Pinging at half throttle and on !

[Bb70charger500]

Guys I am driving the 72 440 4 speed charger I normally don't get on it but I decided to last night . Anyway light throttle it's fine heavy throttle it is pinging like hell! Then to add to its issues it diesel s when you cut the key off it won't quit till you let off the clutch in gear !
So I'm assuming timing is off but wanted to check before I start playing with it . I didn't build this motor don't know much about it except it is very low miles !
Am I on the right path what should the advance be on the 440 motor?

 

[Sweet5ltr]

Basics, you're running 93 - octane correct? Sounds like a possible timing issue, light throttle, low-rpm, you're not experiencing anywhere near total timing yet or any reasonable amount of load. Iron heads, anywhere between 36-38* total. Aluminum, 32-34*. I use an MSD 6AL 2 to control my timing curve and lock my distributor, sorry, I can't really help with a factory electronic distributor in terms of tuning/spring setup.

Could be as simple as carbon build-up on the valves. Maybe try some sea foam if the timing looks correct.

 

[Yatzee]

Guys I am driving the 72 440 4 speed charger I normally don't get on it but I decided to last night . Anyway light throttle it's fine heavy throttle it is pinging like hell! Then to add to its issues it diesel s when you cut the key off it won't quit till you let off the clutch in gear !
So I'm assuming timing is off but wanted to check before I start playing with it . I didn't build this motor don't know much about it except it is very low miles !
Am I on the right path what should the advance be on the 440 motor?

First you need to decide what octane of fuel you're going to use and stick to. Anything above what you decide in octane will be OK, anything below not. Warm the engine thoroughly and take it out armed with a Sharpy and a 1/2 inch wrench (or socket wrench). Mark the base of the distributor at the manifold and the top of the intake manifold for reference when rotating the distributor so you know where you were before you started adjusting. Now drive until you hear pinging. Stop the car, loosen the distributor bolt and nudge it very slightly clockwise by the vacuum advance pot. Tighten down the unit and drive again. You will have to repeat this until no ping is present. If the engine runs sluggish or starts harder afterwards, you will have to do this all over again with a higher octane fuel. Use your reference marks to reset the distributor position. In some cases the perfect timing is found by advancing or retarding timing but pinging will always indicate the upper timing limit for any particular octane of fuel. In rare cases the vacuum advance can be adjusted to limit it's effect on advance but that's a whole new and involved process. Try this first.

 

[Ranger16]

I had a similar dieseling problem (not much pinging under load in my case). I'm pretty sure mine was carbon build up. I simply used the water induction method to clean it up. If you suspect carbon, get a glass of water and with the engine at operating temperature, put a vacuum hose into the glass, run the RPM up to about 2500 and plug the vacuum line into one of the carb vacuum ports. Once the water has been sucked down, your dieseling problem will be solved, assuming of coarse that carbon was the problem. Solve my problem after just one application.

 

[Bb70charger500]

Hmm OK I'll see I know the old owner kept adding octane buster .now that you mention it I think my wife filled up a can of reg 87 I will dump a can of octane booster the motor shouldn't need high high octane it's not a super race motor

 

[dieseldazzle]

What's your total timing at??

 

[Bb70charger500]

Not sure going out in a bit to check was to dark last night

 

[AR67GTX]

Do you know anything about the motor - compression ratio, cam, heads, etc? Is it all stock and original?

 

[727]

Not all gas stations are created equal. I do get bad gas from time to time and experience similar issues. Burn that tank down and start with the best gas you can find from a busy gas station.

 

[Bb70charger500]

I know nothing about the motor besides its newer and it has a 68 crank in it 68 block over bore not sure how much .

 

[Sweet5ltr]

I know nothing about the motor besides its newer and it has a 68 crank in it 68 block over bore not sure how much .

If you're at 1/2 a tank or more, mix in 93 octane (89 (+/-) octane). Verify the timing. Try either the water method or seafoam to verify there isn't a significant carbon build up on the valves. Then do a compression test to get a better idea of your dynamic compression ratio. In that order.

 

[Bb70charger500]

OK timing was at 8 or so advanced my tag doesn't have lines or numbers so Im Guessing. I brought it to 0 and the dieseling stopped but the car is chocking really bad when you get on it ! So apparently it's been doing this since built it isn't bad till it gets hot .

 

[Bb70charger500]

Take that last bit back ,adjusted the carb back a bit and it ran a little better but still lagging and studdering at wide open .then after a brief romp it dieseled again

 

[Bb70charger500]

Big blocks are freaking finicky

 

[AR67GTX]

Referencing a stock engine - since we know nothing about yours - you should be able to run 12 to 14 deg initial timing and at least 34 degrees combined initial and centrifugal on 93 Octane with no issues. And it should pull strong from idle and shut off immediately with the key. A stock 9.5 - 10 compression motor with the stock magnum cam can be sensitive to pinging due to the relatively mild cam and high cylinder pressures. I know because mine is. But with 14 degrees initial and 34 total it run just fine. If it's dieseling maybe the idle is too high.

 

[Bb70charger500]

It idels at 700-750 rpm I just got some 93 and octane booster to put in it

 

[oldbee]

Gotta agree with the 'water' or 'seafoam' method. Water is cheap&plentiful(!). Get rid of any carbon first and go from there. Water equals a lot of steam & a little hydraulic pressure to loosen that crap up.

 

[Bb70charger500]

OK a bit more adjustment s and I add 93 octane plus the booster and my god I swear the thing grew a extra 100 HP I still have a little pinging but no where near as bad and no more diesel ing ! We're getting close I never felt this car move like this it used to keep up with a srt10 truck I believe it's getting close again !!!

 

[oldbee]

Pinging is never good, lock that into your brain pan! ( or dieseling either!)

 

[Moparfiend]

A vacuum leak can cause pinging as well just make sure that's not the issue or you will never be able to adjust timing and get rid of it........ just my 2-cents...