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Ironbutt
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25 Posts
Discussion Starter #1
I am looking for some help for my engine pinging problem. The bike has always had some pinging but with everything I have done, it has become worse. I don't want to keep guessing at possible solutions and sinking more money into the thing without a little more knowledge and hopefully some good suggestions from you experts out there. Here is a short summary of what I have currently:
Harley Stage II 95inch
Power Commander PCIIIusb
Andrews 37G gear driven cam
Harley Davidson adjustable push rods
Harley Davidson lifters
Heads reworked by Dewey Custom
-Head port and polished, Ferrea (larger) intake valve, Manley (stock size) exhaust valve, Andrews springs, Cometic .030 head gasket.
Rinehart True Dual exhaust
Dyno Tune, HD SLC Max. HP/92.56 Max./TQ 96.83.
Baker DD6-6 speed transmission
These are other things I have tried:
TCC Biker True Dual Headers with HD Screaming Eagle slip ons.
HardKrome, T-Rex True Dual Headers
Dyno Tune, HD SLC Max. HP/91.2 Max./TQ 98.43
Rinehart 2 into 1 exhaust system Dyno Tune, HD SLC Max. HP/91.2 Max./TQ 98.43

Anyway, would appreciate any suggestions that might help the pinging.
 

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Cabo Wabo '06
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587 Posts
ping

dynageno said:
I am curious as to what your compression is?
No expert, but, ultimately it does come down to this. Just changing the thickness of a head gasket can make a big difference here if everything else is close (your dyno etc.-I'm getting the same numbers as you). I have a little ping too and it happened after I put the .030" Commetic H. gaskets on. I'm going back to thicker ones this winter. I can't get 93 octane around here, but while is San Antone this last summer using 93, my ping was all but gone. Good luck.

PS: With your roll on's, try easing into the throttle at lower RPM. You will probably find your ping is greatly reduced if not alleviated at engine speeds above 3250 RPM, even with hard roll on's.
 

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Premium Member
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1,047 Posts
When do you get pinging? If it occurs at specific loads/rpm points, you can add fuel/retard timing in those scarios.

Generally, pinging occurs because there is too much retained heat in the combustion chamber and that excessive heat ignites the residual fuel/air in the combustion chamber. (The exhaust stroke doesn't completely evacuate the combustion chamber of all gases, so some fuel/air is retained in the combustion chamber after the exhaust stroke. The excessive heat in the combustion chamber ignites these unburned combustible gases causing pinging.)

One solution is to richen the mixture since one of the functions of fuel is to cool the combustion chamber: a cooler combustion chamber will help get rid of pinging.

One virtue of the SERT is that in data mode it will record when pinging occurs allowing the user to address a/f and timing in those load/rpm cells where pinging occurs.
 

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Registered
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5,100 Posts
The PCIII has the provision to adjust timing. Tape on the throttle grip and a tach and then you now when (rpm) and at what throttle opening (% by the grip tape marked in increments) the problem occurs. Back it off. If the tune was done by linktune the mixture should be close in the problem but even adding a tad more fuel there could help. Tweak the tune to get it right.
Namooz
Same answer
Tweak the tune to get it right. The small compression decrease you will realize by a thicker gasket will be offset by a wider squish space and that most likely will excentuate the problem. Back the timing off in the problem area. Make sure there are no lean spikes at the problem area of the rpm and load / throttle opening range.
 

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Ironbutt
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25 Posts
Discussion Starter #6
Thanks for all the help. I don't know what my compression is for sure. I was told by the guy that did the heads that the compression should be around 9.5. Each time I've had the bike Dyno tuned, I've had to increase my fuel across the board to minimize the ping. Adding fuel does help but definitely does not correct the problem. I have tried retarding the spark with not much affect and I've also tried some advance, but again not much change. With throttle control and can ride without much ping but my rpm's need to remain high, 3500 plus. I'm hoping to get to where I can accelerate to pass another vehicle without having to rev so high. The engine seems to pull real strong even while pinging but I'm sure the engine isn't going to take too much of that before I lose a piston. Anyway, I'm going to try to isolate the throttle position and rpm where the pinging is at it's worst and dial it in at that specific spot. Again, thanks for the feedback.
 

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Banned
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5,114 Posts
Install the ''Accelerator Pump'' program off the Dynojet web site...this will add fuel at the point of attack when accelerating and eliminate your pinging.
 

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Cabo Wabo '06
Joined
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587 Posts
ping

nw_guy4_fun said:
The PCIII has the provision to adjust timing. Tape on the throttle grip and a tach and then you now when (rpm) and at what throttle opening (% by the grip tape marked in increments) the problem occurs. Back it off. If the tune was done by linktune the mixture should be close in the problem but even adding a tad more fuel there could help. Tweak the tune to get it right.
Namooz
Same answer
Tweak the tune to get it right. The small compression decrease you will realize by a thicker gasket will be offset by a wider squish space and that most likely will excentuate the problem. Back the timing off in the problem area. Make sure there are no lean spikes at the problem area of the rpm and load / throttle opening range.
Hey nw_guy,

Not doubting your comments, but I'm running real close to .030" squish. After my 2nd rebuild when I went to a .046" with the gasket kit, the ping was gone. Now, I may just leave her alone and definately agree the answer also lies in the timing and fuel. ~!Awesome!
 

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Registered
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13,064 Posts
Do you have a stage I or stage II flash. I understand that the pcII has limitations on how much it can tweak the ECM. If the ECM is halfway there, it will be easier to get a better tune and you can retard the timing more.
 

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Fastest Chkn N the South!
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897 Posts
You might also try one heat range cooler on the plugs.
 

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Premium Member
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252 Posts
I had some pinging in my 03 SERK after some engine work that the dealer couldn't get rid of with tuning. I worked on it myself and finally got rid of the pinging (except in extremely hot weather-100+). I think the biggest change I made that solved the problem was changing the acceleration enrichment table with the SERT. I still get good mileage and the bike runs excellent, but pinging gone. I actually ended up with nearly the same timing tables as the dealer used, but the pinging was gone
If you can alter your acceleration table with the PC, then I'd try that.
 

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Premium Member
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252 Posts
With the SERT all the values in the table are increased, but I'm not sure how it's set up with a PC. I actually used a table from another persons map that had higher values in it than mine did.
 
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