Accel Coils
Senior Member
Joined: May 2000
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From: Virginia Beach, VA
Originally posted by Mach1
Signmaster--it sure is nice to respond to someone that knows...You got the spark theory down...however you did not mention --
Flame probagation..the flame front that moves evenly and controlled throught the combustion chamber...
Signmaster--it sure is nice to respond to someone that knows...You got the spark theory down...however you did not mention --
Flame probagation..the flame front that moves evenly and controlled throught the combustion chamber...
Senior Member
Joined: May 2000
Posts: 1,317
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From: Virginia Beach, VA
Tiger,
What you are referring to is known as side gapping. Both side gapping and indexing are methods to unshroud the spark. I've never messed with side gapping, just seems a lot of hassle compared to indexing. Of course I have a 5.0 powered truck, so indexing is much easier than with the Trition engines. I can actually see my plugs!
Nacho,
It will vary from engine to engine. I believe my stock gap is .040 or .045. After getting my box and coil, the starting point Jacobs recommended was .060. I worked up from there, and have reached a point of maximum gap. The recommendation from Jacobs is to keep increasing by .005 until you feel a miss or decline in performance, then back off by .005. In my case I have pushed the limits to experiment. I have found that best mileage with no noticed performance loss comes at a point where throttle response is "soggy" until the truck starts to warm up.
The better the coil, wire combo the more you can increase. Although the stock coils these days are much stronger, the stock wires still have a lot of resistance. I would guess trying no more than an additional .010 over stock.
Also keep in mind that to some extent you will generate slightly more heat in the combustion chamber due to the more complete burn. On my truck I've noticed that full throttle bursts under heavy load conditions when the water pump isn't spinning as fast causes the temp needle to swing a little. Heat is horsepower....
What you are referring to is known as side gapping. Both side gapping and indexing are methods to unshroud the spark. I've never messed with side gapping, just seems a lot of hassle compared to indexing. Of course I have a 5.0 powered truck, so indexing is much easier than with the Trition engines. I can actually see my plugs!
Nacho,
It will vary from engine to engine. I believe my stock gap is .040 or .045. After getting my box and coil, the starting point Jacobs recommended was .060. I worked up from there, and have reached a point of maximum gap. The recommendation from Jacobs is to keep increasing by .005 until you feel a miss or decline in performance, then back off by .005. In my case I have pushed the limits to experiment. I have found that best mileage with no noticed performance loss comes at a point where throttle response is "soggy" until the truck starts to warm up.
The better the coil, wire combo the more you can increase. Although the stock coils these days are much stronger, the stock wires still have a lot of resistance. I would guess trying no more than an additional .010 over stock.
Also keep in mind that to some extent you will generate slightly more heat in the combustion chamber due to the more complete burn. On my truck I've noticed that full throttle bursts under heavy load conditions when the water pump isn't spinning as fast causes the temp needle to swing a little. Heat is horsepower....
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Joined: Jun 2001
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From: Spicewood
Signman---you got it again....Man you bring back memories...I have been out of it too long...
I dont know that indexing can benefit a stock vehicle...The plug gap thing is a definite must....
Good advice on the gap...Although I think I will try .060---
The wires and coils should not have any problem with this...Ford has always used quality wires IMHO...
On the bikes we were double the stock recomended gap...
The side cut is effective as well..instead of jumping the gap the spark is spread out and like you say opened up to the cc...(unshrouded)...
a good quality plug is a must espically in the older carb vehicles...
A good quality ignition is a must on these...
We did not have the high tech plugs like today so we invented ways to have improvements over the stock...
So you are running the Jacobs...Are these any good ???I have been running the MSD from the mid 70's(still have the original box) The mustang blocks say to use these..Is it a capacitor discharge unit???
I tell you what--I got hit by that MSD w/Accel super coil...That will get your attention...
I dont know that indexing can benefit a stock vehicle...The plug gap thing is a definite must....
