I think you missed my point. Look at the stock system. The pump always turns. When the thermostat is closed it makes a loop through the block back through the water pipe and around and around. It is still flowing. If the electric pump was in this loop it could always be on. Even when the coolant is too cold to open the thermostat you still want circulation in the block so as not to create hot spots. You could boil the water around the liners without even getting the thermostat open. I didn't think that the pump would physically sit in line with the water pipe, but that it could be modified so that hoses could be run.

 

my brother's old roomate's girlfriend's dad (lol... seriously) owns a coaxial cable company. Is that the kind of RF wire you are talking about. If we could figure out the specs I bet he could make us a bunch of these.

 

... a bypass hose from the upper to lower radiator hose with a restrictor plate acts exactly like the stock thermostat works by restricting the flow ... all this would do is put a static restriction(unlike a dynamic one like a thermostat) on the flow of your coolant system ..

expected results from adding a static restriction=
1) Your car would warm up quicker....
2)once warmed up it would make your coolant operate at a slightly higher temperature than stock because their is more restriction in the coolant system
3) this would place more stress on your electric motor because of the excess strain because of the increased friction...

If you mean to say that the restrictor plate opened and controlled electronically via a switch that would change things a bit...

One would still have to flip that switch manualy and fabricate the electronic door ... intresting idea....
Has some good and bad points ...

 

I understand what you are trying to say now... Sounds pretty difficult though... I don't particularily like drilling holes in the engine and installing modified water pipes or hoses to substitute as a new bypass...

Great Idea....

I started running through several different ways of going about doing this in my head... pretty scary stuff... I would want to have a couple extra b18c1 engines lying around to start experimenting first...
Alot of work and possible complications ....

 

I already tried insulating the coaxial cable with a really effective reflector and insulator for interference ... 3 layers of aluminum foil and electrical tape ...
seems to me that the problem would not be solved by a better insulated coaxial cable... so I have to look elsewhere ....

It can be done .. I just need to iron out the electrical and EMI gremlins first ...

I'm thinking that possibly the interference is being picked up by the actual temp probe itself in the water pipe and that despite all the insulation and grounding I cannot stop it from being picked up....

I have several different ideas .. I can play arounf with a Noise filter , I could try tapping the existing water temp wires .... I can change the placement of the ground .. ect.... I have already played around with it alot but have not exhausted everything yet ....

 

i was thinkin of sheilded twisted pair wire with possibly an outer sheilding.. unless you have a bad ground theres no way for rf to get in there with that

 

How about instead of the electrical thing you bought, using a mechanical thermostat. It would work just like your CSI gauge, exept mechanically (like a house thermostat)...that should solve the interference problem.

Do they exist such that you can apply it to a car?

Hmmm...just checked on the internet, most mechanical thermostats are for home applications...there's gotta be one for your application though.


[Modified by Lsos, 8:09 PM 12/19/2002]

 

mechanical theromstats usually work with a mercury filled cylinder ... take the cover off your thermostat at home and you'll see it .. in a moving car this wouldn't work because acceleration an deceleration would cause the mercury to move around changing the preset .....
good idea though


[Modified by dasher, 3:38 PM 12/19/2002]

 

Thats why I think It might be comming from the probe...
CSI says that the Water temp wire is where the interference gets picked up... maybe it is also being picked up by the power wire to the electric water pump which is connected to the relay which is connected to the guage ....

I could also try shielding the power wire or maybe put an inline capacitors and inductors to help eliminate the feedback...

Their is a solution... it will just take some more time

 

Hmm...good point with the mechanical thermostat. I was thinking more along the lines of a spring one, where the spring expands until it closes a circuit, but you're right, that wouldn't work either in an environment where vibrations are present. But then again, the stock thermostat is a mechanical one....

You could probably rig something up such that when the stock thermostat opens, it closes a circuit or activates a relay that supplies power to the pump...but that's probably more trouble than it's worth.

 

To control the electric water pump why not just use a thermo switch like whats already on the motor??...If I rmember correctly thier are two water temp sensors on your motor...one for the guage and one for the ECU to sense when the car was warmed up...that second water temp sensor is tied into the VTEC system and will not let the ECU trigger the VTEC solenoid until it is completely up to a certain temp...can anyone verify if the second water temp sensor is a resistive type or just a basic on/off switch??

Or the second way you could do it is to use an Autometer warning light sensor...it is basically an on and off switch...so it would be perfect...the only thing is if the temp setting are in the right range for the Honda motors??


Here are the part numbers and temps:

PRO-LITE WARNING LIGHT SENDERS
3246 / Water temp. sender 187°-203°F
3247 / Water temp. sender 210°-230°F




[Modified by 1fastVX, 12:36 AM 12/20/2002]

 

http://www.crracing.com/estore/partd...category=therm

put one of those between the radiator and pump and route the bypass from the head to the bypass inlet...then remove the stock thermostat or put in a restrictor

 

how could you over coool an engine? my b18c made more power when slighlty cooler temps!!

 

QCKGSR -- Running slightly cooler than stock is helpful, but my temperature needle is buried to the far left... my exit temperatures are 60-80 F after the intercooler ... much colder than needed and my car is loosing power and running inefficiently... My coolant temp should be around 190 F after the thermostat ...

vtec also isn't even being activated because my car is not running at normal operating temp...


