Click Here -> Please Consider Making a PayPal Contribution to the FordSix Forum!
2019 Contributors:
NJwpod, 1strodeo, mightynorseman, maxtrux, 6d7coupe, broncr, Phase3, 68Flareside240, bmbm40,
mustang6, WorldChampGramp, justintendo, BigBlue94, ags290, motorsickle1130, Rooster, ousooner919, ethanperry
rzcrisis, DoctorC, jamyers, Motorboy, fastpat, Silverback280, chad


<<< New Site Update >>>

Headers glowing red/ low vacuum

Moderator: Mod Squad

groucho
Registered User
Posts: 34
Joined: Thu Oct 14, 2010 1:07 am

Headers glowing red/ low vacuum

Post #1 by groucho » Thu Jan 24, 2013 8:21 pm

So I was trying to dial in the timing for my carb 4.9 conversion. By the time that the choke had opened up the I noticed the headers were glowing.

Initial timing is set at 10 degrees with the vacuum unhooked.

Engine specs: carb 4.9 conversion with an edelbrock 1403, offy c intake, comp 268 cam, and AL timing gears straight up.

The vacuum gauge is reading at 10 inches water column.

All cylinders are at 140-145 psi during the compression check.
Last edited by groucho on Thu Jan 24, 2013 8:23 pm, edited 1 time in total.

User avatar
Asa
Registered User
Posts: 4355
Joined: Thu Nov 28, 2002 2:40 pm
Location: Tampa, Tallahassee, Hangin out in some Florida woods somewhere
Contact:

Re: Headers glowing red/ low vacuum

Post #2 by Asa » Thu Jan 24, 2013 8:23 pm

How do the plugs look? If my brain hasn't failed me, lean conditions cause heat.
Right and Wrong are just words, what matters is what you do

Susie - a work in progress
Clyde - ya mule!

groucho
Registered User
Posts: 34
Joined: Thu Oct 14, 2010 1:07 am

Re: Headers glowing red/ low vacuum

Post #3 by groucho » Thu Jan 24, 2013 9:01 pm

Brown. They look good.

Luckyman
VIP Member
Posts: 617
Joined: Mon Jun 14, 2004 3:42 pm
Location: Helena, MT. pop. enough

Re: Headers glowing red/ low vacuum

Post #4 by Luckyman » Fri Jan 25, 2013 11:07 am

groucho wrote:........... The vacuum gauge is reading at 10 inches water column...............


What elevation above sea level are you? The vacuum reading seems low. I can get 17 at 4100' and 19-20 at sea level. (but that is with the stock cam and factory timing gear locations, Holley 4V and EFI Exhaust) You might try advancing the timing up to 14 and see what happens.
1 "76" F150 RC, LB, 2WD, 300, NP435, 9" open 3.00, special order 2-76/Delivered 4-76. Still "new".

1 "73-79" F150 RC/SS/SB/4WD, "84"-300, T18, NP205, 9" open 3.50, Dana 44 3.50 open, Offy DP, Holley 470, EFI + single 2.5" exhaust. Gathered from 15+ donor/parts trucks. "Fubar". Runs good, safe, still needs details/project continues.

User avatar
80broncoman
Global Moderator
Posts: 3315
Joined: Sat Oct 18, 2003 10:49 pm
Location: The Great state of Ohio!!

Re: Headers glowing red/ low vacuum

Post #5 by 80broncoman » Fri Jan 25, 2013 11:38 am

with glowing headers/glowing exh manifolds it means combustion is happening much more than normal in the exh rather than in the engine. The cause is Very late (retarded) ignition timing.
Is this a new duraspark ignittion steup? ?
If so make sure your magnetic pickup wire are hooked up with the correct poleirity.
If the wires are wrong the timing will retard was RPM increases instead of advanceing.
To check for this Use a timeing light to see and record your base timing.
then switch the wires and check again. The timing will advance if you switched them to being correct.
OAPSE Union Member

Real men don't wear Bowties
When it come to engines If its .001 loose nobody knows, But if its .001 too tight EVERYBODY KNOWS!!
80 bronco FUV (farm utility vehicle)300 T-18 3.50s EFI head, offy C dual plenum, 500 edel carb, 1.7 roller rockers, Crane 260 cam EFI Exh

Harte3
VIP Member
Posts: 2643
Joined: Sat Oct 21, 2006 9:17 pm
Location: Spokane, WA

