Test pipe question

You could make flanges with a grinder and a drill, just make a paper template against the cat flange and cut the copies out of some thick steel plate. You could post a picture of your cat flanges and the pipe diameter too.

mydooris4 said:

You could make flanges with a grinder and a drill, just make a paper template against the cat flange and cut the copies out of some thick steel plate. You could post a picture of your cat flanges and the pipe diameter too.

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after measuring i found out that Center to center of the mounting holes is 3 1/2" (the bolt holes are a 15/16" long by 9/16" wide) and The flange itself is 2 15/16" x 4 3/4" the problem is ive had a hard time finding a flange online that matches

What diameter is the hole for the exhaust?

What are you trying to accomplish?
If you want to delete it, you could just have a shop cut it out and weld a pipe on the original flanges.
Or, the ones I saw 40 years ago were a ceramic honeycomb inside that you could break it out with a punch.

He might live in a smog state like I do, in which case you need to make a full replacement pipe so you can swap in the cat when you go for the smog test. If they see a cat delete it's an instant visual inspection fail and you wasted 200 bucks

Dave Datsun Tech. said:

What are you trying to accomplish?
If you want to delete it, you could just have a shop cut it out and weld a pipe on the original flanges.
Or, the ones I saw 40 years ago were a ceramic honeycomb inside that you could break it out with a punch.

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i'm trying to make a bolt in test pipe i can easily swap in and out for smog. The shop i took it to said they aren't able to cut of the flanges from the cat and weld them on to a pipe but they would be able to if i could source some flanges. Im also unable to break out the ceramic because my catalytic converter has a massive hole in it

mydooris4 said:

What diameter is the hole for the exhaust?

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im pretty sure its 1 7/8

Does this work or are yours like the oval-formed shape?

I believe the link I sent should work, your flanges are flat. Your bolts are diagonal but the normal flange should work with it as long as your welder remembers to put them at the right angle

mydooris4 said:

I believe the link I sent should work, your flanges are flat. Your bolts are diagonal but the normal flange should work with it as long as your welder remembers to put them at the right angle

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alright ill order those would i be able to use the stock cat gasket or would some rtv work?

Don't use RTV on exhaust, get the factory gaskets. I don't know of any high-temp RTVs that will last the hot-cold cycling

1983 NISSAN 280ZX 2.8L L6 Pipe Flange Gasket / Seal | RockAuto has the gaskets.

mydooris4 said:

Don't use RTV on exhaust, get the factory gaskets. I don't know of any high-temp RTVs that will last the hot-cold cycling

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will do