s/cL3.0

Well it is not RPM dependant so it will push more consistantly, and I believe it does flow more than a stock but I do not know what a stock pump flows..

NismoPick

When you don't have a thermostat, the engine doesn't heat up very much at all, as there is no restriction of water, & no regulation on temperature (hence the name thermostat). If you look at a thermostat, the passage hole is much smaller than the housing, allowing LESS water to pass through...

Again, that's what a thermostat regulates.... the water stays in the engine warming up, until the thermostat opens... doesn't matter if you have an electric or mechanical pump, nor the speed, as it's the thermostat controlling the basic temp level.

True, but the mechanical power required to turn a water pump is greater than the electrical pull from an alternator. Besides... you already have an alternator: put it to use!

Precisely why everyone is now buying an electric pump, as they DO have better impellers & have better flow ratings.

From everyone that is using electric water pumps, I haven't heard a single complaint.

NismoPick

Another cool thing about electric water pumps... you can let it cycle w/ the car off! Cools the engine much faster that way... Also, on dyno runs you don't have to rev the engine after every pull to cool it down... the pump is already helping!

lww

I'm curious about this observation. It seems to defy the laws of thermodynamics that I was taught in Chemistry while working towards my Chemical Engineering degree...

Could you explain a little more? I assume you're saying that the water passes by the hot engine so fast and in such quantity that it doesn't have time to transfer it's heat to the water, thereby overheating the engine?

I'm somewhat skeptical but willing to hear your logic...

lww

Yes, I pulled the thermostat and have the pump connected to a temperature switch installed in a spare port on the thermostat housing.

No thermostat to go bad and the CSR pump will not turn on until the motor is up to operating temperature.

I also plan to add a shutdown timer, similar to the turbo timer's out there so it'll continue to circulate water for about two minutes after taking the keys out of the ignition.

Since my turbo has a water cooled center section, this will also help cool it without having the car run during the cool-down like a traditional turbo timer requires.

Save's some of that $4/gal gas!

jfairladyz

jm is right that you can over circulate the coolant. But its not something that most people have to worry about. On REALLY long drives on REALLY hot days then what he mentioned is known to happen. It's exactly like you said lww; The coolant isn't in the radiator long enough to disipate the heat out. But at the same time it's not conducting very much heat as it rapidly passes through the engine. Because of that it takes a considerable amount of time and a considerable amount of heat to get to the piont where the car starts overheating because of no thermostat. None is always better than one thats stuck shut though But this is why you see restrictors in race cars like NASCAR. To control the flow of coolant otherwise they'll end up overheating their engines due to the long periods of time they spend on the track at high RPM's. The coolant needs to be in the engine long enough to conduct heat away from the cylinders and what not. Driving around town or an hour long commute to work isn't going to overheat your car with no thermostat. But you also have to beware of the fact that the engine is actually running hotter than the coolant is. So with no thermostat the coolant isn't picking up all the heat in the engine due to rapid flow and so the temperature of the coolant is not an accurate representation of the temps the engine is actually at.

Now for my next point: The stock water pump will far outflow the thermostat. With that being said, if you run a thermostat or a restrictor then the flow of the pump above what the thermostat or restrictor are able to flow is moot. So it doesn't really matter if the pump will outflow the stock pump or not. Basically it's wasted energy and wasted pump life. A votage regulator to the pump is a good idea to keep flow down to just where you need it. This will put less strain on the alternator, less strain on the water pump, and will equate to less power being robbed through the alternator by trying to flow 38GPM through an opening that will only allow a portion of that I will say that it's good to know that a pump will outflow the engine though, cause then when it's life starts to diminish and its not operating at it's full potential atleast it'll still be able to flow enough coolant.

lww

Described like this, it makes sense and works within the laws of physics.

Unfortunately, this is not correct and defies the laws of physics although the two seem to be the same, they are not.

In a closed system, getting the additional heat dissipated to the atmosphere is far more difficult than getting it dissipated from steel to water. Air just isn't a good conductor. The water not spending enough time in contact with the engine is not the issue, it's that after it leaves the engine, it doesn't spend enough time in contact with the radiator before being pumped back into the engine.

Water is an excellent conductor of thermal energy which is why it's used in most vehicles and why air-cooled vehicles are in the minority and generally relegated to small displacement engines where air-cooling is adequate although not optimal, although there are exceptions.

It's the disparity between the thermal transfer rates that causes the overheating problem. Steel to water vs. water to steel/aluminum then to air.

The ideal setup would be to have the water move quickly through the engine keeping it as close to ambient temp as possible, maximizing the disparity between the engine temperature and the coolant temperature, then have the velocity of the coolant slow significantly as it passes through the radiator to give it time to dissipate it's thermal energy through the fins and into the air until it returns to ambient temp. Then speed back up as it passes through the engine again.

Unfortunately, for a couple of reasons this is impractical.

1. Maintaining two different flow rates is not sustainable without a considerably larger coolant reservoir that would probably add huge amounts of weight to the vehicle. Not good in a race car or practical in either a race car or street vehcile.

2. Engines operate more efficiently at higher temperatures than ambient air.

The compromise is a smaller coolant reservoir for engineering/production reasons and to maintain coolant temperatures that allow the engine to operate at the temperature that maximizes it's combustion efficiency.

