red hot manifolds and exhaust!?? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

hjalbert · 03-30-2003, 01:41 AM

I Just put in a new cam and vortec heads on my 1975 350. I have ramhorns with dual exhaust. On the first start up to after running it at about 2500 RPMS for 5 minutes, the exhaust manifolds and pipes were red hot, you could almost see through them it seemed.the engine is running great, except for this. Any help would be appreciated thanks HJ

dmurphy68 · 03-30-2003, 06:12 AM

i have seen this when a cat goes bad or is cloged on newer cars. maybee you got some little fuzzy creature in your exhaust. Did both sides do it or just one side . do you got the duals h ar xed ?

JimKshortstep4x4 · 03-30-2003, 07:16 AM

Late timing would be the first thing that I would suspect.

Jim

junkyardjohn · 03-30-2003, 11:06 AM

I 2ND THE TIMING

>X< · 03-30-2003, 11:13 AM

why the timing?

FRENCHBLUE72 · 03-30-2003, 11:14 AM

Timmming i just went threw that with my new motor......I guess it's time to but a good timimg light!!!!

Longhorn Man · 03-30-2003, 11:59 AM

Running real lean will heat it all up too, but I don't know about red hot though.

ChevLoRay · 03-30-2003, 01:00 PM

All are possibilities, although we know that only those vehicles built since the mid-70's were equipped with the converters. I have seen GM converters that were filled with the palladium-coated pellets, that blinded-off when the pellets turned to dust. When they did that, not only was a red-hot converter in the making, but the performance went down the big tube....like no power. Still ran, but what good did it do?

The later model converters that use a porous, honeycomb construction are much less prone to blockage than the early types. At ALCOA, we prototyped the honeycomb-construction that is more prevalent.

knucklebuster · 03-30-2003, 01:06 PM

I had a friend who called me over to his house once to look at his truck.His timing was off so bad his passenger side manifold was glowing orange!!So i would have to say timing.Does it start up fine?

Dean23 · 03-30-2003, 06:41 PM

timing is the cause. At school we ran a 2.5l gm tech for on base timing only up to 3000 and in about 3 min the manifold was glowing red

mikep · 03-30-2003, 06:56 PM

Retarded timing. When you fire the spark late the A/F mixture is still burning when it exits the cylinder. Thats why your pipes are glowing red. seen it before . Time the engine and I bet it will go away.

03-30-2003, 01:41 AM	#1
hjalbert cracker Join Date: Sep 2001 Location: Wilmington, NC Posts: 1,021	red hot manifolds and exhaust!?? I Just put in a new cam and vortec heads on my 1975 350. I have ramhorns with dual exhaust. On the first start up to after running it at about 2500 RPMS for 5 minutes, the exhaust manifolds and pipes were red hot, you could almost see through them it seemed.the engine is running great, except for this. Any help would be appreciated thanks HJ __________________ FOUNDING MEMBER OF THE DRUM BRAKE CLUB Harry John Albert III located in Phoenix, AZ 1972 GMC JIMMY, 1969 lwb Chevy Frame, 1999 bmw k1200 ltc 1992 Kawasaki concours 1991 bmw k75 1973 cortez motorhome

03-30-2003, 06:12 AM	#2
dmurphy68 Registered User Join Date: Nov 2002 Location: Middletown ohio Posts: 1,058	i have seen this when a cat goes bad or is cloged on newer cars. maybee you got some little fuzzy creature in your exhaust. Did both sides do it or just one side . do you got the duals h ar xed ? __________________ The very atmosphere of firearms everywhere restrains evil interference. When firearms go, all goes, we need them every hour. - George Washington No free man shall be debarred the use of arms - Thomas Jefferson Later Darren http://www.myspace.com/dmurphy68

03-30-2003, 11:06 AM	#4
junkyardjohn Registered User Join Date: Aug 2001 Location: SOMERSET KY. Posts: 6,425	I 2ND THE TIMING __________________ junkyardjohn 69 1 TON TOW TRUCK // 84 4WD CUCV BLAZER// 85 1 TON 4WD STAKE TRUCK// 86 M1031 5/4 TON 4WD CUCV// ALOT OF OLD TRUCKS FOR ONE OLD MAN TO DRIVE. THERES ROOM FOR ALL OF GODS CREATURES RIGHT NEXT TO MY MASHED POTATOES// LIFE MEMBER OF P.E.T.A (PEOPLE EATING TASTY ANIMALS) DON'T RENT U-HAUL ALWAYS TELL THE TRUTH IT WILL AMAZE PART OF THE PEOPLE & ASTONISH THE REST

