Moparts
I still have pinging problems with my 512
Posted By: Boise Chall
I still have pinging problems with my 512 - 04/02/11 05:32 AM
the 512 in my 72 Challenger is still pinging on me. The motor is a 512 stealth aluminum heads Holley 950 HP carb Comp cams XE295HL-10 cam, 11.3:1 compression, MSD 6Al, MSd Billet distributer, 3,200 Rpm Stall,2"TTI headers, 3" pipe to 3" Flowmaster 40 series , 3:55 gears. Timing is 16 initial 32 total all in by 2,800 RPM. The pinging occurs at about half throttle and it's a pretty loud ping The things I have done to try to solve the problem are
1. Brought the timing down from 34 total to 32 total
2. Upped the primary jets 4 sizes
3. increased the power valve from 2.5 to 3.5
4. Added 5 gallons E85 ( 110 Octane )to 10 gallons of 91 octane
5. went up 2 heat ranges on my plugs
Nothing helped at all I'm at a loss on this problem. Could it be that I'm bringing my timing in too soon? if all of my timing is in at 2,800 and my stall is 3,200 could I be too far advanced when the stall comes in? My engine temps are 185-190 and pretty steady, At this point I'm willing to try anything. I prefer not to tear the motor down but at this point if I need to I will before the pinging tears the motor apart for me.
Posted By: Darryls-Demon
Re: I still have pinging problems with my 512 - 04/02/11 05:49 AM
Looks like you put hotter plugs in it? Need to go the other way. Do you know what your cylinder pressure is? Are the pistons at zero deck or are they down in the hole?
Posted By: Dodgem
Re: I still have pinging problems with my 512 - 04/02/11 05:57 AM
I would think your power valve should be more like 6.5 in gear idle vacuum - 1.5 to 2 numbers.
at light throttle your power valve is staying closed instead of enriching the system the way it is designed.
Posted By: dOc !
Re: I still have pinging problems with my 512 - 04/02/11 06:04 AM
KILL the motor during the pinging ...and then take a plug-check and "read them".
Posted By: Boise Chall
Re: I still have pinging problems with my 512 - 04/02/11 06:34 AM
I'll have to check my Idle vacuum again but I think I have 9" at idle in gear Holley recommended the 2.5 power valve. Somebody suggested that it might be a lean ping but going up 4 jet sizes didn't help at all. I went to a hotter plug because I fouled one when the motor was still pretty new.I will change to a colder plug in the morning and see if that helps.
Posted By: Boise Chall
Re: I still have pinging problems with my 512 - 04/02/11 06:37 AM
I don't know what my cylinder pressure is I can check it while I have my plugs out tomorrow I think they are zero deck the motor was designed to be 11.3:1
Posted By: 451Mopar
Re: I still have pinging problems with my 512 - 04/02/11 07:04 AM
Try a 160 degree thermostat.
What is your cranking cylinder pressures?
Posted By: Boise Chall
Re: I still have pinging problems with my 512 - 04/02/11 07:08 AM
I don't know my Cranking pressures. Maybe that's why I can't solve this problem I don't know the important info like pressures and piston height
Posted By: RapidRobert
Re: I still have pinging problems with my 512 - 04/02/11 12:54 PM
Quote:
4. Added 5 gallons E85 ( 110 Octane )to 10 gallons of 91 octane
5. went up 2 heat ranges on my plugs
I will before the pinging tears the motor apart for me.
I'd suggest forgetting the E85 & put several gallons of race gas in per tank & adj your proportion from there and go back to your colder plugs if they were in the ballpark correct range (& I'm assuming they were close)
Posted By: ahy
Re: I still have pinging problems with my 512 - 04/02/11 01:05 PM
Quote:
1. Brought the timing down from 34 total to 32 total
2. Upped the primary jets 4 sizes
3. increased the power valve from 2.5 to 3.5
4. Added 5 gallons E85 ( 110 Octane )to 10 gallons of 91 octane
5. went up 2 heat ranges on my plugs
Comment on the E85 - it is high octane but lower energy per gallon. Adding it to the fuel mix effectivly leans out the mixture. Even with the bigger jets you may have leaned it out overall with the E85. Two or three gallons of 110 race gas added to pump premium should help without leaning the mixture. That and reading the plugs and likley going to a colder plug should quiet it down.
