diagnosing running rich

[c00nhunterjoe]

Odds are you have low compression pistons in your rebuilt 383. The hotter stock plug is fine and would not cause an instant problem after driving anyway

 That is my assumption that the pistons are a low compression. I guess I will just go get the NGK plug that is cross referenced to the RJ12YC Champion to make the Pertronix happy, And just watch how they are running. I am going to pull the Champions today and see what they look like.

Did you ever pull the Champions to see what they looked like ?

Black / Rich ?

Gas Fouled ?

With a flat top piston sitting about 20 under 0 deck, .041 gaskets, racer brown ssh 42 cam (think mopar 509) and 516 heads the stock autolite plugs in mine were always good. I would pull 1 or 2 each spring and put them back in.
http://www.dodgecharger.com/forum/index.php/topic,124876.0.html

[nvrbdn]

Here is what the Champions look like. They are clean on one side and have discoloration on the other. These are the plugs from 4 and 8.

[nvrbdn]

The brand of plug will not make or break the ignition system and in your case, 1 heat range will not either. Something else sparked your instant poor running problem.
[/quote

            Yep, I agree. The NGK plugs were in the car when it was running rich. I think the carburetor has been the issue all along. then when I rebuilt the carb and wanted to change the plugs, I am not sure that I fixed the problem and the car is still running rich which I wanted to blame on the Champion plugs. As I looked at my 650 DP just now while pulling it off, the throat is as black as can be. So is the intake. It is very possible that I have a float out of measurement.

[bee1971]

The plugs look wet and gas washed


Float issue s or needle and seat s

[nvrbdn]

Yep, I am retiring from rebuilding carbs. It is off the car and a brand new one will take its place. and next Thursday this car will be at the drive-in.

[bee1971]

Replace all the plugs before installing the new carb

What did you purchase

[c00nhunterjoe]

Those plugs do not look fuel fouled.

[c00nhunterjoe]

Did you verify if fuel was running out of the boosters ?

[nvrbdn]

Did you verify if fuel was running out of the boosters ?

no, I just seen how black the inside of the carb was and decided I really did not get this carb rebuilt to where it corrected the problem. After it was off I did throttle it and had gas coming out, but not out of the boosters. It seemed that the primary flow was poor. I will take it to a rebuilder I know and let him do it properly.

[c00nhunterjoe]

Carbon or soot buildup is not from fueling in the carb. It is either backfires up through the intake or oil being drawn through. What air cleaner do you run? Stock style with hose from valve cover? Pcv?

[nvrbdn]

Air cleaner is a small chrome disc as seen in the pic. PVC valve is hooked to the vacuum port on the rear base of the carb. Is this too much draw from there?

[c00nhunterjoe]

If those valve covers have baffles in them, you should be fine. If there is no baffles and you can see the rockers, you are probably sucking oil through the pcv

[bee1971]

Those plugs do not look fuel fouled.

I see zero carbon on the first few threads , nothing

Threads look almost wet to me like gas and shiny clean

Electrodes are shiny clean , no carbon

Have him pull the dipstick to see if there is gas in the oil

High = Gas in oil

Low = PCV or Valley Pan Gasket

You mentioned PCV

Also intake valley pan sucking oil possible

[nvrbdn]

Those plugs do not look fuel fouled.

I see zero carbon on the first few threads , nothing

Threads look almost wet to me like gas and shiny clean

Electrodes are shiny clean , no carbon

Have him pull the dipstick to see if there is gas in the oil

High = Gas in oil

Low = PCV or Valley Pan Gasket

You mentioned PCV

Also intake valley pan sucking oil possible

He was relating to the carb throat being black. I was thinking it was black due to too much fuel or something. He was stating that it would be from backfires or oil. I have never heard the engine backfire, and the pcv valve hose was connected to the rear base port on the carburetor. The pcv valve is a pollution device that I am not sure needs to be hooked up and think I am going to just let it vent and not be connected to vacuum. The oil on the dip still looks clean. I will probably just change it anyway. It has around 100 miles on it. The pic will show the dip stick pulled just now. No gas smell. I even had my wife smell my finger. Ha Ha. Just oil smell.