Re: Headers glowing red/ low vacuum

Post #6 by Harte3 » Fri Jan 25, 2013 11:58 am

What is the idle RPM? A Comp 268 cam is a bit lopey and may show a low on vacuum at a stock idle speed.
'83 F150 300, 0.030 over, Offy DP, Holley 4160/1848-1 465 cfm, Comp Cam 260H. P/P head, EFI exhaust manifolds, Walker Y Pipe, Super Cat, Turbo muffler, Recurved DSII, Mallory HyFire 6a, ACCEL Super Stock Coil, Taylor 8mm Wires, EFI plugs.

groucho
Registered User
Posts: 34
Joined: Thu Oct 14, 2010 1:07 am

Re: Headers glowing red/ low vacuum

Post #7 by groucho » Fri Jan 25, 2013 6:08 pm

It's the factory duraspark set up. I set the timing to 10 degrees using a timing light. I am in austin Texas which is 200-300 ft above sea level. When I advance the timing more I get pinging.

groucho
Registered User
Posts: 34
Joined: Thu Oct 14, 2010 1:07 am

Re: Headers glowing red/ low vacuum

Post #8 by groucho » Fri Jan 25, 2013 6:09 pm

80broncoman wrote:with glowing headers/glowing exh manifolds it means combustion is happening much more than normal in the exh rather than in the engine. The cause is Very late (retarded) ignition timing.
Is this a new duraspark ignittion steup? ?
If so make sure your magnetic pickup wire are hooked up with the correct poleirity.
If the wires are wrong the timing will retard was RPM increases instead of advanceing.
To check for this Use a timeing light to see and record your base timing.
then switch the wires and check again. The timing will advance if you switched them to being correct.


Which ones are the pick up wires. The red and white, or orange and purple that go to the dist?

Baron Von Ottomatic
Registered User
Posts: 197
Joined: Sat Jul 24, 2010 11:56 pm

Re: Headers glowing red/ low vacuum

Post #9 by Baron Von Ottomatic » Fri Jan 25, 2013 7:54 pm

The orange and purple wires go to the magnetic pickup in the distributor. Dunno how switching them would affect mechanical advance, though.

To which port on the carb do you have the vacuum advance connected? Using manifold vacuum vacuum will advance the timing at idle, should reduce the exhaust temp and raise the vacuum at idle.

User avatar
80broncoman
Global Moderator
Posts: 3315
Joined: Sat Oct 18, 2003 10:49 pm
Location: The Great state of Ohio!!

Re: Headers glowing red/ low vacuum

Post #10 by 80broncoman » Sat Jan 26, 2013 12:04 am

Baron Von Ottomatic wrote:The orange and purple wires go to the magnetic pickup in the distributor. Dunno how switching them would affect mechanical advance, though.

To which port on the carb do you have the vacuum advance connected? Using manifold vacuum vacuum will advance the timing at idle, should reduce the exhaust temp and raise the vacuum at idle.


It doesn't effect the mechanical advance. it is the triggering in the module. You know how if you hook up a analog ohm meter to the pickup and turn the dist you get a wave? The wave has a certain point where the module triggers the coil. it is either voltage rising or dropping. If you switch the wires it inverts the wave. It then gets triggered in whole nother place. (its almost like beable to turn the cam inside a points dist with moving anything else.) The waves are closer together as RPM increases. I've seen this on a osillscope.
OAPSE Union Member

Real men don't wear Bowties
When it come to engines If its .001 loose nobody knows, But if its .001 too tight EVERYBODY KNOWS!!
80 bronco FUV (farm utility vehicle)300 T-18 3.50s EFI head, offy C dual plenum, 500 edel carb, 1.7 roller rockers, Crane 260 cam EFI Exh

User avatar
80broncoman
Global Moderator
Posts: 3315
Joined: Sat Oct 18, 2003 10:49 pm
Location: The Great state of Ohio!!

Re: Headers glowing red/ low vacuum

Post #11 by 80broncoman » Sat Jan 26, 2013 12:06 am

groucho wrote:
80broncoman wrote:with glowing headers/glowing exh manifolds it means combustion is happening much more than normal in the exh rather than in the engine. The cause is Very late (retarded) ignition timing.
Is this a new duraspark ignittion steup? ?
If so make sure your magnetic pickup wire are hooked up with the correct poleirity.
If the wires are wrong the timing will retard was RPM increases instead of advanceing.
To check for this Use a timeing light to see and record your base timing.
then switch the wires and check again. The timing will advance if you switched them to being correct.


Which ones are the pick up wires. The red and white, or orange and purple that go to the dist?


