choke block off plate.

[bad440]

so i put the 2 barrel intake and 318 carb on the dd.made a block off plate for the gapimg hole in the ex man.well bought gasket material for this cost 17.00 a sheet.the car burns it up quickly then has a big *** ex leak.made the plate out of aluminum.even used that all metal epoxylittle better, 3 days it lasted.any suggestions????:angry7:

 

[DustyRoads]

I think you're talking about the EGR blocking plate. The choke sits up in a well on the top of the manifold, and usually doesn't leak since it is on the outside of the manifold.

If it's the EGR hole (on the side of the exhaust manifold, below the carb), you need an EGR blocking plate. The one I have is really thick (like 3/4") so it won't warp and blow out the gasket. There is one now on eBay for $22.

If the blocking plate you are using is thin it will warp under the heat/torque/pressure and blow out the gasket. ALso, I don't think aluminum is a good choice for anything in an exhaust system, especially a pressure boundary. It expands/contracts too much, cracks under heat, and corrodes when exposed to exhaust. The eBay one is stainless steel.

Use a new gasket, with good prep on the exhaust manfold seating surface, and torque it down with no sealant. Should work for you.

 

[805moparkid]

he is talking the air injection hole on the rear most of the head... best thing to do is make the plate out of 1/8" strap, use a small wire wheel or something to clean out the hole, fill the hole with high temp silicone, and then install the plate with just a little silicone on the flange... let it sit for a couple of days and should never be an issue...

 

[DustyRoads]

"he is talking the air injection hole on the rear most of the head."

Hmmm. maybe. But it sounds like he did a Super Six conversion, and that wouldn't require a head swap. I thought he was talking about plugging the EGR hole that happens when you put the post-EGR super six manifold onto a non-EGR earlier vehicle.

 

[67Dart273]

What 805 said also applies to my method for EGR. Just make a plate that will cover it, fill with sillycone and install the plate. If possible, allow the engine to sit for 24 hrs.

 

[bad440]

ok i am talkig about the choke stove the big damn hole about an inch from the head on the ex man . let me get a pic be back....

 

[67Dart273]

Well same deal. Either get the original choke well and install that with silicone, and if you don't like the appearance, put a flat plate over top, or just make a flat plate and install that with silicone.

 

[bad440]

View attachment Img_00611.jpgthere you go...made that plate , burns the gasket out quickly.even useing high heat gasket material. solution???????

 

[805moparkid]

View attachment 1714608863there you go...made that plate , burns the gasket out quickly.even useing high heat gasket material. solution???????

i dont think that should have pressure in it... or direct gases at all...

 

[64ragtop]

i dont think that should have pressure in it... or direct gases at all...

I understand the early chokes WERE open to the exhaust stream, but later the choke pocket was closed. To solve your leak, I would use a STEEL plate at least 1/4" thick and high temp sealant - if there IS a sealant that will stand up to direct exhaust temperature. Maybe JB Weld?? Or find the later exhaust manifold.

Good luck!

BC

 

[805moparkid]

I understand the early chokes WERE open to the exhaust stream, but later the choke pocket was closed. To solve your leak, I would use a STEEL plate at least 1/4" thick and high temp sealant - if there IS a sealant that will stand up to direct exhaust temperature. Maybe JB Weld?? Or find the later exhaust manifold.

Good luck!

BC

interesting! good to know

 

[BillGrissom]

I understand the early chokes WERE open to the exhaust stream

I think it was the later exhausts where the choke pocket connects to the interior of the exhaust, because a guy posted a few months ago about his 1974 slant leaking exhaust from there. He lives near me and I later saw his engine when he bought a carb from me, though the leak was fixed. I think if the OP finds a 74+ choke thermostat, it will plug the hole. I don't know what gasket or sealant the factory used there, but hi-temp silicone might work. My 69 slant had a closed choke pocket, as does my 64 slant.

 

[bad440]

well it's open,i guess i will make a new plate out of steel.and try some high heat silicone.i'm thinking the aluminum just isn't the right material for this application.all the egr plates for example are 1/4 inch thick steel.thanks guys

 

[pishta]

ultra copper is good for like 700...thats pretty hot for a good tuned motor. lean will get uberhot. The large under intake chokestove gasket is embossed metal. JB is not good only 500, but there is a exhaust epoxy at autozone thats good to like 1800,its iun a little jar.