Pinging with HEI, any thoughts?

[Kaiserman]

Finished installing a Gronk 2100 and HEI last weekend. Been running around all this week playing with my timing. Best I can advance the initial timing with no pinging is 5*. 6* or higher it will ping at WOT. Power sucks at 5*.

I have it set at 8* right now, and it pings at wot and just below wot with the vacuum advance hooked up AND disconnected.

Seems to me it has too much centrifugal advance, pinging at 8* with the vacuum advance unhooked and plugged. Anyone run into the same thing? I've found no real good info via a google search.

I'm running NGK copper core plugs, new fuel pump, 89 octane and I just ran some upper engine cleaner through it via a drip/vacuum set up we have at work.

[Amc1320]

Do you have vaccum hooked to ported vac on the side of the carb? Should be

I had the same issue, adjusted the vacuum advance with an Allen wrench in the hole where the vac hose goes, took a few times to get it right but the ping went away.

Out of the box my hei was adjusted all the way out, seems like I backed it off about half if I remember right

[Amc1320]

Seems like I remember setting it around 6, then adjusting the vac advance from there.

I may have adjusted it from there so I'm  not sure where it is now, I used a vacuum gauge to set everything up, and I usually do the timing by ear and test drives.

i also had trouble with plugs other than auto lights, I've had better luck with colder plugs in amc 6's not sure about nkg's

[Kaiserman]

This one seemed okay at 6, light pinging under heavy load.  6* just seems awfully low. I have a set of Autolites gapped and ready to go into it. I'll try those tomorrow. I guess I'll set it down to 6* again, and dial my vacuum advance down. I'm going to try manifold vacuum as well, HEI's seem to like that.

[Amc1320]

I tried the manifold vac too. Never could get it right

I fooled around with it for days till I final,y got it dialed in, all in all it's much better than when it was stock but it about drove me nuts getting it figured out

[macdude443]

I had the same problem.  Had my initial timing set back at 4 and still had issues.  I have the Skip White HEI.  It comes with weak advance springs installed that allow way too much advance, too fast.  I have a hard time believing they actually curve them correctly, especially at the price they charge for the whole unit.  What I did was buy an MSD advance spring kit and install the heaviest springs into the HEI.  It's about cured it.  I run it at 9* initial now and I don't hear the pinging anymore.  Give it a shot.

The Duraspark distributor has a primary and secondary spring which allowed quicker advance just off idle and then slowly add advance higher into the RPM range.  I've plotted my advance curve and working with that distributor enough to realize that the 258 doesn't like a lot of advance really quick, especially when lugged.  The CJ guys have a lot of room to work when making things peppier, but Eagles, especially wagons, are just too heavy and will cause you problems.  Once I wrapped my head around the factory distributor on my wagon, it was easy to figure out the pinging problem on my SX/4's HEI.  Heavier springs.

MSD Advance Kit 8464:
http://www.summitracing.com/parts/msd-8464?seid=srese1&gclid=CjwKEAjwpPCuBRDris2Y7piU2QsSJAD1Qv7ByydCsZgvku5KMsGQyTbmC_05pz4V_bVmhLZ5jprt6RoCQ2vw_wcB

Just install the heaviest springs into your HEI and see if it helps you.  Run it with the vac advance disconnected until you're happy with the initial and the springs.  THen re-connect and go from there.  The centrifugal advance should really be limited as well, but it's very hard to do on some of the HEI's.  It's easy on the original distributor.

[Amc1320]

X2 on that, I got the spring kit and put in the heaviest ones

Also the vac advance can be adjusted with a tiny Allen wrench in the hole where the hose goes, I had to turn that way down as well

[macdude443]

X2 on that, I got the spring kit and put in the heaviest ones

Also the vac advance can be adjusted with a tiny Allen wrench in the hole where the hose goes, I had to turn that way down as well

I don't know about you, but that Skip White vac advance can takes one strange size allen wrench.

[carnuck]

It's metric so...   I switched to NGK BKR6EK plugs to help kill ping too.

[macdude443]

It's metric so...   I switched to NGK BKR6EK plugs to help kill ping too.

I tried that.  It must be one of those metric sizes that my kit doesn't include.  Figures.

I used those plugs at your suggestion, too and they did help, back before I installed the heavier springs.

[carnuck]

Check with Skip White to see what size it is. If the motor is used, you could have carbon buildup on the pistons. (See my post on the water trickle down the carb with the motor running post) or search decarburizing on youtube.

If the motor is a reman, I would look into changing the timing set for one from a '92 or newer 4.0L or find the 3 keyway set to retard  the cam timing and cut volumetric efficiency which will cut ping. It's how Mopar got rid of the EGR in the HO motors. It also increases the horsepower at higher RPM. as an added bonus but drops the takeoff power at lower RPM slightly.