Engine Cut out

[Southern75]

My sud is nearing track car completion and am fairly soon to get it logged.

One problem is the engine cut out switch.

Someone tells me that I only need a 2 pole isolation switch breaking the active from the battery. DONE

Problem = the fact that this rarely kills the engine.
Problem 2 = I spent time ensuring that this switch would neatly fit into on of the sud's guage holes ... so it looks rather tidy ... therefor due to the huge size of a 6 pole switch ... I'm not so keen to get one.

Potential solution. Old mate at Rev racegear said that it can be done with a 2 pole switch if there is a relay installed somewhere.

My theory with relays i suspect is flawed. If i run a relay (normally open) which is triggered when i turn the switch on, which switches the active (or earth) to the coil.

Will this work?

The only problem i envisage is that if the car still runs then shouldn't it have adequate voltage in that active link to keep the relay energized?

Advice please

[colcol]

A master kill switch isolates the battery in case of a fire, sometimes isolating it won't stop the engine as, depending on wiring, your coil will still have power due to it running of the alternator, i hated running a master kill switch in the 33 in the old days when i used to sprint it, there always seemed extra problems with bad connections with the master switch, thats my 2 cents worth anyway, Colin.

[Rigi]

HI Southern75

To only way to make sure the engine stops when the isolator is flicked off is to ensure the alternator charge wire is on the battery side of the isolator. This may mean running another wire, same gauge as the original alternator wire, from the starter motor (easier) or from the engine side of the isolator switch to the fuse box where the alternator was originally wired in.

The isolator switch should be an emergency only method of stopping the engine. It's best if you switch the engine off by the ignition switch as switch is designed to take those kinds of loads. The risk is that you may get an ark on the isolator if there is load on the isolator when you try and disconnect it.

Relays are always a good idea in the starter motor solenoid, as this takes the load off your ignition switch too. It's sure easier and cheaper replacing a relay than a ignition barrel!!!

[Southern75]

Thanks,

I have a starter relay already ... as it also ensures a better current for old started solenoids ...
I usually only ever turn the car off by the ignition anyway ... red key is at this stage only for testing, and i'm used to turning it off by the key anyway.

I will check this out ... but it seems to make a fair bit of sense.

I might need to see a schematic though ...

Sadly to my other friend who posted ... sadly this switch is something i cannot do without, but thanks for your opinion.