Lucas 'OPUS' dizzy

chalky · Post by **chalky** » Sat Jan 10, 2009 7:02 pm

First off Hi to all from a noobie! Hope you can help.. I'm building a trike with an SD1 V8, it has the 35de8 opus ('opeless..) dizzy. Unfortunately the guy who supplied engine forgot to give me the amplifier & I've only just found that it needs one! He remembers that it's a bulkhead or inner wing mounted one about the size & shape of a motorcycle CDI unit but that's it! the rest of the car has long since been scrapped

the only ones I've found are the units that mount on the dizzy or on the coil, can't afford to go the alternative aftermarket route! Any ideas on other options & how to wire it up? Thanks muchly in advance

ChrisJC · Post by **ChrisJC** » Sat Jan 10, 2009 7:19 pm

I would get a later unit from a Range Rover, with amp-on-distributor, and with the coil to go with it. Then it's simply a case of wiring IGN +ve to the coil +ve and amp, and connecting coil -ve with the amp.

Chris.

jrv8 · Post by **jrv8** » Sat Jan 10, 2009 9:38 pm

Hi ,
It's not an external amp that you need for the OPUS system , it's a ballast resistor block.
I have some secondhand ones in stock that have been tseted ok, if you're interested , please drop me a pm.
Regards
Jim

chalky · Post by **chalky** » Sat Jan 10, 2009 9:56 pm

Cheers, I'll have to stick to the opus for the moment, trike's using up my funds quicker than a footballer's wife

I'm pinning my hopes on Jim for the moment

Darkspeed · Post by **Darkspeed** » Sat Jan 10, 2009 10:21 pm

Just connect it to a 12V dizzy with a good 12V feed and dont bother with the ballast pack.

Red to positive White.blk to negative

Andrew

chalky · Post by **chalky** » Sat Jan 10, 2009 11:03 pm

tried wiring it up direct but no spark! might try again in morning but not holding my breath... I presume I can take the test socket out of the loop? also, is that a condenser attached to the side of the dizzy? certainly looks like one!

Darkspeed · Post by **Darkspeed** » Sun Jan 11, 2009 7:03 pm

Never had a test socket in the loop on any of mine and yep thats a condenser so check it.

Andy

jrv8 · Post by **jrv8** » Sun Jan 11, 2009 8:09 pm

Darkspeed wrote:Just connect it to a 12V dizzy with a good 12V feed and dont bother with the ballast pack.

Red to positive White.blk to negative

Andrew

I wonder why Rover went to the trouble and expence of providing a ballast resistor in all their cars, if they could just have connected it up like that.
Maybe , just maybe, this is not a good idea.

Jim

Darkspeed · Post by **Darkspeed** » Sun Jan 11, 2009 10:49 pm

I could go into a long post about the introduction and the benefits of the ballasted low voltage ignition system but its well documented and easy to find elsewhere.

Suffice to say its a production car system for people starting cars with weak batteries on the coldest day of the year with lights on etc. etc.

Hell what do I know he may have electric windows a heated screen and a 400W stereo on the trike and need a low voltage system......

Andrew

chalky · Post by **chalky** » Mon Jan 12, 2009 5:43 pm

I've decided to go the points route, don't need high performance in a trike that weighs under a ton

it'll be easier to fix if it breaks down up the road as well! Thanks for your advice & help everyone, especially Jim the mad tractor builder! I'll try to put a photo on when I figure out how... computer illiterate? Me?

Pocket rocket · Post by **Pocket rocket** » Mon Jan 12, 2009 7:04 pm

Pics of the ballast resistor unit and the OPUS wiring are in this thread

http://www.v8forum.co.uk/forum/viewtopi ... highlight=

chalky · Post by **chalky** » Tue Jan 13, 2009 10:29 am

cheers for the link to pics but, luddite that Iam, I'm going for points, easier to fix at the side of the road

ppyvabw · Post by **ppyvabw** » Thu Jan 15, 2009 12:14 am

jrv8 wrote:
Darkspeed wrote:Just connect it to a 12V dizzy with a good 12V feed and dont bother with the ballast pack.

Red to positive White.blk to negative

Andrew
I wonder why Rover went to the trouble and expence of providing a ballast resistor in all their cars, if they could just have connected it up like that.
Maybe , just maybe, this is not a good idea.

Jim

. For the reasons already stated a ballasted system has benefits for starting with weak battery etc etc...gives the ignition a higher voltage kick when you start it by bypassing the resistor.

The only problem I can see with removing the ballast resistor is the coil will die quicker from having to much juice going through it. No other disadvantages than that. I have no idea how long it would last tho. I don't know much about the OE 'opeless' systems, but a non ballasted coil would fix that problem wouldn't it? Or is there electronics in the dizzy that might die from not having the resistor?

This is why I stick to points, it's bloody easier and the dual point dizzys are fine for performance if you keep them well maintained i used to find.

Eventually I got sick of adjusting the f***ers though.

chalky · Post by **chalky** » Thu Jan 15, 2009 12:19 pm

when I'm on my way to a bike rally with a slab or two of beer with my name on 'em, the last thing I want is to need Magnus Pike to explain why my dizzy is a spark-free zone...

as for the opeless dizzy, too many wires, too complex for me, electronics are fine when they work, my wagon' dash looks like blackpool some cold mornings, all flashy lights & gongs but nowt wrong! It is Italian though...

satancom · Post by **satancom** » Tue Jan 20, 2009 8:37 pm

Darkspeed wrote:Just connect it to a 12V dizzy with a good 12V feed and dont bother with the ballast pack.

Red to positive White.blk to negative

Andrew

This is how I wired mine up as its all I had available.. Starts fine in the cold (big battery and no accessories). Has been reliable and not caused any issues.. Only done a 1000 miles in it so far and have a spare (well 2) coil in the back anyhow so not worried as they only cost about £5 each!

It works as this guy says with no ballast resistor etc

The V8 Owners Forum -

Lucas 'OPUS' dizzy

Lucas 'OPUS' dizzy

'opeless dizzy..