That's Good...

But the other one I e-mailed you the linky to has a almost a radiator-hose diameter flow capability, along with the ability to completely plug the internal block bypass passages, and external passage allowing for more flow during at-temperature operation instead of continually wasting possible flow through a recirculation scheme that is not required after warmup...

 

If it's moving 3 times the water then it should be using up some HP to so right?

 

I've just been thru T-stat ****.Six to be precise.

First three were Mr.Garbage "Hi-flows" like the one pictured.All were NFG right out of the box.
Next was a Stant.Garden variety parts store.It worked well,then a week later it failed.
Tried a Nissan($34.00)It claimed to be a 180 degree but didn't open untill about 202 degrees.

Tried a Robert Shaw.That opened late.

Finally tried a MotoRad.So far so good.

Also found out that the fan clutch that the"Book" calls for doesn't lock up untill 212 degrees.

 

where did you guys get the nissan t-stat???? does nissan still carry them or do you have a source online?

 

RexRoach 83zxt Wrote:
-------------------------------------------------------
> where did you guys get the nissan t-stat???? does
> nissan still carry them or do you have a source
> online?


Here's part of the problem.The Nissan stat that the dealer SAYS is correct isn't.It's made for later vehicles(that run warmer) and Nissan thinks it'll work in a 70's L-motor.It doesn't.

 

Just put a Nissan thermostat kit in, part # 21200-P7991

"For all vechicles with L Z A E CA H engines - except H20"

Seems to be working fine, tested before installed.

Also put in new Paraut water pump & fresh coolant.

 

I've been around the machine shop too much, the only thing I could think of when I looked at those pictures was "oh he's got an SPI digital caliper!".

 

JPZX Wrote:
-------------------------------------------------------
> Just put a Nissan thermostat kit in, part #
> 21200-P7991
>
> "For all vechicles with L Z A E CA H engines -
> except H20"
>
> Seems to be working fine, tested before
> installed.
>
> Also put in new Paraut water pump & fresh coolant.

What degree is that?

 

Now I will interject a question:

Isnt the purpose of the Thermostat size also important to slow the coolant so it can have dwell through the radiator so the heat can be carried away by the air passing through it?

 

"Isn't the purpose of the Thermostat size also important to slow the coolant so it can have dwell through the radiator so the heat can be carried away by the air passing through it?"

Only on vehicles with an under capacity radiator. Such vehicles also tend to overheat in hot climates. GM and Ford built vehicles with under capacity radiators for years.

Joe

 

No

It's restriction function is more to provide a place to build up pressure against the water pumps flow. (Remember I say boost is merely a reflection of flow...)

IF the pressure in the system is raised accordingly with a proper radiator system pressure relief cap, then the pressure built up inside the block becomes less important to prevention of the boiling in the boundry layer between flowing coolant and stationary castings.

Then, all efforts can be placed on flowing as much coolant through the exchanger (block) as can be physically handled, in order to maximize heat transfer.

Read the Grape Ape Racing Article on Nucleaic (sp) Boiling and it should be clearer. Excellent Article, and the point of 'slowing down the flow' is addressed in it specifically.

I had an argument here about block pressure with someone, and they never did install the gauge to monitor what happened. I know what happens, but they never dared convincethemselves that their outlook was elementary and foolish.

Such it the nature of the beast here, very few come ot actually learn, most come to argue the points they don't want to agree with because it means work on their part to do something right!

 

DMS, those are my thoughts also, quantified in my Heat transfer class/ lab.

A higher flow could mean a higher op temp.

A dirty system will bugger things up, clean is better as I am sure we all know.

A stat with a large opening will close to the size of the previous one achieving the same flow? ( for a given rpm and pump spec).

Thoughts, flames? Damm I love these cars.

 

Huilo asks:
-----------------------------------------------------
> A stat with a large opening will close to the size of
> the previous one achieving the same flow?
> ( for a given rpm and pump spec).

That would depend on the total length of movement of the temperature sensitive bulb/valve versus the opening size in the thermostat as related to flow capacity/regulation. The thermostat has a flow curve based on opening, which can be restricted by limiting the movement of the valve or taken to a maximum flow rate at some valve opening beyond which there would be no further control of flow, as the ratio of the valve opening to the pipe diameter wouldn't increase anymore.



