Headers are special pipes that help the car's engine get rid of exhaust gases faster and better. This helps the engine run smoother and makes the car perform better.
Cast iron manifolds are the older style exhaust parts made from heavy metal. They work well but don't help the engine breathe as well as newer parts called headers.
Pulse flow means the exhaust gases come out in bursts or pulses. Headers use these bursts to help suck out more exhaust, making the engine work better.
Valve overlap is a moment when the engine's breathing parts are both open at the same time to help push out old gases and bring in fresh air, making the engine work better.
The Rams Horn manifold is a special shaped exhaust part from Chevy that helps the engine get rid of exhaust gases better, making the car perform better.
Ceramic coating is a special heat shield paint that helps keep the heat inside the exhaust pipes, protecting other parts and helping the engine run better.
Back pressure is like a pushback against the exhaust gases trying to leave the engine. Some is normal, but too much can make the engine work harder and less well.
Straight cut gears are gears with straight teeth that can make a loud noise when the car is running, sometimes sounding like a blower or supercharger.
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We haven't heard, we haven't heard a lick of, driver response, you know, driver response times upkeep. We, we don't hear anything. Do you all even drive?
Rose BB14: gonna happen. She said, no,
Emily BB14: He said headers are tubular exhaust manifolds. They're typically equal length for each cylinder, and we're designed to help the engine breathe so the exhaust doesn't get caught up in the earlier log type manifolds. So pretty much, I mean, that
Emily BB14: So they're, uh, the manifolds are cast iron, sorry, Emily BB14: Okay. Sure. They're all cast iron as far as I'm concerned.
headers scavenge the exhaust gas. Pulse flows out of the header tube and into the collector creating a negative pressure wave that will travel back up the header tube during valve overlap.
Rose BB14: Well, the advantage of a header is that you have a consistent shape for each sonder, so you do have more balanced shapes and volumes. Like Ryan said, something that I think is a little unspoken in this is that the inside is less consistent. I'm not saying it's a really wonky casting, 'cause the inside molds are nice, but it's not like a tube, you know, a mandrel drawn tube that's consistent everywhere.
You can get short tube headers, long tube headers. I like to call them nut hugger headers. They call them block huggers, but I call 'em nut huggers. They are just, they're right against the block and. It's not much different than a manifold. But the reason why I thought that we had a little bit of hair splitting to do on this topic is that there are things like the rams horn manifold from Chevy that is a pretty good flowing.
A ceramic coating. There's different coatings. 'Cause heat with headers is a big deal. Headers next to your starter, your starter will go through what's called heat soak. Right. So the header puts off quite a bit more heat, and it, you know, it winds up going over to your starter. Well, heat is resistance in an electrical circuit.
Rose BB14: that becomes a problem. So people will put a stainless steel, you know, stainless is not a great conductor, so they'll put. Stainless steel shields over their starter or aluminum shields or something that does help.
Rose BB14: I'm a little of the, like, I don't believe in back pressure, like it's the boogeyman, like there has to be something, right? There's like, but back pressure is weird. But I mean, there is pressure for sure. And then the size of the quote unquote primary tubes on the header.
Emily BB14: I won't. Yeah. I love that answer. Great. Thank you for also answering my question. Yeah,
Rose BB14: but it would, it could be funny, but I was like, and then I, contemplated going to O'Reilly's and pretending that I don't know what headers are and asking them. But I was like, I don't think I could ever go back in there again. They would just, they'd think I'm a moron because I don't know what headers are. I don't know. It's nice that our listeners go out and to the world and figure this stuff out.
Rose BB14: Hide the ball into the It was sick. Uh,
Rose BB14: I'm gonna give you a hint. Spear in the whale would work really good with steering wheel. We've got the spear in the whale. I'm hitting the road, grabbing my steering wheel.
Rose BB14: Fun to drive, he said. Yep. Gina also piped back in and said, Dean knew this answer as well, and Benny said, I don't care. I'm just kidding.
Well, um, yeah, I think that Jesse said that, you know, because it was supposedly that you could drop rocks in it and just keep on going and crush 'em up and whatever, which, yeah, probably, I mean, tool steel's harder than some rocks.
Rose BB14: Yeah. I'll say that. A few other people got this one right. This was not a singular thing. So the whole deal with this trans is that's French or is it, Spanish?
If they did the M 20, the M 21 Muncie, and that means that they're made in their plant. So it's not a Muncie brand, it's actually just made at the Muncie Indiana plant. And if you watch Parks and Rex, then you know about taking vacation in Muncie.
Rose BB14: Ter Haute. Fuck off Larry Bird. Anyway, the Muncie plant,
They have a straight cut gear and that's why the car sounds like it has a blower. And it's actually just that timing gear.
Emily BB14: Sorry, I didn't mean to discredit that designer. What was his name again? Her name. Was it a girl? F-O-D-R-E guy?
Rose BB14: Is inside the lines of your brake system when you mash that big hairy Bigfoot Sasquatch slipper, not your actual foot down on the pedal below, what? And I'll let you go in hundreds of PSI below what PSI, I've already limited it, right? We're below thousands because I said hundreds. I'll give you that below.
Emily BB14: My favorite kind of. Class of a car. Class of a car. What does that mean? Favorite style of a car?
Rose BB14: Chrysler Small block. How do you build a good three 18? Build a 360.
About this episode
A lively discussion unpacks the technical details and nuances of automotive headers, including their design, materials, and heat management challenges. The hosts dive into the differences between tubular headers and cast iron manifolds, the impact of heat on components like starters, and common misconceptions about back pressure. They also touch on transmission trivia related to the Muncie plant and share playful banter about automotive knowledge and terminology. The episode blends technical insights with humor and community interactions, making it an engaging dive into engine and drivetrain components.