1fastVX-- good idea, might work but still have to figure out the appropriate voltage which is sent when the thermo-switch is open when said temp is met ... basicly the thermo-swich would be more of a mechanical brain that would act as a gate when the temp is met... the question is -- is 12 volts passed through this gate and how responsive is this gate, can it repeatably be opened and closed(because thats what is going to happen when the car is warming up).. great idea...

Shu - costly... but this is the best solution thus far.. thanks you are a lifesaver ...


I would probably place this thermostat between the stock thermostat and the electric water pump and route the bypass line back to upper radiator hose ... will probably try to plumb it into the water outlet cover(where the bleed screw is located)..... this solution will also help solve air pockets from developing in the engine because it keeps coolant circulating , rather than turning the electric water pump on and off...





[Modified by dasher, 8:10 PM 1/5/2003]

 

The bypass should be plumbed so that it flows in just behind the thermostat otherwise the thermostat won't see the same temperatures as the water circulating in the block and won't open at the appropriate time. Don't forget the pump needs to be present in the "inner loop" so as to keep coolant flowing. I wonder if there are any cheaper alternatives such as thermostat housings from other model cars or such that may exist inline. Don't really need the fancy racing one I posted, just need something inline.

 

does the cold coolant directly cause the block to be less efficient, or is this jsut a problem with the FITV/IACV/ECU?

how does this all compare with the cooler the intake air > the more dense > more fuel > more hp?

i guess even hondata doesnt address this issue huh

 

One of the biggest problems is that vtec wont engage until the engine reaches operating temp. Which in this case I believe is 187 degrees.

 

My car will idle between 2000 and 2500 rpm because it senses that the coolant is too cold and it is trying to warm the engine up to normal operating temperature ....

their is a certain coolant temperature which allows the car to run most efficiently .... around 190 F...

don't get confused with a cold intake charge of air creating more HP and a cold coolant causing the same thing....you want the intake charge to have cold dense air ... but here are some things to think about when it comes to the coolant...

--- all the tolerances have not heated up to the appropriate size.. ie the pistons expanding slightly to create a smaller gap....

--- the oil being too cool and dense -- more frictional losses ...

---- Air and fuel combusts most efficiently under high heat and pressure inside a cylinder .. if car is running too cold than the burn process isn't as efficient...

 

oic. as far as the high idle, if you have a 90-93 you can just remove the fast idle valve all together.. g3's dont have that on the intake manifold anymore right? if so what is it replaced with?

 

With or without the fast idle valve the computer still tries to achive a high idle based on coolant temperature. Without the fast idle valve it must open the IACV more than it would with one. I don't know if the airflow potential of the EACV/IACV is changed to accomodate this or it always could flow enough air if needed.

 

yes, IMO you should aim at 190F so the car works fine, the idea of the CR thermostat should work, but you should spend more money on it. and if you are going to do it, you should take off the stock thermostat and put the CR on the upper house and put a line that takes that water/coolant just before the water pump.

I think this would be the cheapest, best way to fix this, i don't think any other thermostat housing from another model would work, and if they do you probably have to modify it. It's a tough desition, but come on, go for the CR thermostat, you want to do things the right way.

By the way: you mentioned that you have two coolant temp sens, one before the radiator and one after the radiator, if so, what are the changes? i always wanted to do this, but i didn't wanted to spend money on an extra temp sens.

 

I might be able to help you with the EMI problem ... But I need some specifics on the temperature sensor they used. What resistance cold and hot if you can, is it two or three wire, is one side grounded?

If you are using coax grounded on both ends, it acts as an antenna. More to come when I get specifics.

You are picking up ignition EMI on the sensor leads, it likely needs a low pass filter near the controller head.

As for the ultimate solution, I would use the temperature sensor to run a PID PWM controller on the water pump. --> variable speed based on temperature. Because of the "thermal inertia" of the system .. a PID controller will lock on better. But may not be mandatory. A "bang - bang" algorithm may work as well. On/off.

Regards,
BigMoose

 

the water temperature sensor after the radiator reads 60-80 F while it is warming up... after 10 minutes it reads 110 F

The one after my thermostat is my stock one in my stock housing ... so ????? my guess is that it is running 100-120F before and 190 F after warmup...

 

I was using a coaxial cable which runs from the water temperature sender to the guage .. which the outer layer is "fish eyed" and grounded at both ends ...

I was thinking about using a low pass filter near the controller head(CSI guage) but was worried about the possible effects it would have of the output of the actual temperature readings ....

Thank You for any input... I think I'm going to give CR a call about their racing thermostat .. it will eliminate the problems associated with air pockets developing which might happen from turning the water pump on and off to heat up the coolant ...


[Modified by dasher, 6:24 PM 1/8/2003]

 

Try grounding the shield ONLY at the controller end. Carry the braid as close to the sensor as you can, but as strange as it sounds, only ground it at the controller.

Thats why I was wondering about the resistance to see if we could put a little series impedence and a few caps at the controller. If not, use a couple of high quality 0.1 uF ceramics from the sensor leads to ground at the controller. Actually, inside the controller would be preferable.) Keep the caps leads as short as possible.

No problem, glad to help.

Regards,
BigMoose