Good advice on the gap...Although I think I will try .060---
The wires and coils should not have any problem with this...Ford has always used quality wires IMHO...
On the bikes we were double the stock recomended gap...
The side cut is effective as well..instead of jumping the gap the spark is spread out and like you say opened up to the cc...(unshrouded)...
a good quality plug is a must espically in the older carb vehicles...
A good quality ignition is a must on these...
We did not have the high tech plugs like today so we invented ways to have improvements over the stock...
So you are running the Jacobs...Are these any good ???I have been running the MSD from the mid 70's(still have the original box) The mustang blocks say to use these..Is it a capacitor discharge unit???
I tell you what--I got hit by that MSD w/Accel super coil...That will get your attention...
Senior Member
Joined: May 2000
Posts: 1,317
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From: Virginia Beach, VA
Mach 1,
I don't know that indexing is worth the trouble on a stock engine, but have seen tests in an old Rod mag that showed 3-4 HP on the average run of the mill 350 Chev. I figure if I do several of these small things it's enough to make a difference.
I've been real happy with the Jacobs. In features it is very similar to the MSD off road box. Multi strike at lower revs, single long spark at higher revs, CD, digital and potted. The Jacobs coil is rated at up to 65,000 volts... I haven't got hit by this one yet and don't inted to! I did get hit on one of my old cars with a big Accel coil..... wakes you up fast!
As for side gapping, I might give it a try. Just seems like a PITA to alter the plugs. Maybe side gapped and indexed?
As for the wires and coils, the stockers usually aren't that bad, but I have seen gains in my old street cars. The resistance of the stock wires eats up some of the lesser juice coming from the coil. Combined the result is less spark. On my old Chevelle the hot coil and good wires shaved a little (one to two tenths) off the ET. Of course this is a car throwing a lot more mixture into the jugs.
My next "test" is with the TPS adjustment. Many say to adjust for a 1 volt reading, but the 'Stang crowd claims a slightly lower reading nets better throttle response. I'm going to throw it both directions and find out....
I don't know that indexing is worth the trouble on a stock engine, but have seen tests in an old Rod mag that showed 3-4 HP on the average run of the mill 350 Chev. I figure if I do several of these small things it's enough to make a difference.
I've been real happy with the Jacobs. In features it is very similar to the MSD off road box. Multi strike at lower revs, single long spark at higher revs, CD, digital and potted. The Jacobs coil is rated at up to 65,000 volts... I haven't got hit by this one yet and don't inted to! I did get hit on one of my old cars with a big Accel coil..... wakes you up fast!
As for side gapping, I might give it a try. Just seems like a PITA to alter the plugs. Maybe side gapped and indexed?
As for the wires and coils, the stockers usually aren't that bad, but I have seen gains in my old street cars. The resistance of the stock wires eats up some of the lesser juice coming from the coil. Combined the result is less spark. On my old Chevelle the hot coil and good wires shaved a little (one to two tenths) off the ET. Of course this is a car throwing a lot more mixture into the jugs.
My next "test" is with the TPS adjustment. Many say to adjust for a 1 volt reading, but the 'Stang crowd claims a slightly lower reading nets better throttle response. I'm going to throw it both directions and find out....
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From: Spicewood
Sign-m keep us posted....on the tps sensor adjust...you know what you are talking about...And you bring up a good point about indexing the plugs...every little bit helps...
Before I went with a upgraded ignition...I would be running quality coils and wires....The jacobs sounds pretty good and the mustang crowd likes them..
I have always been a MSD ignition guy and still have my original box from 1977.....
Those things are bullet proof...and they bite big time...(twice in one life is too many times)
Before I went with a upgraded ignition...I would be running quality coils and wires....The jacobs sounds pretty good and the mustang crowd likes them..
I have always been a MSD ignition guy and still have my original box from 1977.....
Those things are bullet proof...and they bite big time...(twice in one life is too many times)