Also, ping at half throttle suggests the timing curve is too aggressive. A slow mechanical advance with full advance delayed to 3000 RPM may help.
The other benefit of adding the race gas is it should run without hurting itself while you get the plugs, timing and mixture dialed in.
Posted By: tboomer
Re: I still have pinging problems with my 512 - 04/02/11 01:26 PM
Just a couple of thoughts here..You are at 0 deck and don't know piston heighth...You may be at more than 11.4-1 compression..What kind of pistons and what is the cylinder head ccs...Lots of stuff to look into...Wouldn't want to see you hurt that engine!! Here is a pic of my 13.4-1 512..
Posted By: JohnRR
Re: I still have pinging problems with my 512 - 04/02/11 01:31 PM
Quote:
I don't know my Cranking pressures. Maybe that's why I can't solve this problem I don't know the important info like pressures and piston height
Who built this engine ? you need to know what you are dealing with.
Also what or who gave you the idea to dump E85 in there ? It's not the same as mixing in 110 race gas. You either build it to run on E85 , or on Gas , you can't really mix the 2 , but the fact that you have e85 you might want to think about converting to it .
Posted By: jbc426
Re: I still have pinging problems with my 512 - 04/02/11 02:36 PM
Put a compression tester on it and find out what it's cranking. E85 is not what you need to increase pump premium's octane. To effectively increase your octane, try running some % of 100 octane unleaded or add 110 octane leaded to your tank. You will have to rejet no matter what you do when you start blending your fuel, so be consistent with the mixture once you get a ratio that works. You may want to get a knock sensor to detect detonation and a wideband with data logger. FAST has a nice wideband unit.
I only drive my car for fun and rarely burn more than a tankful a month, so I intentionally opted for high compression (12.8 to 1 @ 225psi cranking). I've always liked how it runs with it, and I don't really care about the cost difference to run high compression because of the performance trade off. I don't drive the car that much. Also, I know you can't get 100 octane unleaded everywhere, so I had a larger tank made to extend my cruising range.
I do have to pay about 1/2 again more for each gallon of the fuel to meet the octane requirements. I was going to mix 110 octane unleaded, but that's illegal in California now. Fortunately, my motor likes the 100 octane unleaded at about $6.50 a gallon.....and rising, but I knew this going in. Sounds like you didn't know your compression is too high for normal pump gas.
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Posted By: DAISYDUSTER
Re: I still have pinging problems with my 512 - 04/02/11 03:55 PM
If she is pinging drain the tank and fill with racing gas; not a mixture. If that stops the pinging then play with mixtures and the like but don't mess up a good build playing with detonation. There are too many unknown varibles and you can get lost in the testing game without first feeding your motor a quality fuel.
Posted By: BB Dart 69
Re: I still have pinging problems with my 512 - 04/02/11 04:46 PM
E-85 + 91, might as well put 87 octane in it
. I have a 493-0 deck-84cc milled to74cc,runs on 93 octane .
Posted By: Challenger 1
Re: I still have pinging problems with my 512 - 04/02/11 04:52 PM
Like what a few guys have already said, get rid of that swill gas you have now, and put some real gas in it.
I'm betting the compression is higher than you think. 0 deck? I would have CC the engine after I had the heads on, when I put it togeather so I knew for sure what the compression is.
Get good gas first. Like what already said, I'd start with a straight 110 leaded. You maybe be able to blend down from there, but at 11+-1 gonna need more than prem pump gas. Hopefully you have someone nearby who sells race gas at the pump or buy it by the drum. Speed and horsepower cost $$
We have a place nearby that sells 100 octane unleaded and 110 leaded at the pump, makes it nice.
Posted By: Boise Chall
Re: I still have pinging problems with my 512 - 04/02/11 05:03 PM
I don't drive the car much when I bought the motor I also knew the compression was high for the street but didn't care. The car has been done for almost 1- 1/2 years and it has less than 1,000 miles on it. I was driving it last night and it pinged on me a couple times. I drove by a gas station that sold E85 and thought I would try it to see if it helped but it didn't. It's raining here but as soon as it stops I will get cranking pressures and put the colder plugs in it. I got the RJ12YC plugs that 440 source recommended for the motor and I'll try them.
