Pinging 440 under heavy load !!!!

[jg68]

I"ve been fighting this problem for awhile, just wanting some ideas of what it could be, it seems if i run a stock type spark plug it gets really bad, a colder plug helps but tends to foul out, i also have to jet up alot to help the issue too, could it be the octane or cheap gas, the total timing is at 35-36* all in at 3000, my plugs always run dark, if i jet down to clean them up, it pings bad, its a basic .030 440 with 9.1 compression, large summit cam with 150 lbs. cranking pressure, all thats avalible in this area is 91, it doesn't seem to ping with 5670-6 NGKs, but with the RX5 extended nose (factory replacements) it does.

It seems like this problem gets worse during the summer months, so i don't know if its just the heat or crappy summer grade fuel, Ron has been a great help to me with all my Qs, so i figure i'll ask others too

[70charger_boy]

Are you running 87 octane?

[y3chargerrt]

Are you running with your vacuum advance hooked up? If so disconnect it, plug the carb port and test drive it like that. My 440 pings when the advance is hooked up.

[aifilaw]

I doubt you are running 9:1 compression, it is probably higher than that.
Try what y3chargerrt suggested. But I'm betting the solution to your problem will be "fixed" with either timing or better gas. But you will still suffer from the colder plug + having to clean the soot off of them every 6,000 miles unless you can get some better gas.

[firefighter3931]

Joe, have you run a cranking compression test on the motor....i don't recall if you did ? Curious as to how much cylinder pressure it's making. 


You could try dumping some race fuel in there to see if it's an octane issue or something else. 

Might have to slow the timing curve down or reduce the mechanical advance. It could be a hot fuel issue ? Are you running the 1215 intake bath tub ? Carb insulating base gaskets ?


Just some ideas to throw out there.



Ron

[jg68]

I ran a cranking test, its between 148-152 in all cylinders, i calculated the compression & its at 8.94, Ron, i am running the 1215 bathtub, carbs & intake stay cool.

pistons are FT badgers, .090 in the hole, .018 gaskets, 90cc 452s on a 4.350 bore, 3.75 stroke

All we have around here is 91 octane, it helps but its still not enough, i'll try taking more total timing out, if i disconnect the vacuum advance its a pig, plus it only pings under heavy or WOT when vacuum drops, so i'm sure the vacuum advance is no longer working at this point, i guess i'll either have to slow the total curve down or lower the timing, just hope it doesn't kill off the power

Is there an octane booster out there that works decent, or is it all junk?

It seems i have to run alot of jet to calm things down, but then the plugs burn dark

Hey Ron, should i post some pics of the bad boy or will i get shunned

[aifilaw]

hmmm
from what you said it sounds like the CR is plenty low, probably 180's without the cam bleedoff, which should be ok on 91 octane depending on your altitude. It sounds more to me like you have some serious quench issues, almost like running a domed piston in an open chambered iron head produces....
try the race fuel and see what you get, try backing the timing off a tad.
If the race fuel fixes it, I would suggest starting to go to your local airport and mixing your fuel with avgas at 25% av-gas 75% fuel... gas costs will go up, but at least you won't be destroying your engine, have all your power, et cetera.

[firefighter3931]

Joe, where is the total at ? What rpm is it coming in at ?

I'd try about 15* initial and 36* total all in at 3000 and see how it goes. @ medium springs should be about right.

Fwiw, i never use the vacuum advance.....once the curve is dialed in you won't need it. 



Ron

[aifilaw]

Fwiw, i never use the vacuum advance.....once the curve is dialed in you won't need it. 

Ron

I find it fairly necessary in std. stroke 383's with high dynamic CR

[jg68]

Ron, all the timing is in at 3000, it really likes the Vacuum advance, it doesn't seem to ping under moderate light throttle or even 1/4 throttle or so when the vacuum advance is full on, its just under hard to WOT when the mech. all comes in, i'll try lowering the total to 32-33* & see if that helps.

The timings at 15* int. & 35* total all in at 3000


Heres a pic, don't shoot me, its still a Mopar

[aifilaw]

Ron, all the timing is in at 3000, it really likes the Vacuum advance, it doesn't seem to ping under moderate light throttle or even 1/4 throttle or so when the vacuum advance is full on, its just under hard to WOT when the mech. all comes in, i'll try lowering the total to 32-33* & see if that helps.

