Pinging 440 under heavy load !!!!

[jg68]

Ron, its just your common aluminum stock from Lowes or Home-Dippo , more pics it is

[jg68]

Another

[jg68]

Nother.., i have my aluminum fuel cell stuffed away in the tool box

[firefighter3931]

Awesome Joe.....luv those Convo Pro's ! 


Ron

[jg68]

Thanks Ron , Hey, are you good at reading plugs? what do you think of these, they are the 5670-6 race recessed tip, i'm wondering how to read the heat range.

[firefighter3931]

Joe, the heat range looks good but it looks like the jetting is rich 

Here's a helpful link with some pics :

http://cochise.uia.net/pkelley2/sparkplugreading.html



Ron

[aifilaw]

plug heat range is a factor of engine compression for the most part. You can also figure it out by reading the plugs you have in there now.

Look at the plugs threads, you'll see (hopefully if you aren't completely off) that the threads closest to the electrode will be burnt/heated. whereas lower down they look new and unmolested. you should have about 2-3 threads that are "heated". If you have more threads than that, get a colder plug. If you have less, get a hotter plug.

it looks from the pic like you need a hotter plug... but if you plan on running a higher octane, nitrous, or just romping on it, and you have not been. Stick with those.

Your timing looks dead-on.

they look a tad rich

[jg68]

Update: i went out for a long cruise today & put some 91 Amoco with alittle Outlaw Octane booster, it still rattles , i don't understand it, i'm sure its something simple, just has me stumped, the only thing that seems to help is jetting the piss out of it, but then the plugs burn dark, almost black down in the porcelin, i've changed out fuel pumps, that doesn't help, is it possible that it needs all this fuel , the colder plugs helped it from pinging, but what i don't understand is why it pings with a factory plug, its truely just a 9.1 engine, lowering the timing doesn't help a whole lot, but it runs poorer & feels sluggish.

With the 750 Demon, it would ping with 77/85 jets, i had to go with 84/90 & it stopped, the power felt better.
With the TQ the same thing, i had to jet it way up so it would'nt ping

The ONLY carb that seemed to work really well was a 650dp, even with the stock jetting it was almost dead on, But it wanted a bigger carb, thats why i went bigger, even when i ran one of the 600 holleys it was close, but of coarse the carb was too small, could it be that this 440 is that thirsty

So final thoughts, what is this telling me, i really need to fix this before i tear up a good engine

[firefighter3931]

Joe, it sounds like the engine is going lean when you step on it hard....the vac secondaries and no rear accelerator pumps could be causing all this grief.  It could be rich on the primaries and lean on the secondaries.....

Do you have a chassis dyno in your area ? Might be worth it to do some testing with a wideband o2 sensor to see what's going on. 

The fact that it ran descent with the double pumper leads me to believe that's it's a secondary issue with the transition from mid to full throttle....just a thought 



Ron