OPEN HEADERS... Friend or Foe?

[bac1755]

Will open headers cause problems with your engine? I know the obvious is being noticed by the cops, but I have heard everything from loss of HP&TRQ to bending valves and blowing your engine up.

Does anyone have any advise for me?

[QKENUF4U]

not that ive ever seen other than LOUDER THAN FUDGE INSIDE and ATTRACTS PO PO !!!

[Shane]

Originally Posted by QKENUF4U

... ATTRACTS PO PO !!!

[Longhorn Man]

you may drop a couple horses, esp if you can't tune for the increase in exhaust.
The whole burning exhaust valves thing is bunk. I've never heard of breaking valves or blowing the engine.
It isn't the best idea in the world (for the street) but it isn't gonna mess up the motor

[Stocker]

One of my more memorable drives was in 1968 when a friend helped me install a set of Hooker headers on my '65 Corvette (327/365, yeah I wish I had that one back) near Fresno, CA. We finished the job on a Sunday morning and couldn't find anyone to weld up the collectors, and I had to be at work Monday morning in Barstow, about a 240 mile trip.

You guessed it, open headers all the way -- they dumped right in front of the footwells so you can imagine the sound inside the car. It actually wasn't too bad at a steady cruise, but got loud if you let off the gas.... and LOUD under acceleration.

The engine wasn't hurt (only about a 3.5 hour drive) and most of my hearing returned, but I was only 19 and it took a while to get the grin off my face.

[magsnubby]

Originally Posted by Stocker

One of my more memorable drives was in 1968 when a friend helped me install a set of Hooker headers on my '65 Corvette (327/365, yeah I wish I had that one back) near Fresno, CA. We finished the job on a Sunday morning and couldn't find anyone to weld up the collectors, and I had to be at work Monday morning in Barstow, about a 240 mile trip.

I've made that trip a few times. How long before you got your hearing back?

[Stocker]

Originally Posted by magsnubby

I've made that trip a few times. How long before you got your hearing back?

What?

[1968SWBBigBlock]

As long as your ears can stand it you will be fine running open headers - drag cars have been doing it forever

[bac1755]

will it drop lowend torque?

[Longhorn Man]

probably... again, esp if you don't tune for it.
In high school I had an 81 chevy citation with the iron duke 2.5 4 cylinder, all it had on it for exhaust was a bare manifold. Drove it likle that for 6 to 9 months, mostly in the winter... not a single issue. Drove it to Cincinatti (240 mile round trip) every weekend for about 4 of those months.
Again, never had an issue.

[Sport/Truck]

I think long tube headers alone will drop low end torque, open or not.
s/t

[texanidiot25]

What sort of tuning is needed LHM?

[spinning wheels]

Without backpressure, yes you will loose your bottom end torque. Your whole power curve moves up the rpm scale. Most likely you will have some major flat spots, and they usually show up right at your cruzing speed

If you live in an area with a lot of hills or mountain roads, you will notice a major drop in your drivable torque. If you live in an area with flat straight roads, you will love it. One added plus, with open headers. You will get to meet people in high places, such as your local judges and police/sheriffs.

Open headers aren't allowed in most racing organizations anymore (NHRA pro classes is one exception). So most tuners now tune the carbs, ignition, ect.. to a motor with mufflers.

I think the local tracks (out here in LaLa Land anyways), are trying to keep dbs down to 95 or 92, measured from 10'. Not sure if they test every single vehicle, maybe just the way too loud ones.

Stocker, I can relate to your story. I didn't drive your distance, but after getting my '70 Z28 running, I had to drive it to a muffler shop to weld up the collectors. As it was raining, it was hard to keep the rpms down, when the rear tires would loose traction. When I came to a stop sign, a '60s Vette was going the opposite direction, when he herd my poor attempt at leaving the stop sign without wheelspin, he just smiled and gave me a thumbs up.

[Stocker]

In general, everything about an engine , including the intake and the exhaust systems, needs to work together as a unit -- in other words, all parts need to be properly 'tuned' to get the best results.

Restriction, or back pressure, does not create more torque. If it did, we'd all be running tiny exhaust pipes on our stump-pulling monsters. And a more free-flowing exhaust won't rob torque, but as has been said, it may move it up in the rpm range.

At the risk of oversimplification, large-diameter short header tubes are typically used on high-rpm high-HP engines (think top fuel) -- while streetable engines needing more bottom and mid-range torque will benefit more from smaller-diameter, longer (but equal-length) headers.

Assuming the entire engine package is designed to work together as a unit....

[spinning wheels]

Stocker, your explanation was much clearer than mine

texanidiot25, I would not try to run open headers too often unless you live out in the sticks. And I hope your local law enforcement has a good sense of humor.

Blasting down the road with open headers can be fun. Kinda lets you fantasize that you are in a NASCAR, just don't over do it and wear a full face helmet.

[texanidiot25]

Originally Posted by spinning wheels

Stocker, your explanation was much clearer than mine

texanidiot25, I would not try to run open headers too often unless you live out in the sticks. And I hope your local law enforcement has a good sense of humor.

I'm on the verge of the sticks, close enough. It'd only be for a few days though, I leave for school at 6:50, and my neighbors don't mind it cranking up cold so far (very cam'd sounding, lots of rumble), so I obviously don't want to blow that out of the water too long

[67_C-30]

Originally Posted by spinning wheels

Blasting down the road with open headers can be fun. Kinda lets you fantasize that you are in a NASCAR, just don't over do it and wear a full face helmet.

[Longhorn Man]

usually unplugging the exhaust will make it lean out, so adding a little more fuel... sometimes just turning a screw, other times a jet chainge.

[texanidiot25]

Next time I have to replace collector gaskets, I'll let ya'll know how the power feels

[bac1755]

This helps alot guys. And it does get the cops looking. got pulled over for it tonight. told him it must have fallen of down the road. he cracked a smile and told me to "take my smart ass home and put the exhaust back on"....

[bac1755]

+ =

[1970 CST Short Wide]

I have electric cut outs on my headers so I can open them up any time I feel the need and I feel the need at least once every drive. It’s so fun to pull up next to a ricer and open them up then leave him in a VERY loud cloud of smoke I love it.

[bac1755]

So I'm still running open headers on my truck, I love it its so loud. I had one of my neighbors call the sheriff on me at 12 in the afternoon. I live in an old subdevelopment in the country. come on alot of the people ride harleys out here, not much louder. basically the sheriff told me im doing nothing wrong, he liked my truck and then told the guy if he wants to sleep in the afternoon get some ear plugs the next time he calls it will be inproper use of the 911 system.

[onlyifihadachevy]

bac your so lucky, my dad and i got in trouble at like 10 at night because we just got my truck and wanted to hear it.

[john02fxdl]

A very good friend of mine bought a 80 Malibu drag car that ran high 7s, low
8s in 1/4 mile. Test and tune the day after he bought it, first pass car shut off at the 1/8th...we were confused. He got back to the trailer falling out of the car and crying his eyes out. That's what happens when:
1. Car runs open headers
2. Car runs on alcohol
3. Forgot to put the access covers back in the floor.

He didn't do that again.