Pinging at higher rpms

[ottawamerc]

Hi guys my 440 6 pack has got a ping at higher rpms and loads. It's a fresh motor 3000 Mi on it last year. It is a 72 truck block bored 0.60, Eddy E-Street heads sorry I'm not sure of the cam but its alittle loppy at idle. It has a MSD RTR distributor. I think the engine builder said it was a 10:1 comp build but I'm not really impressed with his work on my engine (funny ticking) and vibration from it that he is not really interested in fixing Oh well what would a guy expect for a $6000 investment really! I ran it through some checks today and here's what I found if you guys could comment on them.

Idle 950 RPM
Vac 16.5"HG
Base timing is 18*
timing starts to advance at 1250 RPM
1500 RPM its 25*
1750 RPM 27*
2000 RPM 33*
2250 RPM 35*
2500 RPM 36*  All in

its has a 195 thermostat and runs cool at hiway and city. It runs on 91-93 octane (all I can get here)

So what do you think?

Thanks
Scott

[Back N Black]

Do you have the Vacuum advance connected? if so, try without the advance.

[ottawamerc]

Oh yeah forgot to mention that, I do have the vacuum advance disconnected.

Scott

[tan top]

 could try backing the timing down to  all in 34 * then see if that makes any difference     have you checked plug color ?

[cudaken]

While 195 degrees is fine, my self I like 160 so you might try that. I would all so back off the total advances as Tan Top suggested.

Have you checked your Air Fuel ratio? Most cars run to rich, but you never know. 

Cuda Ken

[BSB67]

While 195 degrees is fine, my self I like 160 so you might try that. I would all so back off the total advances as Tan Top suggested.

Have you checked your Air Fuel ratio? Most cars run to rich, but you never know. 

Cuda Ken

And try cooler plugs.  What is you cranking cylinder pressure?

[ottawamerc]

I'm getting around 170 PSI cranking.

Scott

[firefighter3931]

Scott,

The 170psi is fine with pump gas and aluminum heads. Timing curve looks ideal as well 

My old 446 used a 160* high flow Milidon thermostat and the temps would allways settle at 175-180 once it warmed up. I don't like them to run hotter than 180.

That engine combo (yours) should be using an NGK "6" series plug. I used the BCPR-6ES in mine gapped at .040 and it ran great. 



Ron

[ottawamerc]

I dont remember what plugs I have in there other than they are short header plugs. So you think the 195* is too hot? Bloody internet provided the wrong info I thought that never happened I had read that the 6 packs needed the 195* to run right. I will try the 160*

Scott

[myk]

I thought most engines including ours had a normal operating temperature of at least 190. My 440 does 160 at freeway speeds then does 180-200 in city; depending on weather and traffic conditions...

[Cooter]

Imo, 160 is too cold to get a proper burn in a good running engine. 180-190 is optimum, but pre-ignition can force 160 T-stats.

[ottawamerc]

Ok "update" today I noticed that the pinging starts just before the outer carbs start to open. I pushed it a little further into the ping to see if it would dissipate but it didn't and I didn't go much more than a second and a half beyond the start of the ping. I guess I need to put a A/F meter in to tell for sure But for now I think its leaning out just before the secondaries  come in to play.

Scott

[b5blue]

Lighter springs will open outboards sooner and a #65 jet in center carb may help. My Six pack loves vac. advance, I'm set at 12* initial with vac unhooked and capped. Vac. advance adds about 10* and I run it off full manifold vacuum.
I'm running a Firecore RTR dizzy with one heavy and one stock spring with mech. advance limited @ 16*. I just tested with 91 octane and have no ping. How high are you where your at? Where are your outboards idle mix screws set at?
Here is a link to some generally good tuning tips:
http://board.moparts.org/ubbthreads/showflat.php?Cat=0&Board=QuestionAnswer&Number=5995396&Searchpage=1&Main=5995174&Words=+Warrant_Officer&topic=&Search=true

[ottawamerc]

Ok so today amazingly it's not raining and I tried out the O2 sensor. At idle its kinda all over the place 13.8-15 so I figure that 14.5 is the median At cruise its 12.0 and vac is 20"HG at WOT its 13.2 but pinging bad The A/F seems ok? no? So I guess I should pull a bit of advance out?
Also my idle adjustment needles seem to be out alot (not confirmed) but like 3 turns?
I took a couple of pics but my Iphone cam sucks and they didn't turn out.

Setup at idle
http://s1322.photobucket.com/user/ottawamerc/media/IMG_1160_zps76fddeac.mp4.html
AEM wide band O2 sensor installed



Scott

[firefighter3931]

At 13.2 AFR wide open it should not be detonating with 10:1 and aluminum heads. 

How hot is the engine running ? What plugs ? Compression test numbers ? Total advance and where it comes in ?

