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Spark Plugs - Does this look like Lean or Too Much Timing?

Started by cudaragtop, December 29, 2019, 04:13:07 PM

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cudaragtop

Had a couple people comment this looks lean and too much timing...
I don't know. Looks okay to me. I aint no mechanic though.

If anything my AFR gauge shows a little more towards the rich side than lean.
No pinging that I can tell. Does diesel once in a while when I turn it off.

418 Stroked 340, 650 QFT Double Pumper, LD340 Intake, Eddy Heads, Full roller, Solid Lifters, 10.5:1
Don't remember where the timing was when I set it. Blocked off the Vacuum advance.

What do you guys think?
Should I back the timing off a couple few degrees?



- Randy D. 1970 'Cuda 340 4-Speed Convertible
69 Barracuda G3 Hemi/8HP70 Resto-Mod Project Album: https://goo.gl/photos/XjsAsx4LDo7psimU8

Katfish


cudaragtop


- Randy D. 1970 'Cuda 340 4-Speed Convertible
69 Barracuda G3 Hemi/8HP70 Resto-Mod Project Album: https://goo.gl/photos/XjsAsx4LDo7psimU8


MoparLeo

moparleo@hotmail.com  For professionally rebuilt door hinges...

chargerdon

Quote from: MoparLeo on December 29, 2019, 07:04:46 PM
Hook the vacuum advance back up. Disconnected is only for foot to the floor driving . Why are you looking at the plugs ?? Any perceived problem ? How many miles ? What type of driving ? To get a true read on the plugs you have to start at with new plugs, do a full throttle run, shutoff engine and then look at them. Look at attached youtube video
https://www.youtube.com/watch?v=rxuXl_ax7BI

I agree with using the vacuum advance.   I read in hot rod magazine (https://www.hotrodders.com/forum/distributor-tuning-theory-part-1-a-59033.html), that "hot high duration camshafts" need a lot of static timing to idle correctly.   Edlebrock says the same thing !!    They recommend running at 30 btdc...   BUT right you cant run that and still not have kick-back during starting.   

So, my two cents worth !! 

So...set the timing in the 15-20 btdc range, and then use the vacuum advance into the FULL port on the carb to add another 10-15 to get to the 30 !.   Most Mopar brand distributors, have an allen wrench fitting that allows you to increase or decrease the amount of vacuum advance.   Set the combo of static and vacuum to be at the 30 btdc while idling.   But when starting there is no vacuum so back to 15-20 to prevent kick-back.    Now you MUST modify the distributor so that mechanical does not add more than another 18 to 20 degrees so that you get to around 38-39 total more than that under load is suicide on most mopars.  Now that does not include the vacuum at heavy throttle because under heavy load vacuum decreases...but under light load say at 2500 rpm, you could be running as much as 50 btdc...i.e.  15-20 static, 10-15 vacuum, plus another 10-20 mechanical.   yes, you better be running 91-93 octane to get away with it without pinging.   


JS29


Brads70



cudaragtop

Let's try this

- Randy D. 1970 'Cuda 340 4-Speed Convertible
69 Barracuda G3 Hemi/8HP70 Resto-Mod Project Album: https://goo.gl/photos/XjsAsx4LDo7psimU8

JS29


73_Cuda_4_Me

What plugs are you running?

Looks lean to me, or plugs too hot...

:alan2cents:
73 340 `Cuda 727 Auto on Column

BS23H3B

Brads70

I'm no expert but you say your A/F gauge is saying all is good them maybe you would want to try dropping down  in heat range?  Plugs don't look bad to me though?  :notsure:


Shane Kelley

Those look good to me from what I see. But you really need a hand held microscope to know for sure. Looking at plugs with the naked eye will tell you if it's way to rich or way to lean. You need the microscope to look for tiny metal deposits caused from silent detonation that you can't see otherwise. But from what I see your really close on jetting.


fronteyejack

Quote from: cudaragtop on December 29, 2019, 04:13:07 PM
Had a couple people comment this looks lean and too much timing...
I don't know. Looks okay to me. I aint no mechanic though.

If anything my AFR gauge shows a little more towards the rich side than lean.
No pinging that I can tell. Does diesel once in a while when I turn it off.

418 Stroked 340, 650 QFT Double Pumper, LD340 Intake, Eddy Heads, Full roller, Solid Lifters, 10.5:1
Don't remember where the timing was when I set it. Blocked off the Vacuum advance.

What do you guys think?
Should I back the timing off a couple few degrees?



Does diesel once in a while when I turn it off.

Means front blade just little bit to much open,back of little bit,and open rear blades just a little to correct RPM.

cudaragtop

Idle is about 800-900, it's a 4-speed
Plugs are Champ RC12YJC


Quote from: fronteyejack on December 31, 2019, 06:51:54 AM
Does diesel once in a while when I turn it off.
Means front blade just little bit to much open,back of little bit,and open rear blades just a little to correct RPM.
Is that an adjustment on the Carb butterflys?

- Randy D. 1970 'Cuda 340 4-Speed Convertible
69 Barracuda G3 Hemi/8HP70 Resto-Mod Project Album: https://goo.gl/photos/XjsAsx4LDo7psimU8