Pinging B$@&%@rd 440!

[a70duster]

Did you confirm that the timing mark's TDC correlates with the piston's TDC?

 

[mopower440]

Did you confirm that the timing mark's TDC correlates with the piston's TDC?

yessir

 

[Killer6]

I will have to check as i cant remember. I BELIEVE i am using the standard heat range plug for a 1975 new yorker with 440 as thats what the engine came out of originally.

That's an RJ14YC, ....or NGK's equivalent, waay too hot for hotrodding. 440 I put together over 25yrs ago running 10:1 with the smaller 280°/.474" Purple Shaft, 1.875" headers & 3" exhaust, cold iron intake 750VS Holley,..... happy @34° total........and that's with a MP electronic dizzy,...notorious for a fast curve....

 

[watt340]

My guess is that your timing mark on the harmonic balancer is off. With a piston stop, bring the #1 piston to Top Dead Center, then check the timing mark. I bet the elastomer has allowed the outside of the balancer to rotate.
34 degrees of total timing shouldn't allow spark knock.

 

[1968rt]

oh man that sucks. I have been getting ready to buy some 84cc aluminum heads for this thing and thats going to raise compression even more and probably make this worse! Unless being closed chamber would help for some reason or other?

Higher compression will be fine if you have quench. Are the new heads closed chambered?

 

[MrCab]

440 .030 over
TRW 2355 pistons, 2.062 compression height, around 9.5:1
MP 284/484 cam installed at 104 (4 degrees advanced)
Bone stock 452 heads..no milling or porting.
Holley street dominator
Demon sizzler built TQ
1 7/8 fenderwell headers
3000 stall convertor
This is in a dart swinger. So I cant get rid of the pinging at the very last 1/8 throttle. Its fine everywhere else. I can stab it and no pinging but when i put that last bit into it, it pings. Even with secondarys open, its fine until i try to shove the pedal through the floor and it pings..Its like the secondarys are open most of the way but that teeny last bit makes it ping, but it also has a good little bit of power in that area. So if i want to richen up that last bit of the secondaries, wouldt i want to tighten the secondary air door more so it takes more to drop it open? The carb was built to the engines specs. So i sent off for a curved distributor to Ron at Halifax and it did help because it was worse but its still there. Its at 16 initial and 34 total. I believe its all in by 3200 rpm. Im thinking it has to be a slight lean spot on that last bit of throttle blade opening since there is no pinging at any other throttle position no matter how quick you stab the throttle. Its so aggrevating, i mean, i can stab the throttle to the carpet and no pinging, but then push down hard and it opens that carb that last little bit and it does this and there seems to be a nice bit of power right there..This is running 93 octane pump gas..i would think 9.5:1 could be fine on that..

Maybe it is running out of fuel at WOT in the higher RPMs
Does it surge or buck when it starts pinging?

 

[a70duster]

My guess is that your timing mark on the harmonic balancer is off. With a piston stop, bring the #1 piston to Top Dead Center, then check the timing mark. I bet the elastomer has allowed the outside of the balancer to rotate.
34 degrees of total timing shouldn't allow spark knock.

Read post #52 - two behind your post.

 

[mygasser]

Maybe it is running out of fuel at WOT in the higher RPMs
Does it surge or buck when it starts pinging?

like freiburger's 'crop duster' did when the fuel pump pushrod was worn down?

 

[Kern Dog]

If all else fails and you want to go through it and build it with quench through whatever means.

I don't claim to know it all but I do remember what works for me.
2012, I posted on several forums about my issues with detonation with my 440/493. I was at 10.8 to 1 with flat top pistons and Edelbrock aluminum heads. Several people tried to help but I was stubborn to accept the truth.
I tried several "fixes" including slowing the rate of spark advance, reducing the advance and.....trying gasoline like this:

With 110 octane unleaded, I could run it to 34 degrees and the dude would really scram. That told me that the regular pump gas 91 octane was simply not enough for the compression that I had in the engine.
Some strongly advised against using thicker head gaskets to lower the compression based on the belief that it would carry with it the elimination of "quench" and likely make the engine knock worse.
It actually worked. I went with Cometic MLS head gaskets almost twice the thickness of the common .039 Fel Pro gaskets that lowered the CR from 10.8 to 10.17 to 1.
It was a gamble but it ran great. I ran 34 degrees total for years with that combination.
But wait, there's more.....
In 2022, the cam went flat so I decided to pull the engine and go through it. I went another .010 over to .040 and used quench dished pistons that were at zero deck on one side but dished at the other. This resulted in a 9.8 to 1 ratio. It allowed me to alter the advance curve to come in sooner, increasing throttle response at low speeds. I also have run 89 octane without detonation. I am tempted to try 87 just to see if it would run on the cheap stuff!
My point?
Your issue could be as simple as mine was. Either raise the octane of the fuel or lower the compression of the engine.

