The BS On Backpressure 

Rob B that is a great insight. I appreciate that. 👍🏻

@@bjr2379 Too true. Nobody learns anything without asking questions.

@@bjr2379 Riced out honda morons, cough cough

Yeah but he's the only one to have ever answered what I've had in my head since 15 yrs ago when I saw someone try to start a motor without manifolds on and I saw how it didn't even want to start and would immediately die if it did and like he said I was 18 and at the time thought huh guess back pressure does exist lol

Its from 2-stroke engines. 4 stroke engines don't need back pressure as Uncle Tony correctly states, but the 2 strokes do. And then when you get to nitro RC 2 strokes, the exhaust is actually tuned to recycle unburnt fuel. The honda tweens won't watch this video unfortunately, so the myth may continue to spread. Thank you uncle tony for explaining why manifolds and headers are actually needed though-- much appreciated & I learned something today!

Lmfaooooooo

Use a portaband, much easier.

@@jerrytee2688 Uncle Tony’s new tagline!

My dodge truck i deleted the muffler. But it was rusty and needed to go

you don't need to tell me twice brb.

I do the same, it's not much. But it's the least we can do. Seriously if I'm watching something else I just open another window and mute it. By the time I'm ready its ready to go and I do the same if there's adds at the end.

I dont skip ads here either. Just another squirrel tryin to get a nut...in other words just another guy who lives paycheck to paycheck and supports my 3yr old grandson.

Cledus Snow.....are you Hank Snows brother?

Ok scottie I seen what you done there.😂😂😂😂😂😂😂

@john beaver no you even beat in your header pipe quite a bit and will lose minimal horsepower. At least based on the engine masters header bashed test

Pirate Labs well those aircrafts also don’t stop at red lights, Go ahead and drive your car around with 4” stacks.

@@ze_german2921 I already do, thanks. I get a lot of tickets, ha ha.

Hook up your headers run 3" pipe where the flame stops in the pipe is where you cut the pipe anything more is a waste of pipe

Well that may be a bit different. If I'm correct almost all those engines were supercharged. Supercharged engines don't need to depend on exhaust scavenging to get a good fill of air/fuel charge into the cylinders. They just pump the air right in, and during overlap the spend charge would be blown right out.

@@Poop-nu1so you're partially correct. Nearly all WW2 aircraft were supercharged, certainly all the high performance aircraft. It wasn't long before WW2 many high performance aircraft were not supercharged. The short exhaust stacks actually served 2 purposes other than simply directing the exhaust away from the motor. First, the airflow past the tips provided vacuum to the cylinder. Second, at power the exhaust flow itself provided some bit of thrust increasing the performance. A supercharged engine doesn't "need" scavenging, but it certainly helps more effectively clear the cylinder of spent exhaust gasses, resulting in an increase in power and efficiency.

I can definitely see this in play. I've had coworkers tell me that I shouldn't touch the factory exhaust because it's designed specifically for the car. Or it'll run like crap. I've noticed people don't want to tune after letting it breathe better.

@@jamesharris5232 the "stock is best" people rarely know what they're talking about. EFI cars can often compensate through fuel trim though some are better than others at doing that than others.

@@lb9gta307 some efi vehicles are designed to runs a little rich from the factory. So by opening the exhaust up it actually leans it out closer to where it should be

@@konnerkramer329 if they're in closed loop they normally just try to run their target air/fuel ratio. Short term and long term fuel trim only has so much room though

@@lb9gta307 right but most stock tunes only has so much room for adjustment. I know on my 6.0 Chevy it ran 11-11.5 to 1 stock. Then with long tubes a catless x pipe and flowmaster supper 44s it ran 12.5-13 to 1 when it went into closed Lope which is when the coolant was over 180 degrees

And even more mystical... the two stroke turbo, which uses a tuned pipe followed by a turbo which acts as a variable restriction after the tuned pipe, maintaining good back pressure in the pipe, even as air pressure in the intake tract is increasing...

check out this one! V8 two stroke! ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-JVfqqSbB3Po.html

2 stroke Detroit v8s run best with smaller pipes as opposed to those goofy 10 or 8 inch pipes!

