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Carb running lean? #2697876
09/15/19 08:57 PM
09/15/19 08:57 PM
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Posts: 356
Greenwood Lake, NY
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fuelishnsilly Offline OP
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Greenwood Lake, NY
I’ve been noticing that my valve covers are starting to blister on my 440. The engine temp for the coolant is a nice 170*. When I took an infrared thermometer to the exhaust manifolds it was around 400-500* on the exhaust manifolds at idle. What are normal exhaust temps for idling? Also, the engine is not misfiring or anything. Is my carb the problem?

Thanks for the help.


inherited a 69 roadrunner from my grand pop.
Re: Carb running lean? [Re: fuelishnsilly] #2697886
09/15/19 09:16 PM
09/15/19 09:16 PM
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Lincoln Nebraska
RapidRobert Offline
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I dont have an answer (others will) but on a side note I 'd want the coolant temp at least 180


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Re: Carb running lean? [Re: RapidRobert] #2698615
09/17/19 11:50 PM
09/17/19 11:50 PM
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Greenwood Lake, NY
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fuelishnsilly Offline OP
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Greenwood Lake, NY
Bump?


inherited a 69 roadrunner from my grand pop.
Re: Carb running lean? [Re: fuelishnsilly] #2698634
09/18/19 01:51 AM
09/18/19 01:51 AM
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Sobieski Wi
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bee1971 Offline
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The HP manifolds , especially the passenger side so close to the valve cover will cause the paint to burn

400-500 is fine at idle - 800-900 under normal operating


If your concerned about a lean carb condition , pull your spark plugs and look at color there

If you want to keep your factory valve covers looking pretty , try a high heat paint or install these on your exhaust manifolds
Made to protect the valve cover gaskets from heat


https://www.summitracing.com/parts/fel-ms90425/overview/make/dodge


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Re: Carb running lean? [Re: bee1971] #2699965
09/22/19 09:18 PM
09/22/19 09:18 PM
Joined: Apr 2016
Posts: 356
Greenwood Lake, NY
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fuelishnsilly Offline OP
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ok. great news. thanks and I appreciate those numbers. I had the engine running around 3000 rpm for a while and checked out the exhaust temps and it was around 700-800 degrees just stationary in my garage with no air movement other than a fan I had in front of the car.

After that I let it cool down and checked the plugs and they were still perfectly white on the porcelain. Even with letting the car rev for about 10 mins or so at that speed, the coolant temp never overheated which I'm happy to say is still the factory core in the 26" rad.

I appreciate the info on those exhaust gaskets. While it might not be pretty, it will save the paint which I think will look better than the valve cover looking like it has a major sun burn with the blistering of the paint ! lol.


inherited a 69 roadrunner from my grand pop.
Re: Carb running lean? [Re: fuelishnsilly] #2700036
09/23/19 08:10 AM
09/23/19 08:10 AM
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Oregon
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earlymopar Offline
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Short of having a n air-fuel ratio gage, a better method is driving the car and pulling a long hill at road speed. Pull off the road and shut the engine down immediately and pull a plug. "perfectly white on the porcelain" is not what you want.

- EM

Re: Carb running lean? [Re: earlymopar] #2700084
09/23/19 10:52 AM
09/23/19 10:52 AM
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Bend,OR USA
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Cab_Burge Offline
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Originally Posted by earlymopar

Short of having a n air-fuel ratio gage, a better method is driving the car and pulling a long hill at road speed. Pull off the road and shut the engine down immediately and pull a plug. "perfectly white on the porcelain" is not what you want.

- EM

I like perfectly white way better than black or oily and brown work
OP, what brand a nd heat range, part number, on the plug are your spark plugs? Can you post a picture of one of your plugs on here? If so that will help a bunch on giving you good information up
Let us know, maybe a colder plug will help on the color on your plugs


Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
Re: Carb running lean? [Re: Cab_Burge] #2700100
09/23/19 11:21 AM
09/23/19 11:21 AM
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nowhere
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Sniper Offline
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Perfectly white is lean. You want a light tan or reddish brown and you should be able to see the "fire ring" about halfway down on the center electrode .

This one is a touch lean but you can see the ring towards the top of the electrode, it's a range too hot, should be pretty close to centered up/down.

[Linked Image]

Re: Carb running lean? [Re: Sniper] #2702558
10/01/19 10:41 AM
10/01/19 10:41 AM
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Halifax, VA.
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moparjack44 Offline
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If it is a Holley, screw your adjusting screws (on front of carb), not idle speed screw, all the way in. DONOT over tighten. Then screw back out 1 1/2 turns. If Edelbrock, 2 turns. This will be really close to perfect, just teek as needed to get perfect. A vacumn gauge is suppose to be used for best results, but I just go by ear.
I agree, little tan is best, not white or black.
Jack


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Re: Carb running lean? [Re: Sniper] #2702622
10/01/19 01:25 PM
10/01/19 01:25 PM
Joined: Aug 2003
Posts: 43,007
Bend,OR USA
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Cab_Burge Offline
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Originally Posted by Sniper
Perfectly white is lean. You want a light tan or reddish brown and you should be able to see the "fire ring" about halfway down on the center electrode .

This one is a touch lean but you can see the ring towards the top of the electrode, it's a range too hot, should be pretty close to centered up/down.

[Linked Image]

I strive to get that exact look on all my engines up Lean is mean grin scope
I would like to see the other side of the ground strap as well as look down in the plug to see more of the insulator and what it looks like also before saying that it is perfect on all aspects of the tune up twocents
Timing, jetting and spark plug heat range all need to be correct to get the motor to make the most power and economy at idle, light throttle cruise and at WOT.
The old saying about the light tan look on spark plugs was made back when we had lead additives in all gasoline work
Not so now whiney


Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)






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