 

[Ricks70Duster340]

I don't claim to know it all but I do remember what works for me.
2012, I posted on several forums about my issues with detonation with my 440/493. I was at 10.8 to 1 with flat top pistons and Edelbrock aluminum heads. Several people tried to help but I was stubborn to accept the truth.
I tried several "fixes" including slowing the rate of spark advance, reducing the advance and.....trying gasoline like this:

View attachment 1716563386

With 110 octane unleaded, I could run it to 34 degrees and the dude would really scram. That told me that the regular pump gas 91 octane was simply not enough for the compression that I had in the engine.
Some strongly advised against using thicker head gaskets to lower the compression based on the belief that it would carry with it the elimination of "quench" and likely make the engine knock worse.
It actually worked. I went with Cometic MLS head gaskets almost twice the thickness of the common .039 Fel Pro gaskets that lowered the CR from 10.8 to 10.17 to 1.
It was a gamble but it ran great. I ran 34 degrees total for years with that combination.
But wait, there's more.....
In 2022, the cam went flat so I decided to pull the engine and go through it. I went another .010 over to .040 and used quench dished pistons that were at zero deck on one side but dished at the other. This resulted in a 9.8 to 1 ratio. It allowed me to alter the advance curve to come in sooner, increasing throttle response at low speeds. I also have run 89 octane without detonation. I am tempted to try 87 just to see if it would run on the cheap stuff!
My point?
Your issue could be as simple as mine was. Either raise the octane of the fuel or lower the compression of the engine.

Do you remember specifically what head gasket you used? Summit shows thicker Cometic MLS can be had with 0.060 to 0.094 compressed thicknesses. And what pistons you used?

 

[RustyRatRod]

I don't claim to know it all but I do remember what works for me.
2012, I posted on several forums about my issues with detonation with my 440/493. I was at 10.8 to 1 with flat top pistons and Edelbrock aluminum heads. Several people tried to help but I was stubborn to accept the truth.
I tried several "fixes" including slowing the rate of spark advance, reducing the advance and.....trying gasoline like this:

View attachment 1716563386

With 110 octane unleaded, I could run it to 34 degrees and the dude would really scram. That told me that the regular pump gas 91 octane was simply not enough for the compression that I had in the engine.
Some strongly advised against using thicker head gaskets to lower the compression based on the belief that it would carry with it the elimination of "quench" and likely make the engine knock worse.
It actually worked. I went with Cometic MLS head gaskets almost twice the thickness of the common .039 Fel Pro gaskets that lowered the CR from 10.8 to 10.17 to 1.
It was a gamble but it ran great. I ran 34 degrees total for years with that combination.
But wait, there's more.....
In 2022, the cam went flat so I decided to pull the engine and go through it. I went another .010 over to .040 and used quench dished pistons that were at zero deck on one side but dished at the other. This resulted in a 9.8 to 1 ratio. It allowed me to alter the advance curve to come in sooner, increasing throttle response at low speeds. I also have run 89 octane without detonation. I am tempted to try 87 just to see if it would run on the cheap stuff!
My point?
Your issue could be as simple as mine was. Either raise the octane of the fuel or lower the compression of the engine.

The addition of quench can really change how one runs.

 

[Kern Dog]

Do you remember specifically what head gasket you used?

I have detailed notebooks on my cars. I think the Cometics I used came directly from Cometic themselves and were .075 or .080 thick.

Summit shows thicker Cometic MLS can be had with 0.060 to 0.094 compressed thicknesses. And what pistons you used?

My old Ross Pistons:

My current Icon pistons:

The raised section sits flush to the deck, the step down has a 24 cc dish.

 

[Ricks70Duster340]

I have detailed notebooks on my cars. I think the Cometics I used came directly from Cometic themselves and were .075 or .080 thick.



My old Ross Pistons:

View attachment 1716563456

My current Icon pistons:

View attachment 1716563457

The raised section sits flush to the deck, the step down has a 24 cc dish.

Some are saying the block surface needs to be prepped, as in very smooth like after a modern decking process. Did you do anything special to prep the surfaces before using the cometic gaskets??

 

[MopaR&D]

Some are saying the block surface needs to be prepped, as in very smooth like after a modern decking process. Did you do anything special to prep the surfaces before using the cometic gaskets??

It's "recommended" but not needed. I've had Cometics on my unmachined 5.9 Mag block with Edelbrock heads for years and no issues. I asked my machinist at the time about the whole deck surface smoothness thing with Cometic gaskets and he said "don't worry about it". Coming from a guy whose bread-and-butter is 800+ HP BBC drag race engines.

 

[mbaird]

The addition of quench can really change how one runs.

Yep …. It would run better with 10.5:1 and .040 quench .
Drive a 70s motorhome or C body with a 440 and it will ping at 1/2 throttle under load on hot days .

 

[SpeedThrills]

OP MIA since April 21.

 

[Kern Dog]

Even though the guy disappeared, the question and answers to it will benefit someone that comes along.

Some are saying the block surface needs to be prepped, as in very smooth like after a modern decking process. Did you do anything special to prep the surfaces before using the cometic gaskets??

As stated, they recommend the surfaces to be finished to a specific point but no....I didn't do that and the gaskets still sealed up just fine.