CIS Air Box Disassembly

[porschedude996]

Hi, I have a 1983 911SC that I am rebuilding on another thread. I have the Air Box broken down to just the upper and lower halves. I removed all the screws and it just doesn't what to separate easily. The right side seems to open a hair of two, but the left side acts like it was glued. Any thoughts?

[Flat6pac]

There is a sponge seal between top half and bottom. Once bolts are out it should open unless you’re splitting the seam that’s glued with the small screws, that’s epoxied
Bruce

[porschedude996]

Bruce, just to clarify in my head. I can get the fuel distributor/flapper valve assembly off the airbox, but what I would call the lower half where the fuel enrichment spider is. Is that where you are talking about a foam seal?

Originally Posted by Flat6pac

There is a sponge seal between top half and bottom. Once bolts are out it should open unless you’re splitting the seam that’s glued with the small screws, that’s epoxied
Bruce

[E Sully]

The sponge seal is between the air box and air metering plate.
The air box upper and loser sections are glued and not meant to separate. Quite a few threads on what sealant to use, but I've never read of a definitive way to re-seal them.

[boyt911sc]

Remove all the metal screws around the seam of the air box. To split open the Airbox, you need to apply heat using a heat gun and start at the opening where the throttle body is located.

I use a specially designed contraption to pry the upper section from the lower section and apply moderate amount of heat to unglue the top and lower sections. Do not over heat the plastic Airbox! Apply gradual lifting pressure without breaking the Airbox and continue heating the perimeter using a heat gun. Or use the kitchen oven when the BOSS is out shopping. Temperature below 300°F is enough to split open the plastic CIS Airbox unless someone applied JBWeld earlier.

Patience is your FRIEND.

Tony

[PeteKz]

Why are you splitting open the airbox? Is there something wrong with it? This might be a case of "if it ain't broke, don't fix it." You could cause yourself more problems.

[john walker's workshop]

No commonly available glue is going to get a grip on that type of plastic. Better research it.

[RDM]

Mine leaked at the joint. 3M makes a special sealant for this purpose that worked well for me.

[Edit] What John Walker says in post 10. 3M DP8005.

[porschedude996]

There was a partial separation on the joint. I was able to pop it loose without any damage. I’ll be looking for a structural epoxy. It is a very good opportunity to clean the spider and the lower chamber.

I just ordered this Loctite to join the halves.

[john walker's workshop]

From past discussions about bonding rotomolded polypropolene/polyethylene plastics, 3M DP8005 and loctite 3030 were recommended.

[porschedude996]

Thanks John.

[E Sully]

I found this to be an interesting product.
https://tbbonding.com/repairvideos/

[porschedude996]

That caught my eye, but it’s a premium Super Glue. Years ago i came by some SG accelerator called Zip-Zap. I think I bought it at a Hobby Shop. The filler is interesting, that would work great for the tongue and groove that seams the air box.

Originally Posted by E Sully

I found this to be an interesting product.
https://tbbonding.com/repairvideos/