Plug gap after timing advance...
Thread Starter
Senior Member
Joined: May 2009
Posts: 974
Likes: 11
From: Jacksonville, FL
Plug gap after timing advance...
I know there's a million threads out there on the timing bump. But my question is, what should I gap my plugs to if I don't feel like side gapping? I'm hesitant to cut the plugs I have, I just want to gap them. I did a full timing upgrade with 8mm wires, brass cap and rotor, and msd blaster coil and I'm at 16 degrees advanced but I may bring that down to 14. If I don't side gap should it still be .056?
Senior Member
Joined: Jul 2008
Posts: 58,557
Likes: 1,165
From: Long Beach Calimexifornia
If your running a stock 195F thermostat. & you haven't desludged your engine w/ Seafoam & flushed your cooling system. I'd go w/ 14BTDC. More advance than that requires more ducks in a row to do safely.
A bottle of "Water Wetter" added to coolant is helpful insurance against potential Ping incited by further base time advance above 10BTDC.
Motorcraft stock copper cores are also highly recommended as opposed to Platinums. Less likely to ping & much less likely to cause damage if in fact they do.
W/ your set up, if ping occurs, reduce advance. Don't go up in octane.
If stock gap was .042-.046, I'd go w/ .054 w/ your upgrade set up w/ copper cores. Shave that a bit for Plats.
I really like my copper core side gaps, but recommend not to go side gap initially w/ the upgrade. Get comfortable w/ your new set up first. Then you can play w/ side gap.
If you're like me, it's your daily driver & you don't need any disruptions in it's usability. It's not a race to optimizing your engines performance.
I piddled w/ my truck for 6 months. Ridding error codes, cleaning AIC & EGR portways, Removing combustion chamber deposits & injector cleaning, upgrading, trying different thermostat temp ratings, different plugs & gaps, air filters, with/ without additives like "Water Wetter". Dilution % of antifreeze, base time set. The only "no brainer" was desludging, then switching to Synthetic.
Remember, while your compression doesn't have to be that great, only relatively balanced, to do the upgrade. Your compression does have a lot to do w/ what your upgrade ultimately yealds. I'm getting over 20 mpg w/ my 87' 302/87K. But my compression averages 180 psi also.
I went from 10 mpg hwy. to a best of 23 (@65mph) Actually,when I first got the truck, it wouldn't even do 65 mph, unless it was downhill. It's settled into 20mpg hwy for some reason, I think it's time for a plug change. My first set of Side Gap, not sure how many miles they're supposed to last.
A bottle of "Water Wetter" added to coolant is helpful insurance against potential Ping incited by further base time advance above 10BTDC.
Motorcraft stock copper cores are also highly recommended as opposed to Platinums. Less likely to ping & much less likely to cause damage if in fact they do.
W/ your set up, if ping occurs, reduce advance. Don't go up in octane.
If stock gap was .042-.046, I'd go w/ .054 w/ your upgrade set up w/ copper cores. Shave that a bit for Plats.
I really like my copper core side gaps, but recommend not to go side gap initially w/ the upgrade. Get comfortable w/ your new set up first. Then you can play w/ side gap.
If you're like me, it's your daily driver & you don't need any disruptions in it's usability. It's not a race to optimizing your engines performance.
I piddled w/ my truck for 6 months. Ridding error codes, cleaning AIC & EGR portways, Removing combustion chamber deposits & injector cleaning, upgrading, trying different thermostat temp ratings, different plugs & gaps, air filters, with/ without additives like "Water Wetter". Dilution % of antifreeze, base time set. The only "no brainer" was desludging, then switching to Synthetic.
Remember, while your compression doesn't have to be that great, only relatively balanced, to do the upgrade. Your compression does have a lot to do w/ what your upgrade ultimately yealds. I'm getting over 20 mpg w/ my 87' 302/87K. But my compression averages 180 psi also.
I went from 10 mpg hwy. to a best of 23 (@65mph) Actually,when I first got the truck, it wouldn't even do 65 mph, unless it was downhill. It's settled into 20mpg hwy for some reason, I think it's time for a plug change. My first set of Side Gap, not sure how many miles they're supposed to last.
Last edited by ymeski56; Feb 25, 2011 at 04:34 PM.
Thread Starter
Senior Member
Joined: May 2009
Posts: 974
Likes: 11
From: Jacksonville, FL
I set my timing to about 13 degrees advanced yesterday. I'm currently running a 180 degree thermostat, and like I said I did the full timing bump upgrade a little while back. I'll have to double check what I gapped the plugs to and set it at .054. With the timing down to 13 btdc it's running really well. Idling around 750-800 rpm and pretty smooth.
Running 16 I was getting a little popping and my idle would fluctuate a little bit. The engine seems a lot less stressed at 13. Also I have a very unrestrictive dual exhaust setup that dumps under the cab and no egr system. I was getting about 16 mpg at 16 degrees according to my old notes. I'm filling up today, then I'll see what it gets at 13. I'm thinking better since it idles better and seems healthier. If I can hit 18mpg I'll be more than satisfied.
Running 16 I was getting a little popping and my idle would fluctuate a little bit. The engine seems a lot less stressed at 13. Also I have a very unrestrictive dual exhaust setup that dumps under the cab and no egr system. I was getting about 16 mpg at 16 degrees according to my old notes. I'm filling up today, then I'll see what it gets at 13. I'm thinking better since it idles better and seems healthier. If I can hit 18mpg I'll be more than satisfied.