ZZ4 PINGING
Thread Starter
Heel & Toe
Joined: Jul 2001
Posts: 19
Likes: 0
From: Alamogordo NM USA
ZZ4 PINGING
Like to know if anyone else has this same problem with their ZZ4. I get a pinging right after I start to accelerate...If I keep going or ease up it will go away....I have MSD, true duals with headers,Xstream, etc...along with Rapidfires 5. Engine temp is typically about 180F... My Qjet has 72/54 and even at 72/52 I still have this same annoying problem...Gas in this area is 91 Octane at best. Altituded is about 4.5Kft. I am at 10BTDC....Any one have any ideas or suggestions how I can get rid of this problem ??
:confused:
:confused:
Burning Brakes
Joined: Aug 2000
Posts: 1,239
Likes: 0
From: NY
Re: ZZ4 PINGING (JD/76-ZZ4)
The Rapid Fire plugs suck.
Go with NGK or good ole GM AC DELCO (non rapid fire) & a good octane booster
[Modified by 81ZZ4, 8:24 PM 2/3/2002]
[Modified by 81ZZ4, 8:25 PM 2/3/2002]
Go with NGK or good ole GM AC DELCO (non rapid fire) & a good octane booster
[Modified by 81ZZ4, 8:24 PM 2/3/2002]
[Modified by 81ZZ4, 8:25 PM 2/3/2002]
Racer
Joined: May 2000
Posts: 386
Likes: 0
From: Niedernhausen, Germany
Re: ZZ4 PINGING (JD/76-ZZ4)
- I would change over to the original spark plugs first.
- What harmonic ballancer do you use? If it is one from a mild small block (6,5" diam.), then it is too weak for a ZZ4 (should use the 8" HD version) and the outer ring will slip thus screwing up your TDC-mark. With this, any adjustment of advance will be useless. So better double-check the TDC-mark with a piston-stop and then make a copy of the TDC-mark on the crankshaft pully (cannot slip...). Of course a differently positioned TDC-tab on the timing-chain cover could also be the reason for a wrong TDC marking.
- Reduce initial advance to 6 deg BTDC.
- You might as well tune your distributor by means of different (stronger) springs for the centrifugal weights and/or also install an adjustable vaccum actuator for the distributor (ACCEL offers a distributor recurve kit with all that included).
- Change the thermostat to a 160°. This is actually too cold but better than a pinging engine.
- Check carb jets: If the main system is too lean, you will experience pinging, too.
Hope that helps.
- What harmonic ballancer do you use? If it is one from a mild small block (6,5" diam.), then it is too weak for a ZZ4 (should use the 8" HD version) and the outer ring will slip thus screwing up your TDC-mark. With this, any adjustment of advance will be useless. So better double-check the TDC-mark with a piston-stop and then make a copy of the TDC-mark on the crankshaft pully (cannot slip...). Of course a differently positioned TDC-tab on the timing-chain cover could also be the reason for a wrong TDC marking.
- Reduce initial advance to 6 deg BTDC.
- You might as well tune your distributor by means of different (stronger) springs for the centrifugal weights and/or also install an adjustable vaccum actuator for the distributor (ACCEL offers a distributor recurve kit with all that included).
- Change the thermostat to a 160°. This is actually too cold but better than a pinging engine.
- Check carb jets: If the main system is too lean, you will experience pinging, too.
Hope that helps.
