8 replies to this topic

[o0OWILKSO0o]

Getting confused by distributors...the number on my dizzy is 41907A, which according to the forum is a Lucas 59D4. But mine doesnt have the vacuum trumpet thing. Any ideas if mine is a 59D4 or if the PO took of the vacuum?

[jaydee]

Probably removed the vacuum thingy to have it with fixed advance curve. Probably has bobs and weights modded to have more max advance.
http://members.home....distributor.htm

[o0OWILKSO0o]

could i tell by removing the cap and having a look?

[bmcecosse]

Fit a dizzy with a vacuum advance - you need it for decent economy, and to 'brighten' the engine on initial acceleration.

[o0OWILKSO0o]

is this possibally why she pulls away so crap without building the revs quite a bit?

[carbon]

Is your car a 998 post-82?

The 41907A is a 59D4 fitted as standard to some of the 998s, and did not have vacuum advance.

[o0OWILKSO0o]

It's a 1999 mpi but engine swapped to a 1380 with HIF44. No idea when the engine is from.

[lrostoke]

Pretty much every link I could find for the dizzy mentioned gives it as for 998 A plus

Part Number is ADU 5789 and it does show as having a vac advance unit

As standard it gives a low maximum advance of about 20 degrees @ 4400 rpm

[carbon]

This distributor may not be well suited to your 1380, will need quite a lot of static advance. Centrifugal advance for this dizzy is :
- 2 deg @ 1000 rpm
- 8 deg @ 2000 rpm
- 14 deg @ 3000 rpm
- 18 deg @ 4400 rpm

Above are degrees of advance at crank, and at engine rpm. This is for standard spec unit, as long as nobody has messed with springs or weights.