Ford 460 Pinging Under Moderate Load

Status
Not open for further replies.
P

panthermike

Joined
Apr 1, 2008
Messages
4,183
Location
Arizona
I've probably mentioned this on the boards before, but now I finally want to do something about it.

The 460 motor in Ol' Yellar pings under load. More specifically, under hard acceleration and going up steep grades.

The motor is actually a built 429, bored out to 460. I recently changed the carburetor to a 750 Edelbrock unit, and that seemed to reduce the pinging by itself. I've ran multiple fuel cleaners, and tuned the truck up recently. Also, it was built to run on premium, so all it sees is 91 octane.

I'm wondering what steps I can take to try and track down the source! Drives me crazy, plus I know it's not good for the motor.
 
Advance the timing and make sure your cooling system is healthy. Had this problem several years ago with an old Mustang. If still an issue you may need to check your air/fuel ratio, too lean on good ole Arizona will make it ping... I would pull the plugs also and check their condition but my guess is your running to lean and a simple advance of timing might solve your issue.
 
Originally Posted By: panthermike

The motor is actually a built 429, bored out to 460.


A 429 can't be bored out to 460, increase in displacement is accomplished by installing the 460 crank & pistons... IF has the 429 crank & overbored the max .030 recommended, you have a 435...

Why does it ping??? Too high of compression ratio for fuel used, too much timing, carbon in cylinders that's creating hot spots and/or increasing compression...

Originally Posted By: zloveraz
Advance the timing and make sure your cooling system is healthy. Had this problem several years ago with an old Mustang. If still an issue you may need to check your air/fuel ratio, too lean on good ole Arizona will make it ping... I would pull the plugs also and check their condition but my guess is your running to lean and a simple advance of timing might solve your issue.


Advance timing to reduce spark knock??? In 46 years of vehicle ownership that's a new one on me...
 
Originally Posted By: TFB1

Originally Posted By: zloveraz
Advance the timing and make sure your cooling system is healthy. Had this problem several years ago with an old Mustang. If still an issue you may need to check your air/fuel ratio, too lean on good ole Arizona will make it ping... I would pull the plugs also and check their condition but my guess is your running to lean and a simple advance of timing might solve your issue.


Advance timing to reduce spark knock??? In 46 years of vehicle ownership that's a new one on me...

I have to disagree as well; this is clearly a case of a bad muffler bearing. The bad bearing tends to resonate at some specific frequency that is dependent on the exhaust system design. This harmonic does tend to sound exactly like pinging.
 
Originally Posted By: Colt45ws

I have to disagree as well; this is clearly a case of a bad muffler bearing. The bad bearing tends to resonate at some specific frequency that is dependent on the exhaust system design. This harmonic does tend to sound exactly like pinging.


Yeah I forgot about that problem, thanks for setting me straight...

Can be hard to find quality muffler bearings, these guys have some of the best...

http://kalecoauto.com/index.php?main_page=product_info&cPath=12&products_id=48
 
We've had plenty of 429s, beginning in '68.

TFB1 is right. The 460 is just a longer stroke 429. The latter holds together a little better at sustained redline.

I've seen a few exhaust issues cause ping-like noises. But most of the time it is genuine, caused by a combination of substandard fuel and/or aggressive timing. The early one was a 10.5 or 11 to 1 compression ratio. It was designed for much better than 91 octane. The hot, dry climate is not helping any. Dumping more fuel in won't fix it.

The quick and easy way is to retard the timing one or two degrees. And check that any advance springs are not tired.

A better fix is the installation of a water injection system, which is what we used to do with them for street once gas got bad.

Unless you change out the manifold, the stock 4V carb is not usually bettered by an aftermarket one.

It's been at least 20 years since I've been around these, so my memory is not as sharp as before, or I'd remember more. Although, I still have a small scar on my right hand from a 429 exhaust manifold.
 