@@gallupcustomknives2293 ah, I see you beat me to the punch :)

Well diesel 2-strokes are another beast altogether. I don’t know much about them, I was referring to gas power sports 2 strokes

That's what I always say, "Back pressure? So how does a top fuel engine work?"

@@livewire2759 Those engines work on "Pressure to Win"

@@livewire2759 A supercharged engine doesn't need the help of the exhaust to fill the cylinder.

@@mcplutt Yes, obviously, but the point is that most people who believe in back pressure think that every engine needs it.

The stacks even add downforce for traction. Flipin cool

Not only do they run poorly with no exhaust, you can warp the exhaust valves that way. When the valves heat up, then you shut it off, the cooler air is right there, the valve is right inside the port, so the cool air touches the valve and it cools unevenly, causing it to warp.

@@livewire2759 I've heard this several times but have never seen any proof of it. I've ran several engines open manifolds and open headers. Even ran a 283 right off the head. I've never wrapped a valve or seen anyone warp a valve from a lack of exhaust

@@konnerkramer329 I've seen it. It won't happen right away, so a test run with no manifolds probably won't hurt, but repeated heat cycles with open manifolds can and will warp the valves eventually... especially in cold weather. When I was young, a friend of mine was wanting his truck to be as loud as possible, so he took his pipes off right at the manifolds (mid 90s f-250 with a 460) He ran it that way all summer with no problem, then about halfway thru the winter he suddenly stopped driving it. I asked him why, he said it was running like crap, took it to a mechanic and they told him the valves were warped. they did a valve job and told him to put the pipes back on it. Some years later I had a customer (I'm a GM tech) who brought in a truck (early 2000s 1/2 ton with an LS) that was running rough and had the exhaust pipe broken off on the drivers side. He said he'd been driving it that way for several months. All the misfires were on the drivers side, all had low compression, all the exhaust valves were leaking. We sent both heads to the machine shop for a valve job and replaced his Y pipe, complete with converters. It may not happen very often, but it CAN.

@@livewire2759 I'm sure on a hot engine with high egts it's possible. but I ran my 327 for almost 5,000 miles open manifolds until I got a set of heddmans for it. I ran it for probably another 10,000 open headers before I put an x pipe and 3 feet of tubing. I ran it like that for about 2 years until I tore the engine down.The engine was ran hard for a long and other than 10lbs oil pressure It seemed to run fine. It cruised 65mph all the way to my shop with with basically no oil pressure. I tore the engine down and found 1 broken piston ring and 3 cracked rocket arm nuts but everything else was fine.

@@livewire2759 More likely the drivers side exhaust pipe broke, because of a dead o2 sensor commanding max fuel on that bank, rotting out the exhaust and fowling the plugs, leading to intermediate missfires.. (based on load) Back fires from this are known to blow the baffles out of mufflers and glass out of glass packs too.

Yup. However, if he swears by those 1 5/8" headers on every engine he builds, they are ALL of similar displacement to each other, and that displacement is not very large. Otherwise, he is leaving power on the table for the larger engines.

That would be very helpful. And also for inline 6's.

Jason Thunders my 67 Mustang with the stock 200 6 would benefit greatly from this video! Haha preferably before I waste some money on the wrong setup!

I was gonna say that. He should cover how cam shaft overlap and duration as well as primary pipe length and diameter and how they affect engine performance. It would be an in-depth and pretty long video cause there is a lot to cover and explain there

Thrill Hill Racing same thing with me except someone swapped in a 250 and got rid of the 200

lucas swearingen interested in a 200? I have an extra complete engine. I’d be interested in that 250 for sure.

Josh Not to mention it would sound like ass. If your head was literally inside the ass.

Extra large mid pipe size doesn't really hurt power. Engine Masters proved that. If it's a dual system the crossover won't be as effective but the scavenging is mostly done with the manifolds/headers. That's where proper diameter is most important. Overly large pipe is pointless weight though.