Posted By: superbeedave
Re: I still have pinging problems with my 512 - 04/02/11 05:28 PM
I would think with that high of compression you would need a colder plug than that! And I read in mopar muscle that in order to use E85 you need to switch parts of your fuel system such as the rubber needles in your carb. The rubber are the things that E85 will deteriorate over time. I could be wrong! Anyone read that issue from 4-6 months ago? it was the one guy's Valiant that they did it to.
Posted By: Challenger 1
Re: I still have pinging problems with my 512 - 04/02/11 05:36 PM
Quote:
I would think with that high of compression you would need a colder plug than that! And I read in mopar muscle that in order to use E85 you need to switch parts of your fuel system such as the rubber needles in your carb. The rubber are the things that E85 will deteriorate over time. I could be wrong! Anyone read that issue from 4-6 months ago? it was the one guy's Valiant that they did it to.
Definitely, 85% alcohol requires special items like needles and get rite of rubber from the fuel system.
To the OP, I wouldn't store the car with E85 in it, I'd get it out of there but fast and run some straight gas threw there without ethanol in it.
Most of the gas sold nowadays has at least 10% ethanol in it which sucks for performance and storage. Straight 100% gas 91 without ethanol is way better than 91 with 10% ethanol blended, way better.But hard to find nowadays. 
Posted By: Boise Chall
Re: I still have pinging problems with my 512 - 04/02/11 06:13 PM
I will get the corn gas out of it. I forgot about it eating the rubber in the fuel system. I have a Phillips 66 about a mile from my house that sells straight gas no ethanol I'll get some. I can't get any race gas until Monday unless somebody is on here from Boise and Knows where to get it on a Saturday.
Posted By: Neil
Re: I still have pinging problems with my 512 - 04/02/11 06:33 PM
United Oil sells race gas from what I hear. I have no idea if they are open on weekends though.
Posted By: Boise Chall
Re: I still have pinging problems with my 512 - 04/02/11 07:01 PM
I usually get it from there But their closed on the weekends
Posted By: Dabee
Re: I still have pinging problems with my 512 - 04/02/11 10:26 PM
Quote:
ping at half throttle suggests the timing curve is too aggressive. A slow mechanical advance with full advance delayed to 3000 RPM may help.
I had the same pinging issue with my street 512. Similar build only with Indy EZ heads and Gear Venders. I recurved the distributor, MSD billet. I had the silver springs installed to get full advance at 1800 RPM. Good for a race engine not so good on the street. I replace one of the silver springs with a blue spring to slow down the advance. Problem solved. 
Posted By: 64Post
Re: I still have pinging problems with my 512 - 04/02/11 10:48 PM
Quote:
I'll have to check my Idle vacuum again but I think I have 9" at idle in gear Holley recommended the 2.5 power valve.
I believe a 4.5 PV is recommended with 9" of vacuum in gear, not to suggest this your only problem. General rule of thumb is half of the idle vacuum.
I agree with the other suggestions of fuel, and possibly slowing the curve.
Posted By: Dodgem
Re: I still have pinging problems with my 512 - 04/03/11 03:13 AM
No my holly books say 1.5 to 2.5 below in gear idle vacuum so a 6.5 would likely be spot on.
you use 2.5's om 300 @ .050 roller cams!!
You must have misunderstood or the 3.75 a hour kids are confusing you!
Thrust me try a 6.5
the 1/2 vacuum numbers are for real stock cams with 17 in gear vacuum so 1/2 is 8.5
Power valve is $9 and won't hurt anything (you probaly have a 6.5 laying around) quick and easy to try an cannot hurt anything. If it was a 8.5 with 9: vaccum it might flutter open at idle and be a bit rich but a 7.5 and down will be just fine.
Posted By: Cudajon
Re: I still have pinging problems with my 512 - 04/03/11 03:27 AM
Trash the E85, its will cause an engine to lean out. You need to geta tank full of good gas and then get a O2 meter and see where your really at, one that can be wired up while your driving it. All this hit and miss stuff is chasing the problem. Do a real logical diagnosis. Im bettin you are way off on carb, timing and plugs. But you'll never find it if you just throw things at it.