03-30-2003, 11:13 AM	#5
>X< registered IWATA user Join Date: Feb 2002 Location: Baton Rouge Posts: 4,481	why the timing? __________________ -'63 Ford Fairlane 500 coupe, v8, auto, faded and rusty. awaiting built roller 302 and some flat black -'99 Honda Prelude. vtech/5spd. no pipe, no intake, bone stock. awaiting new top end. -01 GMC Yukon SLT 5.3 dented and scratched with a noisy tranny. Take off that Von Dutch hat before i stab you with a 000 Mack.

03-30-2003, 11:14 AM	#6
FRENCHBLUE72 PROJECT 7DEUCE Join Date: Dec 2002 Location: GRANTS PASS OR Posts: 21,606	Timmming i just went threw that with my new motor......I guess it's time to but a good timimg light!!!! __________________ GO BIG GREEN GO DUCKS MEMBER #6377 72 k-5 daily driver 6'' lift 35'' 350-350-205 slowly getting rust free. Project "7DEUCE" check out my build http://67-72chevytrucks.com/vboard/s...d.php?t=267665 Tim Powell..R.I.P EastSideLowlife..... R.I.P..

03-30-2003, 07:16 AM	#3
JimKshortstep4x4 Senior Member Join Date: Jul 2001 Location: Muskegon,MI,USA Posts: 6,026	Late timing would be the first thing that I would suspect. Jim

03-30-2003, 11:59 AM	#7
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,690	Running real lean will heat it all up too, but I don't know about red hot though.

03-30-2003, 01:00 PM	#8
ChevLoRay Old Skool Club Join Date: Jun 2001 Location: Benton, AR "The Heart of Arkansas" Posts: 10,880	Timing, Lean mixture, Catalytic converter... All are possibilities, although we know that only those vehicles built since the mid-70's were equipped with the converters. I have seen GM converters that were filled with the palladium-coated pellets, that blinded-off when the pellets turned to dust. When they did that, not only was a red-hot converter in the making, but the performance went down the big tube....like no power. Still ran, but what good did it do? The later model converters that use a porous, honeycomb construction are much less prone to blockage than the early types. At ALCOA, we prototyped the honeycomb-construction that is more prevalent. __________________ Member Nr. 2770 '96 GMC Sportside; 4.3/SLT - Daily driven....constantly needs washed. '69 C-10 SWB; 350/TH400 - in limbo The older I get, the better I was.

03-30-2003, 01:06 PM	#9
knucklebuster Failure is NOT an option! Join Date: Feb 2003 Location: greenwood s.c. Posts: 811	I had a friend who called me over to his house once to look at his truck.His timing was off so bad his passenger side manifold was glowing orange!!So i would have to say timing.Does it start up fine? __________________ House payment or truck parts?????.........why does life have to be so complicated? 1969 Chevy Shortbed Fleetside 1969 Camaro ps pb a/c(drove in high school now it's just a yard ornament,but it's next on the list for resto) 1990 Ni$$an hardbody( daily beater that has been really beaten!) 1999 Grand Am GT(wifes ride...never buy a pontiac!!Trust Me)

03-30-2003, 06:41 PM	#10
Dean23 68cst_ss490 Join Date: May 2001 Location: edmonton,canada Posts: 1,363	timing is the cause. At school we ran a 2.5l gm tech for on base timing only up to 3000 and in about 3 min the manifold was glowing red __________________ Dean edmonton,canada a winter wonderland 2005 Chevrolet Avalanche LT cold air intake, performance exhaust, Comp cams cam, jba shorty ceramic headers. http://www.cardomain.com/ride/3090973

03-30-2003, 06:56 PM	#11
mikep Used to have a truck Join Date: May 2002 Location: port orchard WA Posts: 1,552	Retarded timing. When you fire the spark late the A/F mixture is still burning when it exits the cylinder. Thats why your pipes are glowing red. seen it before . Time the engine and I bet it will go away. __________________ No truck :-(



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