Engine Bay Foam inserts?

[Porboynz]

While taking my 1972 911 back to bare metal I removed the remnants of some sort of foam filler between the engine crossmember and the body work. This is the gap where the wiring loom enters the engine bay, between the crossmember that the shocks mount into and the sheet metal of the rear seat bucket area. Question. It is probably desirable to block this gap again so that the engine bay is relatively air tight again, but what should I use? I am thinking of using standard closed cell foam rubber cut to shape and wedged into the gap. The original foam material turned to dust when poked with a screwdriver, to be expected after 30 years exposure to engine fumes. Any recommendations?

[tevake]

Could that be the bottom of an old engine sound/ heat pad? The tail of those do fit down into the slot that you are speaking of. Have you painted the firewall area, if you are not replacing the pad, I think you could put some closed cell foam in there to fill the space.
Ending up a ten year restore, good on ya! Have you sent us pics? We love em!

Cheers Richard

[Porboynz]

The original engine pad is long gone. The entire area was stripped, then undercoated with 2 pack and body shutzed as close to original as we could get it. I have a new engine pad on order. There are a few photos in my garage area, I must load some updates.

[JJ 911SC]

I think you are looking for # 31




Plastic Block @ $25 each at PP. 911504930 Pelican Parts - Automotive Parts and Accessories - Porsche & BMW

Check this thread for option like foam impregnaed with tar or other solution; Hot engine bay-

[RWebb]

there is an old thread on this with pics - might be the one given above
one bit of advice was to stuff some pipe insulation foam up in there

[JJ 911SC]

Originally Posted by RWebb

... one bit of advice was to stuff some pipe insulation foam up in there

or those oversize foam "spaghetti" use as floater in smiwming pool.

[Porboynz]

That earlier thread is a big help. I also like the suggestions to use pipe insulation or a section of swimming pool 'noodle', I think I have some of those from when the kids were younger. 2 excellent suggestions thankyou.

[proffighter]

Originally Posted by JJ 911SC

or those oversize foam "spaghetti" use as floater in smiwming pool.

I am not sure if the kind of foam they are made of really withstand the heat...

[JJ 911SC]

Originally Posted by proffighter

I am not sure if the kind of foam they are made of really withstand the heat...

It's a bit away from direct heat and is sandwich between 2 big heat sink.


Porboynz

Let us know how it turn out.

[sc_rufctr]

I posted this in another thread... Worked fine for me. The tar helps hold it in place.

If you want to replicate what's there from the factory you should be able to buy some dense foam with an adhesive back from a specialty shop.
Locally we have a chain of stores called "Clarke Rubber"... They sell all sorts of stuff like this.

But why not buy the OEM part? I know it's expensive but for some owners that doesn't matter so much.

Originally Posted by sc_rufctr

I got some tar impregnated foam from the hardware store to replace mine.
It's normally used for sealing gaps in a roof of a house. The one I got was about 1 inch square through the cross section.

I think it cost about $6 for a 1.2 meter length.

Just crammed it in all the way across with a flat stick and folded back about what was left at each corner.

[BlueWing]

After a ten year resto why not use the factory item small change by now. Maybe for the rest of us how would the black pipe insulation do?

Terry

[Porboynz]

I tried a length of 1/2 inch pipe black foam insulation (OD about 1 1/8 inch) and it fits nicely in the space between the shock towers. The area from the shock towers to the outer chassis will need the next size up to fit snuggly. The original parts would be good but there is a reason my username is porboynz and why its taken 10 years to get where I am. I need to spend my money where its needed and economise where I can. This is one of those times. The swimming pool noodle is far too stiff to insert into the space available and it may dissolve if it gets sprayed with hydrocarbons. The black pipe insulation is the right colour and fits nicely. Good job.

[JJ 911SC]

Originally Posted by Porboynz

... The original parts would be good but there is a reason my username is porboynz and why its taken 10 years to get where I am. I need to spend my money where its needed and economise where I can... Good job.

Good for you mate.

Just like when I zoom by someone on the road, they can not see the my option sticker does not list Option Code 505 or 506 (Factory Slantnose )

Having more money then brain (according to my wife ) I ordered the real one. As usual, when I'll look at it, I'll say; I'm in the wrong &*^%$# business

Once you got them fitted, I would like to see a pic (or two...) of the one the side where the engine harness wiring travel by.

Cheerio

JJ

[zithlord]

You need part number 901 504 991 20. Its a piece of foamfilled rubber hose that fits behind the horisontal crossmember in the engine compartment. In the parts picture above you can se a piece of it, but not the number(11)
, its bent and to the right of the cross member in the picture.
John

[Porboynz]

I found some bitumin impregnated foam at my local hardware store



This is the gap I needed to seal off



Hard to see clearly, gap all sealed up.



Thanks for the suggestions, this foam looks almost original and its designed to seal cavities, plus it stays in place.

[JJ 911SC]

Look great...

[Ramathorn]

damn i wish my underside looked that clean!

[911pcars]

What's the real purpose for this foam insert? Weather resistance, sound mitigation?

Thanks,
Sherwood

[Porboynz]

I have 2 theories on what the foam filler is for.
1. Seals the engine bay from BIG water splashes, same as the rubber seal around the engine tinware.
2. Seals the engine bay area so that all the air going into the engine comes via the fresh air vent in the engine cover, rather from underneath where the heater flappers and exhaust headers are helping Global Warming. (Cool air good, warm air bad)

I think I read somewhere that there is a slight high pressure area above the engine lid when at speed so this foam is ultimately making me go faster by helping a ram air effect into the aircleaner, almost as good as a turbo on a 930....... nah just kidding :-)