Morris Minor Owners Club

Sourced 2nd hand flame trap and metal vacuum advance pipe, so replaced the fitted plastic mini type. So now it screws onto the distributor, rather than pushed onto the remnant of a broken original.

Bill_qaz wrote: ↑Wed Feb 11, 2026 4:52 pm Sourced 2nd hand flame trap and metal vacuum advance pipe, so replaced the fitted plastic mini type. So now it screws onto the distributor, rather than pushed onto the remnant of a broken original.
20260115_140527.jpg

At the risk of sounding like an idiot.. what does this do? I’m seeing this as an educational opportunity because I know so little!

It was originally to mitigate the risk of fuel getting from the carburettor to the distributor via the vacuum advance pipe and possibly igniting

Later thought unnecessary so no longer fitted.
I believe my 62 had one originally as the remnant of the pipe was still screwed onto my distributor.

Bill_qaz wrote: ↑Wed Feb 11, 2026 8:04 pm It was originally to mitigate the risk of fuel getting from the carburettor to the distributor via the vacuum advance pipe and possibly igniting

Later thought unnecessary so no longer fitted.
I believe my 62 had one originally as the remnant of the pipe was still screwed onto my distributor.

Aah interesting! I quite like the idea of such a feature… I wonder if Nell would have had such a thing originally… she’s a 1960. I’ll have to have a look for clues

The diaphragm unit on distributor will have a thread for a pipe and nut, if it had one fitted. I believe other type is just a small straight unthreaded pipe for the rubber to push onto, and has plastic or metal pipe to carb, with a similar rubber fitting.
Not the copper pipe in picture,thats to my oil pressure gauge

mrs.smith2012 wrote: ↑Wed Feb 11, 2026 7:54 pm

Bill_qaz wrote: ↑Wed Feb 11, 2026 4:52 pm Sourced 2nd hand flame trap and metal vacuum advance pipe, so replaced the fitted plastic mini type. So now it screws onto the distributor, rather than pushed onto the remnant of a broken original.
20260115_140527.jpg

At the risk of sounding like an idiot.. what does this do? I’m seeing this as an educational opportunity because I know so little!

Supposedly it mitigates against fuel vapour from the Inlet Manifold getting to the sparks at the Distributor Points and causing a little explosion.

According to the parts manuals, on Minors they always fitted the solid pipe with the spark arrestor device in it, but the same engine in many other vehicles didn't have it. I think it became realised that it was there to prevent a hazard that didn't exist, but those responsible for the Minor never bothered to alter it.
When you consider that the engine when running is always sucking on the vacuum pipe what are the odds on petrol vapours making their way along 3ft of pipe to the Distributor when the engine isn't running. There's no airflow of any sort along that pipe; the inner bore is perhaps 2-3mm diameter.

My car has an electronic points unit anyway, so even less chance

That's virtually what I said in my reply to mrs smith, Berni.
I also have electronic ignition but just fitted in place of the mini plastic one that was on the car when bought it.
Hence the title of original post

My car has always had the plastic pipe since I first had the car in 1989. The distributor vacuum advance unit did not have the thread for the metal pipe. Whether this means the late Minors (mine is 1969) had the plastic pipe rather than the metal one or that mine had been changed before I got the car I don't know. I have since had the distributor rebuilt, including the vacuum unit and I stayed with the plastic pipe because I had assumed that was original to that date of car.

Stephen

I’m still getting to know Nell’s inner workings. All I’ve done so far is change plugs and do my routine oil and water checks. Having no garage and almost constant rain means I’ve not been able to get under the bonnet as much as I would like… looking forward to the weather clearing a bit so I can get to know her a bit better! That’s when the fun starts!