headers_straight

Brady91 GT · 09-25-2001, 09:16 PM

I was wondering if i could run straight headers on my stock 5.0. I just wanna run shorties for a day. Can this hurt my car? i was told that it could burn my valves. Thank you Very much in advance.

BowTie Eater 5 Liter · 09-26-2001, 12:19 AM

I Wouldnt Try It, What Are Your Reasons For Wanting To Do So?

Later

------------------
1988 Mustang GT, T-5
3.08's, No Smog Pump (Shorty Belt), Dumps At The End Of Stock H-Pipe, K&N Air Filter (Stock Air Box), Removed Air SilencerMy Stang

Plane Ticket To Afghanistan= $800
High Powered Sniper Rifle= $1000
Hotel With Accesible Roof= $200
Shooting A Piece Of Shit Like Osama Bin Laden= Priceless

WADS56 · 09-26-2001, 01:13 AM

You can warp a valve if you do it with shorties. Your car will be a turd, and it will sound like crap.

------------------
79 hatch w/ NA 347,stage 2 Canfield heads, out of the box Victor 5.0 intake, solid roller cam, Aeromotive fuel system, proshifted TKO II.MY CAR http://www.mustangworks.com/cgi-bin/...splay.cgi?1288
93lx all stock + tremec

09-26-2001, 01:36 AM

you might get away with it if. it's a short run and not cold temps, we used to have cut out's back in the day's just flipped the lever & instat open header's but! they were longer header's that went under the fire wall . don't want to thrash your engine for a fast run .

------------------

Brady91 GT · 09-26-2001, 04:42 PM

I was just wondering this because i was gonna cruise my car to school for a day just so it would be loud but im not gonna do it anymore , i dont wanna risk screwing stuff up for a day of fun. Thanks to all that replied .

PGkelly · 09-26-2001, 05:32 PM

well. I drove my old POS civic around for a day with an open header. it was cool. find your handy-dandy summit catalog and order up some weld-in exhaust cutouts. then have some fun!

------------------
If it ain't broke, make it go faster

AOL: MCVillain45

PGkelly · 09-26-2001, 05:36 PM

oh, yeah, explain to me how running open headers could warp the valves?

------------------
If it ain't broke, make it go faster

AOL: MCVillain45

Five0 · 09-26-2001, 10:18 PM

I started my old motor on the shorty headers and like wads56 said it sounds like crap.
I too was told that it can warp a valve running it like that if any cool air gets into the combustion chamber around hot valves but I don't know if it's true or not.

------------------
James Cox
nochevy@hotmail.com
1991 Mustang LX
No good times with 347 stroker yet!

PKRWUD · 09-27-2001, 04:11 AM

I've never heard of it "warping" a valve, but it could certainly burn a valve.

Take care
~Chris

------------------
Retired Moderator
MustangNet

My site: JimPorterRacing

RACECAR spelled backwards is RACECAR

HEY !!! Are you ASE Certified ??? If you are, ask me about iATN. The best tool you'll ever have, and it's free !!!

84LX89GT · 09-28-2001, 12:45 AM

The reason (as far as i know) that valves get burnt when you run close ending exhaust is because when you don't have a certain length of pipe retaining heat within the exhaust, scavanging can actually pull OUT the heat of combustion and the exhaust valves are exposed to extreme heat and then are cooled off really quickly. This causes hair line cracks in the exhaust valves and that leads to pieces of valve chipping off and getting sent out with the exhaust.
By the way, It would be safe to take off your cat-back exhaust (behind the catalytic converters) and it's relatively easy to take out and it will be pretty loud as well and have a nice deep tone and probably help power as well.

------------------
Mustang Parts Specialties ripped me off, it could happen to you as well.
'84 Mustang 5.0 LX
my LX
'89 Mustang GT
my GT

PKRWUD · 09-28-2001, 08:23 AM

Interesting theory.

During engine operation, there is a brief moment between the exhaust stroke and the intake stroke where the piston actually draws a very small amount of exhaust gas back into the cylinder. This combined with the vacuum created when the valve does shut, will draw a mixture from the exhaust to the engine. With a full exhaust, the gasses that could reach the head are no further than the cat. With open headers, you will draw oxygen rich air back into the exhaust, and up to the exhaust port. This Oxygen will raise the temperature substantially. The burning of an exhaust valve can only occur when the temperature is raised above the melting point of the valve metal.

Take care
~Chris

------------------
Retired Moderator
MustangNet

My site: JimPorterRacing

RACECAR spelled backwards is RACECAR

HEY !!! Are you ASE Certified ??? If you are, ask me about iATN. The best tool you'll ever have, and it's free !!!

Stang Runner · 09-28-2001, 01:03 PM

I car might get on fire. Stated it up and had fire shooting out in the hood.

