High temperature sensor as optimum controller?

[BoyntonStu]

High temperature sensor as optimum controller?

To increase MPG a leaner mixture than 14.7:1 is used.

The resulting mixture will increase temperature.

Some increase in temperature will be acceptable with no damage to the engine.

Somewhere about a 100*F rise seems to be the upper maximum.

A current limiting PWM controls the heat in the cell and also prevents runaway.

Would it be possible to use the output an engine block temperature sensor to control EFIE, MAP/MAF/O2?

BoyntonStu

[timetowinarace]

I've been thinking about that.

I think no for coolant temp. Engine block temp? Is this ever monitored in a standard way? Even so, I think no.

Exhaust gas temp would be the way to go. This should be monitored by anyone attempting to lean a engine anyway. I have not measured the voltage output of my EGT probe but these values should be available through the manufacturer. If the voltage output is higher than the o2 sencer, it may be possible to put a simple resister to match the values of the o2 sencer. Even if it is not quite this simple, it may be simple enough to replace or integrate the o2 signal with the egt signal. If the egt's get too high, the ecu richens the mix.

[BoyntonStu]

I've been thinking about that.

I think no for coolant temp. Engine block temp? Is this ever monitored in a standard way? Even so, I think no.

Exhaust gas temp would be the way to go. This should be monitored by anyone attempting to lean a engine anyway. I have not measured the voltage output of my EGT probe but these values should be available through the manufacturer. If the voltage output is higher than the o2 sencer, it may be possible to put a simple resister to match the values of the o2 sencer. Even if it is not quite this simple, it may be simple enough to replace or integrate the o2 signal with the egt signal. If the egt's get too high, the ecu richens the mix.

I like your idea. Monitoring EGT is perhaps better than block T.

I am not certain of that.

"If the egt's get too high, the ecu richens the mix." Exactly!

We would all feel a lot safer messing with the ECU if we had a high temp limit.

BoyntonStu

[Jaxom]

I agree that EGT is the way to go. The responsiveness of a block temp. sensor would be totally inadequate. By the time the excess heat is conducted through the block to the sensor, the cylinder temp will have already exceeded the "safe" range. Cylinder head temp. sensors are currently in use in some production cars (Ford trucks among others) but they are slow to resond to changes in combustion temp.

A relatively simple circuit could be devised to use a transistor in parallel to pull the O2 voltage down (simulating an excessively lean condition) based on a voltage input from the EGT sensor. I'm too rusty on my electronics to design it myself but it shouldn't be hard to do.

[JojoJaro]

I don't think monitoring EGTs as a feedback for gen input will not work.

I've read that HHO injection actually lowers EGTs. So, injecting HHO will actually lower your EGT. Your EGTs will be lower inspite of all the leaning you do.

Although I read in another post an interesting solution. Simply install a exhaust temp gauge. Lean your engine until it is 100F higher, then inject HHO.

[smartHHO]

I am thinking you could use a block sensor but you would have to be way lower on temp then you might think. Say the piston temp is 100 when it blows but the block temp is 65. Then you got to acount for the temp difference and put a way lower sensor and just pray that it works. Sounds risky to me.

[timetowinarace]

I don't think monitoring EGTs as a feedback for gen input will not work.

I've read that HHO injection actually lowers EGTs. So, injecting HHO will actually lower your EGT. Your EGTs will be lower inspite of all the leaning you do.

Although I read in another post an interesting solution. Simply install a exhaust temp gauge. Lean your engine until it is 100F higher, then inject HHO.

That is partially the point. It is heat from leaning the fuel that destroys engine components. Lean the engine for hho and then have your electrolyser quit while cruising down the road. If you or the ecu is not paying attention and correct the problem, it's time for a new car. I don't think your catching on to that little fact with your insistance to lean out the engines.

