12 replies to this topic

[MattEvans]

Hi All,

I'm hoping someone can tell me the degrees BTDC that my engine/distributor should be set as.

I have a Lucas 64DM4 distributor and a 1275 metro engine.

being a metro set up, it doesn't appear to be listed in the opening to the ignition chapter in the mini workshop manual.

Cheers,

Matt

[JakeJakeJake]

should be set to about 10 degrees

[Ethel]

There are different Metro engines, compression ratio is the main criteria for ignition timing, is it the original dizzy for the engine, do you know what Metro it came from or the engine number?

[MattEvans]

Thanks for the speedy reply Jake!

[MattEvans]

Ethel:

Engine number is: 12HC01AA

The Dizzy that was on it when i bought the car was a 59D, but with a bit of research (and help from various posts here!) i discovered that the 59D was for a metro 998.

i was told the correct one for the engine was the 64DM4, which i have just fitted. I've got the car running now with the new dizzy, but the timing is off, misfiring etc. i didn't want to advance it too much in fear of breaking something!

Thanks again!

[Ethel]

59D was used on all A Series - it just describes the basic type - using the same pattern of points, dizzy cap etc. What makes a dizzy specific to the engine is the centrifugal & vacuum advance - there's a 5 figure stamped on the side that identifies a dizzy fully.

The 65DM4 should work well enough - it would just cost you a little power or economy if it's advance curve differs from the engine's requirements; and like; a stopped clock; it can be set to be right at one point at least.

Are you using the correct coil for Rover electronic ignition? GCL143 or an equivalent?

[MattEvans]

The stamp on my old 59D dizzy was 41882 (not sure of the number on my new one and I'm at work right now so can't check!). I did find a large spreadsheet of dizzy models once; maybe i did figure it was for a 998 by the 5 digit number and not the model number of the dizzy.

i do have the right coil and spark plugs to fit the 64DM4 electric ignition.

If i could get you the number stamped into the side of the dizzy could you tell me (or tell me how to find out for myself!) the exact degrees BTDC or would you need other information as well?

Thanks.

[Ethel]

A quick google does confirm the 41882 is for a leaded 998 from 1985 to 89. It also suggests the engine is from a 1985 Metro with 9.75:1 compression

The serial number of the type 65 fitted to (manual) Minis is 42535A. It's timed to zero degrees BTDC @ 1000rpm, vac advance disconnected - on the original engine.

[MattEvans]

once again, thanks for the reply Ethel!

on the guessworks site my engine number throws back the following info:

Source Vehicle : Metro
Engine type & CC : A Series 1275 cc Transverse mounted

Engine features :
Pre-engaged starter
1985 Requirements
Breakerless (electronic) ignition

is it a fair assumption to believe the 'Breakerless (electronic) ignition' to fit the engine should be the 64DM4 dizzy? and if so it should be, like you said, set to zero BTDC as it would have been the original engine?

Last night i set it to 10 degrees BTDC as Jake suggested. it is running a hell of a lot better, but setting it to zero may well make it better still. i'm tentative to try without knowing a little more as i don't want to advance it too far and cause damage!

side note: does anyone have experience of using a vacuum gauge to set the timing? i've been told it's a good way to set it as it accounts for wear and tear and gets it the best it can be for the particular engine?

Cheers.

[JakeJakeJake]

The stated values are always a starting pont rather than something to set to exactly and leave at.

Usually takes a bit of fiddling to get it perfect.

[bmcecosse]

Swing the dizzy back and forth with vacuum connected until you get the best /smoothest idle. then road test to make sure there is no pinking.

[Ethel]

As above, both your engine and dizzy were built for leaded so the timing will differ with today's juice. If you have a vac gauge you can play around, getting it to run at a good steady cruising speed with the most manifold vacuum - the more it needs throttling, the more power it's producing.

[MattEvans]

thank you for all of your help guys, very much appreciated