Stang Runner · 09-28-2001, 01:04 PM

sig

------------------
14.28@103.0 on a G-Tech Engine: Steal Mounts, Under drive pulleys, K&N, Home ported Lower Intake, No power steering, No A/C
Drive Train: 3.55, World Class T-5,
NOW it is time for Real power STUFF I Have and will put on after I get everthing: Mac cold intake, 70MM TB, Valve covers (COOL ONES)255 Fuel pump NOS Dry 75HP.
Next to get: Rocker Arms,Cam,TFS Heads,Injectors 24,Holley Intake, What might I need???See It at <A HREF="http://www.computerconquest.com" TARGET=_blank>www.computerconq

84LX89GT · 09-29-2001, 12:18 AM

I'm sure you're right PKRWUD on how that works, i've read about scavanging and thermodynamics, so i was just taking a guess on how it works, I've never had any one explain to me how that worked so i just pictured it in my head. I'm glad you posted because i've never been absolutely sure on how that works....
...no matter how hard you try not to, you learn something everyday

------------------
Mustang Parts Specialties ripped me off, it could happen to you as well.
'84 Mustang 5.0 LX
my LX
'89 Mustang GT
my GT

PKRWUD · 09-29-2001, 12:25 AM

That same process is why an exhaust leak between the head and the exhaust manifold will result in a burned exhaust valve in no time. The leak is allowing oxygen rich air to reach the exhaust valve itself with no effort at all. Moral? ALWAYS fix exhaust leaks immediately!

Take care
~Chris

------------------
Retired Moderator
MustangNet

My site: JimPorterRacing

RACECAR spelled backwards is RACECAR

HEY !!! Are you ASE Certified ??? If you are, ask me about iATN. The best tool you'll ever have, and it's free !!!

09-25-2001, 09:16 PM	#1
Brady91 GT Registered Member Join Date: Sep 2000 Location: Las Vegas NV Posts: 68	headers_straight I was wondering if i could run straight headers on my stock 5.0. I just wanna run shorties for a day. Can this hurt my car? i was told that it could burn my valves. Thank you Very much in advance.

09-26-2001, 12:19 AM	#2
BowTie Eater 5 Liter Registered Member Join Date: Nov 2000 Location: Maple Ridge B.C. Canada, The Best Place In The World Posts: 871	I Wouldnt Try It, What Are Your Reasons For Wanting To Do So? Later ------------------ 1988 Mustang GT, T-5 3.08's, No Smog Pump (Shorty Belt), Dumps At The End Of Stock H-Pipe, K&N Air Filter (Stock Air Box), Removed Air SilencerMy Stang Plane Ticket To Afghanistan= $800 High Powered Sniper Rifle= $1000 Hotel With Accesible Roof= $200 Shooting A Piece Of Shit Like Osama Bin Laden= Priceless

09-26-2001, 01:13 AM	#3
WADS56 gear banger Join Date: Aug 2000 Location: CHICAGO Posts: 1,144	You can warp a valve if you do it with shorties. Your car will be a turd, and it will sound like crap. ------------------ 79 hatch w/ NA 347,stage 2 Canfield heads, out of the box Victor 5.0 intake, solid roller cam, Aeromotive fuel system, proshifted TKO II.MY CAR http://www.mustangworks.com/cgi-bin/...splay.cgi?1288 93lx all stock + tremec

09-26-2001, 01:36 AM	#4
mustang marty gt Guest Posts: n/a	you might get away with it if. it's a short run and not cold temps, we used to have cut out's back in the day's just flipped the lever & instat open header's but! they were longer header's that went under the fire wall . don't want to thrash your engine for a fast run . ------------------

09-26-2001, 04:42 PM	#5
Brady91 GT Registered Member Join Date: Sep 2000 Location: Las Vegas NV Posts: 68	I was just wondering this because i was gonna cruise my car to school for a day just so it would be loud but im not gonna do it anymore , i dont wanna risk screwing stuff up for a day of fun. Thanks to all that replied .

09-26-2001, 05:32 PM	#6
PGkelly Registered Member Join Date: Feb 2001 Posts: 274	well. I drove my old POS civic around for a day with an open header. it was cool. find your handy-dandy summit catalog and order up some weld-in exhaust cutouts. then have some fun! ------------------ If it ain't broke, make it go faster AOL: MCVillain45

09-26-2001, 05:36 PM	#7
PGkelly Registered Member Join Date: Feb 2001 Posts: 274	oh, yeah, explain to me how running open headers could warp the valves? ------------------ If it ain't broke, make it go faster AOL: MCVillain45

09-26-2001, 10:18 PM	#8
Five0 Registered Member Join Date: Apr 2000 Location: middleburg, fl, usa Posts: 1,134	I started my old motor on the shorty headers and like wads56 said it sounds like crap. I too was told that it can warp a valve running it like that if any cool air gets into the combustion chamber around hot valves but I don't know if it's true or not. ------------------ James Cox nochevy@hotmail.com 1991 Mustang LX No good times with 347 stroker yet!

