Distributor

[Guest Jonathan Tall]

I've gone to twin 45s with the standard bosch vacuum advance distributor, whats the advantage of vacuum advance and how can I regain it? Do i need some hyperexpensive non vacuum advance type dizzy?

[Guest stevey]

vacumn advance will allow the timing to advance(and retard)to allow the optimum timing for all throttle conditions. to illustrate this some racing engines are reluctant to fire when cold as the timing is set for full throttle operation,whcih would be a real hassle on the road. If you look at your manifold there will numerous blank areas on the casting which may have a plug in or at worst you may have to drill a small 3/16th hole into manifold and araldite a piece of brake pipe in and that will sense change in manifold pressure,if you do not feel safe doing this contact "Burton engineering" in Essex they are the leading Ford tuning people in the country and will sell all you need to make it work

[Guest boggie]

Hi Jonathan,

I had the same issue as you when I fitted the 45's. You are basically faced with 2 options;

1. Get your self a non-vacume dizzy.

2. Drill holes in the inlet manifold.

 

However it is no good just drilling one hole in one branch of the manifold as you will get pulsing at the distributer as the inlet valve for that particular cylinder operates and you will not get proper advance. The only way to achieve a true vacume advance is to drill each of the four branches at the top, insert a short piece of pipe into each one and then join them into a slightly larger common pipe running along the top (it will look rather like a common rail fuel injection system). Also I would not recommend simply using alaldite to fix them in as with heat/vibration this will fail eventually and you will loose your vacume. Make the holes an interference fit so you have to tap the short pipes in firmly with a hammer. To join them into the common pipe you will be best to use plummers solder and a blow torch. This is all a lot of hassle so you may decide to go down the non-vacume route but it is worth doing as you will get a better advance and a more efficient engine.

 

Hope this helps, Boggie

[Guest Bazwaz]

You do not need to use the vacumn advance. I went down this route myself some time ago. If you tap the manifold you are picking up the vacumn at the wrong side of the carb and the distributer will be getting full advance straight away. If you search through the old disscussion board you will find all the answers you need.

Barry.