Need source and part # for flame arrestor.

[autobonrun]

I asked about this earlier and found my SC should have one in one of the vent lines to the airbox. The schematic on the attached link does not list it. I've also checked the Porsche parts CD I bought. I'm finally following up on some issues I wanted to complete and this has been on my list to install. I've read about a few explosions on 914 engines that resulted from backfires propagating back down to the crankcase.

Does anyone know where can I locate the correct part and what the number is? I've checked the Pelican site and it doesn't show as a separate item. Here's the initial thread with some very helpful info but now I need to follow up and buy/install it.

Where's the flame arrestor?

And here's the diagram where I thought it would show up. None of the numbers is descibed as a "flame arrestor"

http://www.pelicanparts.com/911/911_Parts/1978-83/1-6.JPG

[RoninLB]

try investigating 901 107 729 00

the pic doesn't show it.

[RoninLB]

pelicans part search doesn't make sense to me ?

Backfire Grid, 911 (1978-81)
A-107-729-00 $97.85

my #'s corresponds to '74-83 Flame Protection Insert

good luck

[RoninLB]

the part# 901 107 729 00 is listed in the pic as #44

[autobonrun]

Thanks RoninLB, I'lll check into that number today. I have a parts order to place and wanted to include this piece while I'm doing it. I'm also installing a new vent hose there and thought this would be a good time to do everything at once.

[autobonrun]

The part number you identified is the correct one. Porsche calls it a "Backfire Grid" just as you stated. Special order from Germany. Around $110 plus shipping. I'll either try to locate one used or fabricate my own. I have an idea how to do it; just need to read a little more on flame arrestor design before I put it together. I'm sure adding some stainless steel mesh will do the trick. I just need to see how much and how to secure it so a backfire doesn't blow it back into the oil tank vent. If all else fails I can still order it. However, it's so pricey it's worth trying a couple more options first.

[RoninLB]

Originally posted by autobonrun

However, it's so pricey it's worth trying a couple more options first.

ok.. some progress is better than nothing.

maybe start a new thread asking for ideas or just forget about it if you have the CIS backfire flapper valve installed in the box.

$110+ would buy a CHT gauge, probe, and wire extension. A single CHT is great heat monitoring.. meaning you would have a heads up to preventing an increase in oil temp. CHT reacts immediately and oil temp is 10min after the fact.

[autobonrun]

I was able to locate a used one for $25. It's on the way. Just as well I did not try to fabricate the piece. I'm interested to see what the real thing looks like. I'll look into the CHT gauge as well.

Thanks again.

[Wayne 962]

Originally posted by RoninLB
pelicans part search doesn't make sense to me ?

Backfire Grid, 911 (1978-81)
A-107-729-00 $97.85

my #'s corresponds to '74-83 Flame Protection Insert

good luck

Common part probably superceded to include older cars...

-Wayne

[autobonrun]

Here's a photo of the Backfire Grid. It was definitely missing from my car. The top end shown inserts from the inside of the airbox toward the outside. You can see the steel wool looking material sealed inside. Very little pressure drop as would be expected. I can blow through it with no discernible resistance. Thanks again RoninLB.

[smestas]

I posted this on another thread but after thinking about it (hijacking) I thought it would be better here.

http://forums.pelicanparts.com/porsche-911-technical-forum/229122-engine-died-while-checking-oil-other-qs.html#post1995143

I just looked at my air box and the mentioned hole has a rubber plug in it. Then I looked to the two hoses from the top of the oil filler and one goes to the top of the engine (breather) and the other goes to the top of the CIS rubber boot? Am I missing somthing? Where would a hose on the pluged hole go to?