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Anonymous
Guest
im curious as to what you guys gapped your spark plugs to? mine is currently at .045, but am thinking to play around more + or -...
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Anonymous
Guest
I run a 42 with my Pertronix II. Think 45 is common. Don't recall seeing anyone suggest using more than 45.
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Anonymous
Guest
I have mine gapped at .048 with a Duraspark & stock module. After I get my MSD module installed I'm going to try increasing it to .050 
Later,
Doug
Later,
Doug
66200i6
Famous Member
I am running .075 (the most I can get from a Autolite) with the Jacobs Mileage Master. With a healthy system (tuned regular) you can increase easily another .006. With a good low resistance wire set you can add another .006. If you add a good high-energy coil you can add .007. Or, with a full Jacobs system (includes computer, coil, wires) you can add .025.
On the other hand if you don't tune often you can start subtracting .004 gap. If you are going use all you’re new found power in that six most the time, you can subtract .010 gap.
Of course every system is different so experiment and find the best setting for your rig.
Ric.
On the other hand if you don't tune often you can start subtracting .004 gap. If you are going use all you’re new found power in that six most the time, you can subtract .010 gap.
Of course every system is different so experiment and find the best setting for your rig.
Ric.
howdy 66 tang stang and All:
Ric hit the nail on the head. If you continue to increase the plug gap with no reference to improvements you will increase wear and continually find your weakest link. That gets unneccisarily expensive. To experiment, get a tape recorder, a stop watch and an accurate, easy to read speedometer or tach. This is best done with two people in the car, but, I've done it alone. Identify a range, say from 20 to 40 MPH in 2nd gear, or 1.500 to 3,500 rpm. Start the tape recorder, read off the times into the tape recorder. Play back and analyize once you're done driving. Write them down to record for reference. Do this on a safe, lonely stretch of straight road. Start by establishing a base line before you change anything. Do each test several times to establish consistancy. Do each test exactly the same. The goal is to identify change, and hopefully improvements. If opening the gap shows no improvement, you've reached the capacity of your spark plug system for your engines state of tune. Now begin reducing the gap .005" at a time until you see a decline in performance. At that point go back to the previous setting. This is your engines optimum gap for that plug on that engine on that day. Any more than that will simple taxes all the components to an earlier failure and increase heat.
If you change timing, heat range, plug manufacture, or other ignition, intake or exhaust components you will need to start over. Heck, the weather, from day to day, can be a factor.
So, with a top notch electronic ignition system in a clean running street car, .050" gap is a good generality. .040" with a good point system.
Adios, David
Ric hit the nail on the head. If you continue to increase the plug gap with no reference to improvements you will increase wear and continually find your weakest link. That gets unneccisarily expensive. To experiment, get a tape recorder, a stop watch and an accurate, easy to read speedometer or tach. This is best done with two people in the car, but, I've done it alone. Identify a range, say from 20 to 40 MPH in 2nd gear, or 1.500 to 3,500 rpm. Start the tape recorder, read off the times into the tape recorder. Play back and analyize once you're done driving. Write them down to record for reference. Do this on a safe, lonely stretch of straight road. Start by establishing a base line before you change anything. Do each test several times to establish consistancy. Do each test exactly the same. The goal is to identify change, and hopefully improvements. If opening the gap shows no improvement, you've reached the capacity of your spark plug system for your engines state of tune. Now begin reducing the gap .005" at a time until you see a decline in performance. At that point go back to the previous setting. This is your engines optimum gap for that plug on that engine on that day. Any more than that will simple taxes all the components to an earlier failure and increase heat.
If you change timing, heat range, plug manufacture, or other ignition, intake or exhaust components you will need to start over. Heck, the weather, from day to day, can be a factor.
So, with a top notch electronic ignition system in a clean running street car, .050" gap is a good generality. .040" with a good point system.
Adios, David
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Anonymous
Guest
Hi everyone.
A friend of mine just tried the new Bosch Platinum+4 plugs and he said that they are excellent. You can feel the difference in starting, idle and acceleration.
Does anyone has any exprerience with them? Do they really make a difference? Cost vs improvement?
Thanks
Vas
P.S. My car has the stock ignition.
A friend of mine just tried the new Bosch Platinum+4 plugs and he said that they are excellent. You can feel the difference in starting, idle and acceleration.
Does anyone has any exprerience with them? Do they really make a difference? Cost vs improvement?
Thanks
Vas
P.S. My car has the stock ignition.
I haven't tried them in a ford six, but I put a set in the Jag. The engine did feel better and idled smoother. It has also picked up 1mpg on average over the last several tanks of gas.
The Bosch +4's are like having four j-gapped electrodes on each plug. Of course, only the one with the lowest resistance will fire, but I suspect that in the high swirl, pent-roof, high compression Jag engine, it may vary according to condition. And the fact that the spark kernel is completly unshrouded may be a factor as well.
Not all plugs will work best in all engines, but I think there's some merit in the newer plug technology.
The Bosch +4's are like having four j-gapped electrodes on each plug. Of course, only the one with the lowest resistance will fire, but I suspect that in the high swirl, pent-roof, high compression Jag engine, it may vary according to condition. And the fact that the spark kernel is completly unshrouded may be a factor as well.
Not all plugs will work best in all engines, but I think there's some merit in the newer plug technology.
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