Oh shit! Send our best along to him.

There are some commonly used calculations. The problem is that everything from port shape, primary tube lengths, bends, collector style, collector diameter, cats, mufflers, tailpipe, even the tip, need to be taken into consideration when trying to optimize a setup. That's why stock vehicles always leave some on the table, because everything in a street vehicle is a battle of compromises. Also, electronically variable intakes lengths or tunable headers will greatly expand your powerband.

You let a small thing like an injured child stop you from watching UTG? Priorities, man, priorities.

@@rcnelson yeah, Tony is my uncle, but that’s my baby boy....

@@UncleTonysGarage thank you! He’s doing much better today....might get to go home Thursday

Theres a company that sells a naturally aspirated 2.4 liter i4 engine that makes over 300 whp. They sell an upgraded 2.7 liter version that makes over 500 crank. Engine tech has come a looong way. Edit: based on the Honda k24 series of engines

@Michael Madden Because a larger displacement engine is capable of flowing a larger amount of air and fuel because it has more displacement to do so.

@@snakeballs8965 At what, 12000 rpm?

@@ghj1502 www.4pistonracing.com/k24-480-2-7l-complete-engine Not quite

@@snakeballs8965 not hating but u kinda agreed that more displacement makes more power i.e. the 2.7 makes more then the 2.4. Small engines dont make as much power bc they are " better" they just displace air and fuel mixture faster then a larger motor usually will.

This really makes me wonder about the future of the hobby. I see dino powered stuff being around reliably for about 30-40 years and likely becoming a niche thing. I absolutely love this stuff, but they are likely going to go the way of the reciprocating steam engine, and this knowledge will largely be lost outside of engineering textbooks of our day. It's kinda hard to predict when, but it will happen. Sad since there really is nothing quite like the idle of a nasty cam with a single plane. Also nothing quite like hearing and feeling the bark of a steam engine.

Too bad they will be illegal, very soon...

@@herpnderpn2484 What's "dino powered stuff"?

An Auto-Zone fartcan muffler will add 100 horsepower! Ask any high schooler!

did the header [s] come with a sticker? has to be visible, back window preferred. scavenging effect.

@@dreadpenguinlord340 leave my cherry bomb Honda Civic out of this. Sure it may sound like a angry cloud of mosquitoes but it has character with the wing off a Boeing 747 and a hood scoop off a dragster

I once hit a HUGE pothole on a mountain road and smashed three header primary tubes on the driver’s side halfway flat on my 70 Dart. The car ran fine on those same headers for the few years they stayed on the car. Still, I was very surprised at their dyno test. Very interesting.

“On this episode, we beat a couple Hookers with hammers to see if they still work.” Engine Masters proving PimpTheory on the dyno.

180° headers

He needs a pipe and big glasses as well like he teaches at a collage up north.

Prentice Chafin to be fair, that jacket is the mechanics lab coat

And some Buddy Holly glasses with a pocket protector. 🤣

no no don't do that doctors are liars and hypocrites you make great videos with common sense

Needs a professor jacket, a glass of bourbon lol

I've said for years that you can do more by removing mufflers than by installing headers.

Live Wire except sound better, manifolds sound like tractors and shit. You can do more with headers.

@@Shade_tree_garage01 Manifolds sound just fine to me, but it depends on what you bolt to them. The point I was making is that putting a set of headers on and then reattaching the stock pipes and mufflers (like people tend to do with shorty headers ) makes little to no difference, where just cutting off your stock muffler does.

@@livewire2759 I did that to my 1990 f-150 4.9L straight six when the muffler fell off, just left catalytic convertor and straight pipe behind tire. Had a decent sound.

So anyway, I started cuttin'.

Yup, been doing that on collector extensions since the 70's

@@UncleTonysGarage Heard the same thing about using a grease pencil on the collector on drag cars....where ever the grease doesn’t melt, cut it there and that’s the optimum position for torque

if you drive a civic you dont have a hope in life anyways , dont race trade , buy american

Long tube headers usually won't, but shorty headers absolutely will.