Typical header tube temperature at idle?
#3071626
08/26/22 01:59 PM
08/26/22 01:59 PM
|
Joined: Jan 2003
Posts: 7,490 Minnesota
Hemi_Joel
OP
master
|
OP
master
Joined: Jan 2003
Posts: 7,490
Minnesota
|
What is a typical temperature for header tubes at idle? On my hot rod Coupe, it is 140 on the left bank and 450 on the right bank. Obviously one of them isn't right, and I'm thinking it is the left bank. Maybe my idle circuits are plugged so I'm not getting much combustion at idle? Either that or the right side idle circuit is plugged so that side's running really lean and thus hot?
[img]http://i.imgur.com/boeexFms.jpg[/img]31 Plymouth Coupe, 392 Hemi, T56 magnum RS23J71 RS27J77 RP23J71 RO23J71 WM21J8A I don't regret the things I've done. I only regret the things I didn't do. "Wise men talk because they have something to say; fools because they have to say something. ~ Plato"
|
|
|
Re: Typical header tube temperature at idle?
[Re: Hemi_Joel]
#3071629
08/26/22 02:07 PM
08/26/22 02:07 PM
|
Joined: Aug 2003
Posts: 43,204 Bend,OR USA
Cab_Burge
I Win
|
I Win
Joined: Aug 2003
Posts: 43,204
Bend,OR USA
|
It depends on which fuel and idle RPM. I would try swapping the carbs from side to side and see if its them or maybe a vacuum leak on the intake I can't remember now if you have Stromberg Carlsons, Holley carbs or the other brand that I can't think of right now Either way they are fixable, it is a matter of figuring out which part needs fixing, idle circuit, transition circuit, float level or???? Good luck, let us know what you find wrench: up
Last edited by Cab_Burge; 08/26/22 02:07 PM.
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
|
|
|
Re: Typical header tube temperature at idle?
[Re: RATTRAP]
#3071652
08/26/22 03:50 PM
08/26/22 03:50 PM
|
Joined: Jan 2003
Posts: 8,165 Plymouth, MI
Blusmbl
master
|
master
Joined: Jan 2003
Posts: 8,165
Plymouth, MI
|
I see 450-500*F at idle typically on every tube, I check it about an inch from the flange with an IR gun. Do you have thermocouples, or was that an IR reading?
If that 150*F is real, those cylinders aren't contributing anything.
'18 Ford Raptor, random motorcycles, 1968 Plymouth Fury III - 11.37 @ 118
|
|
|
Re: Typical header tube temperature at idle?
[Re: Hemi_Joel]
#3071653
08/26/22 03:51 PM
08/26/22 03:51 PM
|
Joined: Feb 2008
Posts: 714 Central TEXAS!!!!
sr4440
super stock
|
super stock
Joined: Feb 2008
Posts: 714
Central TEXAS!!!!
|
If I had a cylinder that was at 140 degrees idling, I would suspect that it's not firing.
Joe
Without Data, you’re just another guy with an opinion.
|
|
|
Re: Typical header tube temperature at idle?
[Re: sr4440]
#3071656
08/26/22 04:15 PM
08/26/22 04:15 PM
|
Joined: Jan 2003
Posts: 8,027 Tulsa OK
Bad340fish
master
|
master
Joined: Jan 2003
Posts: 8,027
Tulsa OK
|
Intake manifolds are a mess at idle with large cams and overlap. I'd rev it up to 2500 or so and see how they look.
68 Barracuda Formula S 340
|
|
|
Re: Typical header tube temperature at idle?
[Re: Bad340fish]
#3071658
08/26/22 04:18 PM
08/26/22 04:18 PM
|
Joined: Jan 2003
Posts: 7,490 Minnesota
Hemi_Joel
OP
master
|
OP
master
Joined: Jan 2003
Posts: 7,490
Minnesota
|
It is gasoline, 1500 idle, big cam. 8 carbs on a crossram, each side has its own plenum with 4 carbs, 2 of which have idle circuits. I'll rev it up enuff to get it off the idles circuits and recheck.
HF IR temp gun.
[img]http://i.imgur.com/boeexFms.jpg[/img]31 Plymouth Coupe, 392 Hemi, T56 magnum RS23J71 RS27J77 RP23J71 RO23J71 WM21J8A I don't regret the things I've done. I only regret the things I didn't do. "Wise men talk because they have something to say; fools because they have to say something. ~ Plato"
|
|
|
Re: Typical header tube temperature at idle?
[Re: Hemi_Joel]
#3071669
08/26/22 05:15 PM
08/26/22 05:15 PM
|
Joined: Nov 2015
Posts: 877 Missouri
jwb123
super stock
|
super stock
Joined: Nov 2015
Posts: 877
Missouri
|
Yep with a heat gun on the outside of the tube at idle I see 400 to 600 degrees depending on the engine. If you have a cylinder a couple hundred degrees less, there is a problem. First thing I would do is run a compression test to verify base engine condition. And read the plug while it is out.
Last edited by jwb123; 08/26/22 05:16 PM.
|
|
|
|
|