I was looking at getting a new coil. I have the 7AL3 on my car. I currently have the Pro power coil. It has been on there for quite some time. I am going to change it but when I got on MSD's website I wasn't sure which one to get.

Which coil is better the HVCII or the pro power. One has 70:1 turns and the other is 100:1 turns. I'm not sure what that means.

Any help would be great.

Thanks

I’m old school. In the past oil filled coils rarely went bad.

Modern dry coils fail regularly. I see it often on machines I repair.


I use a Pro Power with a 7AL3 and a Grid controller. I don’t know if the Pro Power is an oil filled coil but it works for me.

The coil is 10+ years old and has worked with alcohol injection or carb and gas carb. on 2 engines

This message has been edited. Last edited by: SCDIV1,

The Pro Power 8201 coil is compatible with 7al2 / 3 + MSD 8.

The HVC-2 8261 is compatible with 7al2/3, MSD 8 and all Digital 7 to include Grid 7720.

More information HERE

Mark, do you know why you aren't supposed to run a 8251 coil with the digital 6 plus ignition? I have a friend who has that box and I have an extra 8251 we were going to put on it but don't want to ruin anything.

Curtis

The 7-AL2 is supposed to have the Pro power coil or the 8251. Now I have been told that one of the Ford factory coils has same specifications and almost same size as the 8251. The 8251 is $150 and the other is like $14 at NAPA or someplace like that. Does require a pigtail but I think they have them now that has wire screws and does not require that pigtail. I have the 8251 on my car but I bought one of the Ford type and keep it in my trailer as a spare.

Also I think this is same thing as I got but with a nice finned aluminum mount and pigtail included.

https://www.ebay.com/itm/A-TEA...047675.c100005.m1851

quote:

Originally posted by Curly1:
The 7-AL2 is supposed to have the Pro power coil or the 8251.

or the 8261

Bruce
You are right that is a FD478 coil in a pretty case. That’s actually a really good deal.
Here’s my story with the FD478 coil. After reading this post on yellowbullet.
https://www.yellowbullet.com/f...1375693&postcount=15

I went to rockaauto and bought a fd478 coil for $15 and a s539 connector for $3, with shipping I was into it for under $25.

I had my engine sitting on the dyno for about a month testing all kinds of stuff, headers, cams intakes..ect. So I ran an A-B-A test with it and my pro power coil and there was no significant difference between the 2. (< .5 HP) This was on a 825 HP 12.5 to 1 menthol injected engine. Now that coil is my spare in case my 15 year old pro power ever takes a dump.

The FD478 doesn’t have a real good way to mount it, that case they put around the one you link to looks like it will work on the motor plate.

Joe

quote:

Originally posted by CURTIS REED:
Mark, do you know why you aren't supposed to run a 8251 coil with the digital 6 plus ignition? I have a friend who has that box and I have an extra 8251 we were going to put on it but don't want to ruin anything.

Curtis

I’m just speculating, but it’s possible the coils designed for the Drag Race ignitions (7al2,3,8, Dig7, Grid) are for shorter running periods at high rpm. I believe this is why they don’t recommend this type of ignition in a circle or street car.

Good post information about the FD478 coil as well.

quote:

Originally posted by markemark:

quote:

Originally posted by CURTIS REED:
Mark, do you know why you aren't supposed to run a 8251 coil with the digital 6 plus ignition? I have a friend who has that box and I have an extra 8251 we were going to put on it but don't want to ruin anything.

Curtis

I’m just speculating, but it’s possible the coils designed for the Drag Race ignitions (7al2,3,8, Dig7, Grid) are for shorter running periods at high rpm. I believe this is why they don’t recommend this type of ignition in a circle or street car.

Good post information about the FD478 coil as well.

That would make sense.

I was having issues with my car last year and traced it to the coil. I had a pro power coil and 7-al2. Replaced it with another pro power coil and ran well the last couple of races.

A friend was having the same issue at the same time. We sent our old coils to be tested and were told by MSD that neither of the coils were working and our cars were running off of the MSD

MSD stated that the Pro Power Coils are not meant to be run in areas where they may get warm, and that gets driven for more than a few seconds.

We were both told by MSD to use the HVCII coil. While neither of the cars have been to the track yet, they both ran better with the HVCII Coil.

I've had the same HVC coil on my car since 2000. I've never tried a Pro Power so I cant say which is better. I do know I've never had any troubles with the HVC coil though.

Alky sbc with a 15 year old Blaster SS street coil on my 20+ year old 6al box.

^^^^^^^^ recommended or approved coil with the ignition = success.

I've got the same deal with the I bought used almost 20 years ago 6AL and Blaster coil. Never had any problems and have doubles of everything. I do see where MSD and many carb builders recommend the blue HVC coil with the 6AL box.

Not to derail the thread. I was reading through the link sr4440 provided. Is it ok or more efficient to just ground the coil - directly to the engine or head. It seems that the coil ground is thru the box by the 10ga ground wire coming from the box. In my case I have a 7al2 ign box with a pro power coil that msd recommend to work with that ignition.

quote:

Originally posted by Wooley:
Is it ok or more efficient to just ground the coil - directly to the engine or head. It seems that the coil ground is thru the box by the 10ga ground wire coming from the box. In my case I have a 7al2 ign box with a pro power coil that msd recommend to work with that ignition.

You want to leave the negative from the ignition box to the coil in place. You can also add a wire from the coil negative to the heads if you desire. This is perfectly acceptable (MSD will also tell you this) and is just redundancy to assure you have completed the secondary circuit of the coil.

Not to derail, but I had an old record holding superstock racer tell me years ago that if you run an extra ground from the coil directly to each cylinder head using fine strand silver wire it will pick up .05 and 2 mph in 1/4. I've never tried it.
Has anyone else ever heard of such a thing? To me it sounds too good to be true, and normally those things are.

I don't know about picking up anything but I ran a ground to my cylinder heads and it goes to the battery. I just got through rewiring some of Pivotdoc's dragster and I did add the ground to the heads plus he added a new HOP alternator to the mix.

Everything worked great in Ennis, the battery maintainer works properly now and the car starts like a dream.