Help Me with my Pinging issue... Please

[Gordz32]

Alright everyone, So for the last couple of weeks I've been trying to solve my pinging issue on my El Camino. The pinging starts at about 1800rpm when I'm accelerating just beyond cruising speed, and it happens only when the car is up to temp. I'm running a 454 bbc 9:5:1, cleaned up iron chevy heads with a Wieand stealth plane manifold, Edelbrock 1411, and for a cam I've got an Isky #396286 with 224 degrees on the intake and exhaust at .050" lift. The trans is a turbo400 with a Hughes 2500 stall converter. The carb is jetted two stages richer on the edelbrock 1407 chart with 116 main jet with .070 x .047 rods and pink springs secondaries are stock with 107 jet. I've got a Accel HEI distributor with adjustable vacuum advance turned all the way in to provide zero advance right now. Initial timing is at 12 degrees with mechanical all in at 3000rpm at 32 degrees. Plugs are r43xls delco's set a .045 gap .So this stuff is all new to me and I've been learning on this car. But it's my dd so I'm worried about the pinging. Any help is always appreciated.

[GregWeld]

"Pinging" is PRE ignition....

This can be caused by something "hot" (think embers from a fire) firing the charge off before it should be --- and or incorrect timing.

12* initial looks about right but 32* total is probably a bit low on the fully advanced side. BBC's can handle 36* even with iron heads.

So = have you checked the timing with the advance connected? It sounds to me like you might have screwed the vac cannister all the way in - and maybe added timing and just don't know it. Only way to tell is to hook up the old timing light and check it.

What is your vacuum under LOAD? You'll have to get yourself a vacuum hose long enough to run from the source (carb) into the passenger compartment and have someone read it while someone else drives. Cruise light load - flat terrain.... read it - then get it into ping mode and see what it reads. Just searching for an anomaly here...

How are your plugs? If they've been glazed or fouled - they could be the uncontrolled ignition point.

[Vegas69]

I agree with Greg, get a vacuum gauge on it and go for a ride. I just did the same today in my car. Not for pinging, but to dial in my power valve which I found was on the money. That leads me to my next question, does the edelbrock have a similar enrichment circuit when manifold vacuum reaches a certain point? You timing numbers look good at first glance but...:unibrow: You have a pretty tiny little cam that makes a boat load of vacuum. Your mechancial advance may be bringing in the timing to quick under load. I'm not familiar with Accel but you should be able to tune your timing curve. If not, I'd try say 5 degrees less timing and see if it goes away. How many miles are on the engine? If it has some miles and has been run way to fat or burns oil, you could have a hot spot like Greg mentioned. Pull a plug and see if it has oil or fuel deposits.

[Gordz32]

Thanks guys, I played with the weights and springs in the dist yesterday and I think I might have taken care of it. I had a hunch that my mechanical advance was coming in to early. Had time to take a quick ride around the block and lay in it a bit and didn't hear any pinging. So today I think I will hook my vac advance back up and bump up my initial and see what happens. I'll let ya know

[LowchevyII]

good luck man, hope it all works out for ya. I figured id leave any advice to someone that knows a thing or two. the only thing i know a thing or two about is these nagging little gremlins that can really make you pull your hair out. good thing for people like greg and vegas whom really know what theyre talking about. hope the problem is solved.