440 pinging

-
wazoo64

wazoo64

Well-Known Member
Joined
Aug 22, 2006
Messages
766
Reaction score
14
Location
York, South Carolina
Just picked up a coronet with a built 440 but pinging and off idle hesitation. It's got a vacuum dizzy and specs below. Any quick tips to troubleshoot? Also, I'm curious if I should go MSD, aluminum heads with roller rockers. Would i see a big HP gain? Here are the basics.


Engine: 1964 440 cu.in (.30 over)
*balanced and blueprinted
*906 heads w/stainless valves, double springs and new guides/seals
*double roller timing chain
*10.9-1 KB pistons
*steel crankshaft
*HP windage tray and HP hi-performance oil pump
*street hemi (purple shaft) cam (284 degree duration)
*mopar high performance medium rise, dual plane intake manifold (M-1)
*edelbrock 750 CFM carburetor (Carter AFB)
*professionally built
*very strong and rated 500hp
 
If it really has 10.9 compression, there's your problem.
 
Pistons and cylinder head volume and head gasket....block deck height and such.
 
W eneed details. Piston part number. Head gasket thickness. Assembled deck height. Head chamber volume. Just because it had "10.9:1 pistons doesn't mean it has 10.9 compression. Although since it is spark knocking, it might.
 
All the above, plus, get a timing light on it and find out total advance (not including vacuum adv.). Shouldn't be more than ~34*.
 
Is this a street car? If so, the vacuum advance is your friend for part throttle power and mileage. I'm sure you can adjust the timing to compensate. Was it hooked to ported or manifold vacuum?
 
Yes it's a street car but I just want it to run as smooth and fast as possible. I don't care about mileage. The advance was connected to carb and I plugged the carb.

I'm thinking of just going MSD mech dizzy with 6a box. My valiant runs flawless with that set up.
 
What I am asking is if the vacuum advance was hooked to a manifold source or ported source. The carburetor has both. It sounds like it might have been on a manifold source. If it was, you should be able to run it. It will run better with it.
 
That has to be with the vacuum advance hooked up. The longest plate I've ever seen was 22 and that is still only 44 degrees mechanical. You should be able to stick an allen wrench in the pot and tone it down some for the best of both worlds.
 
Just remember, adjusting that allen screw does not adjust the amount of timing. That stays the same. All that adjustment does is make the spring stronger or weaker....in other words it adjusts when the advance is all in.
 
wazoo64 said:
8* was at idle. 58* total. Spring or ECU issue?
Click to expand...

ECU has notheing to do with advance. You may have to change springs, or restrict the total mech advance by welding up the slots. Should be around 34* at approx. 2000/2500rpm, with vac advance disconnected. After you get that nailed down, you can add vacuum advance of around 10/15* for driveability. Initial should be as much as the engine will stand without "hitting against the starter" when cranking.
 
65Val said:
ECU has notheing to do with advance./QUOTE]

This isn't entirely true. The MoPar blue and orange box both retard timing at high RPM. The Standard Ignition LX 101 does not. On a really hot engine, you probably want some timing retard at high RPM to keep detonation from happening.
Click to expand...
 
Ok I think I can tackle the dizzy problem now. What about the off idle stumble with carter AFB? Acc pump, squirters, ? I'm not familiar with this carb and adjustment.
 
You must log in or register to reply here.
-

Back
Top