As you say it would appear that if the flow is higher and you get better heat transfer in the radiator, the engine would be running cooler and the themostat would close down some. That's true to a point. If the flow through the radiator is too rapid there can be less cooling capacity and the engine would be running warmer, causing the thermostat to open up some. It then gets into more complicated heat transfer exponential equations based on an increasing coolant temperature, flow rates and heat transfer boundary layers both on the water side and air side. It's possible way too much flow could result in eventual overheating due to poor heat transfer. Whether the water pump can reach the flow rates to cause enough poor heat transfer is an issue also.


Thoughts? Flames? It may be time for me to read the Grape Rape Racing article.

 

If anyone is wondering:
http://www.grapeaperacing.com/tech/index.cfm

specifically here:
http://www.grapeaperacing.com/tech/coolingsystems.pdf


I havent had time to read it yet. Is this the article Tony? "Nucleate Cooling Phase"?

 

Why not just run straight H2O...........hehehehe

 

<Why not just run straight H2O...........hehehehe>

Specifically, the boiling point is the issue. Given that water has a heat transfer of 1 Btu/lb/°F, glycol has a transfer of about .8 or so. A 50 50 mix of glycol and water gets a transfer rate of about .7-.8, but additionally the boiling point is raised with the glycol. That is why most people run a 50 50 mix, and to stop freezing in cold weather.
Now, there is a coolant, evans coolant that is not your standard glycol, propylene glycol is their take and that raises the boiling point much higher then standard anti freeze, to about 375 degrees F.

 

DMS, thanks for the link. A good read. Some of the theory has a kink here and there. Such as, in talking about radiators it says that the aluminum dissipate heat faster because the metal is thicker; that seems very contrary to the fact the thickness of the metal is a resistance to heat flow; more surface area to a larger aluminum radiator, more likely; if thicker is better, then thicker cylinder walls would increase heat dissipation. That isn't going to happen.

Also,, too many separate paths of flow out of the pump, such as additional pipes to the rear of the engine, can result in short-circuiting flow thru the least restrictive path, causing starved flow thru higher restrictive paths. Basic pump engineering. It was even discussed about the uneven side-to-side flow in the Chevy engine.

But such observations are for another day when someone wants to modify their cooling.

 

Another Day...

dumbestone Wrote:
-------------------------------------------------------
> But such observations are for another day when
> someone wants to modify their cooling.

Some here have been going over that extensively for some applications.
Many people think pumping the way the stock pump does is actually the most efficient.

Let me ask you, what engineer would put a heat transfer system into operation that introduces coolant in the COLDEST portion of the equation first, so it can warm up before it hits the WARMEST position of the equation.

Every industrial cooling application I have EVER dealt with introduces cooling medium in its coldest state to the heat source at the HOTTEST point. Counterflow cooling, it's the most efficient method of transferring heat.

Most engines, save for some newer GM's have coolant in the block, out the heads.

It should be IN THE HEADS, OUT THE BLOCK!

GM did experiments in the 50's on the SBC and realized that...they didn't implement it until the last redesign on the mill. Economies of scale and tooling costs I guess... morons! Sometimes OEM packaging is just too much of a compromise when you are making big HP and actually need an EFFICIENT system to transfer the heat!

 

No argument with those facts, Tony.

The only concurrent applications I can think of were highly sensitive materials or inverse viscosity fluids that didn't want to be overcooled in countercurrent flow by the cool liquid from whatever ambient reservoir/source entering the hot end (now partially cooled approaching the hot end in concurrent flow).

You've been around a lot of control equipment so you probably have many more ideas on coolant control. If the need warranted the effort, a spring-loaded, pilot/pressure operated flow balancing valve with center piston in an opposing dual flow chambers in a single-body could be used to equalize engine coolant flow. There are a lot of more sophisticated controls that could be adapted with basic industrial controllers for dual coolant return temperature control.

 

You would like JeffP's conversations...

When he's lucid, we both lament not stealing sufficient quantities of Avionics Bay 'Fluid, Coolant, LCS'... Last I recalled it was somewhere north of $2000 a gallon, and we used it to cool F15 and RF4C components in flooded bays.

VERY low surface tension, excellent wetting capabilities, and nice specific heat characteristics.

How we both wish I had snagged it, or even took a photo of the cans so I could look for it surplus by NSN!

In the interim, that Evans Propylene Glycol will have to suffice for out little experimentations in horsepower...

We were discussing the variability of flow through portions of the engine, but have gone towards the 'less complex the better' for the application. Likely that will work better and be applicable to others if we choose to share the results.

We have already found a willing cohort for a high speed test bed...saving us the expense of building one from scratch!

