Dolomite Sprint Distributor Lucas 44D4

[Peter Truman]

Haven't seen many queries re Sprints here but here goes

I have a 76 Sprint supplied new here in Aus by Leyland Aus, it's one of around 50 recorded as supplied originally with a LSD.

My question were all Sprints supplied with auto advance retard vacuum on their 44D4 distributors as the one fitted to my Sprint doesn't have it, the place where it is normally fitted has a pressed & formed bulbus cover (presumably Lucas) utilizing the normal advance/retard mounting screws. the carb vacuum offtake has a plastic plug over it.

I have a spare engine and that 42D4 distributor which I have recently cleaned and recoed has the auto advance/retard diaphragm fitted.

The Leyland or Hayes maintenance manuals only mention the auto advance/retard fitted distb, same the Leyland Spare Parts Book.

Were some Sprints fitted without the auto advance vacuum & does anyone know why?

Could it be a Leyland Aus fixture for the 50 LSD models which I assume was something to do with the Sprints homologation for the Aus Bathurst 1000 race around 1976.

Regards

Peter T 

[Pete Lewis]

the vac advance is just an economy device , maybe they were'nt interested and it was left off the spec, the full curve is perhaps a compromise 

sorry dont have 42 or 44 D4 in my lucas data book ....got lots of others  35  45   48 etc  no 44  mentioned

so even the spec number wont help from me 

pete

[Peter Truman]

Pete my typo their both 44D4 one with the other without the advance.

Peter T

[NonMember]

The 44D was the slightly weird one fitted to Dolomites, 45D was the "normal" one fitted to other 1970s Triumphs. Earlier cars were 22D or 25D with some 23D (I think) on PI, which didn't have vacuum advance. I think there was also a 43D (no vacuum advance) but I don't think Triumph used it.

I've not come across a 44D without vacuum advance but perhaps it was a "special option".

[A TR7 16V]

Only a few years later:

Here's a 44D4 I've removed the vacuum advance unit from. What I wonder about Peter T's one is, how the plate the advance unit normally moves is held fixed? If you just take the advance unit off and blank the hole with one of these £4 plates, it would flop about massively. I've a vague memory that if you use a longer setscrew to hold the points plate down, it jams the moving plate against the fixed plate. Or perhaps the plate from a 43D fits.

So, as you can probably see, I've attached a long set screw to the pin and put a knurled nut on it, so I can change the advance without slackening the bolts holding the distributor to the block. There's a strongish coil spring on that setscrew, to hold it all tight. Gives about 20 degrees of adjustment, about 1 degree per turn.

It only fits under one of the points plates I have, one with a wide slot for the pin to move around. The one I have with a narrow slot pushes the setscrew down, so the spring fouls the tops of the mechanical advance mech pins. It seems a little odd that the plates are different, as they are both from 44D4 A's. But the trouble is Lucas...

That's a rotor arm from a 25D4 Herald dizzy, BTW. Needed it because the 45D electronic ignition unit fouls the normal 44D4 one and the 45D one is too long a reach. The mod to the advance would work with points and a std rotor arm as well.

I will be fitting it as soon as I can expect the rain to hold off long enough.