2500pi on carbs what distributor?

[Danwedges]

I have an early mg prefix 2.5pi engine that I will be running on twin hif44 carbs with what I believe to be a tr6 distributor with no vac advance and was wondering if changing to the correct 2500pi distributor would be better or would the 2500s/tc distributor be a better suit as it's now running on carbs? The main reason being that it's unable to return more than 18mpg no matter how sensibly it is driven so I was thinking switch to a distributor with vacuum advance 

Any advice is appreciated 

Thanks 

Dan

[Clive]

The distributor wants to match the cam/head, so yes the correct distributor with vacuum advance should help. 

As will a rolling road session to get the needles correct (amazing what a difference it makes to the way the car drives and economy)

And being obvious, the distributor and carbs need to be unworn (HIF have replaceable ptfe bushes for the spindles IIRC? but check for wear. And the dizzy will want springs that are not all stretched, plus the correct vac advance capsule)

[Pete Lewis]

This is the problem of a mix and match or not components where there is no deadicated spec to match too.

A vac unit does give aroind +4  mpg on touring consumption 

Think we have rambled about the HIF earlier but a dizzy from a 2500S would be close   ( not looked )

Pete

[dave.vitesse]

I agree with Clive and Pete's comments

The early 2500PI, up to MG75000, had the same cam as the Vitesse 2Litre Mk2. That would suggest that dizzy. Or maybe an early Mk2 2000.

Dave