Did you put a new module or pick up coil in the dist recently??
OAPSE Union Member

Real men don't wear Bowties
When it come to engines If its .001 loose nobody knows, But if its .001 too tight EVERYBODY KNOWS!!
80 bronco FUV (farm utility vehicle)300 T-18 3.50s EFI head, offy C dual plenum, 500 edel carb, 1.7 roller rockers, Crane 260 cam EFI Exh

groucho
Registered User
Posts: 34
Joined: Thu Oct 14, 2010 1:07 am

Re: Headers glowing red/ low vacuum

Post #12 by groucho » Sat Jan 26, 2013 9:40 am

80broncoman wrote:
groucho wrote:
80broncoman wrote:with glowing headers/glowing exh manifolds it means combustion is happening much more than normal in the exh rather than in the engine. The cause is Very late (retarded) ignition timing.
Is this a new duraspark ignittion steup? ?
If so make sure your magnetic pickup wire are hooked up with the correct poleirity.
If the wires are wrong the timing will retard was RPM increases instead of advanceing.
To check for this Use a timeing light to see and record your base timing.
then switch the wires and check again. The timing will advance if you switched them to being correct.


Which ones are the pick up wires. The red and white, or orange and purple that go to the dist?


Did you put a new module or pick up coil in the dist recently??


I did both individually to try to alleviate the problem. Does anybody else have an eddy 1403? If so where are your idel mixture screws set? I believe mine are at 1.25 turns out. The vacuum advance is unhooked right now because I am trying to solve this problem, but when I have hooked it up before it I put it on the ported vac.

groucho
Registered User
Posts: 34
Joined: Thu Oct 14, 2010 1:07 am

Re: Headers glowing red/ low vacuum

Post #13 by groucho » Sun Jan 27, 2013 10:15 pm

I just saw abandon broncos thread at FTE. Same symptoms, I will check the intake runner terminations to see if the are planed flat, change the the headgasket, and while I am at it port and swap valve springs. I will report back once its complete. I bet it is going to be the intake though, but doing the other stuff won't hurt.

Lazy JW
FSP Moderator
Posts: 5560
Joined: Fri May 16, 2003 10:25 pm
Location: Careywood, Idaho

Re: Headers glowing red/ low vacuum

Post #14 by Lazy JW » Tue Feb 12, 2013 4:49 pm

Luckyman wrote:
groucho wrote:........... The vacuum gauge is reading at 10 inches water column...............


What elevation above sea level are you? The vacuum reading seems low. I can get 17 at 4100' and 19-20 at sea level. (but that is with the stock cam and factory timing gear locations, Holley 4V and EFI Exhaust) You might try advancing the timing up to 14 and see what happens.


I suspect that should read "10 inches of Mercury column". Ten inches of water would be WOT.

I'm wondering if the harmonic balancer may have slipped, causing the indicated timing to be incorrect.
Joe
"The White OX" 1974 F-350 300-6, Stock single exhaust, Carter YF, T-18A, Dana70 w/4.11, Flatbed dually w/dump bed. "Where no oxen are, the crib is clean, but much increase is by the strength of the ox" (Proverbs 14:4)
Image

groucho
Registered User
Posts: 34
Joined: Thu Oct 14, 2010 1:07 am

Re: Headers glowing red/ low vacuum

Post #15 by groucho » Tue Feb 12, 2013 11:46 pm

Lazy JW wrote:
Luckyman wrote:
groucho wrote:........... The vacuum gauge is reading at 10 inches water column...............


What elevation above sea level are you? The vacuum reading seems low. I can get 17 at 4100' and 19-20 at sea level. (but that is with the stock cam and factory timing gear locations, Holley 4V and EFI Exhaust) You might try advancing the timing up to 14 and see what happens.


I suspect that should read "10 inches of Mercury column". Ten inches of water would be WOT.

I'm wondering if the harmonic balancer may have slipped, causing the indicated timing to be incorrect.
Joe

I am a former HVAC dude and we measure in inches of water column. Habit of thought.

I had the offy intake planed down. It was pretty uneven. Think large pipes on the church organ. I suspect it was the main offender for the low vacuum. I changed the head gasket anyway and it was cracked too. The motor has more ware than what I'd want, but its factory bore. I plan in the long term to design a blow through turbo set up with a solid axel dana 44, but this motor will get me by for now until I get the rest if my drive terrain sorted.

The only problems I have encountered so far I with efi to carb is the timing curve, but that will just take some dilly dallying to satisfy.

