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-   -   Uh oh? (https://www.rx7club.com/1st-generation-specific-1979-1985-18/uh-oh-1004889/)

curtisharrington 07-14-12 10:03 PM

Uh oh?
 
So I noticed today that for whatever retarded reason I had, that my coolant didn't swish when I wiggled the tank. I opened it to see it was nearly completely dry, and that a black mark had stained to the plastic, giving the illusion that it was full. Anyways, I just drained e coolant from the radiator and filled it up with water from the spicket. Now my heater only blows cool air, where as before it only blew hot air...... Did I mess something up by filling my radiator with water? Engine was cold when I did this, let it sit for ten mins and then idled car for 7 mins with the heater on full and hot, still cold like ac....... There's no ac in my car anymore.....

Qingdao 07-15-12 01:14 AM

Did you burp the coolent system? fill the radiator and then let the car run. while its running keep the radiator cap off and wait for the thermostat to open. When it does you'll be able to add more coolent.

Also, I'd sugest using radiator fluid. Just because it has rust prohibitors in it, if nothing else.

curtisharrington 07-15-12 04:59 AM


Originally Posted by Qingdao (Post 11157303)
Did you burp the coolent system? fill the radiator and then let the car run. while its running keep the radiator cap off and wait for the thermostat to open. When it does you'll be able to add more coolent.

Also, I'd sugest using radiator fluid. Just because it has rust prohibitors in it, if nothing else.

Thanks, can you explain why my heater worked after I did this venting step? Thanks a lot.

Curtis

Qingdao 07-15-12 09:07 PM

No fluid in the core means no heat.

The heater core is just a tinny radiator inside the cabin. If there isn't coolent running in the heater core no heat will sink from the engine to the cabin.

DivinDriver 07-16-12 09:19 AM

Never run a rotary on water only, especially TAP water which is full of minerals and usually slightly chlorinated as well.

Water will rust your cast-iron housings.

Minerals will clog your radiator core passages & lower the boiling temperature of the water.

Chlorine will attack the radiator core and any other brass or copper components in the cooling system. It's also not good for hoses.

Always use a 50/50 mix of DISTILLED water and antifreeze, or premixed antifreeze.

OneRotor 07-16-12 09:53 AM

Plus, in Alaska, your cooling system will freeze in the winter (maybe even the summer depending on where you are...) and wreak havoc on the entire system. cracked block. burst radiator. burst heater core. burst hoses. Not fun. Get some 50/50 pre-mixed and be done with it.

xXGslseSleeperXx 07-16-12 02:09 PM

you can just run water kinda! like at certain dragstrips you cant run if you use coolant, but if you do just run water, than you can run water wetter with it (if they sell that up there, but do use distilled with it!) it will lubricate the pump. nothin removes heat like just water. but come winter it will freeze!

DivinDriver 07-16-12 05:46 PM


Originally Posted by xXGslseSleeperXx (Post 11158765)
nothin removes heat like just water.

:scratch: Orly?

Once water boils, what happens to its heat-transfer capability?

xXGslseSleeperXx 07-16-12 07:56 PM

water boils at 212 degrees! thermostat is rated at at 180 in my seven(i hope for the sake of yours and every one else motor, theirs is too!) and my drag vega is at 160!( the one i run water wetter in) Thats why we also have rated radiator caps. pressurising any system brings up the boiling point. i also run pure water in my gsxr all the time.(gsxr during traffic goes to abou 195 when not moving but a 100 miles an hour my temperature is 140-135F and is super responsive)

xXGslseSleeperXx 07-16-12 08:07 PM

antifreeze actually lowers heat transfer capabilities! but does raise the boiling point and lowers the freezing point of water

deadphoenix52 07-16-12 08:08 PM

you dont know much about thermodynamics do you?

xXGslseSleeperXx 07-16-12 08:17 PM

and if you do then please correct me! ive only been doin this as a living for 8 years!

xXGslseSleeperXx 07-16-12 08:42 PM

please point out where my statements contradict your thermodynamics! lol

DivinDriver 07-16-12 09:35 PM


Originally Posted by xXGslseSleeperXx (Post 11159144)
water boils at 212 degrees!

At 1 bar relative (2 bar absolute), it boils at around 230f.

Pure deionized water that is, at sea-level pressure.

Impure water, depends on the impurities.


Originally Posted by xXGslseSleeperXx (Post 11159144)
thermostat is rated at at 180 in my seven(i hope for the sake of yours and every one else motor, theirs is too!) and my drag vega is at 160!( the one i run water wetter in)

Thermostat does nothing to keep the engine cool; it helps the engine warm up. Once it opens, it's job is pretty much done unless you're in the arctic.

How long does the drag car have to stay running at any time?


Originally Posted by xXGslseSleeperXx (Post 11159144)
Thats why we also have rated radiator caps. pressurising any system brings up the boiling point.

See the above regarding relative pressure. Stock replacement cap is rated for just less than 1 bar, ( 13-14PSI depending on year) so even pressurized, pure-water cooling system in a car is only good to about 220-ish before the cap will let go.

& of course, with a rotary, once you actually boil it over you're on borrowed time before you have expensive problems.


Originally Posted by xXGslseSleeperXx (Post 11159144)
i also run pure water in my gsxr all the time.(gsxr during traffic goes to abou 195 when not moving but a 100 miles an hour my temperature is 140-135F and is super responsive)

Motorcycle is not a car. Very different thermal situation, from lower masses on down. Is the engine all-aluminum, by any chance?