The idle vacuum seems really good...


Ron

[ottawamerc]

I know eh Ron?

All the details are at the top of this thread. Its not running hot either?

The plugs are Accel 416S

Scott

[b5blue]

I'd bench check the carbs.
I set my outboards AFTER replacing the needles and tiny cork "O" rings that seal them so the tip of the needle just peeks out the hole, about 3/4 of 1 turn. Checked float height by holding the bowl upside down and adjusting the new Viton tipped fuel valve so it hung level inside the bowl.
My center had a clogged accelerator pump from sitting too much and crap in the bottom of the bowl that only Lacquer thinner would cut for clean up. Are you getting a good shot from the accelerator pump? 
I installed a Firecore RTR dizzy from Ron and set mech. advance limited to 16* using one heavy and one standard spring to restrict the curve at the transition where you have ping. I'm running bone stock 346 iron heads and 9.5 to one Speed Pro pistons and have no more ping even running mid grade (91 oct.)
With Aluminum heads you should not be having issues @ 10 to 1 unless your way way advanced in timing. (?)

[ottawamerc]

Today while I was pulling the plugs I found that the boots on cyl #1 & 3 where burnt and badly cracked. I suspected this would happen even though I had put protection sleeves on them cause # 1 header tube touched them due to the angled plugs. So now I'm heating and massaging my  header tube but its not easy

Here's a plug from #3 cylinder with over 3000 miles on it, sorry for the bad pic again.



Scott

[firefighter3931]

I know eh Ron?

All the details are at the top of this thread. Its not running hot either?

The plugs are Accel 416S

Scott

Dang, I should have re-read the thread....the info is all there. 

Ok the numbers all seem to line up fine....170 psi cranking is well within the limits of pump gas. I'm starting to wonder if your timing is off. When the engine was rebuilt did the shop check the indexing on your harmonic balancer ? Is it a factory balancer ? The reason i mention this is because often the outer ring will slip on the hub due to deteriation of the elastomer ring and when that happens your timing adjustments will be off.....depending on the amount of slippage it can be quite a bit. 

Do you have an infrared heat gun ? I'd be interested to see what the cyl head surface temps are reading. 


Ron


Ps. It was just a matter of time before the plug boots split being so close to the header tubes. The Hookers can be clearanced with a lot of heat and a 

[ottawamerc]

Ok So I installed the new plugs under Ron's guidance and WOW big difference across the board! The A/F rich`d up and I was able to take a 1/2 turn leaner on the idle needles, a annoying ticking coming from cylinder 4 or 6 is GONE! I test drove it tonight and at idle I have 13.7- 14.2, cruise is 12.7-13 and WOT is 13.3. I checked the engine temp and its 178*F at the cylinder head and the top of the rad and 143 at the base of the rad. I can't get a good reading from each exhaust cause of the ceramic headers. The engine idles smooth (more than I wanted, I was hoping for some rumble ) There is still some ping at high RPM under load but it`s no where near where it was! A straight line blast from a dead stop was well exhilarating to say the least

Thanks Ron

Scott

[firefighter3931]

Good Data  The engine temps look great....no problem there ! 

From what i can see, the cruise looks a little rich and the WOT is a bit lean. To lean out the cruise AFR you'll need to pull some jet out of the center carb. To richen up the WOT AFR you'll need to add some jet to the outboards. 

You're getting closer and by the time it's properly dialed in there should be no detonation. 



Ron

[ottawamerc]

Hey

So today when I got home from work I pulled my 3 carbs and found my center carb had 68 jets so I dropped them to 65's that I had on hand and my outboard carbs had 82 and I bumped them to 84's. I cleaned reassembled and set my out board needles at 1/2+ on each bore, I reset my center carb to 1 1/2 turn then set the float levels. Now I have 13.7 A/F at idle and this short video for the balance What do ya think? Still some singing coming at the same RPM's and load guessing maybe like Ron said possible bad vibration damper( indicator off)?

Scott

http://s1322.photobucket.com/user/ottawamerc/media/IMG_1185_zps4fb5c3cc.mp4.html

[b5blue]

Boy you are getting close! 

[firefighter3931]

It's looking better Scott 

The AFR's are still lean at WOT so i would throw some more jet in the outboard carbs and retest. If you can get it to high 12's it should work just fine. Try running Shell 91 which is pure gas (ethanol free) The ethanol does affect AFR's somewhat in that the jetting needs to be richer to accomodate that fuel. All i use now is the V-power 91 

Here's what i would do ; go out for a nice long cruise and burn off whatever fuel you have in there and fill up with the 91....then re-check the AFR's.....then re-adjust as necessary. 


Ron

[ACUDANUT]

How can you even hear a ping at those rpm's ? Then again, I can't hear shit anyway.