HEI Accel coil vs. OEM. - The 1947 - Present Chevrolet & GMC Truck Message Board Network

68 Suburban · 02-25-2003, 04:57 PM

Is it really worth the cost of installing an Accel HEI Super Coil? I got a brand new one at a good price, but I am wondering what, if any, benifits there will be on a basic stock engine? Thanks

jku72 · 02-25-2003, 05:59 PM

In order to benefit from a hotter coil, you must have good plug wires, as well the most important thing is to open the plug gaps.
Whether or not its worth it is up to your judgement. I got the super coil, 8.8 plug wires, and opened the plug gap to .055
I think it was worth it for me, as I am trying to make my trucks runs as smooth as possible, and squeeze every bit of power and mileage out as I can, on my extremely limited budget.
just adding a coil without other tuning will provide only limited benefit.

68 Suburban · 02-25-2003, 06:07 PM

Does larger gaps increase gas milage, or just smooth the engine out? Thanks

jku72 · 02-25-2003, 06:13 PM

The bigger gap takes advantage of the increased voltage. It allows a larger spark area, which apparently lights off the fuel charge better. That smooths out the engine, which by definition yeild better power and better mileage. It is an all around win situation.

68 Suburban · 02-25-2003, 07:08 PM

Did you do the gap by trial and error? I guess what I am asking did you ever try a larger gap than what you have and see what would happen? How will the engine react if your plugs gaps are to big? Thanks

jku72 · 02-25-2003, 07:30 PM

It takes a long time to find the right gap. It is difficult to judge unless the conditions are exactly the same for each run.
I use trial and error for setting the gap, I went up .005 at a time. My engine got, in my best judgement, the best all around performance at .055 Your engine may like .060, or it may only want .045 Try each setting and see how it goes.
I also use trial and error for setting my timing, and use the factory setting as a start point only. By doing this, you can optimize the timing for your engine, instead of setting it to a compromise setting that GM made up.

70c10 · 02-25-2003, 07:52 PM

68 Suburban, Accel recommends .045 gap with their coil.

crazy longhorn · 02-25-2003, 08:09 PM

Im running .042 gap , have the Accel coil & module. I havent tryed opening the gap up. As a rule, if you get into a really hot box, like an MSD they will like more gap. Best bet is to play with the gap & see what your combo likes best........crazyL

02-25-2003, 04:57 PM	#1
68 Suburban Registered User Join Date: Oct 2000 Location: From Chicago, Live in Phoenix, AZ Posts: 6,802	HEI Accel coil vs. OEM. Is it really worth the cost of installing an Accel HEI Super Coil? I got a brand new one at a good price, but I am wondering what, if any, benifits there will be on a basic stock engine? Thanks

02-25-2003, 05:59 PM	#2
jku72 Registered User Join Date: Jan 2002 Location: cornville, maine Posts: 659	In order to benefit from a hotter coil, you must have good plug wires, as well the most important thing is to open the plug gaps. Whether or not its worth it is up to your judgement. I got the super coil, 8.8 plug wires, and opened the plug gap to .055 I think it was worth it for me, as I am trying to make my trucks runs as smooth as possible, and squeeze every bit of power and mileage out as I can, on my extremely limited budget. just adding a coil without other tuning will provide only limited benefit. __________________ jku Cornville, Maine 68 C10 burb 42 Willys MB 46 Dodge WF-32 1.5 ton 53 & 56 Olds' 60 Cadillac 22 Dodge Brothers

02-25-2003, 06:13 PM	#4
jku72 Registered User Join Date: Jan 2002 Location: cornville, maine Posts: 659	The bigger gap takes advantage of the increased voltage. It allows a larger spark area, which apparently lights off the fuel charge better. That smooths out the engine, which by definition yeild better power and better mileage. It is an all around win situation. __________________ jku Cornville, Maine 68 C10 burb 42 Willys MB 46 Dodge WF-32 1.5 ton 53 & 56 Olds' 60 Cadillac 22 Dodge Brothers

02-25-2003, 07:30 PM	#6
jku72 Registered User Join Date: Jan 2002 Location: cornville, maine Posts: 659	It takes a long time to find the right gap. It is difficult to judge unless the conditions are exactly the same for each run. I use trial and error for setting the gap, I went up .005 at a time. My engine got, in my best judgement, the best all around performance at .055 Your engine may like .060, or it may only want .045 Try each setting and see how it goes. I also use trial and error for setting my timing, and use the factory setting as a start point only. By doing this, you can optimize the timing for your engine, instead of setting it to a compromise setting that GM made up. __________________ jku Cornville, Maine 68 C10 burb 42 Willys MB 46 Dodge WF-32 1.5 ton 53 & 56 Olds' 60 Cadillac 22 Dodge Brothers

02-25-2003, 07:52 PM	#7
70c10 67-72 Addict! Join Date: Feb 2002 Location: The TAX State! Posts: 7,857	68 Suburban, Accel recommends .045 gap with their coil. __________________ Jim 1970 C/10 Fleetside w/Ghost Flames Lowered 4.5" front and 4" rear (Raked) 355/350 Turbo w/shift kit 10" Redneck Performance Verter w/2500 stall Hooker Super Comps part#2808-1 Performer RPM Air-Gap 12 Bolt w/3:73 gears- Eaton Posi Comp Cams XE262 with 1.6 Crane Energizers, Road Demon 625 and Brodix IK 180 heads

02-25-2003, 06:07 PM	#3
68 Suburban Registered User Join Date: Oct 2000 Location: From Chicago, Live in Phoenix, AZ Posts: 6,802	Does larger gaps increase gas milage, or just smooth the engine out? Thanks

02-25-2003, 07:08 PM	#5
68 Suburban Registered User Join Date: Oct 2000 Location: From Chicago, Live in Phoenix, AZ Posts: 6,802	Did you do the gap by trial and error? I guess what I am asking did you ever try a larger gap than what you have and see what would happen? How will the engine react if your plugs gaps are to big? Thanks

02-25-2003, 08:09 PM	#8
crazy longhorn Fabricate till you "puke" Join Date: Jun 2002 Location: Ill Posts: 9,403	Im running .042 gap , have the Accel coil & module. I havent tryed opening the gap up. As a rule, if you get into a really hot box, like an MSD they will like more gap. Best bet is to play with the gap & see what your combo likes best........crazyL __________________ 69 longhorn,4" chop,3/5 drop, 1/2 ton suspension/disc brakes,1 1/2" body drop,steel tilt clip, 5.3/Edelbrock rpm intake/600 carb, Hooker streetrod shorties,2 1/2" exhaust/ H pipe/50's Flows , 6 spd Richmond trans,12 bolt/ 3.40 gears....



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