[nvrbdn]

Did you verify if fuel was running out of the boosters ?

The arrows show where the fuel shoots from when throttling.

[BLK 68 R/T]

That's the accelerator pump discharge not the boosters.

[nvrbdn]

That's the accelerator pump discharge not the boosters.

Right, He was asking if fuel was running out of the boosters. It was not as far as I could tell.

[cdr]

Did you verify if fuel was running out of the boosters ?

The arrows show where the fuel shoots from when throttling.

That squirt-er is installed 180 off, the notches that you can see go the other way to keep it centered

[nvrbdn]

Ah, thanks.

[69wannabe]

The 650 should work good on that engine, I built my buddy a 383 with 30 keith black pistons 9.0 to 1 with open chamber heads, mopar dual plane intake and moper distributor set at 18 initial with 18 mechanical with a total timing of 36 degrees and he is running a 625 street demon carb that actually runs the engine really great. The only difference is the choice of the cam, I put the XE274 comp cam in this engine vs the mopar 284/484 which is a good 10 degrees bigger in duration @ 50 which makes it a good bit bigger so driveability may suffer and engine vacuum will suffer also. getting your timing dialed in should help like Ron say's and should be the first thing you do and once the timing is set then work with the carb and get it dialed in. Once you get the timing set up the carb will come around alot better. Depending on the actual compression I have seen some run a XR4 NGK spark plug since the 4 is a little hotter than the 5.

[nvrbdn]

Well, I may have to take this thing to a real mechanic instead of me trying to figure it out. It may be that the cam is just all wrong for me, or something else. I ran compression and am at 110. I put a 600 carb on to check everything out. It fired right up and had no hesitation on throttle. but when I ran timing it was running around 30+ degrees. (being the tab goes to 20 so I estimated the extra space. This is a pertronix flame thrower dist. with a matched flame thrower coil. Mechanical advance, so no vacuum running to it to pull while doing timing. When I tried to retard the timing it gassed me out of the garage. I played with it a bit, but had no luck keeping it running half decent without being out around 30+ degrees advanced. So today I pulled #1 and on the compression stroke at top dead center ( I used my camera and watched the piston to assure it was there) checked the timing mark and it was right at the 0 degree mark (actually a few degrees retarded). Then I checked the distributor and seen where #1 should fire. It was stationed between 1 and 8 on the cap. So in my mind, TDC on compression and cap lined in the vicinity of #1 and timing mark lined up, a simple adjust while running and it is all sweet. But not here. I am lost. and with the attempts to retard the timing, the plugs do look fouled now.

[c00nhunterjoe]

110 psi will put you in the 8:1 range if not lower. It will want 25 initial timing and try 38 total to start and increase from there. Depending on your quench and fuel quality you will most likely end up with 42 total. Thats a low comp motor for sure that will be difficult to perfect but will run ok once sorted out.

[nvrbdn]

Thank you. I appreciate you hanging with me on this one. I am heading back out to put it all back together and will get the Holley rebuilt and await its return. So I am headed back out to fine tune the timing.

[nvrbdn]

Well. Here is how things went today. I put on an Eddy 600 cfm carb while the 650 goes off to rebuild. I gapped the plugs to 40. I put the timing at around 30-32. ( where it is most happy)  The engine fires right up, and at throttle it has no hesitation. It has a bit of a rough idle (as expected) but drives out really nice. When cruising in second and punching the pedal it will plant you in the seat. Lots of power and aggressive. I am assuming that when I get the 650 DP back on there the top performance will improve, but have to say that this car hasn't ran this good in a long time. Thanks for all the input. If I knew what I know now about the cam I bought for 100.00 at a swap meet back in the day, I would have bypassed it. But I do love the sound of that thing.

[c00nhunterjoe]

How did you set the timing at 30-32?