Cut out engine when missing oil pressure

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Kvinnhering

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I have a MSD ignition system (4217) that I bought from Jim Comstock (very good system) that has a choice to cut the engine at an adjustable PPM (launch system).
By conducting a wier to ground, the ignition system will cut beyond the set point. By connecting this wier to the oil pressure switch, for example from Don's system and also connected a red light to the oil pressure switch, then the engine will automatically decrease to, for example, 2750 or 3000 RPM, while it is also will be indicated by the red light.

Some thought;
Way do not use only a large flashing red light, and do not worry about cutting the engine. In my opinion this will be ugly.
Imagine what happens if the engine cuts in a critical bypass or a critical turn. Is there any difference between cutting the engine or getting a exploded motor due to lack of oil pressure.

One positive side is that it is possible to prevent even greater / more expensive bike and engine casualties.

What thoughts do you have gentlemen, should I just forget about it?
 
Not heard of this type of cut off before, but off the top, I would think that by making your ignition codependent on oil pressure, you run the risk of engine cut out at inconvenient intervals. I have Don's OP switch installed and, once the oil is good and hot (after expressway run), the light will sometimes flicker when idling at a light, I know I wouldn't want my bike cutting out on me in that scenario.
 
Agree on this. But the engine will not stopp, the ignitionsystem will only refuse the RPM to come over the set point. That is the advantage of this method
 
In my opinion, the answer is completely dependent on your faith in the red light (flashing or steady): Will you notice it?
If yes, the rev limiter is redundant and (as you point out) possibly a hazard.

The motor will survive a short distance without oil pressure, not likely to seize up immediately.

I have a red light, and found that it was hardly noticeable with a standard bulb. Replaced it with a red LED bulb, feel much better.
 
Another reason why a GAGE has a lot of utility. An oil pressure TREND is helpful.

"Suddenly" losing oil pressure is most always predictable.
 
Sounds like a good idea, but there is no oil pressure when the motor is not running, so how do you start the bike if the ignition system is cut out ? I have enough trouble remembering to reconnect the oil feed to the motor before starting it.
 
...so how do you start the bike if the ignition system is cut out ?
This seems to be a recurring misconception; this is not an ignition interrupt, merely an RPM limiter. The engine will run without hindrance up to the pre-programmed RPM whether it has oil pressure or not, at which point a closed oil pressure switch (no pressure) will cause the engine to "park" at that setpoint.

That ought to get your attention barreling down the freeway!

Nathan
 
Sorry if I have not explained this clearly enough

But you Natan, have understood how the system will works.;)
 
In my opinion, the answer is completely dependent on your faith in the red light (flashing or steady): Will you notice it?
If yes, the rev limiter is redundant and (as you point out) possibly a hazard. I have a red light, and found that it was hardly noticeable with a standard bulb. Replaced it with a red LED bulb, feel much better.

I agree with you - don't want to mess up the ignition system with sensors possibly sending false signals. As for the warning light, i will fit this on my Mk3 also, but to be sure the warning light get's noticed, I will add a buzzer also which is activated after a few seconds of continous low pressure signal. A similar device is in my VW car. I don't bother if it sounds when switching the ignition on. The latter may be circumvented by electronics as well.

-Knut
 
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I agree with you - don't want to mess up the ignition system with sensors possibly sending false signals.
The are easy to eliminate this false signal. It is easy to disconnect the cord from the oil presisere switch or to connect my PC to the ignitionsystem and turn the function off for testing.
But you are right, the easiest and safest method is to mount a powerful red LED light along with my manometer.
 
When my bike is parked, it has a big bolt stuffed up the oil feed line to stop the motor from wet-sumping. My nightmare is about forgetting to re-connect the feed line before starting the motor. What would a red light tell me more than a grinding noise from the crankcase ?
 
I had a car once that cut out as you accelerated for a few seconds, as it was normally as I changed down a gear to accelerate past a slower car in front I would not be limited revs based on a electronic switch detecting low oil pressure. I like to overtake without hinderance ;)
 
I think the audible alarm would be a good way to go, they use them on yachts for various things with gauges also. Nothing gets your attention as fast as those alarms. trust me.
 
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