Thank you! I'll be here all week. Good Night!

icice9

lol kinda hard to argue with a man who knows his thermodynamics.... ê¿~

lww

I knew those 7.5 years of college would pay off one day!

jfairladyz

But this doesnt explain why the engine heats up so much more slowly. This would explain how an engine would heat up more quickly. I was saying the former, not the later in the statement you were reffering to.

I'm not saying no heat is being absorbed by the coolant. I'm just saying the amount of heat being absorbed is very little in comparison to having a thermostat in there allowing the vehicle to warm up. The radiator can do it's job just fine (even without a thermostat) until it starts to heat up.Then the radiator becomes even less capable of dissipating what heat the coolant brings its way. Now technically this is a closed system. And I didnt mean faster as in speed, but faster as in the amount of coolant being moved: volume. If the volume of coolant being cooled is greater than the volume of coolant being heated by enough to make up for the difference in the temperature changes of the two, then the temperature goes down. WIthout a thermostat the coolant is rapidly flowing into the large volume radiator and then rapidly back into the lower volume coolant passages (only those around the cylinders, cause thats where the heat is generated). This causes an unbalance on the side of cooling. Thus, the water is not absorbing enough heat from the engine in comparison to how rapidly it is being cooled. If the thermostat is there to restrict it then the volume in the combustion chambers becomes greater than the volume being cooled.

And normally a closed system such as this wouldn't allow such an event to take place. But the fact that the system has a radiator to disipate the heat is what allows the system to act as if it werent a closed system at all. So you cant really treat it like a closed system when looking at it from the laws of thermodynamics point of view. Every time the water leaves the radiator its like fresh water is coming in, just like an open loop system. So you cant make the comparison that way. If it were a completely closed system then I would agree 100% with you. In terms of physical characterics of the components themselves it is indeed a closed system. But the out side interaction through the radiator means it's not a true closed system. A true closed system does not involve the interaction of anything not within it's system. The air flowing through the radiator means the system is acually open.

Think of it like a computer (for a car). In closed loop the computer relies only on signals from its sensors within the engine and nothing else (such as coolant temp). Switch it to open loop mode and now it relies on signals from variables such as air flow and oxygen content of the exhaust (sensor outside of the engine). It's still only using it's sensors which are wired into the closed system but those sensors are now monitoring parameters outside the engine so it is no longer considered closed loop, it's now open loop.

When the thermostat is closed it's a closed loop system. Once that thermostat opens (or is removed) it's no longer a closed loop. It's an open loop system.

You better be, you're the head muckraker

81 Black L28E

dam lets all read a book....**** super posting dammmmmmmmmmmmmmmm

SHADY280

Ill Agree With Black, It Takes Me Longer To Read All That Then It Takes You Guys To Type. All That Being Said It Works The Way It Does, So If It Aint Broke Your Not Trying Hard Enough, Or Dont Fix It (which Ever Comes First!)

Bleach

We're here to have fun, not learn stuff! enough already...

s/cL3.0

Post your progress like the topic says and we wont have these probs.. LOL

Good info though..

jfairladyz

Yeah this is all Bleach's fault

Bleach

alrighty then. No pics for you though!

I got the BOV pipe welded on the J-pipe. I cleaned the FPR and J-pipe and got two coats of primer on each. I'm taking my own advice from a long time ago.... stock regulator, painted blue!

I broke off a bolt in the lower thermostat housing and couldn't get it out. So there goes lower thermostat housing #2 into the garbage can this month. From now on, I'm hanging onto these things when I come accross them. I have one more housing. I hope this last one is good.

I pulled out the sensors because they were from an '82. The '83 sensors in the stat I believe are different to work with the digital dash. (ya, this was a digital dash turbo car) oh, and I guess I do have the stat housing that is currently in my 280ZX, but I was planning to get this engine complete by itself without pulling any parts of the NA L28.

I'll be gone most of the evening tonight, so I'll probably just get some coats of paint applied.

NismoPick

I've learned that it is important to have a set of carbide drill bits for broken bolts. Just drill a hole in the center & use a tap to reverse it out.... then again, why go through that if you have a spare!

That would explain why the temp gauge didn't work on the 280zx I converted to Digi Dash... oh well, I sold that one!

Bleach

Is that all that didn't work?
I also thought the gas tank sending unit was different.
and I thought that the talking lady was replaced by a Transformer...

NismoPick

I didn't have a prob w/ the fuel gauge, but the temp gauge would show 1 bar, all the time... I think.... either one bar, or maxed out.

Bleach

fumez....
super blue FPR


hyper white J-pipe


just a picture of the engine

jfairladyz

That J Pipe is going to look good installed. I mean it looks good now, but on the engine it will probably look even better. Just dont go putting rusty hardware on that thing (nobody is ever satisfied )

s/cL3.0

DAYMM.. Man.. That will look nice.. especially with the chromed out BOV.. PPPPSSSSHHHHH

lww

DAMN! And I had a REALLY good reply for J too... Would have set him straight... BUT, I guess he'll have to continue living in the dark...

So sad...

Lost Vegaz

Nice engine, the white looks soooooo good. Damn, I may have to go pull my engine and paint it

s/cL3.0

Okay so I have been doing little things and taking BIG pictures

NEW Brake master cylinder.. Need to find my nuts though (for it to stay on)



Replacing the steering rack Bushings..



this is after one minute in the GOO.. I am telling you this shiit is great..


Before I started cleaning The inside fender..


10 Minutes later



My plans are now to get the Engine bay paint stripped and painted by next Sunday and all next week getting the Motor/Tranny in the car.. I want this bad boy running no more waiting..