NetManiac

I'm not really sure what to search on here, so if this has been gone over recently please feel free to post a link to the previous conversation.

With that said, I had my first Club Race of 2006 this past weekend at California Speedway. Fun track, fun weekend. Well... up until the Sun. AM sprint race. 3 or 4 laps into it my car sputters and dies. At present all I know is that the tip of the spark plug in cylinder #6 broke off and now there is zero compression in that cylinder. Checked #5 and there is compression, so my mechanic just stopped there.

So this topic is a two-parter (maybe I should make it two different posts???):

Part 1: The Cause. Has anyone with a 996 or 986 based motor ever experienced this problem before? What on earth could cause the spark plug to break off like that?

Part 2: What to do. So now what do I do? I like racing in D. It's nice to be able to drive the car around on the street between races. So I would sorta like to put the 3.2L back in it. But do not want to just replace the motor and have it fail again at a future event. If I do put the 3.2 back in, what can be done to make it more durable for racing? If I opt for something else, I do not just want to up to a 3.4 that will fail just like my 3.2 did. What else is there?

Anyone ever turned a water-cooler car into air-cooled? Might be nice to have a rock-solid air-cooled 3.2 in there. Less HP, but more durable.

Thanks, in advance for any and all suggestions.

Bill L Seifert

I'd try the Boxster site. Never heard of this problem, but my Boxster is a 2.5. I have a friend with a trashed Boxster motor, but the engine was flooded with anto-freeze, including the exhaust. It was hydro locked and wouldn't turn over. I assume a cylinder broke, letting anti-freeze in. Yours sounds like detonation, but I ain't that good of a mechanic.

There are some pretty sharp guys on the Boxster site. That is not to say that there isn't sharp guys on this site, but I wonder how many race Boxsters. Every problem I have had with my Boxster has been solve there.

Bill Seifert

1983 944 Race Car

NetManiac

Which "boxster site"?

The 986 3.2 and 996 3.4 are very similar, so I wanted to hear from both 911 and Boxster owners who might have information. I am not opposed to posting on Boxster specific sites. But I get far better answers to my questions/issues here on Rennlist than anywhere else.

bruinbro

Were we twins separated at birth?







(I used to have a green 89 RR also)

My Boxster engine died last September when the intermediate shaft snapped. It died in the same manner yours did, with the same postmortem symptoms. Not to say that this is your problem, but it's verifiable once you separate the engine from the tranny. I had a used 2001 motor stuck in and Brad is in the process of boring and stroking the broken motor to 4+ liters and adding an Eaton blower.

I would take your tale of woe over to the BRB http://www.iq.dynip.com/%7Eracing/index.cgi and ask for suggestions.

BTW, did you remove the A-pillar padding?

Bro

SundayDriver

This is a pretty common result of detonation. Wrong fuel, incorrect fuel choice, mechanical problem that changed the timing are some of the things that could cause detonation.

I'm sure there are other things that can cause that failure (even a defective spark plug), but I have seen it a few times and in every case, there was other evidence of detonation when the motor was taken apart.

Bill L Seifert

I meant the Boxster/S Rennlist site. Rennlist is the only list I go on now, but of course you had no way of knowing that. But in MHO Rennlisters are the best,

Bill

Bill L Seifert

By the way, I think Sunday Driver is right. That friend of mine with the blown Boxster motor bought a used motor for $3,500 at PartsHaven, so I guess an S motor would be a little more. But it seems like a good motor.

Bill

jerome951

Mike,
Just remember that if you put anything other than a stock 3.2 Boxster motor in, you're bumping yourself into GT-$ class with PCA.

In this case, you will likely be horribly uncompetitive with a resulting decrease in the fun level without significant additional $$$ and time investment.

NetManiac

Thanks for the input guys.

I will likely put a stock 3.2 back in as I can't afford to go into GT (as Jerome mentions). But I would still like to make sure the "new" 3.2 is going to be better off than the old. So I'm planning to add the BreyKrause oil kit. Plus there's a Porsche Motorsports mod I've heard about which adds an additional oil pickup to the crankcase. But if in fact it was detonation as Mark and the other suggest, these oil mods will not help.

I run 91 octane almost exclusively. (I put 100 in a year or so ago for one weekend, didn't seem to help all that much and was so expensive never did it again). So I do not think it's the fuel that caused the detonation.

Don't know about the mechanical failure yet. Would there be symptoms leading up to the failure that I could/should have noticed?

Now, that you mention timing. I do, on occasion use REVO techlink to set performance settings on the engine (btw, I am not 100% sure it has done anything to increase performance). It's suppose to be a custom setup to compensate for my open pipes on the track. I suspect maybe running this in the wrong setting for the pipes that are on the car could have caused (contributed to) the problem?

Also, I thought these engines have Variocam, which in my understanding is suppose to adjust itself to avoid detonation. Am I not understanding variocam correctly?

bruinbro

Prior to my IS letting go, the engine was making what I would call a growl or rock tumbler noise, kinda like a cement truck. My understanding is the Porsche introduced a design fix for this problem starting in August 2000. My luck, my car was built in June 2000.

Hope this helps,

Bro