Question about 930 engine bay seal

PcarPhil · 07-23-2013, 11:23 AM

Hey there Pelicans,

I've got the engine and trans out of my '87 930 to do some general maintenance stuff including replacing the crusty original 3 sided engine bay seal. I ordered the proper 930 seal from Pelican (instead of the 911 part number seal) and I'm a bit surprised at what I received.

In the rear area (across the back above the turbo and muffler) that section of the 930 engine bay seal is only one layer. On the sides the seal is 2 layers. The 911 seal is 2 layers across all 3 sides.

Why is the 930 seal 1 layer vs. 2 along the back? The 911 seal seems like it would be a longer lasting better seal and it's $35 cheaper!

These pics may be a little hard to see but that rear area has been cut out and is only 1 layer. Thanks for any help you can provide!

JFairman · 07-23-2013, 12:09 PM

That area is so much hotter in a 930 than a 911 because of the turbo, so that probably has something to do with it.

That seal should be made of high temp silicone rubber along the back area above the turbo and muffler if there is such a type that would hold up to the incredible heat and not dry out and harden.

930LDR · 07-23-2013, 12:52 PM

I just installed a new seal on my 930 this AM and had noted the same thing... The old one that I replaced had hardened completely up along that back edge.

Ken911 · 07-23-2013, 01:39 PM

been through 2 of them so far replaced it when i put my car together then a couple years later and now it's all dried out and hard again. wish i could just find a roll of the stock someplace and cut my own new one every time the engine comes out.

TurboKraft · 07-23-2013, 04:06 PM

You can use a 911 seal, no big deal.
If the turbine housing and muffler are coated in a 2,000F+ thermal barrier ceramic coating, these seals last many times longer. Jet Hot and others offer this, and it isn't terribly expensive. Easier and nicer than wrapping a muffler!

Ken911 · 07-23-2013, 04:47 PM

Quote:

Originally Posted by TurboKraft

You can use a 911 seal, no big deal.
If the turbine housing and muffler are coated in a 2,000F+ thermal barrier ceramic coating, these seals last many times longer. Jet Hot and others offer this, and it isn't terribly expensive. Easier and nicer than wrapping a muffler!

probably make the engine oil pressure sender and some of the other associated wiring on that end of the engine last longer also. All of the wiring on the back part of the motor is pretty much cooked also.

T77911S · 07-24-2013, 08:14 AM

any way to insulate that area better? another heat shield?

i have the seals but have not replaced them yet. did you have the drop the motor at all?

JFairman · 07-24-2013, 08:50 AM

What I did works very well but might not be for everybody.

I took a piece of high temp 1" diameter silicone heater hose the length of that back area of the tin and glued it on the top edge of the tin with high temp red silicone gasket glue made for sealing exhaust gaskets.

The hose comes on a big spool at the hydraulic hose supply place I bought it from so it doesn't want to lay perfectly flat while the silicone glue dries so I stuffed and wedged all kinds of heavy things like hammers and whatever else in there to hold it straight and flat in place overnight while the glue dried.
I cleaned any oil and dirt film off the back edge of the tin and the hose with wash laquer thinner first.

5 years later it's still there in place doing a good job of sealing that hot air gap above the turbo and muffler and the heat hasn't done anything to the hose.
You can't see the hose down there unless you know it's there and stick your head into the engine compartment and look down there for it.

It's an inexpensive permanent fix that really works. The rest of the black rubber air seal on the sides and up at the flywheel end is probably origonal and is still flexible.

930cabman · 07-27-2013, 04:35 PM

Now that's my kinda repair, cheep and effective. Hats off JF

IMR-Merlin · 07-27-2013, 05:28 PM

Quote:

Originally Posted by Ken911

probably make the engine oil pressure sender and some of the other associated wiring on that end of the engine last longer also. All of the wiring on the back part of the motor is pretty much cooked also.

Are you trying to say that things in the back get a little hot? Look at my reflector...

Ken911 · 07-27-2013, 06:24 PM

lol yes they do the paint on the bumper is blistered also in a couple places

ertech · 12-04-2013, 07:42 PM

I am a little confused in the first post he talk about the 3 sided seal going over the turbo?should this seal go towards the front of the car not over the turbo?

Pelican Parts - Product Information: 930-504-170-01-M136

Is this the seal that goes over the turbo?
Pelican Parts - Product Information: 911-504-115-02-M136

The consensus is that we should order the 911 one not the 930 one over the turbo?
Thanks

Ronnie's.930 · 08:14 PM

Link number 1 (three sided seal) goes above the turbo and down the left and right sides of the engine bay, and the single piece in link 2 goes on the section closest to the shock towers (as you say, toward the front of the car).

The cut-out section on the 930 seal is actually above were the original catalytic converter was placed (on the right side and above the muffler) - the cat was extremely close to the seal/tin on that side and would have made short work of that section of seal.

It's interesting how in the picture in the first post, the entire back seems to have a cutout section as the ones I have seen only had the cutout on the right half of the back section.

ertech · 12-04-2013, 08:09 PM

Ah now i get it
So i should order the 911 one since my cat has been removed?
Thanks

911tracker85 · 12-05-2013, 04:19 AM

just did this on my '78 930 and noticed the same thing.

I read over this thread and never saw an answer to why only a single layer across the back.

Ronnie's.930 · 12-05-2013, 07:42 AM

Quote:

Originally Posted by ertech

Ah now i get it
So i should order the 911 one since my cat has been removed?
Thanks

I probably would. I changed mine several years ago, and did not even know there was a difference between the two, so I ordered the 930 version.

Ronnie's.930 · 12-05-2013, 08:05 AM

Quote:

Originally Posted by 911tracker85

just did this on my '78 930 and noticed the same thing.

I read over this thread and never saw an answer to why only a single layer across the back.

It's answered in post #2 (the proximity of the turbo and exhaust to the rear seal).

fredmeister · fredmeister's Garage

Quote:

Originally Posted by TurboKraft

You can use a 911 seal, no big deal.
If the turbine housing and muffler are coated in a 2,000F+ thermal barrier ceramic coating, these seals last many times longer. Jet Hot and others offer this, and it isn't terribly expensive. Easier and nicer than wrapping a muffler!

So dimensionally the 911 seal is the same as the 930 seal except its 2 layers all around?

It looks like the 911 seal is alot cheaper and readily available so its a no brainer to use this as opposed to the 930 seal.

Since there is no material difference in the rubber compounds between the two of them I see no other advantage to the 930 seal.

Someone tell me I am missing something.

Fred