The quick fix is to back off your initial timing closer to 0*BTDC and then get you some stiffer advance springs. You can also get an adjustable vacuum advance, but the stiffer advance springs are a sure bet. I used to own a '70 Cougar with the 351C-4V. I know what it's like to own a high compression engine and having to do what's necessary to prevent pre-detonation from occurring. It's better to give up a little performance than to let pre-detonation destroy the engine.
 
Originally Posted By: panthermike
I've probably mentioned this on the boards before, but now I finally want to do something about it.

The 460 motor in Ol' Yellar pings under load. More specifically, under hard acceleration and going up steep grades.

The motor is actually a built 429, bored out to 460. I recently changed the carburetor to a 750 Edelbrock unit, and that seemed to reduce the pinging by itself. I've ran multiple fuel cleaners, and tuned the truck up recently. Also, it was built to run on premium, so all it sees is 91 octane.

I'm wondering what steps I can take to try and track down the source! Drives me crazy, plus I know it's not good for the motor.



You need to reveal how many miles on the engine. Carbon build up in the heads is very common if the engine is not run HARD frequently. Easiest and first thing to check.

Second, some sort of combination of measures will be necessary
to fix this. No one thing wrong here.

Richer mix can help many older cylinder head designs to control spark knock. Do you have EGR? Timing is the last thing you want to retard, as this will markedly affect driveability.

It's tricky, that's why we call it "tuning".
 
Originally Posted By: zloveraz
Advance the timing and make sure your cooling system is healthy. Had this problem several years ago with an old Mustang. If still an issue you may need to check your air/fuel ratio, too lean on good ole Arizona will make it ping... I would pull the plugs also and check their condition but my guess is your running to lean and a simple advance of timing might solve your issue.


This is HORRIBLE advice! It will make it knock even worse, and will likely cause engine damage.

If anything, retard the timing a few degrees. Try 2 deg retard. then maybe 2 more.
Make sure your ignition advance is operating correctly. Old Ford breaker point base plates get wobbly, and also advancers stick. Get a new base plate assembly - they are not much.
Make sure your EGR system is operating perfectly. This will attenuate part throttle spark knock.
Make sure your cooling system is in great shape - any dirt on the radiator fins? Too hot thermostat? Water pump belt slipping?
Also, premium used to be 93 octane, not just 91.
Those big pistons are prone to knock - the flame front has to go a LONG way!
Good luck!
 
Originally Posted By: SteveSRT8
Originally Posted By: panthermike
I've probably mentioned this on the boards before, but now I finally want to do something about it.

The 460 motor in Ol' Yellar pings under load. More specifically, under hard acceleration and going up steep grades.

The motor is actually a built 429, bored out to 460. I recently changed the carburetor to a 750 Edelbrock unit, and that seemed to reduce the pinging by itself. I've ran multiple fuel cleaners, and tuned the truck up recently. Also, it was built to run on premium, so all it sees is 91 octane.

I'm wondering what steps I can take to try and track down the source! Drives me crazy, plus I know it's not good for the motor.



You need to reveal how many miles on the engine. Carbon build up in the heads is very common if the engine is not run HARD frequently. Easiest and first thing to check.

Second, some sort of combination of measures will be necessary
to fix this. No one thing wrong here.

Richer mix can help many older cylinder head designs to control spark knock. Do you have EGR? Timing is the last thing you want to retard, as this will markedly affect driveability.

It's tricky, that's why we call it "tuning".


Well put!

- Have you read the plugs?
- Do you have access to a wide-band?
- What is your base and total timing set at?

Basic information that is needed here before any real advice can be given.
 
Seems like the 460s of the 70s always pinged. My dad had 2. Actually, pushrod Fords in general often ping. My 3.9L Freestar pinged. According to the Owner's Manual, it was "normal" (they actually a blurb in there!).
 
my Dad had a 460 in an F-250, pinged too under load IIRC. a friend of mine who worked on them in campers said that they ran too lean, so much so that the exhaust manifolds would glow red under load.
 
Use 93 octane. 91 is likely not enough.

