Originally Posted by Marc Bixen (Post 9810277)

WOW! Just a trans guy? Maybe you should do some research before more stupidity comes out of your mouth gomezo.....

Originally Posted by Marc Bixen (Post 9810277)

WOW! Just a trans guy? Maybe you should do some research before more stupidity comes out of your mouth gomezo..... Pete Zimmerman is a Porsche GOD when he comments, and is ALWAYS correct. If you don't know So.Cal Porsche history, here's a bit for you. Pete Z. opened Red Line Service, the oldest Porsche only repair shop in So. Cal. in 1975 after a stint at the dealer. Pete was a full fledged master of all things Porsche running Red Line until I purchased the shop at Pete's retirement in 1999. I had been working for Pete since 1995, after 13 years experience at other well known shops. One of those shops actually held the patent on, and manufactured the pop-off valves. I've built and boxed thousands of them, and installed hundreds. EVERY car that came in got one. Then I went to work for Pete at Red Line, and he explained that a properly tuned 911 didn't require this, and they cause numerous problems, so here's a short list of issues I've seen: 1) Pop-off installed backwards, first time it opens it gets stuck on the air filter and...giant vacuum leak, no start. 2) pop-off valve sticks to the o-ring, doesn't open and blows the box anyway. 3) Pop-off valve opens, the o-ring falls out, and again giant air leak, no start. 4) Epoxy gets old, pop-off falls out. and #5) MY FAVORITE, epoxy gets old, cracks, causes a lean mixture, and voila, the customer burns a piston and requires a complete engine rebuild. This actually occurred on a 74 Carrera.
Your choice, tune it right, or put on an unnecessary aftermarket part that most likely will create more AAA tows than you really want. In the 22 years plus I've been at Red Line I've seen less than 10 or 15 blown boxes, and probably only 5-10 of those were regular Red Line Clients.

Originally Posted by Peter Zimmermann (Post 9808920)

The original airbox on my '82 lasted 192,000 miles. I had, early on, set the Warm Up Regulator on the rich side of the scale, and simply dealt with a "hunting" idle during the first few seconds following a cold start. I discovered hairline cracks along the assembly seam, above cyl #3, when I had the engine removed to replace the cam shafts, and replaced the airbox at that time. I never even considered adding a pop-off valve, and it's been more than ten years since the replacement, without a single backfire. Jonny H and the iceman said it best, no toilet bowl for me! And, BTW, we NEVER used them at my shop either.

Originally Posted by Marc Bixen (Post 9810277)

WOW! Just a trans guy? Maybe you should do some research before more stupidity comes out of your mouth gomezo..... Pete Zimmerman is a Porsche GOD

Originally Posted by Reiver (Post 9810367)

Ok, you made me go look. You can see the dent in the filter screen, more obvious than the pic shows. I'm guessing you are referring to these screws.
They are all tight, none loose. So, the pop off saved me 400 or so bucks and time/labor. When I put this in I smoke tested it with a proper machine buy a gut familiar with this device...it did take some time to get properly seated. http://forums.pelicanparts.com/uploa...1510356252.JPG

Originally Posted by Reiver (Post 9810367)

Ok, you made me go look. You can see the dent in the filter screen, more obvious than the pic shows. I'm guessing you are referring to these screws.
They are all tight, none loose. So, the pop off saved me 400 or so bucks and time/labor. When I put this in I smoke tested it with a proper machine buy a gut familiar with this device...it did take some time to get properly seated. http://forums.pelicanparts.com/uploa...1510356252.JPG

Originally Posted by Jonny H (Post 9810728)

Your picture suggests otherwise. The two brighter looking screws just happen to be right above the usual failure point for the airbox. It looks to me like they have been replaced which suggests your airbox has cracked at some point in the past.

It has been screwed back together with some longer screws I expect which is a common cheap and temporary fix. It will probably will hold smoke when the engine is not running as there is no vibration or heat to distort the crack.

(BTW, most 911 airboxes use M4 flat head slotted machine screws. Porsche did swap to crosshead self tap screws on the later airboxes but yours looks like an original ABS type).

Originally Posted by boyt911sc (Post 9810776)

Reiver,

Are you aware that your POV is incorrectly mounted and installed on your air box? Take a closer look at the POV and it is resting on the plastic ribs instead on the flat base. This a common mistake committed by many DIYers including professional shops. While it is glued in place it is incorrectly mounted by your guy. This is easy to correct if you want to fix it.

Tony

Originally Posted by Reiver (Post 9810870)

Actually, they are the same color and the bang happened to me not to some prior (about 8 thousand miles ago and for me that's less than a year)....and, it had a top end rebuild not long ago...this is a Euro 83. IOTW, if it were a repair job and I had that backfire I wouldn't expect an already boogered box to survive....those screws were in place when the boom happened. No shop has messed with the box during my ownership.

All of them are tight, all the same color (photo light) and the car runs perfectly. How do I know the box does not leak....I have a wide band AFR in place of my clock and monitor AFR all of the time...it is very consistent and only changes a bit with elevation (I live in the foothills 2600 ft but often go above 5k etc.)

I am not saying your experience is not valid and they may not work all of the time but this one did once.....and for the investment once is good.

Originally Posted by Jonny H (Post 9810901)

I have a Euro '82 and the screws are not like that - they are slotted flat head M4 machine screws. I'm not certain but Porsche could have changed them just for the '83 MY. The replacement boxes DO have self tappers like you have.

Top right of your photo does it say PA6 in the stamping? ABS boxes just have a number in a circle.

Originally Posted by Reiver (Post 9810922)

Well I was hoping you were right and it was a PA6 but the circle simply has a 2 stamp within.
All of the screws are the same color to include the ones on the drivers side exterior of the airbox (US driver side)...same style and color and extend about a few MM below the attaching points and appear to be self tappers.

Originally Posted by Jonny H (Post 9810936)

That’s got to be a good sign if they are all the same. They did make changes right up to the last SC.

Originally Posted by crashmy911 (Post 9811501)

You better pop or your gonna blow!

Originally Posted by boyt911sc (Post 9810776)

Reiver,

Are you aware that your POV is incorrectly mounted and installed on your air box? Take a closer look at the POV and it is resting on the plastic ribs instead on the flat base. This a common mistake committed by many DIYers including professional shops. While it is glued in place it is incorrectly mounted by your guy. This is easy to correct if you want to fix it.

Tony

Originally Posted by Marc Bixen (Post 9814442)

To the others, if "he's only a trans guy" was a joke, you're a putz. That is a huge insult and very rude. There are many neubies, as well as long timers who are still learning, and dissing one of the staples of this forum is just plane rude.
Also Tony, You're 100% incorrect on your install info. As I stated, I worked for the company that manufactured POV's and I can guarantee you they are suppose to be on top of the ribs. What are you doing? Grinding down the strengthening ribs?? I'd love to see a photo of that. Early air boxes, the ones identified by the slotted screws can accept this, but later boxes, phillips screw, have the cold start distribution spider inside, and my opinion is that the pop off would bottom out on the main chamber and not be as efficient. Who told you to cut the ribs???? (If I'm reading your post properly).