Don't doubt the need for a pop-off!

[ohecht]

Just a experience to share with anyone debating whether the pop-off upgrade is really necessary on a later SC:

My car runs fairly smoothly, with no noticeable backfires, etc.

But, I noticed an indentation in my air filter the other day from where the pop-of valve had hit it in the full-open position.

It must have hit the filter with some degree of force to leave the dent.

Olivier

[Brian993]

I just epoxied mine back together, somewhere along the way it was blown into two pieces! Imagine if it wasnt there!

[Leland Pate]

That's why i believe some old skool wrenches are against the pop off valve... because they've seen some that were installed correctly...the end result is the valve lid hitting the bottom of the air filter and sticking in the open position.
That's why it is so important to make sure it is orientated correctly...

Mine is kind of so so.... I've never had a problem with it...but I do have a dent in my airfilter... .

[Bill Douglas]

Scary stuff. I had a pop off valve sitting in my spare parts box for about three years. I installed it about a year ago and sure do feel beter when starting now days.

[83911sc]

OK, this may sound really bad, but can you fill me in what the valve does - I mean beyond the obvious of saving you from what appears to be a really big mess from _something_ being over pressurized? Is it an exhaust system upgrade? How dificult is it to install on an 83 911 SC?

In my own defense, I just bought the car, and am still climbing the learning curve.

Thanks.

[magilla]

83911Sc, Nice car (I have the same thing)!!

The pop-off valve is simply a short plastic tube with a spring loaded cover on it. It gets glued into the opening inside your airbox (under the air filter). It doesn't take too long to install, doesn't require great skill or tools, and is cheap. It can be a huge benefit. It will open under pressure to prevent the entire air box from exploding. Take your pick: install this now, or face replacing your entire airbox later. It's cheap insurance.

Enjoy!
Magilla
-Black '83 SC coupe
SCWDP member

[sammyg2]

I would suggest you go and read http://www.pelicanparts.com/techarticles/911_pop_off_valve/911_pop_off_valve.htm
on this site. It tells all about the need for a pop off valve, and how to install one.
Pleny of good articles here, and when you get all done with them, you can buy Wayne's book :-)

[RarlyL8]

I too learned of the absolute necessity of a popoff valve for the SCs.

My engine has an aluminum intake box with an integral popoff valve. I brag constantly of how well the motor runs and has NEVER hesitated or caughed.

Well - I had it over to the mechanics place for some torsion bar upgrades. The car sat overnight in his garage. The weather turned very cold and very damp overnight. Condensation was all over the car and motor. I got in and hit the key and POW. I looked over to the mechanic and saw horror on his face. I hit the key again and the car fired. It was running on 4 or 5 cylinders. I told him about the air box and valve and that I figured the cylinders were full of condensation that would "burn off" when warmed up (I was really crossing my fingers). Took off and a few miles down the road she warmed up, I hit 3000+RPM and all was good.

If you don't have the famed valve installed do yourself a favor and get it done. Very good insurance.

[83911sc]

Thanks for the info - not only did this project make it on my list, but it just so happened to find its way right up to the top!! Good motoring.

Adam