Chief did you disconnect the vacume advance when you made the timing change? How much higher is the idle then when you started? 94 octain may be too much for you engine to handle. With the compression you have being 8.5/1 you should be able to run on 89 octain all day long (mid grade gas). You still didn't tell us what carb you are using.
Is the vac. adv. still disconnected? or did you re connect it for the test drive? You really need to find out what your total timing is. Leave the vac. adv. disconnected and have some one else rev the engine to 3000, then 3500, then 4000, then 4500, and hold it at 5000 rpm long enough at each step for you to see what the timing is. You have to make sure the advance isn't still going past 4500. You will need a dial timing light for this so if you don't have one ask around to borrow one. Don't buy one unless you really want to have one.( I bought one.) :Here is another cheap test for you to look at the carb. (FREE) place your hand over the primaries and cut off some of the air going into it while its running. Does the engine rev a little higher before it starts to stumble? or does it stumble right away? If it revs a little higher before it stumbles you have a lean condition and you may try to turn out the idle mixture screws another half to full turn to see if it eliminates the lean condition (does not rev when you cover the primaries). If it stumbles you most likely don't have a lean condition. You can also give it a little gas by depressing the accelerator pump with out using the throttle. If you barely push the pump and the engine doesn't stall you have a lean mixture. If it does stall you don't. Simple checks for you carb.:Brow:
Jason, Like Kevin said, EGR reduces peak combustion temps. It mixes exhaust with the incoming mixture to dilute it, and it burns at a lower temp. This prevents formation of oxides of nitrogen. It also lowers power. I've seen many engines equipped with EGR ping when the system becomes disabled. Just going with my experiences. I think richer carb metering will go a long way to reducing the pinging. I'll bet he's got lean jetting. I would check that first. He may also be missing the advance stop bushing in the distributor, and we all know that will allow way too much advance. He needs to check his total advance as you suggested.
tha happend to me because the last owner was putting regular in it. i started to put premium in it and it stopped. its not a car b problem. u just have to spend abo;ut 5 bucks mor for a tanks a gas
Well Larry it looks like I was all screwed up!ou: What you say makes since. I'll have to remember that for the future. Chief may still be to lean but I wanted to save him money if I could and maybe solve the problem with some thing simple. Too often many of us just start throwing money at a problem and waste a lot of time and effort with out solving the actual problem. I've been the victom of this very easy trap more than I would like to admit.
Hey chief, I have a '73 350 that was giving me what sounds like the same symtoms. Mine turned out to be stupid-simple. On the passenger side of the carb, on the manifold, mine has a temperature thermostat that regulates the carb via an arm. (sorry don't know the technical name for it) It turned out that the gasket that seals the opening was fragged and blew exhaust past it. It sounded exactly like what you are describing, only under load. Check it, if it is the problem, you'll save yourself a whole lot of hassle.
One important thing you guys forgot to mention that will cause severe pinging like this is engine overheating. If your thermostat is stuck or you have some other kind of coolant system problem causing the engine to run too hot, it will cause this same problem just the same as incorrect timing will. I had this very problem with my '65 Special with the high comp. 4bbl. 300 engine. Even with 93 octane gas and the timing retarded 2 degrees, it would still ping when I got on it. I finally fixed it completely by putting a 3 core radiator in it out of a car with Factory AC on it. My car was built back when 100 octane fuel was plentiful and was designed for the high octane fuels. The lower octane stuff we have today (93) actually has more energy and causes the engine to run hotter than it would with 100 or more octane fuel. That is why the larger radiator was necessary to run properly on todays fuel.
I guess your reply about the cam bearings was referring to my 300? If so, yes I replaced them when I completely rebuilt the engine. I also added a jumper tube on the back of the block to connect the oil flow between the driver and passenger side cam oil galleys. My pinging problems were all about the car running a little too hot--in the summer time it was noticeable that it didn't stay as cool as it should. It would get up to 200--210 deg. if you got caught in city traffic with it. The bigger radiator cured all of that. My car is a 4-speed car too, so it wasn't related to the transmission heating up.
problem solved!!!! well my noise problem was a series of exhaust leaks coming from the intake manifold. This car is a california model that has a EGR valve that was leaking, the carburetor choke opening was leaking and the air system opening also on the intake manifold. I appreciate all your coments and sugestions. :Brow: case closed!!!!!! :beer