The timings at 15* int. & 35* total all in at 3000


Heres a pic, don't shoot me, its still a Mopar

I like it, looks nice

I would try the low 30's degree's total and all in by 3k, along with the previous suggestions about fuel

[firefighter3931]

I find it fairly necessary in std. stroke 383's with high dynamic CR

That's nice to know but i don't see how it's relevant to the current discussion 

From Joes first post :

its a basic .030 440 with 9.1 compression 

Ron

[aifilaw]

I realize it was off topic... here's another one.

Don't use a cattle-prod on a bull elephant, he may kill you.

[firefighter3931]

i'll try lowering the total to 32-33* & see if that helps.

The timings at 15* int. & 35* total all in at 3000


Heres a pic, don't shoot me, its still a Mopar

Nice truck Joe....and it's got a tunnel rammed 440 ! 


I'm wondering if it's not going lean at WOT with those vac secondary holleys. 

If 30-32* doesn't fix it i would look at secondary jetting on those 600's.  An LM-1 or chassis dyno would sure come in handy....then you'd have a good idea of what's going on.



Ron

[jg68]

Thanks Ron, i'm sure its the octane, i jetted up the fronts from 66s to 68s & put some 31 squirters F&R, i'll try jetting up the rear alittle, i have some extra jet-plates, like i said, the plugs are showing a rich mixture, i have my TCI coming back from PTC, they set it up to flash 3200 & it has a Balloon plate for nitrous, the converter should wake it up nicely down low, so i'll jet up then

[jg68]

 

[Purple440]

Hey jg68 I had the exact same problem with my 440 with 452 heads.  I now mix about 2:1 92 to 110 octane and it's solved.  And not only is the pinging gone but there is a very noticeable power gain.   

g/l

[jg68]

Hey jg68 I had the exact same problem with my 440 with 452 heads.  I now mix about 2:1 92 to 110 octane and it's solved.  And not only is the pinging gone but there is a very noticeable power gain.   

g/l

Thanks Purple, i think i'm going to try it, Hey, what plugs are you running?

[aifilaw]

plug heat range is a factor of engine compression for the most part. You can also figure it out by reading the plugs you have in there now.

Look at the plugs threads, you'll see (hopefully if you aren't completely off) that the threads closest to the electrode will be burnt/heated. whereas lower down they look new and unmolested. you should have about 2-3 threads that are "heated". If you have more threads than that, get a colder plug. If you have less, get a hotter plug.

[Todd Wilson]

I noticed a ping problem with my 440 in my truck in the summer. I also discovered after talking to some fuel company guys in town that some of the 91 gas being sold has ethanol in it and my old truck didnt like the ethanol at all. Especially in the heat of summer. Might Do some more checking on your 91 fuel.


Todd

[jg68]

I noticed a ping problem with my 440 in my truck in the summer. I also discovered after talking to some fuel company guys in town that some of the 91 gas being sold has ethanol in it and my old truck didnt like the ethanol at all. Especially in the heat of summer. Might Do some more checking on your 91 fuel.


Todd

Now that you meantioned this, i'l bet thats the problem, they've been useing ethanol in the gas around here

[firefighter3931]

I noticed a ping problem with my 440 in my truck in the summer. I also discovered after talking to some fuel company guys in town that some of the 91 gas being sold has ethanol in it and my old truck didnt like the ethanol at all. Especially in the heat of summer. Might Do some more checking on your 91 fuel.


Todd

Now that you meantioned this, i'l bet thats the problem, they've been useing ethanol in the gas around here

Ethanol is evil ! 

Joe, the pics look great ! 

Try spiking it with some race gas and see how it responds. 



Ron

[jg68]

Ron, if you look closely at the engine pic, check out the kick down hooked up, thats an $8.00 home made throttle bracket, works great too

[firefighter3931]

Ron, if you look closely at the engine pic, check out the kick down hooked up, thats an $8.00 home made throttle bracket, works great too

I noticed that when you first posted the pics. 

Is that fancy billet aluminum stock ? 



Ron

[Todd Wilson]

Lets see some more pics of the truck! It looks bad ass!   There was a black Dodge truck in Ardmore Oklahoma like yours that was tubbed out back. He had trouble getting power to the ground with that truck. Chryco remembers the truck! Maybe he will chime in!


Todd