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Spitfire Distrubutor

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T

Trevor Triumph

Jedi Knight
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I took the 66 Spit to a to mechanic to adjust carbs. He said part of the problem he was having was a vacuum retard distributor. Never heard of that- he said it was part of the emissions system years ago. Now there is no vacuum and the car seems to run well enough. I'm thinking I could get a new/ rebuilt distributor or replace the vacuum part of the distributor.

Any ideas?

Oh yes, Triumphest sounds good. Getting the car ready.

T.T.
 
I don't think a 66 would have had retard; it generally didn't start until 68. I have a workshop manual supplement for 67 that still shows vacuum advance. Maybe someone has installed a distributor from a later engine? That could create some interesting problems, if the retard module was connected to the advance port.

As noted, the retard was only effective at idle, and supposedly reduced emissions. It does nothing the rest of the time. Vacuum advance, if you have it, will provide slightly better gas mileage, and maybe just a bit better mid-range throttle response, but that's about all. It is not effective at full throttle either, so no effect on maximum power.
 
I agree with Randall that your car should not have a vacuum retard as even my wife's 1968 Mk III did not have a vacuum retard.

Scott
 
Sorry, I left out an important item- the engine is from any early 1500- probably 1974? It had the 1500 engine and a three rail transmission. I install a vacuum advance, does that mean the performance may improve a bit in around town driving, but perhaps not on the autocross course?

T.T.
 
Ah, that would explain it.
You would also need a carb that has the proper port for vacuum advance. Might be there, but most likely not if you have the 74 carb.

The difference in performance would be very subtle, and last for only a fraction of a second. Many people can't tell the difference. Basically, if you are cruising along at 40 mph or so, and step on the throttle, the engine responds a bit quicker. You still get the same amount of power, it just gets there a tiny bit quicker. There are lots of other mods that would make more difference (like installing the dual carb setup from a UK-spec engine), so IMO it's not worth installing a vacuum advance just for that.
 
Again I have failed to tell the whole story. I have installed high compression pistons, the Euro manifold and Euro SUs, and a 4 into 1 header. It sounds like I could just leave it alone?
 
I have a similar setup - a 69 Mk3 with a 1500, UE exhaust header, UE SUs. Haven't shaved the head/done the hi compression pistons yet... My dizzy started howling and I replaced it with one from advanced distribtors - with the advance not retard. In talking with them, they said keep it simple, and go with the advance unit. With your setup you should talk to them about getting a rebuilt dizzy with a EU advance curve, if there is such a thing.
 
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