User avatar
THE FRENCHTOWN FLYER
VIP Member
Posts: 6091
Joined: Sat Nov 09, 2002 9:25 pm
Location: FRENCHTOWN

Re: Headers glowing red/ low vacuum

Post #16 by THE FRENCHTOWN FLYER » Wed Feb 13, 2013 4:02 pm

Headers glowing and low vacuum are symptoms of a plugged exhaust sysytem, usually caused by a melt down inside of the catylitic converter.
FORD 300 INLINE SIX - THE BEST KEPT SECRET IN DRAG RACING

Lazy JW
FSP Moderator
Posts: 5560
Joined: Fri May 16, 2003 10:25 pm
Location: Careywood, Idaho

Re: Headers glowing red/ low vacuum

Post #17 by Lazy JW » Thu Feb 14, 2013 5:18 pm

groucho wrote:...

The only problems I have encountered so far I with efi to carb is the timing curve, but that will just take some dilly dallying to satisfy.


Ummmmm..... just curious, are you perchance still running the distributor that was on the EFI setup? If so, they do not have any mechanical advance mechanism whatsoever, resulting in locked timing.

Some years back I also had a DS2 unit on which the centrifugal advance mechanism failed (it literally fell apart in rusty chunks).
Just a thought.
Joe
"The White OX" 1974 F-350 300-6, Stock single exhaust, Carter YF, T-18A, Dana70 w/4.11, Flatbed dually w/dump bed. "Where no oxen are, the crib is clean, but much increase is by the strength of the ox" (Proverbs 14:4)
Image

groucho
Registered User
Posts: 34
Joined: Thu Oct 14, 2010 1:07 am

Re: Headers glowing red/ low vacuum

Post #18 by groucho » Mon Feb 18, 2013 7:00 pm

FTF no cats on this one. Lazy JW I am running the dist from my locked up 83 motor.

The truck is running pretty good right now. I picked up an extra carb block and head that threw a rod. I am going to go the 360 piston route with a ported head and oversized valves. I have been considering forged pistons and a D66 turbo, but I think it would be best to K.I.S.S. this motor just has to last a year or two.

The vac adv needs to be turned down more. It pings under part throttle even on 93. I know it's not build up either because I cleared the valves and cc when ported the head and replaced the gasket.

The offy got planned and the head gasket replaced and the problem has seemed to stop.

nightwatchman59
Registered User
Posts: 56
Joined: Wed Jan 23, 2013 1:00 pm

Re: Headers glowing red/ low vacuum

Post #19 by nightwatchman59 » Thu Aug 22, 2013 10:04 pm

Once upon a time, I had an obstruction manifest itself in the intake runner, and the primary exhaust tube to that cylinder glowed red- and alerted me there was a problem before I went for a test drive..... just thought I'd share...... :bang:

User avatar
MechRick
Registered User
Posts: 872
Joined: Wed Jan 04, 2012 7:43 pm
Location: Las Vegas, NV

Re: Headers glowing red/ low vacuum

Post #20 by MechRick » Fri Aug 23, 2013 3:15 pm

groucho wrote:The vacuum gauge is reading at 10 inches water column.


I was able to get 17" out of mine with the 268H.

groucho wrote:The vac adv needs to be turned down more. It pings under part throttle even on 93. I know it's not build up either because I cleared the valves and cc when ported the head and replaced the gasket.


This is the reason I ended up with a stock cam. The 268H gains so much cylinder pressure with an EFI head that it puts the 4.9 in race gas territory. Anything you do to raise compression is going to make it worse. You can play with the timing curve and fatten the fuel mixture in the rpm/throttle range where it pings and it will help. But I couldn't tow with mine. The extra load aggravated the ping.

I would go the other way and reduce compression if possible. If you are running the EFI head, a good experiment would be a switch to a carb head with bigger chambers...

groucho wrote:By the time that the choke had opened up the I noticed the headers were glowing.


If it is Hedman's, I woundn't worry too much if they glow once in a while. The 18 gauge tubing used in these will glow dull red especially at night after romping on it. Retarded ignition timing will make it worse...
1994 F150, 4.9L/ZF 5 speed, C-Vic police driveshaft
EFI head w/mild port work, 3 angle valve job
1996 long block, stock pistons, ARP rod bolts
Stock cam, aluminum cam gear
Hedman header, full mandrel bent duals, crossover, super turbos
http://fordsix.com/forum/viewtopic.php?f=2&t=73244
Bronco II with a 2.3L swap http://fordsix.com/forum/viewtopic.php?f=13&t=72863
1988 F250 2x4, 460 ZF 5 speed.

Who is online

Users browsing this forum: MechRick, THE FRENCHTOWN FLYER and 26 guests