330HO ci Spark Plug Gap
July 29th, 2011, 03:23 PM
#1
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330HO ci Spark Plug Gap
Hi- I have a 67 Cutlass with a 330HO, 4bbl, dual exaust, and have replaced the stock distributor and coil with an HID distributor with internal coil. Does anybody out there know if I should set the gap wider on the OEM plugs or swap to a set of plugs more compatible with the higher voltage? Also, the plugs have been fouling and I have a slight skip at lower RPM's and in Drive, but when I floor it, the car still flies. Any suggestions or advice? Thanks and HAPPY MOTORING!!! jimjr
July 29th, 2011, 05:01 PM
#2
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This has been discussed a few times before, and there are a number of opinions.
The factory recommended different settings at different times, all the way from 0.040 or 0.045" to 0.080".
It is generally agreed that anything over 0.060" is too much, and a bit less is fine, but you'll hear different suggestions within the range of 0.035 to 0.060".
I'd say 0.045".
- Eric
The factory recommended different settings at different times, all the way from 0.040 or 0.045" to 0.080".
It is generally agreed that anything over 0.060" is too much, and a bit less is fine, but you'll hear different suggestions within the range of 0.035 to 0.060".
I'd say 0.045".
- Eric
July 29th, 2011, 05:16 PM
#4
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Thanks Eric. I'll try the .040 gap. I also picked up a set of Champion J14YC plugs, which is a hotter plug. Maybe this will help decrease the fouling. Any thoughts on the E-3 plugs?
July 29th, 2011, 05:22 PM
#5
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Just saw your response, Oldsmaniac. I'm really not sure just what the voltage is, only that it's alot higher than the OEM coil. I'll try to find out and maybe adjust the gap up toward .050. Hopefully the new plugs will eliminate the skip. Thanks!!!
July 29th, 2011, 05:27 PM
#7
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I'd be more concerned as to why you're fouling plugs? You have an HEI with wider than stock plug gaps now. Putting in a hotter plug is just a crutch. What type of fouling is it, gas or oil? I have the same engine in my 66 with a stock distributor and stock heat range plugs and it burns clean as a whistle. If you're trying to burn off deposits on the plugs I'd first try and determine what the deposits are and why they are happening.
I'm with Eric on the .045 gap
I'm with Eric on the .045 gap
July 29th, 2011, 05:35 PM
#8
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The HEI distributor is a fairly inexpensive one, not a GM. I probably should pop the original distributor back in, install a Petronix module in it and go with a Mallory or MSD HEI setup. I'm planning on setting up a dual snorkle air cleaner, so I'm going to need all the room I can get. I really don't like my present setup of an Edelbrock open-sided air filter with the valve cover breathers only inches away spouting hot, oily fumes. This can't be good for the mixture. The fouling seems more like oil-related, especially bad on the #1 plug.
Last edited by jimjr; July 29th, 2011 at 05:37 PM. Reason: Add info.
July 29th, 2011, 05:49 PM
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Thanks for all your input. Gotta go off-line for the evening. I'll report my results tomorrow after an oil change, plug swap, etc., along with a good highway run. I'll check compression as you suggest. HAPPY MOTORING!!! jimjr
Last edited by jimjr; July 29th, 2011 at 05:52 PM. Reason: Add info.
July 29th, 2011, 08:47 PM
#13
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Betcha the valve seals became brittle, cracked and fell apart!
Did a 65 442 with A/C a few months ago, and had to clean out all those little pieces - real PIA!
I guess the lifespan on valve seals is around 45 years, running or not, as this car sat for around 20!!
Not a whisp of smoke, once done!
Did a 65 442 with A/C a few months ago, and had to clean out all those little pieces - real PIA!
I guess the lifespan on valve seals is around 45 years, running or not, as this car sat for around 20!!
Not a whisp of smoke, once done!
Last edited by Rickman48; July 29th, 2011 at 08:52 PM.
July 29th, 2011, 10:03 PM
#14
I would go with 060 gap on the plugs.
Unless you're running the car in the 1/4 mile at 9 seconds or less, there is no need for a speical HEI set-up. Stock is fine. I bought a dist from Advanced auto for a 79 Cutlass and threw it in my 1968 Olds 350 in my 1985 Olds Delta 88
Unless you're running the car in the 1/4 mile at 9 seconds or less, there is no need for a speical HEI set-up. Stock is fine. I bought a dist from Advanced auto for a 79 Cutlass and threw it in my 1968 Olds 350 in my 1985 Olds Delta 88
July 30th, 2011, 12:59 PM
#15
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I just finished swapping out the plugs. I gapped them at .050 and went for a trial run. The slight skip disappeared completly, so I feel safe to rule out any plug wire and/or HEI distributor problems. The car also has a huge difference in power. I now think I gapped the old plugs too tight at about .040. The old plugs looked pretty good this time with only a slight brown tinge on the ceramic electrode insulator and no fouling to speak of. I'll run it this way and see what happens. I'll post my results. Thanks for all the help and HAPPY MOTORING!!! jimjr
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