Posted By: Boise Chall
Re: I still have pinging problems with my 512 - 04/03/11 11:08 PM
I just got the E85 Tainted fuel out of the car and I'm replacing it with Phillip 66 no corn fuel I also have a gallon of C-12 race fuel that I will add to the 5 gallons of pure no corn gas. I will get the plugs replaced with colder ones here shortly. I noticed that the heavy silver springs from my MSD distributor spring kit are still in the bag So I will most likely be putting those in as well as getting a cranking pressure
Posted By: RapidRobert
Re: I still have pinging problems with my 512 - 04/03/11 11:12 PM
Quote:
I just got the E85 Tainted fuel out of the car and I'm replacing it with Phillip 66 no corn fuel I also have a gallon of C-12 race fuel that I will add to the 5 gallons of pure no corn gas. I will get the plugs replaced with colder ones here shortly. I noticed that the heavy silver springs from my MSD distributor spring kit are still in the bag So I will most likely be putting those in as well as getting a cranking pressure
You sound pumped
Posted By: Streetwize
Re: I still have pinging problems with my 512 - 04/03/11 11:43 PM
One trick that works well is to run between 18 and 22 degrees initial but then use a relatively slow curve that gives you full advance around 2800-3000, too light a spring gives you full advance at the crack of the throttle, they do that primarily for heaviier underpowered cars to give them some extra "oomph". With a 512 that is not a problem, if it's set up right and the combo is HAPPY, it should feel like a really strong horse that you need to pull back the reigns on most of the time.
You can run zero deck closed chamber with an excellent quench pad and still run 11.4-12:1 in a 512, in fact I recommend it....but that would be a dished piston. A flat top will be over 13 at 512 with any typically sized 75 cc chamber.
Posted By: Boise Chall
Re: I still have pinging problems with my 512 - 04/04/11 02:59 AM
Ok guys my Cranking pressure is 160 I tested it with the motor cold I already have the heavy silver springs in the distributor. and the largest bushing to limit the advance. My plugs look good They have a little bit of black on the outer ring ( top of threaded area )the center is tan/borwnish. They are a little wet with fuel but that's probably because I didn't warm it all the way up when I put it away this morning.
Posted By: Lifsgrt
Re: I still have pinging problems with my 512 - 04/04/11 05:08 AM
Are you running good plug wires, and have you checked them?
Posted By: Boise Chall
Re: I still have pinging problems with my 512 - 04/04/11 05:54 AM
I'm running MSD super conductors they have less than 1,000 miles on them and they run under the headers so no place for them to get hot and they are well anchored so they don't rub on anything. I can check them if nothing else works out.
Posted By: 451Mopar
Re: I still have pinging problems with my 512 - 04/04/11 06:34 AM
Can you see where the spark plug ground strap changes color? It is supposed to help tell if the ignition timing is good?
It sounds like you covered most of the possible issues. I would drain as much of your current fuel from the tank, and put some 110 octane race gas in just to verify the engine will not ping with high octane fuel. Then I would chassis dyno the car using wideband O2 sensors, the see what your air/fuel ratios look like.
Once you get the car in a known good state of tune, then I would reduce the fuel octane an see if the pinging returns.
Posted By: ireland383
Re: I still have pinging problems with my 512 - 04/04/11 10:58 AM
If the 110 don't work drop down to a RC9YC plug. How is your intake sealed? No leaks?
Posted By: Boise Chall
Re: I still have pinging problems with my 512 - 04/04/11 01:49 PM
451 you might be on to something there The color change on the strap is about 1/8 in from the threaded body of the plug saying way too much timing. I wonder if my dampner slipped on the hub or the timing/degree marks are wrong on it. It wouldn't be the first time that a slipping dampner had me second guessing myself and chasing gremlins. I will get the motor at TDC and see if it's TDC on the dampner. I've noticed it being a little hard for the starter to crank the motor when the the motor is warm/hot. If I remember right that says too much advance also.
