Blown Head Gasket Between Cylinders... I Think

[Guest Mike]

I don't think that would work very well, as you'd need a closed-loop system to measure flow. 50% voltage on an electric pump won't equal 50% flow, and a lot of 12v pump motors won't run under load at less then 9 volts, and 70% flow or so, depending on pressure.

 

Thanks for the information eec564. I didn't know this. I wonder if designing a pump and control system would be worth the bother? It's just a thought to improve maximum flow by eliminating restrictions through the thermostat.

 

Maybe a new thermostat design is the simpler way to go... one through which water passes freely through the (((center))) when fully open rather than having to traverse )))around((( the thermostatic valve. Or perhaps an electronically controlled valve could replace the themostat? I'm just talking efficiencies here.. and it's probably useless dribble.

[eec564]

Well, the point of the cooling system is two fold, keep the engine cool, and keep the engine at a stable temperature under all (ideally) driving conditions.

That's why removing the thermostat causes issues. Newer cars rely on switched electric fans in addition to the thermostat. The main reasons old style thermostats are still around is their simple, reliable, and cheap to manufacture.

For race engines, a thermostat that opens at a lower temperature is used, to give the cooling system a head-start. A more efficent radiator makes the engine cool better, requiring less coolent flow. The entire point of eliminating the thermostat would be to allow better coolent flow, resulting in a higher maximum colling effect, the same result as a better radiator, better airflow through the radiator, or any number of cooling system upgrades. Everything I've mentioned is simpler, reliable, tested, and most likely cheaper.

 

That said, I really like the idea. Especially if you're already using a custom fuel injection controller that could handle the computing needed to adjust the extra cooling capacity to prevent overheating by precooling the engine and radiator slightly under high engine loads . I'm thinking along the lines of extra code in megasquirt, or a small pic microcontroller, with MAP and temp sensors. Of course, you could always use a small on dash controller to adjust the base cooling level and leave the temp vs cooling effect ratio stationary and not adaptive. I just like to see base designs where extra features possibal to go ahead and use them.

 

The big question I see is how to modulate the amount of cooling effectively, accurately, and FAR MOST IMPORTANTLY reliabally. A mechanical valve might be nice, such as a stepper motor controlled 2-inch ball valve to limit flow predictabally but still allowing full flow. Or a modulator control for an electric fuel pump, which would require a flow sensor as a certain voltage/current/modulation provided wouldn't result in a consistant flow rate (experience with electric motors, loads, stall points, starting voltages, etc tells me this, I forget which textbook it was in).

 

So there's a few ideas, got any of your own? And do you think we'll be chased by people trying to catch us with their hijacked thread?

[Guest Mike]

Well' date=' the point of the cooling system is two fold, keep the engine cool, and keep the engine at a stable temperature under all (ideally) driving conditions.

That's why removing the thermostat causes issues. Newer cars rely on switched electric fans in addition to the thermostat. The main reasons old style thermostats are still around is their simple, reliable, and cheap to manufacture.

For race engines, a thermostat that opens at a lower temperature is used, to give the cooling system a head-start. A more efficent radiator makes the engine cool better, requiring less coolent flow. The entire point of eliminating the thermostat would be to allow better coolent flow, resulting in a higher maximum colling effect, the same result as a better radiator, better airflow through the radiator, or any number of cooling system upgrades. Everything I've mentioned is simpler, reliable, tested, and most likely cheaper.

 

That said, I really like the idea. Especially if you're already using a custom fuel injection controller that could handle the computing needed to adjust the extra cooling capacity to prevent overheating by precooling the engine and radiator slightly under high engine loads . I'm thinking along the lines of extra code in megasquirt, or a small pic microcontroller, with MAP and temp sensors. Of course, you could always use a small on dash controller to adjust the base cooling level and leave the temp vs cooling effect ratio stationary and not adaptive. I just like to see base designs where extra features possibal to go ahead and use them.

 

The big question I see is how to modulate the amount of cooling effectively, accurately, and FAR MOST IMPORTANTLY reliabally. A mechanical valve might be nice, such as a stepper motor controlled 2-inch ball valve to limit flow predictabally but still allowing full flow. Or a modulator control for an electric fuel pump, which would require a flow sensor as a certain voltage/current/modulation provided wouldn't result in a consistant flow rate (experience with electric motors, loads, stall points, starting voltages, etc tells me this, I forget which textbook it was in).

 

So there's a few ideas, got any of your own? And do you think we'll be chased by people trying to catch us with their hijacked thread?[/quote']

 

 

I really like your idea of modifying the Megasquirt code. Is it proprietary? For the vast majority not using Megasquirt (I'm using carbs) a stand-alone controller is in order as well. Like you said, a manual switch for a blast of precooling might work as a simple and inexpensive solution for that little extra edge. Could one tie into the proper existing sensory data without affecting the engine controller? If it's a matter of digital noise affecting the disparate controllers, UHF filters might eleiminate that issue. Perhaps the controller could also accept TPS data responding immediately to WOT as well as quickly rising temperatures. A step motor sounds like the way to go for valve control. How many steps, do you think... a half dozen? A flow sensor would certainly work, but my concern is sensor failure in the harsh, grungy environment of engine coolant. Also, like you mentioned, simple is good. Given the variables associated with electric water pumps, I agree with your initial ascertation that it's best to let them run full speed. A stepped motor controlling a large ball valve is the most reliable solution.

 

This is moving coolant flow control away from the dumb pump to a smart flow control valve. How much advantage is realized I don't know. An important factor though is allowing for huge instantaneous volume on demand. This might realize a few net HP while helping to protect ones' engine from excess heat.

 

I'm old school having owned a few GM Gen1's ranging from 283 to 455 CID. I think the old carbureted engines are affected more by temperature variation than todays' computer controlled offerings. In my experience, running at the correct temperature is paramount. Even five or ten degrees can make a difference.

 

Yes... we're probably in trouble for hijacking this thread. You have the option though of pointing an accusing finger at me:smile:

[eec564]

Alright, I've started a new threat under Misc Tech for this and suggest to an admin a new catagory for "Cooling Systems" under "Engine Components". Either that or a poll to see if people here want it.

See the new thread (that means you Mike) at http://forums.hybridz.org/showthread.php?t=112947