09-27-2001, 04:11 AM	#9
PKRWUD Junior Member Join Date: Mar 1999 Location: Ventura, California Posts: 8,981	I've never heard of it "warping" a valve, but it could certainly burn a valve. Take care ~Chris ------------------ Retired Moderator MustangNet My site: JimPorterRacing RACECAR spelled backwards is RACECAR HEY !!! Are you ASE Certified ??? If you are, ask me about iATN. The best tool you'll ever have, and it's free !!!

09-28-2001, 12:45 AM	#10
84LX89GT Mustangs Join Date: Jul 2000 Posts: 1,938	The reason (as far as i know) that valves get burnt when you run close ending exhaust is because when you don't have a certain length of pipe retaining heat within the exhaust, scavanging can actually pull OUT the heat of combustion and the exhaust valves are exposed to extreme heat and then are cooled off really quickly. This causes hair line cracks in the exhaust valves and that leads to pieces of valve chipping off and getting sent out with the exhaust. By the way, It would be safe to take off your cat-back exhaust (behind the catalytic converters) and it's relatively easy to take out and it will be pretty loud as well and have a nice deep tone and probably help power as well. ------------------ Mustang Parts Specialties ripped me off, it could happen to you as well. '84 Mustang 5.0 LX my LX '89 Mustang GT my GT

09-28-2001, 08:23 AM	#11
PKRWUD Junior Member Join Date: Mar 1999 Location: Ventura, California Posts: 8,981	Interesting theory. During engine operation, there is a brief moment between the exhaust stroke and the intake stroke where the piston actually draws a very small amount of exhaust gas back into the cylinder. This combined with the vacuum created when the valve does shut, will draw a mixture from the exhaust to the engine. With a full exhaust, the gasses that could reach the head are no further than the cat. With open headers, you will draw oxygen rich air back into the exhaust, and up to the exhaust port. This Oxygen will raise the temperature substantially. The burning of an exhaust valve can only occur when the temperature is raised above the melting point of the valve metal. Take care ~Chris ------------------ Retired Moderator MustangNet My site: JimPorterRacing RACECAR spelled backwards is RACECAR HEY !!! Are you ASE Certified ??? If you are, ask me about iATN. The best tool you'll ever have, and it's free !!!

09-28-2001, 01:03 PM	#12
Stang Runner Registered Member Join Date: Jun 1999 Location: Walker, MI, USA Posts: 1,202	I car might get on fire. Stated it up and had fire shooting out in the hood.

09-28-2001, 01:04 PM	#13
Stang Runner Registered Member Join Date: Jun 1999 Location: Walker, MI, USA Posts: 1,202	sig ------------------ 14.28@103.0 on a G-Tech Engine: Steal Mounts, Under drive pulleys, K&N, Home ported Lower Intake, No power steering, No A/C Drive Train: 3.55, World Class T-5, NOW it is time for Real power STUFF I Have and will put on after I get everthing: Mac cold intake, 70MM TB, Valve covers (COOL ONES)255 Fuel pump NOS Dry 75HP. Next to get: Rocker Arms,Cam,TFS Heads,Injectors 24,Holley Intake, What might I need???See It at <A HREF="http://www.computerconquest.com" TARGET=_blank>www.computerconq

09-29-2001, 12:18 AM	#14
84LX89GT Mustangs Join Date: Jul 2000 Posts: 1,938	I'm sure you're right PKRWUD on how that works, i've read about scavanging and thermodynamics, so i was just taking a guess on how it works, I've never had any one explain to me how that worked so i just pictured it in my head. I'm glad you posted because i've never been absolutely sure on how that works.... ...no matter how hard you try not to, you learn something everyday ------------------ Mustang Parts Specialties ripped me off, it could happen to you as well. '84 Mustang 5.0 LX my LX '89 Mustang GT my GT

09-29-2001, 12:25 AM	#15
PKRWUD Junior Member Join Date: Mar 1999 Location: Ventura, California Posts: 8,981	That same process is why an exhaust leak between the head and the exhaust manifold will result in a burned exhaust valve in no time. The leak is allowing oxygen rich air to reach the exhaust valve itself with no effort at all. Moral? ALWAYS fix exhaust leaks immediately! Take care ~Chris ------------------ Retired Moderator MustangNet My site: JimPorterRacing RACECAR spelled backwards is RACECAR HEY !!! Are you ASE Certified ??? If you are, ask me about iATN. The best tool you'll ever have, and it's free !!!