As others have said:

Compression ratio? Mileage? EGR? Timing? All these things will play a major role in pre-detonation.

Is there any tuners nearby? It'd be best to see what your A/F ratio is under these conditions simulated on a dyno.
 
Originally Posted By: mechtech2

If anything, retard the timing a few degrees. Try 2 deg retard. then maybe 2 more.
Make sure your ignition advance is operating correctly. Old Ford breaker point base plates get wobbly, and also advancers stick. Get a new base plate assembly - they are not much.
Make sure your EGR system is operating perfectly. This will attenuate part throttle spark knock.
Make sure your cooling system is in great shape - any dirt on the radiator fins? Too hot thermostat? Water pump belt slipping?
Also, premium used to be 93 octane, not just 91.
Those big pistons are prone to knock - the flame front has to go a LONG way!
Good luck!


For the most part, all good advice here.

The Autolite distributors were pretty reliable, but when worn would shoot the advance all over the place. The advance springs in particular would weaken after about 50-60k.

FWIW, the early FoMoCo 385 family did not have EGR and the recommended octane was over 100 (research octane). If this is one of the early ones, there's not a lot you can do with modern fuels short of timing retard and/or more aggressive solutions. A couple of octane points isn't likely going to make too much difference. We were actually able to get a couple to run satisfactorily on 87 octane in the '80s with a mix of retard and water injection. Obviously, today's E10 mix now complicates it even further.

Of course, retard too much and the operating temps rise. It's a fine line when dealing with the wrong gas. And running them on unleaded . . .

The irony is that the later ones, even detuned, were even more prone to detonation because of all the emissions garbage on them.

These engines only carbon up in a serious way if they've been running too rich to begin with, which is why just dumping more fuel in (or running a cooler plug) to reduce detonation is a fool's solution. Running a little rich was much easier on the leaded fuels.

Best story about a 429: A guy bought a brand new '69 T-Bird, wasn't satisfied with the idle, and wanted a new engine. Ford refused. A week later it threw a rod, and he got a new engine under warranty. One of the dealer mechanics later confidentially asked him, "so how long did you put the brick on the accelerator?" He responded, "almost 30 minutes". One tough engine.
 
Originally Posted By: mechtech2
Originally Posted By: zloveraz
Advance the timing and make sure your cooling system is healthy. Had this problem several years ago with an old Mustang. If still an issue you may need to check your air/fuel ratio, too lean on good ole Arizona will make it ping... I would pull the plugs also and check their condition but my guess is your running to lean and a simple advance of timing might solve your issue.


This is HORRIBLE advice! It will make it knock even worse, and will likely cause engine damage.

If anything, retard the timing a few degrees. Try 2 deg retard. then maybe 2 more.
Make sure your ignition advance is operating correctly. Old Ford breaker point base plates get wobbly, and also advancers stick. Get a new base plate assembly - they are not much.
Make sure your EGR system is operating perfectly. This will attenuate part throttle spark knock.
Make sure your cooling system is in great shape - any dirt on the radiator fins? Too hot thermostat? Water pump belt slipping?
Also, premium used to be 93 octane, not just 91.
Those big pistons are prone to knock - the flame front has to go a LONG way!
Good luck!


I corrected to retard the timing already sheesh...
 
Status
Not open for further replies.

Similar threads

B
  • Locked
2008 accord 2.4 Slight pinging under light to moderate throttle
Replies
12
Views
2K
BAJA_05
AEHaas
Start up wear, Normal wear, and the relation to various oil properties. SAE 2006-01-3414
4 5 6
Replies
118
Views
13K
Greasymechtech
A
Coyote vct system vs oil grades
2
Replies
36
Views
13K
Stumpy
R
  • Locked
2009 Lexus RX 350 3.5L 2GR FE piston slap/VVTI ticking
2 3 4
Replies
70
Views
26K
Astro14
C
Oil Recommendation for AC Shelby Cobra Roadster replica
2
Replies
37
Views
5K
MacManus99
Back
Top