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Great Debate

1K views 10 replies 7 participants last post by  Beechkid 
#1 ·
Long Tube Header
Will running open long tube header cause damage to the engine? A lot of people say "Yes" and a lot of people say "No"
 
#3 ·
Sir,
I didn't say "I" was or wanted to run open headers! I came across the debate somewhere else and posted it here to get others responses. Thats why the title is "Great Debate". On the other post people responded with a simple "Yes" or "No". Some even went the extra mile and educated a lot of people about the cold air rushing back in will more than likely cause cracked valves.
 
#8 ·
You didn't make it clear whether this was just a general question or whether it was specific to your Mustang.
Generally speaking, running open headers won't damage the engine if the fueling and ignition timing are correct for the application.
 
#4 ·
what "cold air rushing in" ? I'm not sure how that works, first thought is whoever said that does not know what they are talking about, but it could be me who does not know what I am talking about, LOL

I don't know any reason why running open headers would do any damage. The myths about "lack of back pressure" are myths. However I have a feeling that open headers actually might not perform as well as headers with exhaust pipes downstream, due to the flow dynamics
 
#7 ·
😆😆😆 yeah "Cold Air" I dont know..i didnt see any proof of the actually everhappening but didnt investigate to find out either.

Im with you on performance though. I figure running a full set up is best. I was just interested in hearing what everyone else think about the debate or engine failure due to running open headers. Out of wverything i read or saw someone comment there never was proof of actual damage or proof of their being no damage.
 
#5 ·
I suspect that about the only way one might burn a valve with open headers is if the engine runs extremely lean with the open exhaust...and, that it would likely affect a more highly modified engine (more sensitive to af changes) if at all. There is virtually no way for cold air the "rush" into the headers especially considering the amount of heat headers retain and the fairly small pipe diameter. If you want to do it, keep an eye on your plugs for any telltales.

Btw, heard the tales of burning valves, but have never seen it, even in my days of auto parts and mechanic work. I've run open headers and if you've gone to the trouble and expense to install them you may as well give it a try...they're too loud for me!
 
#6 ·
Another tale thats told is that highly modified engines runnin atleast 700Hp will be fine running open headers because of them being built.

I have never heard of anyone cracking or burning their valves due to open headers either lol. Im personally not going to run open header but i know there are people who do. When I first installed my LT, lile any muscle car enthusiast, i cranked it to see what they would sound like lmao. Neighbors nightmare😆😆
 
#9 ·
Hmm so hear me out. I have a 99GT that I bought and was modded alot. I've pretty much made it stock except for the longtube headers and the mid pipe. Also dont know if my PCM is on stock tune because before the stock engine went in I put the stock tune back on with bama but it still gives no codes for the rear o2s which it should due to no cats. Gonna reflash stock tune at Ford tomorrow. Also, the car runs very weird. Idling too long makes the LTFT in both banks go to 25%. Eventually open loop and the car will idle rough and eventually idle surge and then stall usually. If I rev it a couple of times hard the LTFT in both banks drops to 10-17% for a bit untill it idles too long. Also I noticed the o2 sensors in the front always read lean around 0.3-0.5v and usually flatline. After revving a couple times they start to form the waves in the graphs. Could this be due to the longtube headers?
 
#10 ·
Open headers didn't seem to bother much.

Superchargers SCREAMING at 2 minutes plus.

No wonder the other side wore brown underwear.:grin:
 
#11 ·
Ok, now I'm really going to show my age..... and more learning from my dad who ran El Mirage and was a mechanical engineer in the space and aerospace programs...…


The issue of warping a valve by sucking air back through an open header is true with criteria...…as this comes from the days of flatheads and the VW flat 4 engines....


Yes, with running the "real" zoomie pipes, they were so short and the combination of the cam overlap with the head design could cause this to happen when you foot was taken off the gas..... and only likely to occur on a street vehicle - not in race conditions.


So the real answer is- not a chance with our engines from the 60's up and with long headers....


but, the old school with zoomies, yeah (although more of a possibility not probability)...
 
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