fuel pump safety switch

[jzuk7]

I'm using an oil pressure switch to shut off the fuel pump when the engine stops. It is installed on a T fitting at the oil pressure gauge fitting. Today I noticed a large oil leak at the pressure switch. I've never been a fan of this set up as the switch is in a hard to reach location, and under the exhaust header so there is a lot of heat.

Is anyone using an inertia switch as a safety shut off for an electric fuel pump? If so, where do you have it mounted? Would placing it in the battery box work? How did you wire it?

What inertia switch would be good to use? I've heard of people using a inertia switch out of a ford.

Thanks,

Joel

 

[loose_electron]

how necessary is this switch? I power my electric fuel pump off the "Run" power, so not seeing a need here.

 

[alpine_64]

An inertia switch is a good safety feature. On the old forum there was a good write-up on an install.

@loose_electron if the car has an accident and the igntion ia still on even if the car has stalled the pump could still supply fuel risking fire.

 

[DanR]

Here is a shut off system I have on Blue Boy.....

I utilized the oil pressure connection just below where the original fuel pump was fitted.

 

[jzuk7]

Here is a shut off system I have on Blue Boy.....

I utilized the oil pressure connection just below where the original fuel pump was fitted.

This is pretty much the same set up as I have. Except I have the pressure switch close to the engine block. Dan I see that your set up is much better as I looks much easier to remove the switch. Since I have the switch so close to the engine, I may have to lift the engine a few inches to remove it.

If I have to lift the engine, I'm thinking of using a stock mechanical fuel pump. I remember Jose saying to use an electric pump because the engine needs to be removed to replace it. The quality of after market electric fuel pumps and the oil pressure switch doesn't seem to be too good.

If I stay with the electric fuel pump, I will use a oil pressure switch or an inertia switch. In a crash, I wouldn't want to the pump to keep running.

 

[DanR]

If my engine oil pressure is zero the power is cut off. Supposedly!

If anyone can tell be differently, I sure would like to know.

In regards to the mechanical pump, it may make contact with the engine mount as I recall from past discussions.....is the reason for going with the electric pump. I have not had any problem with my electric pump since installed back in 2009 -2010.

 

[65beam]

An inertia switch is a good safety feature. On the old forum there was a good write-up on an install.

@loose_electron if the car has an accident and the ignition is still on even if the car has stalled the pump could still supply fuel risking fire.

I like a good bet! What are the odds this would happen?

 

[alpine_64]

I like a good bet! What are the odds this would happen?

Bob,

If you fit an electric pump as many have, unlike mechanical pumps they will keep going if the engine stalls. Hence the need for a form of cutoff for the pump.

 

[Bill Blue]

I like a good bet! What are the odds this would happen?

About the same as the need for air bags. Bob, that is very slippery and steep slope your standing on top of. You can apply that argument to every safety device ever made.

Bill

 

[Barry]

I like a good bet! What are the odds this would happen?

Pretty close to zero until a car is driven; the probability goes up from there.

 

[PROCRAFT]

Looks like your planning on going on your head?

 

[loose_electron]

An inertia switch is a good safety feature. On the old forum there was a good write-up on an install.

@loose_electron if the car has an accident and the igntion ia still on even if the car has stalled the pump could still supply fuel risking fire.

Yeah, got it, I understand the idea. If the front of my car gets crunched, there are several fuses that will probably blow open as a result of certain cables getting shorted to ground.

I do understand the improved safety aspect of this. What I don't like is how it's designed.

Before I would put a safety shutoff in line with the fuel pump I would put a safety shutoff in line with the battery power feed line to the ignition switch, thus killing everything on the RUN and ACC power feed lines. That way the only power in the car is battery to starter solenoid.

If you want to do a safety kill switch, in case of an accident, that's the place to put it.

 

[65beam]

Bob,

If you fit an electric pump as many have, unlike mechanical pumps they will keep going if the engine stalls. Hence the need for a form of cutoff for the pump.

