Fingers crossed this isnt BAD

[ottawamerc]

Hi guys
Last night I was at my local cruise night, great time. Met a guy there with an amazing barn find never been touched 68 383 Road Runner 48K miles on the clock. but after when I was leaving I noticed an unfamiliar sound. What got me was it sounded like a bad bearing noise nothing at idle but only heard under mild acceleration and it wasn't there on the drive to town?  After a few miles it seemed to be gone. When I got home and pulled into the garage I popped the hood to try to locate any new sounds and I left the garage lights off to check for spark leaks etc. what I did find is that #5 header tube was glowing red and all others were not Any ideas what could cause this, air leak, carbs??? I'm going to pull the plugs this morning and do a compression test too. My A/F meter showed no change from normal 12.4-14.1 and the O2 sensor is on that bank too. I hope my season isn't over already. Also of note the engine temp remained normal and power seemed to be strong.

Any ideas would be greatly appreciated. I'll update my findings this morning.

Scott

[BSB67]

First thing - check torque converter bolts.

[BSB67]

And, what intake manifold do you have.

I would not connect the noise to the red header, at least not yet.  I would consider slightly glowing header in the dark okay/normal.  Get a temperature gun and check temps.

[ottawamerc]

Torque bolts hmm good one. Ok so here's my findings plugs looked leaner than I would like to see, Timing was at 10* I advanced it to 11* floats in all 3 carbs were slightly low, I adjusted the outboards to 1/2 way up sight glass and center to level. Tested the header tubes with heat gun:

#1 457          #2 361
#3 577          #4 641
#5 695          #6 524
#7 530         #8 298

They seem to be all over the map with the offender being the hottest. The engine was at 186*, oil pressure 50 psi (normal for my engine), VAC at 16" steady and A/F 13.7 at idle.
https://youtu.be/9bF0pydctSo
plugs are in order left to right 7 5 3 #1 is a real pain to remove so thats why its deleted from the pic.

Scott

[BSB67]

Temp on #5 is not a problem IMO.  Going from memory, the #8/#5 hole in the six pac intake is a problem.  Poor distribution. I actually stagger that hole from the rest IIRC.  Notice how 5 is the hottest, and 8 is the coldest.

How does #8 plug look, it is usually a little darker than the rest.

Check to make sure you don't have a vacuum leak that is primarily effecting the 5 runner.  It is not uncommon to have two ajacent cylinders have a vacuum leak at the intake/head interface, but I would have suspected #7 being hotter too.  Still a possibility, but for now i'm guessing unlikely.

[BSB67]

Torque bolts hmm good one. Ok so here's my findings plugs looked leaner than I would like to see, Timing was at 10* I advanced it to 11* floats in all 3 carbs were slightly low, I adjusted the outboards to 1/2 way up sight glass and center to level. Tested the header tubes with heat gun:

#1 457          #2 361
#3 577          #4 641
#5 695          #6 524
#7 530         #8 298

They seem to be all over the map with the offender being the hottest. The engine was at 186*, oil pressure 50 psi (normal for my engine), VAC at 16" steady and A/F 13.7 at idle.
https://youtu.be/9bF0pydctSo
plugs are in order left to right 7 5 3 #1 is a real pain to remove so thats why its deleted from the pic.

Scott

So, what is the latest?

[ottawamerc]

Hey BSB Ya I do have some, sorry for any late reply's as I was away. I did the fuel levels and timing then the next day I took it to a fundraiser car show and it ran great again, actually better with the advanced timing. I met another 440 6 pack owner at the show and he said that his is the same and it is normal to be all over the map with the temps just as you said too.

Thanks for your help with this

Scott

[BSB67]

Noise gone?

Open the idle mixture screw on the passanger side center carb a bit, recheck #3 and #5.

[ottawamerc]

Ok wilco, I'll get back to ya on that and let ya know if it changes.

Scott