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.
Rose uncovers the truth behind the rock crusher transmission, Emily learns about headers & gloats about being right.
Recorded @iapdx
Recorded & mixed by Emdognightmare & Queen of the Vans
Editor: Emdognightmare
Production & research Queen of the Vans & Emdognightmare
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Hugs, thank you & high fives to Greg Meleney for the killer tunez!
headers
"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."
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.
Headers are tubular exhaust manifolds designed to improve engine breathing by providing equal-length pipes for each cylinder, reducing exhaust gas interference compared to traditional cast iron manifolds. They help improve engine efficiency and performance by optimizing exhaust flow.
cast iron manifolds
"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."
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.
Cast iron manifolds are traditional exhaust manifolds made from cast iron. They are durable but often less efficient at exhausting gases compared to tubular headers due to their shape and design.
pulse flow
"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."
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.
Pulse flow refers to the way exhaust gases exit the engine in pulses, which can be harnessed by headers to create negative pressure waves that help pull more exhaust out during valve overlap, improving engine efficiency.
valve overlap
"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."
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.
Valve overlap is the period during engine operation when both the intake and exhaust valves are open simultaneously, allowing for better scavenging of exhaust gases and improved engine breathing when combined with proper exhaust design.
rams horn manifold
"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."
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.
The Rams Horn manifold is a type of exhaust manifold from Chevrolet designed with a unique shape that promotes good exhaust flow and performance, often used in performance or racing applications.
heat soak
"So 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."
Heat soak happens when heat from hot parts like the exhaust pipes makes other parts, like the starter, get too hot and stop working well.
Heat soak is when heat from hot engine parts, like headers, transfers to nearby components such as the starter, causing them to get too hot and potentially malfunction or have reduced lifespan.
ceramic coating
"A ceramic coating. There's different coatings. 'Cause heat with headers is a big deal."
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.
Ceramic coating is a heat-resistant coating applied to headers and exhaust components to reduce heat transfer, protect parts, and improve performance by keeping exhaust gases hotter and flowing faster.
stainless steel shields
"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."
Stainless steel shields are metal covers that protect parts like the starter from getting too hot from the exhaust pipes.
Stainless steel shields are protective covers made from stainless steel placed over components like starters to protect them from heat damage caused by nearby hot parts such as headers.
back pressure
"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."
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.
Back pressure is the resistance against the flow of exhaust gases in the exhaust system. While some back pressure exists, excessive back pressure can reduce engine efficiency, but it is often misunderstood or exaggerated.
straight cut gear
"They have a straight cut gear and that's why the car sounds like it has a blower."
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.
Straight cut gears have teeth that are cut straight across, which reduces axial load and can make gear noise louder, often producing a distinctive whine or 'blower' sound.
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