Rusty I have pretty much the same set up as you except for the injection. I had a Holley 650 double pumper on ther and just changed to a Carter 625 (Edelbrock 1406). While there is better bottom end now I had pinging with both carbs about the same and am running 89. Did you get rid of yours? where do you have your timing set and when is you advance in?

 

What is your initial set at? What is your total at say 3000 grand?

 

Most fe dizzys have 16L weight which puts out 32 degrees and 4 to 8 inital is the 36-40 window. I had my old dizzy pulling 50-55 degrees of advance and it pinged all the time. I highly recommend checking it at 3000 or 3500 rpm.

 

What would happen if you retard the cam 4 degrees to begin with?

 

The ping came back, big time. On my way back from southern Iowa too (that's where I was all weekend, helping my brother pull apart an old Chevy pickup, then the cheap-o doesn't even pay for my gas! ). About half way home, it started cutting out, losing power, backfiring on acceleration, etc. I figured the fuel line was plugged up again, since the fuel injection recirculates the gasoline and creates much more of an opportunity for crap from the bottom of the fuel tank to plug things up.

So I take off the fuel injection, remove the line from the fuel pump. Gasoline pouring out just fine. Anyway, I converted it back to the Holley 600cfm vacuum secondary. Didn't help a thing. Still pings like crazy, cuts out, and backfires.

My latest theory is that all the pinging burned up a spark plug. I'll be pulling 'em today and checking 'em. I'll also be pulling the distributor to change the settings in there (from 15L to 10L). I have it at 6 degrees initial now, and the 15L, with a non-adjustable vacuum advance.

I think most of it is the craptacular heads I have on it now. When the machine shop put the hardened exhaust valve seats in, they put 'em in uneven. Some where cut deeper than others. One was flush with the chamber surface, some were about 1/16" in, others were deeper. I was quite angery. Idiots. So I've got a variable compression engine, and I can only guess which cylinder is pinging. Maybe if I cant get it resolved I'll work over my set of D2 heads and pop those on there. Of course, there goes my good gasket seal job.

Another contributing factor is the fact that I've got a 180 degree thermostat in it, and it runs at 195 - 200 going down the road. I am running the old 360 radiator, looks like two core. I'm thinking of getting the biggest 460 radiator available, I believe one for air conditioning.

So that's where I'm at now. Thoughts?

 

You may have a 2 row or 3 row radiator. You would denfinately notice if it were a 4 row because as far as I know they have that massive top tank (compared to the others). Maybe get your dizzy custom curved for your application...

 

Kurt, one more thing, I'm sure you can get 'em cheaper at a radiator shop but I believe LMC Truck sells the heavier duty 4-row radiator.

As a half serious joke, maybe some Edelbrock heads from DSC and an Edelbrock or Weiand aluminum water pump.... But then you would probably want to get the Edel's shaved a little if the chamber are acutally bigger than the advertised 72 cc.

 

Ok just pulled the plugs. #4 cylinder appears to have a massive oil contamination problem. #8 isn't far behind, just looking like it was running a little rich. #4 plug had some thick black sludge stuff on the OUTSIDE of the threads! The rest of the plugs looked fine.

Remember, the machinist screwed up the exhaust valve seats. This wouldn't get oil into the cylinder, correct?

So it's pointing to either an oil ring issue or a valve stem seal. I am hoping the latter. I think it's probably the oil ring though. I'll pull the valve cover and look at 'em. I may need to pull the head to disassemble it to look at the valve stem seals.

Any other ideas?

 

I'm going to recheck the timing and curve tonite but I have a 160 thermostat in and it never gets over 150 on my guage so the engine temp isn't my problem. I'll let you know what find with my timing and curve.

 

Rusty, did your truck start smoking? If you've got a muffed up oil ring, it should smoke, right? Reason I'm asking is I've got oil on the outside of my spark plugs (#4 and #3) and my truck smokes. I have to clean my spark plugs regularly until I can pull the motor and fix it.

 

It did a *little* when I was down at my brother's. Other than that, no. See my new thread for more updates.

 

TastyKlair, you may want to got to a 180 thermostat. Running temperatures below 160 cause engine wear to go way up.

 

I know. Somethng I just learned recently so I will make the thermostat change. My initial timing is at 8 btdc and it does'nt even get to 30 total by 3000 rpm. That does'nt sound like its coming in too fast. Of course with the vacuum hooked up it comes in much quicker and more of it sitting still. Do you think and adjustable vacuum can would help?

 

My 2 cents is, the umbrella type seals are all but worthless. If you get your heads redone, use the positive seal type. and by the way, I got screwed by my 'machinist', too.

 

Positive lock valve stem seals require bronze guides or they'll wipe right out... lack of oil, and all that.