Open headers = engine damage?

[Scot_94GT]

I have been thinking about getting remote operated motorized exhaust cutouts for quite a while now, but I have some concerns.

I've heard that running open headers can damage you engine...something like burning the exhaust valves Is this something to worry about? How can I prevent it...because I know you can run open headers...tons of street rod guys do it. I need to know how to run cutouts (which will essentially be open headers) without hurting my engine.

Thanks.

 

[cb18201]

well are you doing it for sound or trying to gain performance? if your trying ot gain performance then you wont gain anything at all if you dont have about 900hp or more. you will lose all your low end torque and your car will have no balls. i had a slight exhaust leak at the headers and my car went no where. but if you are doing it just for sound i have heard it is not good for a stock motor because it needs backpressure to run properly, i have also heard of people cooking their valve seals.

 

[HazMat404]

yeah, i heard that is why i fried my valve and it ended up cracking off cause i had a big ol leak with my shorty headers and colder air was rushing in. it was when i let off the gas from a WOT that my car went *pop* and i cracked a valve and it was hitting the piston. air coming in that quickly isnt good for our heads at all. just do the motorized cutouts right after your mufflers so it has the dump effect but still have tailpipes. i have been thinkin about doing that for some time now

 

[yellow1995Cobra]

i Dont get why running open headers is bad. There are so many big motor'd cars at the track with just longtubes dumped... Of course their motors are big enough to make alot of power with no exhaust, but it doesnt do damage to there engines..

 

[VIPERn94Five-0]

ur gonna lose power if you do it...and if you do it on shorty headers you will burn valves...LT's are ok but shorties are no good...either way your gonna lose power unless you have big cubes and big power...


Anthony

 

[ShiftTheDrift]

Firstly, our cars depend on back pressure to produce low end torque, plain and simple. Secondly, running open headers in high rpm/rev situations will result in burning valves unless your horsepower is more upwards of 700hp as mentioned by cb18201 and VIPERn94Five-0.

Just thought I'd reinforce your thoughts guys.

The shortys verses long tubes debate is a misconception saying that running long tubes are long enough to produce enough back pressure without damaging effects is wrong. If you're looking for noise, buy some SpinTech mufflers.

 

[Scot_94GT]

ok...so it's the cold air that comes back in that hurts your valves?

I am not thinking about doing it for power. I just want to ba able to flip a switch and make my car loud as hell when I want, and then back to normal for regualr driving.

Right now, i have the stock 4-cat h-pipe, but after that, it is just 2.5" pipe with no muffs all the way out the back. It has a nice rumble and i'm pretty satisfied with it, but the cat's take alot of sound away, and having a remote cutout would just be really fun/cool.

SO how do the drag guys not get burned valves with dumped headers?

 

[cb18201]

i Dont get why running open headers is bad. There are so many big motor'd cars at the track with just longtubes dumped... Of course their motors are big enough to make alot of power with no exhaust, but it doesnt do damage to there engines..

those guys dont need backpressure because they have so much horsepower, their engines run better like that because they are pumping so much air through them, ours arnt, also those guys rebuild their engines all the time and if they dont they eventually will need to anyways.

 

[yellow1995Cobra]

those guys dont need backpressure because they have so much horsepower, their engines run better like that because they are pumping so much air through them,QUOTE]

Yes i know that, like i said in my first post.

 

[ShiftTheDrift]

If all you're wanting is increased dB, the mid-pipe with four cats has got to go. In comparison to a full-on dragster, we're talking about another 100ci or so and higher compression ratios.

 

[cb18201]

those guys dont need backpressure because they have so much horsepower, their engines run better like that because they are pumping so much air through them,QUOTE]

Yes i know that, like i said in my first post.

you said it doesnt do damage to their engines, i was just saying that it does, an they always are rebuilding their engines. not trying to start a dissagreement. sorry

 

[VibrantRedGT]

With the mods in your sig the only thing gained is a headache.

 

[ShiftTheDrift]

A GREAT article on Exhaust Scavenging, BackPressure, and HP.
http://www.veryuseful.com/mustang/tech/engine/exhaustScavenging.pdf

View attachment 524262

 

[yellow1995Cobra]

you said it doesnt do damage to their engines, i was just saying that it does, an they always are rebuilding their engines. not trying to start a dissagreement. sorry

I find it hard to believe that "race motors" (which isnt what i meant in the first place, just big cube cars) need to be rebuilt because of using longtube headers dumped..

 

[cb18201]

believe it, try it and see what happens

 

[95cobra50]

i ran open LT for a week and my car couldn't pull on a v6 firebird. We were dead even it was really sad. But one the up and up you get lots of attention everywhere you go mostly when there are cops sitting 3 places around town talking about you and trying to find out where you are

 

[4Jenna]

Pointless

 

[Scot_94GT]

Funny how I get different answers depending on where I ask. I posted the same question on the Corral, and everyone told me that open headers destroying valves is just and old wives tale.

 

[yellow1995Cobra]

believe it, try it and see what happens

I have had my car running with just longtubes for a little while. I just put the rest of the exhaust on. I have no burnt valves.

Funny how I get different answers depending on where I ask. I posted the same question on the Corral, and everyone told me that open headers destroying valves is just and old wives tale.

Yes that is exactly what i think.

 

[Sleepy McNastee]

I have had my car running with just longtubes for a little while. I just put the rest of the exhaust on. I have no burnt valves.



Yes that is exactly what i think.

Did you get a hood that fits? You should check out young 347's hood. I think it might clear your massive intake.

BTW I ran open headers for a while too and no burnt valves.