Posted By: Dodgem
Re: I still have pinging problems with my 512 - 04/04/11 02:17 PM
I tell you stick a 6.5 power valve in it and it will be way better under light throttle acceleration!!
since you will always be pulling over 2.5 inches of vacuum at light acceleration you have no power enrichment system so it will be lean.
Lean= ping
Your cam is no where near big enough to run a 2.5 power valve you only need one to 1.5 number in gear above the power valve rating to keep it closed in gear idle. so 9 - 1.5 = 7.5 but a 6.5 will work good.
Posted By: DANA60
Re: I still have pinging problems with my 512 - 04/04/11 05:21 PM
I would add couple things:
1) The race gas thing is one way to check, but..
2) I would also think that your power valve may be low. Lean on fuel can also cause ping. The two jet sizes won't mean anything with a wrong PV.
Posted By: Boise Chall
Re: I still have pinging problems with my 512 - 04/04/11 09:39 PM
Ok I put the Champion RC12YC plugs in I had RC14YC plugs in it previously. I put 6 gallons of no corn gas in it I' going to go take it for a ride and see how it does. My initial timing is at 16 with a total of 30 but it still cranks hard like the timing is too far advanced. Ill let you know how it does.
Posted By: JohnRR
Re: I still have pinging problems with my 512 - 04/04/11 09:49 PM
Quote:
Ok I put the Champion RC12YC plugs in I had RC14YC plugs in it previously. I put 6 gallons of no corn gas in it I' going to go take it for a ride and see how it does. My initial timing is at 16 with a total of 30 but it still cranks hard like the timing is too far advanced. Ill let you know how it does.
Your total timing should be higher than that ,it's going to be too hot in the chambers and you are going to end up with detonation more than likely... still .
I thought you were going to confirm top dead center? I wouldn't be skipping steps because you are looking for a quick fix.
Posted By: Boise Chall
Re: I still have pinging problems with my 512 - 04/04/11 09:57 PM
That's true I did skip that I will let it cool down a little and check my TDC
Posted By: Boise Chall
Re: I still have pinging problems with my 512 - 04/04/11 10:48 PM
Ok TDC ( piston all the way up on #1 cyl) is zero on the Dampner so the Dampner didn't slip and is accurate.
Posted By: JohnRR
Re: I still have pinging problems with my 512 - 04/04/11 11:04 PM
Well then bump the timing back up to 34 degrees and go from there .
What is the octane of the fuel you used ?
Posted By: Boise Chall
Re: I still have pinging problems with my 512 - 04/04/11 11:16 PM
I put 6 gallons of no corn 91 octane gas and I didn't mention this in my last post but I put 2 gallons of 110 octane race gas in it also
Posted By: JohnRR
Re: I still have pinging problems with my 512 - 04/04/11 11:20 PM
Quote:
I put 6 gallons of no corn 91 octane gas and I didn't mention this in my last post but I put 2 gallons of 110 octane race gas in it also
Roll the timing up ... 
Posted By: Boise Chall
Re: I still have pinging problems with my 512 - 04/05/11 02:52 AM
I drove it and no pinging I was able to go full throttle for the first time with this car woohoo it felt good. At about 5,500 It pushed the dipstick out of the tube and oiled the steering gear box and engine compartment up pretty good. One problem solved one more comes up.
Posted By: Cudajon
Re: I still have pinging problems with my 512 - 04/05/11 02:54 AM
Probably getting blowbye from the rings not being seated. Hope it clears up and you didn't wet down the cylinders too much earlier.
Posted By: Boise Chall
Re: I still have pinging problems with my 512 - 04/05/11 02:58 AM
Posted By: Challenger 1
Re: I still have pinging problems with my 512 - 04/05/11 12:22 PM
Do you have a PCV hooked up right? If not you definetly need one.
Posted By: Cudajon
Re: I still have pinging problems with my 512 - 04/05/11 12:59 PM
My stroker took a while before the blowbye stopped. And yes the detonation could have kept the rings from seating, however the most common cause is a rich condition whereas the cylinder walls get coated with gas and it washes the oil off. Not only will this cause the rings not to seat it could possibly put a lot of stress on the rings causing premature failure. Drive it for a few days now that you've got the detonation solved and run another compression check, it should be a little better. Look for a weak cylinder, which might indicate a problem. My engine finally settled out with 200 +/- 10 lbs.
