7 replies to this topic

[miniman_78]

I've got a Lucas 65DM4 (42681A NJC10002) distributor today. Can it be used on my 998?
It's a '86 city E high compression (10.3:1) unleaded running on 95RON.
I know I need a different coil but mine is getting weak so needs changing anyway. Is there anywhere a ballast in the wiring that needs to be taken away and if so where?
What would be the best timing to set te engine? On long runs it's getting hot and sometimes it's misfire's when turning the ignition off so I think it will need to be set on 10° advanced instead of 8°.

[Ethel]

It will work, but no 998 came with electronic ignition so can't say how well the advance curve will suit. No ballast is needed, just the correct coil (gcl143). You need less advance if it's pinking & running on.

[miniman_78]

Less? Ok, I'm will check at how much advance it was set before I remove the old distributor and then change it on the new one. (On the info I found 8° was specified as original on 98RON)

[Dan]

Your current ignition system will be ballasted, this is not compatible with the 64DM4 system. The pink/white and white/yellow wires at the coil should be removed, insulated and taped back to the loom safely. Do the same with the other end of the white/yellow at the coil. Then create a new ignition supply (preferably using white cable) from the unfused side of fuse #1 in the fusebox, add a suitable inline fuse to it and use this to suply the coil and distributor.

The advance curve in this dizzy is not very good for the 998, and could be partucularly horrible to live with in a City E. Ignition system specialists can modify the curve quite simply by swapping out the springs and vacuum unit.

[miniman_78]

The engine will be tuned. Next week going to fit a stage 1 kit and in the near future a G202 head and a cam with the 997cooper profile and twin carb.
I my point of view it's lacking power/torque to pull from low revs for the moment (because of the 2.93 diff) and I want it to have more torque over a better range of rev's . I'm not that interested in top BHP, just torque and don't want to change the diff because I do combined city- and long journey driving.
Now I've been told the 65DM4 isn't that good for low down rev's. Is that right?

Edited by miniman_78, 05 December 2010 - 12:15 PM.

[Ethel]

Better ignition (bigger sparks) is always good for torque - the issue is the advance curve, like a stopped clock tells the right time twice a day, you can set any dizzy so its advance curve corresponds with what the engine needs at least once in the rpm range. As Dan says, you can tweak the advance, but that would be easier with a Lucas 45 or 59 as more were fitted to all sorts of Minis & there's better info on them. You could quickly get up to the cost of a programmable system, like megajolt, trying to setup a dizzy to the nth degree. If you don't want to spend that much, look for the best matched factory spec dizzy. If you want torque, I'd also go for the best head spec you can, 998 Cooper over 997 spec.

[1984mini25]

If you have all the bits, try it, you can always switch back. I’ve been running the same dizzy on a 998 with a 2.9 diff for quite a few years now. Yes the advance cure is not a perfect match and if I remember correctly it loses some power at the top end because of it. But it never gets driven above 85ish on the odd occasions anyways.

I tried going back to a proper points dizzy (new points set and timed in correctly), but that lasted all of a few hours, before I switched back to the electronic one. Neither one felt quicker, but the more reliable and powerful spark from the electronic one made is soooo much nicer to drive.

I’ve got so used to just jumping into the car turning, the key, it starts first try and ticks over like ******* cat, plus I’ll never have to worry about changing the points.

Edited by 1984mini25, 05 December 2010 - 01:48 PM.

[miniman_78]

And don't have the problem I had today. This night it started raining and the temperature rised making al the snow melting. There was so much damp the car wouldn't start.