 

Let the tests begin.
Some of the new changes will include the Euro exhaust manifold, ported to match the head flow or better, more flow the better. Stay with the 3" exhaust, it is good for 650hp. Worst case on the head gasket will be a copper part. When I say worst case on the copper I mean that the block will have to jump over the oring cliff, so it will be required in the future of the engine for every build. The copper has a tendancy to seep on the water and oil passages, not always, but as you know, more often time for builders then not, major consideration, NO LEAKS! The copper is the best for heat transfer to the block that can soak it up. The Dual laminant steel head gasket is the other option, but it to poses some questions, like will the 91mm gasket bore promote detonation with an 87-88mm bore @ 1mm. So that may be a single test all its own.
The use of an LD water pump, Evans coolant,additional cooling to the cylinder head from specific locations on the head as a secondary flow to the radiator.

So all we have to do is build it and run it LOL, all we have to do, and a few thousand later LOL. Anyway, so yea there are some things going on in the back ground. Myself, I would love to be an individual mentioned as part of the team that holds a land speed record for the 280z.

 

Copper You Say...

Jeff, I've been in contact with some people that do Teflon Coating, and there is the possibility we can get stuff coated with a 1 or 2 mil telfon coating...that cure your weep issues? Just clean the fire ring, as we don't need Krytox-Like Carcinogens out the pipe on initial fire up!

As for 3" exhaust, we part ways there... The S30 can accomodate 125mm pipes all the way back, so IF we run an exhaust (like with a belly pan on it) then it will have to be big. We loose 20HP on the N/A engine versus open header dump on TWIN 2.5" piping all the way back...which flows more than a single 3"!

 

Re: Copper You Say...

that may just be a very good addition to work in conjubction with the gasket. There really is not issue of the gasket deforming I don't believe. I have found some pretty incredible stuff on the issue
Here is an example of a solution to the problem! well you decide.
--------------------------------------------------------------------------------

<I'll toss out a little trick that I used in lieu of conventional
O-ringing back when I was building hot Datsun 240Z turbo engines. No
one in my area was set up to do block O-ringing on foreign engines and
I didn't want the heads done. I came up with what I think is a pretty
ingenious substitute that worked up to about 30 psi of boost on this
engine.

In a nutshell, what it involved was superglueing 0.030 stainless steel
welding wire to the fire ring of each head gasket cylinder opening
after removing the "special coating" with solvent. This wire was
placed on the aluminum head side of the sandwich and was pinched by
the iron block and the 1/2" allen-head cap screws that I replaced the
puny 8 mm head bolts with. When the head was torqued down, the wire
embossed the aluminum head enough to become rigidly fixed while at the
same time compressing the fire ring and gasket underneath very
tightly. Once I got the block/head joint absolutely stationary with
the large fasteners and about 130 ft-lbs of torque, this setup was
stone-cold reliable.

My technique is as follows. Carefully uncoil the stainless steel
welding wire from the roll so as not to kink it. Wrap it several
turns around a piston (or other object) somewhat smaller than the
cylinder so that when released, it will form a coil about the diameter
of the cylinder, only a little larger.

Cut the wire into single coils with about a half inch of overlap
initially. Carefully position the ring on the fire ring of the gasket
(datsun factory gaskets had a sticky goop on the ring that helped hold
it in place.) and make the ends overlap. With an Exacto knife or
equiv, mark across the two ends somewhere along the overlap. Snip the
wire with flush cutting ***** a fraction of an inch outside the mark
on each end, then with a jeweler's file, bevel the ends at a 45 deg
angle so that when the ends butt together, the fit smoothly and make a
ring of the diameter to fall squarely on the midline of the fire ring.

Next, remove the special goop from JUST the fire ring with solvent and
a Q-tip or equiv. Lay the wire on the fire ring and tack it down with
super glue every half inch or so. Use accelerator to make the glue
set instantly. Make sure the ends butt up against each other and tack
the ends together with superglue.

Repeat for each cylinder, then assemble the engine normally with the
O-ring facing up against the head gasket. If the head is not
positively located with dowels like the Datsun head is, be very
careful to place the head straight down on the block and avoid any
lateral movement which could dislodge the wires. I recommend making
several passes when torquing the head bolts down to make sure the wire
embosses the head evenly.

I found that if I was very careful, I could remove the head and then
reuse the gasket a couple of times before it got beaten up enough to
start leaking. I NEVER blew a head gasket once I started using this
technique.>
============================================================================
so there is one view on the matter, myself I dont believe 130 foot pounds is the way to go.

 

Is Redline's Water Wetter any good? I didn't see any mention of that? The only downside is that it doesn't offer any anti-freezing capabilities.