Coil Replacement?

[Obtong]

Over the past week I’ve spent quite a bit of time cleaning the contacts and grimy parts of my '74 MGB. I removed the coil to clean the area beneath it and shook it just to hear the oil swishing inside. I started up my MGB and it started up quicker than ever. The next day I was back to my normal starts, but when I removed and shook the coil the car once again started up really quickly. Are these the symptoms of a failing coil? Victoria British has the Sports Coils on sale right now, so…if the coil needs replacing then perhaps the Lucas Sports Coil may be the way to go.

My questions are these:
1. Does it sound as if my 12v coil is going bad?
2. Will I gain any real advantages from installing a Sports Coil?
3. What effect will spark plug gap size have?
4. What should I set my plug gaps to if using the Sports Coil, does 0.32 sound about right?

Thanks folks,
Obtong

 

[Gary Lloyd]

If you are staying with the original ignition, it will help some!! If you are going with a Petronix, maybe you should check with them first!! It really sucks when you have to buy stuff twice!!

 

[Obtong]

I don't think I'm going to do the Petronix any time soon. (Save my money for MGB essentials and food.) I noticed that on John Weimer's pics the coil was installed upside down. (I've seen this done before, but it's not like that on my MGB.) Is there a reason for inverting it like that?

Obtong

[ 02-26-2003: Message edited by: Obtong ]</p>

 

[Obtong]

I put my new Lucas Sports coil in this evening and wow, what a difference it made! The car started up first time and the engine was quite steady! I set the gaps to about 0.30, and that appears to work well.

This evening I also noticed that a short right-angled rubber tube coming out of the engine (Oil separator hose? Moss # 367-250)was loose and provided no seal to the tube connecting to it, which must have produced air leak. I replaced this with a length of hose I had and put in new hose clips as well. This too made a significant to the sound and steadiness of the engine.

Those two easy changes have made such a difference to my MGB. Today is day one after these changes. I hope that the improvements to the way my engine now works will be permanent!

Obtong

 

[Gary Lloyd]

You may want to try a little wider gap!! Maybe at least .035, you may try .045 and see what happens!! I do not have mine on the road yet, but I do know that with a sport coil you get a waaaaay bigger spark!! If the gap is bigger, it gives more room to fire!! GOOD LUCK!!!!

 

[Bret]

<blockquote><font size="1" face="Verdana, Arial">quote:</font><hr>Originally posted by Gary Lloyd:
You may want to try a little wider gap!! Maybe at least .035, you may try .045 and see what happens!! I do not have mine on the road yet, but I do know that with a sport coil you get a waaaaay bigger spark!! If the gap is bigger, it gives more room to fire!! GOOD LUCK!!!!<hr></blockquote>

Hmmm? Will the sport coil “alone” help improve the revving of the engine? I’m thinking of ordering the sport coil (or something hotter) to see if I can reach the higher RPM range. Also will the Petronix improve the revving still further?

The reason I ask it that while everything mechanical seems sound. I have noticed that in fourth gear going up a steep-grade, my B can’t manage the same rev levels I can on level ground. Putting my foot to the floor she will creep up eventually but never gets into the higher rev ranges. This doesn’t seem right to me.

Any thoughts or suggestions?

Bret

[ 03-09-2003: Message edited by: Bret ]</p>

 

[Steve]

Unfortunately, you seem to be suffering from the same problem that I am. On late MGBs, the emissions junk sapped so much horepower that this is typical. Mine has trouble getting out of its own way.

 

[Dave Russell]

Just a note on high output coils;

You don't get something for nothing. You cannot get higher spark voltage without increasing the current through the points. This will cause more point burning & shorter point life. It is maybe a good tradeoff if you are aware of it.

Electronic ignitions such as Pertronix are designed to handle the higher coil current.
D

 

[Bret]

<blockquote><font size="1" face="Verdana, Arial">quote:</font><hr>Originally posted by Dave Russell:
Just a note on high output coils;

You don't get something for nothing. You cannot get higher spark voltage without increasing the current through the points. This will cause more point burning & shorter point life. It is maybe a good tradeoff if you are aware of it.

Electronic ignitions such as Pertronix are designed to handle the higher coil current.
D<hr></blockquote>

Dave is correct.

But in my case (78 MGBs came with the 45DE4) I already have an electronic ignition.

However that isn’t stopping me from upgrading my ignition system. I am have already ordered Pertronix Flame-Thrower to replace my older stock coil. Likewise I am upping the existing electronic ignition (pickup) with the Pertronix Ignitor as well. The thing to remember before you order anything is to verify what type of system you have. In my case (like most post 75 systems) I have a Ballasted ignition system. So be sure to note this and order the appropriate coil for your application.

Note: I’ve been reading a lot on this subject over the last couple of weeks. I’ve seen several comments regarding up rating older (pre-75) ignition systems to Ballasted type. This is said to be a major improvement.

For more information on this check out the following link:

https://www.mgcars.org.uk/electrical/ballastschematic.html
https://www.mgcars.org.uk/electrical/ballastschematic.html

Good luck,

Bret

[ 03-11-2003: Message edited by: Bret ]</p>