CVO Technical > Twin Cam

Question about pinging.

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Ironhorse:
My bike is an older 2001 Ultra with M&M FI.
It has 95" kit, .203 cams, TrueDuals, and SE intake.

It always had been a bear to tune. In the old days of PCIII, all they could do was richen the mixture to get rid of the ping. When the SERT for M&M came out, I had the bike dyno tuned, and it runs great. The dyno tune produced a great running bike, but it continued to ping occasionally, mostly on hot days. I took the bike back to the dyno guy, and he had to retard some timing out to get rid of the ping. He showed me how to do it if it ever started again.

Is it possible to pull too much timing out, even if it's to get rid of pinging?
What could happen if the bike is retarded too much?

Would swapping cams help? I have no idea what cam to go to.
I do prefer TQ down low and in the midrange.

Would a porting job on the heads make a difference?

Thanks

Unbalanced:
Ironhorse,

I am going to go out on a lim and take a guess.  What I would look at in the racetuner is retarding the timing a bit first before you go jump into a huge expense and see if the pinging goes away.   Another thing I would definately do is have a shop check and tell you what your compression is for BOTH cylinders and also have them check your cylinders with a bore scope and check for detonation.   My guess is your timing is too far advanced and that is causing your pinging.  

Timing to far advanced with a quick closing intake with compression = detonation (Pinging)

If the pinging were gone, would you still want to throw money at the bike to make it faster / more responsive more hp etc?

If I were going to redo the 95 kit I would go with 10 to 1 compression,  Andrews 55G Cam, headwork done by one of the named guys with the heads clearanced to .550 lift.  It will be really torqey, give you reliability and fun to drive.  I would also consider a 48 to 50 mm Throttle body or having yours bored out a bit, and a Zippers Schim for the oil pump while your in there.

Named Guys,

Branch Heads,
Cycle Rama
John Sachs
Tilley's
Zippers
R&R
Freedom Cycle, Reno
T-Man
Hals Harley
Underground
SBC (Short Block Charlie)

Let me know what you find.

-harry

JimsSEEG:
My first 95 build was on a 02 FI Fatboy with 203s and flat tops, ping'd like a big dog on hot 100+ days. That combo will tend to do that because of the early close of the intake valve of the cams, It will also cause starter kickback on those same really hot days.

You didn't mention if it was an all HD parts build. If so, you might consider swapping the head gasket from the typical stock .050 to the  Cometic .032. This would do two things: 1) give an ever so slight bump in compression and 2) help decrease the area at the edge of the piston (referred to as the quench area) where the flame thends to go out. With a tighter area, fuel burn is more complete and that is good.

Jim

Unbalanced:
Jim,

The only problem with that is if it is a compression ping due to too much, it is only going to get worse.   I recommend they figure out what is causing it first and  if its just timing then sure why not pick up the extra ponies, but if its compression he will need to look for another cam.

-harry  

Ironhorse:
Well I've been e-mailing Tom, and I talked to Steve at AMS in Texas.
I think I'm going to go with their recommendations.

I told them that my 2001 Ultra has always pinged since I got it. It has the 95" Flat Top Pistons, Stage II, .203 Cams, SE intake, True Duals and FullSac Mufflers. Up until recently, the best suggestion most tuners could do is throw fuel at it to keep it from pinging. I got an SERT and had it dyno tuned and it ran great. Then came hot weather and the pinging came back. I had to retard a lot of timing out of it to stop the ping. Now the bike lost it's low end.

Steve said this is a common problem with early HD builds of my kind. The combination of the .030 gasket that they used, the .203 cams, and heat retention from the low flow OEM heads probably gives the motor a compression ratio of at least 10:1. Additionally the OEM heads create and retain too much heat and that is why it pings on hot days and when the engine gets heat soaked.

He suggested I keep my pistons, use AMS heads, an .043 gasket, and Andrews TW26-Gear drive cams. The heads will flow better, and the heat coated exhaust ports will keep the heat down. The .043 gasket will lower the compression to about 9:1, and the cams will let the engine breathe better and give back the low end.

Steve, said my current exhaust would be costing me about 10HP. Like a lot of you, AMS suggests a good 2-1 like the Thunderheader or the D&D FatCat. I told him I was willing to sacrafice a few HP to keep my current Hooker Stepped Tuned True Dual headers and FullSac mufflers. I like the look and quiet sound. At 46+ years, I have had enough if noise, a 10HP loss is worth it to me to keep my sanity and hearing. I told Steve that all I was interested in was a dependable build that would keep the ping away and give me some low end torque. I like to tour cross country and want torque for climbing hills and passing trucks. He assured me that it would. I asked him if I needed to change pistons, cut reliefs in the piston tops, change the cylinders, lifters, go with a larger throttlebody, and what not. He said not to, and that there was no need to. You gotta admire a man who passes up the opportunity to sell you extras.

Quite a few folks on the Delphi EG forums are running this package and are very pleased.

I guess the 6 speed tranny will have to wait till next year.

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