Sign in to follow this  
MikeWilliamsUK

12 volt V12 Zephyr query

Recommended Posts

My 1938 Jensen with Zephyr engine has been converted to 12 volt, using Skip's coils and ballast resistor. All seems to be OK. However, the original 6 volt Ballasts were wired in parallel, and with two wires going forward - one to each coil. Using the single 1960s ballast supplied by Skip with the coils, means there is a single point of failure in the ballast itself and the wiring from there to the condersors. Since everything else in the ignition circuit is duplicated this seems a pity.

Has anyone used Skip's coils with the original ballasts?

Thanks,

Mike

(in the UK and sometimes feel out of touch even with fantastic support from Colin Spong!)

Share this post


Link to post
Share on other sites

I'm not using the Skips coil, but I think the idea is to keep about 3 volts or so at the points. (be careful when measuring, they are close to the fan!) The problem is that the stock resistors have a common source, and the additional ballast resistor is in series with the now 12 volt source. If you wanted separate resistors, you'd need to separate the two stock resistors, or replace the assembly with two larger resistors to drop the 12 volt source to 3 volts at the points. Mount someplace where they will get lots of air, these things get hot. I'd guess you need 50 Watt resistors with a value of 1.2 ohms plus the stock resistor value. Measure yours or maybe someone on this forum will know. You may need to try a couple to get the voltage at the points right.

Abe

Share this post


Link to post
Share on other sites

Hi Mike, i'm in England too ! I want to convert mine to 12 volt , are the 12v coils still available ? if not i'm thinking of machining and adaptor and shortening a jag V12 distributor and converting to electronic ,

Cheers

Wayne

Share this post


Link to post
Share on other sites

Hi Wayne,

So far as I know Skip still supplies the coils. You could convert it the way you describe, but the advantage of Skip's is that they are hidden inside the original housing, so are very neat.

I went 12 volt because the previous owner had already started the job, but most people seem to say they run well on 6 volt, so why do you want to change.

Mike

P.S. Would be nice to correspond off-line, since you may be close by!

Share this post


Link to post
Share on other sites

Hi Mike , most of the 6 volt equipment on my Zephyr is toast, it hasn't been used since about 1970 , the loom is rotten which isn't a problem as i'll make one , I started the zephyr a couple of weeks ago and it sounded like it was only going on 6 ,one of the coils looks to be cracked and an electrode is missing , i'm thinking of making mine 12 volt for parts availability and reliability as i use my old cars a lot , the car isn't really good enough to keep 100% original ,also i'm changing it from a 4 door sedan to a coupe (i build cars for a living) I'm going to use as much of the original steel as i can and i will lead load all the seems etc , My zephyr has been in England for about 16 years and no one has really given it any love until now, I'll post some pics when i start rearranging it ,

I'm near Stratford upon Avon where abouts are you ? My daytime phone number is 01789 450001

Cheers

Wayne

Share this post


Link to post
Share on other sites

I have my coil converted to 12 volts which was done by Skip. I am using 2 of the resistors that can be bought at NAPA I have a wire from each condenser going to each resistors and the main wire to the other side of one of the resistors. I have been driving my car for the last 2 years with no problem. My V12 was installed in a 1932 Roadster if you need my schematics and a picture how I did it let me know and post them here. You can see on my website a picture of the resistors. All of my wiring was installed under the seat. Home

Frenchy

Share this post


Link to post
Share on other sites

Wayne

Here is a picture of my wiring that I was doing for my 32 Ford Lincoln Powered V12. In the picture you can see the two ballist resistors in white mounted side by side. The blue wire on one of the ballist going to one side of the coil condenser. The light green wire on the other ballist going to the other side of the coil condensor. The two dark green wires are to be joined together and going to the hot side of the ignition via the fuse box than to the ignition switch. If you have any issues with this call me. The wiring was placed under the seat for easy access including all switches.

Frenchy

602 257 8680 Office #

post-54855-143138603654_thumb.jpg

post-54855-143138603657_thumb.jpg

Edited by frenchy dehoux (see edit history)

Share this post


Link to post
Share on other sites

Thanks for the pics Frenchy and the link Peecher ,

The wiring makes sense , my zephyr is a long way off yet but these threads will help lots of others too ,

Thanks everyone !

Wayne

And nice roadster Frenchy !!

Share this post


Link to post
Share on other sites

WHAT ARE THE NAPA #S  TO GET   FOR YOUR V-12    THANKS

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
Sign in to follow this