It's true; antifreeze does lower the heat-transfer capability of water a little (about 10-15% depending on mixture) but it makes up for that by preventing boil-over and the resulting over-pressure and loss of coolant (Which can ruin a wankel in a few minutes if you can't shut it down), and also by preventing corrosion, which is a serious problem for our cast-iron endplates.

For a drag or race car where you're never more than a short distance from a place to stop, the story's different. Reliability can take a back seat to performance.

But for a street car that has to be reliable in terms of years and tens of thousands of miles, there's simply no reason NOT to use antifreeze, and many good reasons to do so.

xXGslseSleeperXx 07-16-12 10:44 PM

yes distilled is more at 227. 212 is for general referance at our earthly pressure of 14.7 not talking about distilled water .im aware that under pressure it will raise the boiling temp! thermostat does indirectly help keep car cool in that it will keep water temp relativelyt close to its opening point and not below the minuimum operating temp. the vega runs on the street when i use the street tires. she will get hot at a stand still (seen it go up to 220 but not much over) but runs perfect at 160-165 on the track i keep her at that temp always shuting off in between runs. i put her at about 150 when i stage and by the time i leave the tree shes at 160 again id say about3 min warm up from cold start.

yes the 750 has an aluminium engine .

xXGslseSleeperXx 07-16-12 10:47 PM


Originally Posted by DivinDriver (Post 11158998)
:scratch: Orly?

Once water boils, what happens to its heat-transfer capability?

quote;At 1 bar relative (2 bar absolute), it boils at around 230f.

See the above regarding relative pressure. Stock replacement cap is rated for just less than 1 bar, ( 13-14PSI depending on year) so even pressurized, pure-water cooling system in a car is only good to about 220-ish before the cap will let go.

& of course, with a rotary, once you actually boil it over you're on borrowed time before you have expensive problems.;quote





yes im aware about the rad cap as i just stated that.(1.1bar) i dont think ANY of us let our temps get above 200 hence it will blow the cap before it boils under pressure hence still able to keep its transfer capabilities!

xXGslseSleeperXx 07-16-12 10:52 PM


Originally Posted by DivinDriver (Post 11159268)

But for a street car that has to be reliable in terms of years and tens of thousands of miles, there's simply no reason NOT to use antifreeze, and many good reasons to do so.

i agree im just sayin that it is possible and the reason i said KINDA. i use it to raise boiling point and lubrication in an every day hot runnin vehicle. i only use water for the track and the bike that is never at a standstill. and as long as you use distilled and a ground strap you wont get aluminium oxide pellets or corossion. but you do need some form of a lubricant especially at the higher rpms.

DivinDriver 07-16-12 11:03 PM

:icon_tup:

xXGslseSleeperXx 07-16-12 11:37 PM

:icon_tup:

curtisharrington 07-17-12 05:01 AM

Uuuuuhhhhhhhh
 
Back to the post.
New questions.... My e fan won't turn off and I dont know why. I put the hose onto the t of my radiator with plug removed and I started the car. It ran for about three mins and I shut it off, drained and added antifreeze/coolant and distiller water. Please tell me I didn't break something. My battery is dead and my alternator won't charge it. I'm gonna sand my terminals and connectors and see if that helps,vand then I'm gonna buy a new battery if that doesn't work. Why won't my fan turn off? My engine is COLD.It's 2 am!

Xamnglc 07-17-12 08:54 AM

Put in 50/50 and if your fan stays on check the temp at the probe!!!! It should turn on at around 190. Make sure the black relay for said item did not get stuck!!!

xXGslseSleeperXx 07-17-12 02:33 PM

^ (not sure how you have it wired) but look at relay like he said,

if not the relay then check for a short to ground on the wire of the low amperage side of the relay before temp switch.( if youve got it wired on the ground side)( if its on the powerside than check the temp switch that its not stuck)

as for the battery check it with a volt meter,if it did start the car and died after your 3 min than try a battery out of another car before spending 50 bucks. check that the alternator gives a full 14v with it running. (again i take it that your fan stays on with the ign. on but when the keys are out, it turns off? or even with the keys out, its still on?)
p.s. sorry for thread jacking earlier. just trying to show these "scientists" how they repeat their own contradictory statements over and over.everything is semantics in here.

curtisharrington 07-17-12 11:06 PM

So. I don't know this lingo you guys are speaking. Please bears in mind I don't know how to do any of this. My battery is good, but it was damaged. It's notmat 14 volts anymore it's under 13 w altntr on. Tell me how to check this shit. Pics or vies will come with people's questions. Help me please?

xXGslseSleeperXx 07-17-12 11:41 PM

if you can, post a pic of engine bay, radiator, e-fan, wiring, ect. i think itll help us a little better diagnosing your fan.

With all the accessories OFF you shuld see close to 14 volts. with them ON it shuld be no less than around 13. if its below that than its time for another alternator

curtisharrington 07-18-12 03:35 AM


Originally Posted by xXGslseSleeperXx (Post 11160517)
if you can, post a pic of engine bay, radiator, e-fan, wiring, ect. i think itll help us a little better diagnosing your fan.

With all the accessories OFF you shuld see close to 14 volts. with them ON it shuld be no less than around 13. if its below that than its time for another alternator

Pics galore later. It's midnight now so yeah. Thanks man. And the alt was checked like 3 months ago. Could it have failed since then? The bearings are going out anyways I guess.

Thanks for your help!


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