I have Sunbeams with electric facet pumps installed but all I have to do is turn the key in the ignition switch and it shuts off. I use pumps that work at 1.5 PSI to 4 PSI. There are a lot of pumps that put out a lot more PSI. If you use an electric pump with higher pressure on a Beam with a carb then you have a problem. The max of 4 PSI is a lot less PSI of fuel pressure than our Impala, Malibu , Ford van or our two SUVs push out. The odds of having a fuel related problem or any other problem are pretty high if your car is well maintained and since I am not a person who looks at the worse scenario that could happen nor am I paranoid I don't see a problem with the electric pumps that I use. If your number comes up and it's your time to go there is no fuel safety switch, air bag or seat belt that will save you. As I said, the odds are very high so I'm not falling off the cliff or sliding down a slippery slope. Joel, you know me well enough that if I did happen to slip I always land on my feet and I always come out smelling like a rose.

 

[PROCRAFT]

I have Sunbeams with electric facet pumps installed but all I have to do is turn the key in the ignition switch and it shuts off. I use pumps that work at 1.5 PSI to 4 PSI. There are a lot of pumps that put out a lot more PSI. If you use an electric pump with higher pressure on a Beam with a carb then you have a problem. The max of 4 PSI is a lot less PSI of fuel pressure than our Impala, Malibu , Ford van or our two SUVs push out. The odds of having a fuel related problem or any other problem are pretty high if your car is well maintained and since I am not a person who looks at the worse scenario that could happen nor am I paranoid I don't see a problem with the electric pumps that I use. If your number comes up and it's your time to go there is no fuel safety switch, air bag or seat belt that will save you. As I said, the odds are very high so I'm not falling off the cliff or sliding down a slippery slope. Joel, you know me well enough that if I did happen to slip I always land on my feet and I always come out smelling like a rose.

 

[PROCRAFT]

Like ya said use the key!

 

[alpine_64]

Yeah, got it, I understand the idea. If the front of my car gets crunched, there are several fuses that will probably blow open as a result of certain cables getting shorted to ground.

I do understand the improved safety aspect of this. What I don't like is how it's designed.

Before I would put a safety shutoff in line with the fuel pump I would put a safety shutoff in line with the battery power feed line to the ignition switch, thus killing everything on the RUN and ACC power feed lines. That way the only power in the car is battery to starter solenoid.

If you want to do a safety kill switch, in case of an accident, that's the place to put it.

My alpine has the ignition wired so the pump only runs when the motor is running... Which is a good way... Unless the car has sat for a while and the fuel is low in the carbs.

 

[Bill Blue]

"All ya gotta do". My mother told a story about her grandmother. She would tell the family all the things she would do if the house caught on fire. When that day arrived, she reached up over the dinning room table, unscrewed the light bulb and ran out of the house. That light bulb was the only thing saved from the fire. The fire truck refused to start and the house was a total lose. The point of the story, we don't know how we will react in an emergency because we are reacting, not thinking. That assumes you are still capable of rational thought, which after a traumatic incident, is often not the case.

Loose electron, I really don't understand installing a switch in order to protect fuses.

Bill

 

[65beam]

And after that traumatic incident one of the first you talk to is your insurance agent. So make sure you have a high set value on your Beam.

 

[loose_electron]

Loose electron, I really don't understand installing a switch in order to protect fuses.

If you are going to install a cut off inertia switch to kill power, in an accident, kill all the power, everywhere, not just the fuel pump.

If you put the kill switch in line with the battery power feed to the ignition switch, that kills the power everywhere except the battery to starter cables.

Old or new wiring harness, in both cases, it all goes through the power feed cable to the ignition switch.

 

[Charles Johns]

I agree with Procraft and Bill, a simple switch is probably enough safety. I wire the 1 to 7 psi pump (if adjustable set about 4 lbs) to the ignition side of the key. Usually I add a kill switch in a hidden location as a theft device. Before FI, which needs much more pressure, safety switches were not used. With 50 - 70 psi, fuel-injection created a big problem in accidents. That is why the safety kill switch in the trunk was added. With carb pressures it IS a problem, but no where near the FI danger. I'll be running a carb, electric pump, hidden kill switch, and like Procraft said...just turn off the key. I also keep a good fire extinguisher in the car. With the key off or the kill switch off, and an extinguisher handy, I feel safe. If I am unable to get to either due to being unconscious or trapped...it probably won't matter. When your number is called, you are going...right side up or down, on fire or not! Safety is very important in any car build, but I started life when cars did not have seatbelts, padded dash, collapsible columns, door safety beams, brake-away mirrors, padded visors, air bags, or any of today's safety devices. Anybody besides me ever ride in the rear window package shelf? I believe in some states a parent can go to jail for that today. Me, I prefer my freedom to make my own choices.