Posted By: RapidRobert
Re: I still have pinging problems with my 512 - 04/05/11 01:21 PM
read "breakin secrets" at
www.mototuneusa.com
Posted By: superbeedave
Re: I still have pinging problems with my 512 - 04/05/11 03:14 PM
I have a friend that had too much pinging and he sensed something was wrong after 6 months after rebuild. He pulled the engine back out and his problem was a cracked ring. That could very well have been what has happen to you with all the detonation you were having! So you think going down to the RC12's from 14's stopped your pinging? 14's
would have been way too hot for your engine, you may still want to go down to an RC10 with that compression you have you will need a colder plug. I am running those plugs in my 383 slightly modified engine with 9.3 comp. Good luck!
Posted By: JohnRR
Re: I still have pinging problems with my 512 - 04/05/11 03:21 PM
Quote:
Could the rattling of the pistons from the pinging have kept the rings from seating? I have to thank everybody that helped with this problem. I feel like I have a car I can drive and enjoy now 
What is your total timing set at ?
Posted By: Boise Chall
Re: I still have pinging problems with my 512 - 04/05/11 04:14 PM
34 degrees
Posted By: Boise Chall
Re: I still have pinging problems with my 512 - 04/05/11 04:24 PM
I can't say it was changing to colder plugs is what fixed it. I made 3 changes before I drove it.
1. Colder plugs
2. Got rid of the corn tainted fuel and put pure non corn gas in it
3. Added 2 gallons of C-12 Race fuel to 6 gallons of gas.
I did buy a 5.5 and a 6.5 power valves that was going to be the next change if the above 3 didn't work.I'll drive the car normal this weekend ( without getting on it too much ) and try to get the rings to seat. I'll pull the plugs and see how the look if I can go to colder plugs I will.
Posted By: Boise Chall
Re: I still have pinging problems with my 512 - 04/05/11 04:32 PM
I don't have a PCV hooked up I have it venting into the air cleaner. The setup I have has 2- 5/8 hoses 1- out of each valve cover then they join at a tee then I have 1- 5/8 hose going into the air cleaner. Maybe I'm not getting rid of the pressure fast enough ?
Posted By: Challenger 1
Re: I still have pinging problems with my 512 - 04/05/11 04:44 PM
Why not PCV? There's nothing wrong with it, it don't hurt performance and it insures that you don't blow gaskets out and oil all over. Hook one up, as soon as you said oil out of the dipstick tube, I knew you didn't have one.
You can hookup 3" hoses and it's gonna do the same thing.
Posted By: Boise Chall
Re: I still have pinging problems with my 512 - 04/05/11 04:56 PM
When I first put the car together the goal was as much hp as I could. Last weekends drive made me realize that I need to not worry so much about hp and at least be able to go past 1/2 throttle without pinging and now not blowing oil all over the place. I'll get a PCV setup installed before I beat on it again.
Posted By: Challenger 1
Re: I still have pinging problems with my 512 - 04/05/11 05:09 PM
Yup, I know what you mean. I did the same thing many years ago. Now I get off on having reliablity just as much or more so than performance.
I love driving my cars on the street, way more fun than just the track.
Can you imagine what your motor bay would look like if you drove the car wide open for like 5 miles at a time on the salt flats or somewhere like that?
Posted By: Viol8r
Re: I still have pinging problems with my 512 - 04/05/11 05:20 PM
Quote:
Why not PCV? There's nothing wrong with it, it don't hurt performance and it insures that you don't blow gaskets out and oil all over. Hook one up, as soon as you said oil out of the dipstick tube, I knew you didn't have one.
You can hookup 3" hoses and it's gonna do the same thing.
Agree........you need a PCV, -10 plugs or -6 NGK and 34-36 degrees total timing. If its mostly street driven, all in by 2500rpm. You were just running to hot of a plug.
I run 11:1 on pump gas with -6 NGK on the street, -7 for the track.
Posted By: Dodgem
Re: I still have pinging problems with my 512 - 04/05/11 05:50 PM
Put the 6.5 power valve in you will be able to go down to 93 straight then eventually go back down in the primary jets.