What should my timing be set at to stop pinging at wot

-
J

jerry6

Banned
Joined
Aug 29, 2010
Messages
2,439
Reaction score
78
Location
Mon
have it at 10 , 34 total and it pings when I floor it . 10:5.1 pistons .030 over , x heads , lunati 6043 cam between 195-200 /cylinder on compression test .
Using 94 octane gas , even added some octane booster , pings less with the booster but still pinging a bit as the revs get up there .
Anything I can do besides getting thicker head gaskets ? This is driving me insane .
 
What carb? Try some fatter jets. Could be pinging at wot due to lean condition.
 
I'm gonna guess it needs 100 octane with that cylinder pressure.

Or take timing out of it until it goes away. It may not run that good pulling timing.
 
daredevil said:
What carb? Try some fatter jets. Could be pinging at wot due to lean condition.
Click to expand...

Right now have the carter AVS it came with , edy 800 had to be returned , waiting for replacement , it pinged as well .
 
crackedback said:
I'm gonna guess it needs 100 octane with that cylinder pressure.

Or take timing out of it until it goes away. It may not run that good pulling timing.
Click to expand...

That is not something I want to do , is there any good octane booster , or anything else that would have it run at optimum timing ? Hate to run it de-tuned ! Had to do that with my old 440 , when I got good gas 104+ it ran great , hated it on anything less , had to knock timing back 10 deg at least . Pissed me off running like that .
 
You could try retarding the camshaft timing. It would not have as drastic an effect on power as taking distributor timing out. More work, though. If you go that far, you could probably really do the right thing and stab a larger camshaft in it.
 
Rather than Octane Boosters I have had good success with a similar build on my 70 442 using VP110. 10% VP to the tank allows me to run alot of advance which the Olds 455 motor likes and also gives me lead for non-hardened valve seats. Octane boosters never seemed to do what was advertised. Real fuel did.
 
67Dart273 said:
How about how hot is the engine running?
Click to expand...

Runs a steady 185-200 at all time , 95 deg traffic or on the highway . 22" RAD shroud and clutch fan . Once warmed up temp stays within 10-15 deg
 
where is the cam degreed in at now? what are the cam specs? maybe some other specs on the car such as weight, gearing, tires, converter.
 
69MOPE said:
Pick up a 55 gallon drum of 104 octane leaded fuel. should only cost around $800.00
Click to expand...
Back in the day had a 1000 gallon tank of Sunoco 104 at my shop , regulations got to be to much so no more fuel pump in the yard , but that sure would be the ticket .
Looking for a bit less expensive soloution
 
Baxter61 said:
where is the cam degreed in at now? what are the cam specs? maybe some other specs on the car such as weight, gearing, tires, converter.
Click to expand...
cam is lunati 60403 gears 3:73 weight about 100 lbs less than stock , tires 245/60-14 , converter stock 1800-2200 stall
http://www.lunatipower.com/Product.aspx?id=1545&gid=287

  • Advertised Duration (Int/Exh): 268/276
  • Duration @ .050 (Int/Exh): 226/234
  • Gross Valve Lift (Int/Exh): .494/.513
  • LSA/ICL: 110/106
  • Valve Lash (Int/Exh): Hyd/Hyd
  • RPM Range: 1800-6200












.





110°
 
200PSI seems like a lot of compression on 94 Octane... The cam installs @ 4 degrees advanced, so install it at 0 or 4 degrees retarded and try that maybe? I think that you should aim for 180PSI, max. A bigger cam would work too, but may not work with your converter.
 
I personally would stick a bigger cam in but as StrokerScamp and Dartboy have pointed out, you could also retard the cam and put it in at 108 or 110, but again my choice would be bigger cam. Beyond that you could go with more octane, less timing, or aluminum heads.
 
what kind of distributer are you running vacume advance or full mec distributer what plugs are you running what do your plugs look like . why do you need that much compression in a street engin whats on it for exsaust system and you torque converter is to small try a 3000 stall..
 
My stock 69 Dart 340/727 had the same cylinder pressure as you and a stock cam, with the original AVS, and didn't ping at WOT, or at all for that matter.
If it doesn't ping until the RPM is high, try to limit the mechanical advance in your distributor.
No need for crazy octane snake oil or a different carb until you find the cause, otherwise you're throwing good money away.

George
 
George R said:
My stock 69 Dart 340/727 had the same cylinder pressure as you and a stock cam, with the original AVS, and didn't ping at WOT, or at all for that matter.
If it doesn't ping until the RPM is high, try to limit the mechanical advance in your distributor.
No need for crazy octane snake oil or a different carb until you find the cause, otherwise you're throwing good money away.

George
Click to expand...

robert 68 cuda said:
what kind of distributer are you running vacume advance or full mec distributer what plugs are you running what do your plugs look like . why do you need that much compression in a street engin whats on it for exsaust system and you torque converter is to small try a 3000 stall..
Click to expand...

Running stock mopar electronic distributor with vac advance , it pings at higher rpm . Trying to find out why it pings . Agreed don't need that much compression on a street engine , but that's what it has . Was aiming for 170- 180 , ended up higher . 2 1/2 " exhaust with hedman tight tube headers
Just don't want to damage the engine , looking for solutions
 
George R said:
My stock 69 Dart 340/727 had the same cylinder pressure as you and a stock cam, with the original AVS, and didn't ping at WOT, or at all for that matter.
If it doesn't ping until the RPM is high, try to limit the mechanical advance in your distributor.
No need for crazy octane snake oil or a different carb until you find the cause, otherwise you're throwing good money away.

George
Click to expand...

That's kinda what I was thinking. Bump up the initial and limit the advance some more. I don't know if it would make a difference, couldn't hurt.

My engine is far from yours in build and I run 16* initial.
 
when i ran me 340 it had 200 and i would run 36/38 toiming but my dizzy was locked out..i could run pump gas when i pull it down to 32 but you sure could tell it.. i was running a comp 282xs cam soild...at the track ran 110:D
 
lose the vacume advance and set the timing to ear.....you'll be surprised how well it will run....
 
Man,, I have lived your frustration thru 40 yrs,, 69 Swinger 340, I bought new, built it out to, 12.5, tried diff dizzies, timing total never more than 35/36, went to big cam, it pinged, then biggest cam avail, 336/341 deg, trying to flood the ping outa it, nope, -then trimmed pistons twice, it pinged, -changed to bigger J heads, it pinged, tried playing with cam timing,, and... tried the water spray with washer pump, still pings.. . . . lol... It's always pinged, it just got slower,, still pings today..

It used to run 13.2s,, 2/10th's off the NHRA record at that time,, It won me a lotta hardware... lol

It will prob ping when I finish putting it back to stock.. specially with todays gas..

oh,, through all the tear downs, after a couple of hundred runs, AND a daily driver,, I never saw any sign of piston damage,, not one ... so I let it ping..

guess nitrous is outta the question... lol
 
You must log in or register to reply here.
-

Back
Top