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making a gasket suitable for exhaust temps


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i've bought gasket material before to make intake gaskets and such. is there any similar way to make a gasket for the exhaust ports of an EJ18 head? doubt the stuff i have is good for those temps. there's a hole there that i don't need that i'll be closing up.

 

i'd rather have a gasket than just use RTV...but i suppose that's an option as well. would i be better off using straight RTV or RTV on both sides of the original gasket...which doesn't look horrible but is used and has some rust on the outer edges.

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I assume you are making block-off plates for the small ports on the outboard side of the exhaust ports.?

 

I would just clean the mating sufaces really good and put some Ultra Copper RTV on it.

 

Or if the gasket is fairly good still, put RTV on both sides and reuse it.

 

Either way would probably work OK.

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yes WaW it's those ports on the outside of the exhaust ports, i'm blocking them off.

Why not just buy them?
i tried. i don't know the part number, talked to one of the parts people and they couldn't find it. that's what i will do, just checking if there's a simpler route.
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yes WaW it's those ports on the outside of the exhaust ports, i'm blocking them off.

i tried. i don't know the part number, talked to one of the parts people and they couldn't find it. that's what i will do, just checking if there's a simpler route.

 

Blocking off ports is easy, just do what Waw said.

 

nipper

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I'm not sure if this is the gasket you need but I found this

44022AA020 EXHAUST GASKET FOR FRONT PIPE FOR 1993-1997 IMPREZA 1.8 ONLY sold individually

 

One gasket material I saw listed for high temps is fiberglass/silica. i.e. from mcmaster.com: Square Braided— Made of 98.8% silica. The square design fits many oven and furnace door grooves and provides more sealing surface than round braided. Temperature range is -40° to +2300° F. Color is tan.

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I'm not sure if this is the gasket you need but I found this

44022AA020 EXHAUST GASKET FOR FRONT PIPE FOR 1993-1997 IMPREZA 1.8 ONLY sold individually

 

HOW DARE YOU - NO PICTURES@!!!! just kidding. thanks, i'll check that out.

how did you find that, i couldn't get it to come up on the online parts places.

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This is a small port opening 90 degrees to the exhaust flow.

It's a small hole in the exhaust port of the head.

Come on Porc, I need to see this.

I'm just curious that's all.

 

An opening in the exhaust port??

(meaning in the head?)

 

90 deg from the flow direction?

 

EA's had a plate over the exhaust port that had an

opening for the rump roast (Air Suction System)

 

The opening introduced filtered air into the exhaust flow

to provide enough 02 into the cat.

This done so it could burn left over hyrdocarbons.

 

Could this be the same type opening?

 

But now cast into the head??

 

If the EJ25 has one ?? I'll get a picture.

I have one on a stand at this time.

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As far as the EJ series engines go, I believe this was only used on certain EJ18's

i've got a few EJ22's and EJ25's lying around and i see nothing similar on them. the hole/opening points towards the passengers side fender and has a pipe bolted to it that goes up to the intake manifold.

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Tap out the hole for pipe thread and install a plug from the hardware store.

 

I've done this many times when using carbed EA82 heads on an SPFI motor. Also in the elimination of the Air Suction Valve/ Anti Backfire crap on the old carbed EA82s.

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awesome! good idea. will the plug leak or do they need sealant on the threads.

 

If you use a pipe plug, it will have a tapper to the threads, so it should seal well. Always have for me. But if you are worried, coat the plug with a bit of copper RTV before installing.

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If you use a pipe plug, it will have a tapper to the threads, so it should seal well. Always have for me. But if you are worried, coat the plug with a bit of copper RTV before installing.

 

 

Just remember when you're tapping, not to drive the tap in too far, like only go about half way up the tap in or you will make them to big and the tapers won't seal against each other

 

Will-

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That would definitely be the best solution.

 

I was going to mention the water jacket plugs in that area on the EJ22's. But they are not tapered pipe plugs and are an odd ball size.

 

And didn't know if you would want to by a tap to plug one hole.

I've got a few taps laying around that still look brand new. I look at them and ask myself, "what did I buy that for?".:confused: After a while I usually remember that one job.

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I'll get on the tapered pipe plug band wagon

 

Just remember when you buy the tap

that it says "NPT" National Pipe Taper

not

"NPS" Nat. Pipe Straight.

 

Do you have an idea of the hole's diameter?

 

I do not remember you saying the engine is in or

out of the car,

Is drilling the hole to the proper size an option?

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I've got a few taps laying around that still look brand new. I look at them and ask myself, "what did I buy that for?".:confused: After a while I usually remember that one job.

 

I think sometimes that takes up 1/4 the tool box :)

 

nipper

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Do you have an idea of the hole's diameter?

 

I do not remember you saying the engine is in or

out of the car,

Is drilling the hole to the proper size an option?

 

yes i could measure, engine will go in in the next couple days. memory guesses around 1/2". i think there's access to tap later. i have one NPT tap, doubt it's the right size.

 

so measure tonight and find a tap tomorrow to do it before the engine install, do hardware stores usually carry a few sizes of NPT taps and do they carry the plugs as well? i've never heard of or seen the plugs?

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Most hardware stores will have the NPT pipe taps. Harbor freight even sells them. The pipe plugs would be in the plumbing section. You can get them with a square head for turning with a wrench, or with a recessed hex (though hardware stores don't usually have that style).

 

I don't know what material plug you want, but the typical hardware store materials will be black pipe, galvanized, or brass.

 

I would use a thread sealant since the tapered thread can have a spiral leak path.

 

mcmaster has some info on pipe thread types and such http://www.mcmaster.com/param/html/MetalConnections/

i.e. pipe-plugs-1.gif

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yes i could measure, engine will go in in the next couple days. memory guesses around 1/2". i think there's access to tap later. i have one NPT tap, doubt it's the right size.

 

so measure tonight and find a tap tomorrow to do it before the engine install, do hardware stores usually carry a few sizes of NPT taps and do they carry the plugs as well? i've never heard of or seen the plugs?

 

 

Yes, a good hardware store would have the plugs, they usually either have a square head or an allen head. Not sure if they would have the tap outside of buying a set. You can order the tap (and drill if necessary) from McMaster.com which has pretty fast shipping.

 

if the hole is around a 1/2 inch, that means you'll 'prolly use a 1/4 or 3/8 NPT. The tap drill size for 1/4" NPT is 7/16 so you might check the hole with a 7/16 drill bit if you have one around. The next common size up is the 3/8 NPT which has a tap drill size of 37/64 (one size above 9/16). Doubtful you'd have that size kicking around so you'd need to pick that up with the tap.

 

 

 

Will-

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