I've got a 1964 327 365hp and have a problem with fouling plugs to the point of engine misfire within 500 miles (about 5 of 4 of 8 are bad only 2 remain unfouled). The problem is relatively new but my engine rebuild is about 10,000 miles old (1993) with all correct components (solid lifters, holley carb, etc.). I've got my timing set at the 'A' mark on the timing tab (there are no numbers on the tab with this engine) - I'm pretty sure that correct. The car doesn't burn oil (no smoke). When I take my car out I'm very careful about making sure the car has a chance to run at normal temperatures and I stay in 2nd or 3rd gear when cruising around town with my 3.08 gears. The Holley is new and the choke works and I've got the heat riser installed. I replaced my AC44 plugs with replacement AC43R plugs from the dealer but the problem seems to have worsened. Is this a simple fix or do I have potentially bigger problems.
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Re: fouling plugs
Gavin----
There are a lot of conditions that can cause fouled spark plugs. First off, you need to determine what is causing your fouling condition. In other words, is it oil or gas? Even if your engine is not "burning oil", you could have oil fouling if enough oil is entering the combustion chamber at certain times. Look for OILY black deposits to confirm oil fouling. If this is your problem, there are many possible causes, but the prime one that I would suspect would be valve guides or seals. When your heads were rebuilt were the valve guides "knurled" or were they replaced with inserts? "Knurled" valve guides have a life of about 10,000 miles.
If your problem is caused by excessively rich fuel mixture, there could be a problem with the carb, even though it's new. Other possibilities are a weak spark caused by an deficient ignition coil or other ignition problem.
You are correct with respect to engine initial timing setting. Your engine specification is 12 degrees BTDC and this corresponds to the alignment of the balancer timing mark with the "A" on the timing tab.
As far as plugs go, the AC43R are one heat range colder than your original AC44 plugs. This is the opposite direction of where you should want to go. I'd try the equivalent of an AC-45. I recommend the use of Champion Spark Plugs for Chevrolet engines, so I'd obtain the Champion equivalent of the AC 45 or 45R.In Appreciation of John Hinckley -
Re: fouling plugs
43s are way to cold for the street. The owner's manual for my '63 recommends 44s for "town and country driving",and they were the OEM plug but they would foul, so I switched to 45s for normal street driving I used 43s to hot lap the old 2.25 mile Kent road course. Also, it took me fifteen years to figure out how to make the Delco single point distributor work. Is that what you have or do you have a TI? 308s, eh? Obviously with a CR 4-speed. That's what I have in my 340. It's kinda neat to do 75 MPH in first gear!Comment
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Re: fouling plugs
Gavin -
Try Champion RJ16YC's - equivalent of an AC 46; 43's are "race-only" plugs, far too cold for street use, and Champions for some reason are far less susceptible to fouling than equivalent AC's.
JohnComment
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Re: fouling plugs
Had the exact same problem with my '64 327/300; problem seems to have been the coil not putting out enough energy. Compare Ohms readings between your coil and an over the counter coil. If you have more resistance in your original coil that could be the culpret. Good Luck!Comment
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Re: fouling plugs
I wouldn't use a resistor plug on this application since the available ignition energy (assuming it's a single point) is already marginal, and an AC 46 might be a bit too hot. My '94 Champion catalog cross references both the AC 44 and 45 to the J8C and the extended tip 44S and 45S cross references to the J14YC and J18YC, respectively. These Champions are modern copper core plugs that generally have a wider heat range than the OEM ACs, but I think the current ACs are also copper core. Champions also have a more corrosion resistance shell than ACs. Beyond this understand that hyper engines such as a 327/365 need frequent "Italian tuneups" to keep the plugs clean.
DukeComment
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Re: fouling plugs
Champion uj12yc to uj14yc plugs will solve the problem. They are the equivalent of the 44s plugs that AC no longer makes. They have an extended tip to put the tip into the gas flow and minimize fouling. Do not use resistor plugs with resistor wires. You will overload the coil. Correct coils are expensive. To use resistor plugs, switch to metal core wires - and kiss your radio reception goodbye. Good luck - DaveComment
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