the preventative testing showing no signs of a problem, you might still encounter one.

In buying cars in the past, I have relied on trust. Our racing community is rather small when you think about it. Screw one person and the word gets out. In talking with the seller, you can get a gut feeling. Ask others about the car, get receipts. the condition of the car can give you an idea of how it was abused. Like I said, spending all the money on leakdowns and dynos, won't guarantee anything.

J.PELLEGRINO

I am in agreement with Henry on this.I have serviced and rebuilt many supercup and Gt3r/rs engines and thier is no way that those numbers are acceptable.I would check that the leakdown was done correctly ie: the engine was run first,plugs loosened and then run again before the test was attempted.I would also use ae electronic stethescope to determine where the leakage is from,only then can you determine the realitive health of that,or any other engine.It is not unusual to have leakdown figures well below 10% for a healty cup engine.I would be happy to speak further to anyone that may have other questions about this or any other supercup issues.Good luck,Jerry

Konstantin

I was at Indy this year.
Porsche Factory motorsport (not the US clone) checked all engines for all running 997 Gt3 cup cars.
I can not give you all numbers but anythything over 25% is just to high.
Either the mesurement was not done properly or there is a problem in the engine.
you must know that statical and dynamicaly messurment do NOT show the same numbers.
whta you do is statical messurement.

street car up to 5-10% is ok
cup cars 3% to 20% is ok

you must check both. on cold AND warm engine and see wher eit loses Crancase, head or both
Konstantin

jrgordonsenior

Jim I couldn't agree with you more. That's the only reason I'm still interested in the car and asking questions. The So Cal community think highly of the car, the owner, and the mechanic who set it up, although it's been idle for 3-4 years. Things can deteriorate over that time period, I just can't imagine an engine can though. I'll run it a little next week and throw it on their dyno. We'll see, there's many other cups available, I'll just have to wait a little longer....

Konstantin

as Jim already said. If you do not trust the owner/seller do not buy it.

Konstantin

analogmike

One more point of reference:
Horst Farnbacher is the most successful Carrera Cup mechanic and he does not seem at all concerned about high leakdown. I wish I could speak German to get more detailed info from him, but he says he has seen it before and there's no problem racing an engine with a few cylinders leaking into the crankcase.

paradisenb

The Tub and Frames are two different components on a Cup Car. If I am not mistaken they have a tube frame. Not the same animal as the street cars.

Konstantin

then he must know as simple mechanic more than 100 Porsche engineers or it will be one of his cars who wants to sell
Also do not forget that he is the one in the whole Porsche cup with the most disqualifications for cheating.
more than all other teams together.

anyway respect to him since he is so good at it than even The factory has a hard time to find out what he does.
Ask his former drivers or coworkers if you want to know more about it.
how is possible in a sealed engine and a controled car to change the cams the springs and some more and it takes Porsche 6 races to find it out?

It is what we say "knallhart bussiness man" and be aware of the smile of bussiness man

If the tube or the frame is bend then you need a whole New BODY including tube and frame
about 26000 US $ plus the work to replace all the poarts to the new body.
Better you take a real experinced cup mechanic with you and let him explain what he thinks and why.
after all it is your money and the seller will do everything to get them.
You want the best car for the money. I wish I would be there to help you but I sure you can find someone to do that.
a documented history is very importand.

Konstantin

clubrcr

You might want to wait, I am seeing a lot more GT3 Cup available today than two months ago. I don't know if that is a product of the newer cups now starting to be available or maybe summer time is the time to buy??? If there are more on the market you might see prices start to come down a little.

I personally think the prices might have been inflated becuase of the IMSA Cup series. Take your time and you'll find the perfect car. Whenever I am in the market for a new car, I go by this saying.... "You have to kiss a lot of frogs to find the prince"

MJR911

Jim, you're always in the market for a Porsche racecar! But I do agree, there is a really clean (atleast from the description) '02 with the right updates in the classifieds right now fro $115,000.
JR Gordon, have you looked at that car? or is the car your looking at VERY well priced? I have a feeling it is or you wouldn't be going through the intense process.

Konstantin, thanks for the words... i know what you're saying. There is a fine line, I am reminded of some of the old Mark Donohue/Penske stories.

clubrcr

Mitch, it's a sickness...heard of any good deals???

clubrcr

JR have you talked to Glen Gatlin, I spoke to him the other day and he told me of couple of cars that weren't advertised??