As long as your egt's stay at or slightly above pre hho levels your engine is safe. If your egt probe is incorperated into the O2 sencor somehow(I don't pretend to have a solid idea on how to do this yet) your ecu can go about it's business keeping the fuel mix at acceptable levels. Good in theory, maybe not in practice.

My bullydog outlook monitor does something simular. The truck ecu does not measure egt's. A serious mistake by manufactures since one bad injector can raise egt's to piston melting temps. Anyway, the bullydog programmer puts three different available tuning options in the ecu. I use the performance setting. I set my outlook monitors defuel levels to 1350* egt's. If egt's go over 1350, it drops tuning to the next level and then the next if needed. A simple safety precaution.

[smartHHO]

That is partially the point. It is heat from leaning the fuel that destroys engine components. Lean the engine for hho and then have your electrolyser quit while cruising down the road. If you or the ecu is not paying attention and correct the problem, it's time for a new car. I don't think your catching on to that little fact with your insistance to lean out the engines.

As long as your egt's stay at or slightly above pre hho levels your engine is safe. If your egt probe is incorperated into the O2 sencor somehow(I don't pretend to have a solid idea on how to do this yet) your ecu can go about it's business keeping the fuel mix at acceptable levels. Good in theory, maybe not in practice.

My bullydog outlook monitor does something simular. The truck ecu does not measure egt's. A serious mistake by manufactures since one bad injector can raise egt's to piston melting temps. Anyway, the bullydog programmer puts three different available tuning options in the ecu. I use the performance setting. I set my outlook monitors defuel levels to 1350* egt's. If egt's go over 1350, it drops tuning to the next level and then the next if needed. A simple safety precaution.

Ok,

you just gave me an idea about if your HHO goes and stops working. In order to prevent this scenario, you would have to build a circuit, that is if we are talking about the newer cars, not the older ones with no computer. It would pretty much have to be a relay in series with the fuse/gen. If then gen stopped putting out, then the relay would not get what it needs and you could have that relay trip, which would go to another relay which would shut off your O2/map/maf device, what ever your are using. Then the car would swap back over to normal running, not fast, but computer would compensate. As for the old carburator cars, good luck with that. You lean out the jets, HHO dies, and so does your car. But this is all theory that I am putting down. Unless someone builds the circuit and such, can't prove the theory. And in that case, you would have to have a kill switch inline with the fuse and relay to turn off while driving to see if it works. Hehe.

[timetowinarace]

I am thinking you could use a block sensor but you would have to be way lower on temp then you might think. Say the piston temp is 100 when it blows but the block temp is 65. Then you got to acount for the temp difference and put a way lower sensor and just pray that it works. Sounds risky to me.

Problem with the block sencor. As you have pointed out there is a temp difference.

Rarely is the block directly affected by running lean. 99% of the time a valve will break due to overheating, drop into the cylinder, the piston slams into it, bounces it around in there destroying piston and cylinder walls. Or the piston itself melts, destroying the cylinder.

EGT's are the only way to monitor excactly how much heat your valves are exposed to.

[timetowinarace]

Ok,

you just gave me an idea about if your HHO goes and stops working. In order to prevent this scenario, you would have to build a circuit, that is if we are talking about the newer cars, not the older ones with no computer. It would pretty much have to be a relay in series with the fuse/gen. If then gen stopped putting out, then the relay would not get what it needs and you could have that relay trip, which would go to another relay which would shut off your O2/map/maf device, what ever your are using. Then the car would swap back over to normal running, not fast, but computer would compensate. As for the old carburator cars, good luck with that. You lean out the jets, HHO dies, and so does your car. But this is all theory that I am putting down. Unless someone builds the circuit and such, can't prove the theory. And in that case, you would have to have a kill switch inline with the fuse and relay to turn off while driving to see if it works. Hehe.

That's an acceptable idea. I would still be inclined to use a egt probe to send the signal rather than the hho unit itself. Why? What happens if the generator is fine but the hose to the intake poped off?