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From: Cyril White & Barry Emms
Fromemail: c.white nospam forges.freeserve.co.uk EMMS nospam xtra.co.nz
Category: Technical
Remote Name: 192.168.1.3
Date: 20 Nov 2005
Time: 13:37:42

Comments

I pass on conversation with Barry. The Dm2 changes, rule out cross use of springs. However, there is some good info here that might come in useful. The reference to Maestro's -stems from an article in practical classics where they converted-/ changed a Mini Diz to use an electronic ignition version from a scrap car and I wondered if it was worth while Jowetteers going down that road. From Barry................... Note that the hooks on DM2 springs are at right angles to each other, not in the same plane, as 25D type are. Having said that 1960 dated DM2 type Dizzies have the 25D internals and the later Baseplate. You can tell from the outside by looking at the low tension terminal. It slots into the body as the 25D type does. This > must have been near the change to 25D type. Now to your Moss springs. My set contained 5 springs. I used the heaviest spring which was .039" wire size, .718" long between ID of hooks, .272" OD of coils and 5.5 turns. There is another heavy spring of.039" wire, it is .638" long. Dont use it. The other spring to use looks the same but wire size is .035", it is .626" long, between ID of hooks, .265" OD of coils and 6 turns. There are 2 lighter springs not required. With a 10º Cam (These vary a degree or two but are close enough) The one I used gave me the following result. 1300 - 11º Max 650 - 4º 500 - 1.5º 250 - Nil These are at the Dizzy readings, double RPM and Degrees for Crankshaft. These results are well within Lucas specs for Jav dizzy. Now at about the same time a customer sent me a 1971 Morris 1300 Dizzy for repair. It was 25D4 41257E and had a 10º Cam. Here are its specs.( I dont know if it was manual or auto and there could be a difference) 2500 - 9-11ºMax 1400 - 5.5-7.5º 400 - 0-1.5º 150 - Nil I noted it was fitted with 2 identical springs so I ran it up with just one fitted. Results were: 1450 - 11º Max 1300 - 9º 650 - 2º 500 - 1º 250 - Nil Again this would be close enough to suit a Javelin. 25D dizzies will run OK with just the 1 spring. Some of the Hitachi Dizzies fitted to small Nissans are fitted with 1 spring only, from the factory. Here are the Lucas specs again for the Javelin: 1300 - 9-11º Max 650 - 3-6º 500 - 0.5-3.5º 250 - Nil Regarding the Maestro Dizzy, it still has to be graphed correctly and many Minis use more than 11º Max


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