Cracked airbox it seems JB Weld maybe

[piscator]

Flojo,

I wouldn't either and don't. I just thought I'd try and be thorough.

[G450X]

Originally Posted by Bob Kontak

Found a 38mm for $275 just now.

I guess I need a better search engine...

[Flojo]

Originally Posted by piscator

Since we're on the subject, I might as well ask. Would there be a market for air-boxes made in carbon fiber?

I fear the price as a show stopper.

[mike sampsel]

Originally Posted by boyt911sc

Installed this brand new CIS air box for a PP member several weeks ago and cost less than $250.


Tony

$250 installed, I'll take two!
Are these 44 mm ports for $250?

[boyt911sc]

Originally Posted by mike sampsel

$250 installed, I'll take two!
Are these 44 mm ports for $250?

Mike,

$250 was the price of the new CIS airbox to replace the cracked one. I can not post the name of the source in this forum. The engine was a ‘83 SC US spec with the -2R intake runners (34-mm ID). The new airbox is now identified using the OD measurement for spec.

Tony

Edit:
Looking at the invoice, it was $273 not $250. My mistake.

[piscator]

Thanks Flojo, you're probably right about the cost. There goes my dream of buying a 959 with the profits from my carbon fiber air-box venture! ;-)

[mike sampsel]

Originally Posted by piscator

Thanks Flojo, you're probably right about the cost. There goes my dream of buying a 959 with the profits from my carbon fiber air-box venture! ;-)

Now I’d pay big bucks for a titanium air box ... just saying ... but it would need to be a package deal with a titanium exhaust system

[mike sampsel]

Okay, so with two passes of JB weld my airbox passed my smoke test with no leaks. Hope this does it so my rpm goes down with the oil cap removed. As I said the car ran well before this anyway. But I’ve got the CIS on the operating table so on went mr JB.

Airbox for my runner size is about $480.

[Reiver]

Originally Posted by mike sampsel

Okay, so with two passes of JB weld my airbox passed my smoke test with no leaks. Hope this does it so my rpm goes down with the oil cap removed. As I said the car ran well before this anyway. But I’ve got the CIS on the operating table so on went mr JB.

Airbox for my runner size is about $480.

Do you have the large port box?

[mike sampsel]

Originally Posted by Reiver

Do you have the large port box?

I think so, they measured 44 mm. 78 and 79 are special

[Reiver]

Originally Posted by mike sampsel

I think so, they measured 44 mm. 78 and 79 are special

So are all of the Euro's from that period thru 83…

[bpu699]

There’s some videos on YouTube fixing plastic with screen mesh and a small iron. Just burn the mesh into the plastic. Harbor freight sells the heating iron. Permanent fix...

[fanaudical]

This is all covered in a couple of other threads.

The best epoxy I've found for the plastic used in the CIS airbox is 'Loctitte Plastic Welder'. It actually does bond to the surface (not just stick).

The plastic used din the CIS airbox is not a thermoplastic (it's a thermoset) and it doesn't respond well to attempts to repair with thermal welding.

[piscator]

Fan,

Your comment on thermoplastic and thermoset plastic answers some things I've encountered and wondered about. If my understanding is correct, thermoplastic is the stuff they make kayaks out of -- is it called 'roto-moulding?'

If so, in my experience nothing sticks to that stuff! I've used heat to repair small cracks in a friends kayak. So far it's never opened up, but I always worry about it. It may be just psychological, but I have trouble trusting a repair that I haven't added material to.

[piscator]

Hi Mike,

I'm working on your titanium air-box and exhaust, but I'm afraid we'll have to add a few zeros to the estimate price! :-)

[930cabman]

My vote would go to a new airbox. For $250. what is your time worth fooling around with repairs?

Sure, anything can be fixed but for how long will the repair last?

[fanaudical]

Originally Posted by piscator

Fan,

Your comment on thermoplastic and thermoset plastic answers some things I've encountered and wondered about. If my understanding is correct, thermoplastic is the stuff they make kayaks out of -- is it called 'roto-moulding?'

If so, in my experience nothing sticks to that stuff! I've used heat to repair small cracks in a friends kayak. So far it's never opened up, but I always worry about it. It may be just psychological, but I have trouble trusting a repair that I haven't added material to.

Rotomolding is a manufacturing process. You drop a hot glob of plastic into a warm mold and then spin the mold to coat the surfaces and make the shape. Most kayaks of this type are made from polyethylene, which can be welded for repairs.

Polyethylene doesn't allow bonding to most adhesives. There are some that will bond but difficult to find.

[patkeefe]

The world of plastics is much broader than one paragraph on pelican parts 911 technical forum.

[Paulporsche]

piscator,

Basically, thermoplastic plastics are one that set up as they cool, after being formed with heat. Heat will soften them. Think car model plastic. Thrmoset plastics give off heat as they cure. Unless subjected to exteme heat, they will not melt with heat. Think a cooking pot handle.

Patkeefe is correct. there's more to it than this, but that's the basic difference.

[UROParts]

JB Weld handles heat well up to 500 degrees F, and there's a high-heat version that goes considerably higher. For low-temp applications, West Systems G/Flex is less brittle than most epoxies and is a fantastic 24 hour epoxy.