NACA 66 Special A/BGS

[jl222]

Tech question. Right now I am planning to build the water tank to hold 48 gallons icewater for the engine coolant. The engine that we will be eventually running will make about 2600hp on gasoline. Is this going to be enough? Would like water temps to no more than 200f at the end of the run. I'm imagining that we will only be averaging 1700hp through the course of the 5 mile run. We will start off with icewater (90% ice or whatever we can get). Water will recirculate in the block and heads until it hits 150f then off to the marine heat exchangers in the tank.

  Rob we only have a 28 gal water tank in the 222 car and never run it full, temps never get to 200 degrees and we don't have exchangers or run ice water.


                JL222

[racergeo]

  For a 1 minute long run 48 gallons might be over kill. There is a 700hp gas lakester that uses a 5 gal. Jeep can.

[saltfever]

This has been covered before. Here is a good thread that explains it well. Note my post #19 indicates you do not have to consider all the HP because most the heat is wasted and flushed out the exhaust pipe. There are other losses that do not go into the cooling water also. Eric has done specific heat calcs on other threads regarding intercooling and would probably love to do the calcs for you.  
http://www.landracing.com/forum/index.php/topic,5314.msg74820.html#msg74820

[robfrey]

There are so many variables to this equation that I feel we can't accurately fill in that i feel much better going by experience or someone else's experience then back up our decision with the math. Engine Analyzer Pro 3.9 says that engine is about 30% thermal efficiency.

[Blue]

There are so many variables to this equation that I feel we can't accurately fill in that i feel much better going by experience or someone else's experience then back up our decision with the math. Engine Analyzer Pro 3.9 says that engine is about 30% thermal efficiency.

The biggest levers on this are the compression ratio (high compression puts more energy in the exhaust and less in the block for a given power level), and the shielding/cooling of the exhaust.  If it's well shielded, it takes little cooling air flow to prevent the radiant heat from soaking the engine compartment.
 
30 Gallons is probably more than enough.

[John Burk]

A thermostat allows a smaller tank . Warming the engine up to the thermostat temp. doesn't warm the water in the tank .

[Rex Schimmer]

John is right about using a thermostat, standard thermostats hold the water in the block until the thermostat setting is reached, there is a thermostat from BMW that is a three way configuration and it recirculates the block water until its setting is reached and then it opens to the cooling source. The advantage is that with a standard thermostat the water around the exhaust valves can be a lot hotter than the water at the thermostat before it opens, the three way style assures water circulation through the complete engine and reduces hot spots. Just a thought.

Rex

[Interested Observer]

Using the recently updated/corrected expressions cited in the link above, and Rob’s 1700 average horsepower, To=200F, Ti=90F and a run duration of 1.3 minutes, results are a coolant flow of 26 gpm and a reservoir volume of 34 gallons.  Seems to be in general agreement with other’s experience.

Also, in line with Blue’s “do your own testing” principle, experience has shown that pump sellers, particularly those that offer pretty, anodized, hot-rod pumps are notorious liars as regards the performance of their pumps.  They often can’t flow what is stated even against zero backpressure.  Remote reservoirs with possibly long piping runs and fittings are going to have suction and headloss issues.

The latest CAD results look very sleek, but like Rex, I still worry about getting everything tucked inside.  Maybe it is bigger than it looks!  Hope you carry on the CAD work to include most of the ridiculous amount of stuff that is needed.

Also, a 400 mph run is pretty much a drag race, and the tail doesn’t look too push-truck friendly.  How is it going to get off the line?  Done any vehicle performance simulation yet?  Driveline plans?

[saltfever]

(edit . . . ) there is a thermostat from BMW that is a three way configuration and it recirculates the block water until its setting is reached and then it opens to the cooling source. Rex

Great information Rex, and thanks.  Make, model, or p/n?

[jimmy six]

"those that offer pretty, anodized, hot-rod pumps are notorious liars as regards the performance of their pumps.  They often can't flow what is stated even against zero backpressure."

Defiantly don't believe advertised GPM flows. I have tested every pump I have run first and only one met it's 20 gpm and that was a Jabsco brass centrifugal and it was 22. The pump was below the tank and fed with a 1" line in and a -16 out, no restrictions, even the shut off valve is a true 1". All the ones advertising over 30 could not meet 20. Only the Meziere remote did what I felt I needed at over 35 and it was rated at 55. I have also drilled out all of the fittings to the max.........Good Luck....JD

[racergeo]

 I just love this sight, you get such excellent info. Stuff that's not available anywhere else in the known universe. Thanks to all that contribute. Especially KENT and FREUD!!!!! I love to laugh.

[Rex Schimmer]

Saltfever,
Go to this web site,http://www.bavauto.com/se1.asp?dept_id=320, and look at the thermostats for the 2002 thur 318/320. They cost about $20.

Rex

[robfrey]

John is right about using a thermostat, standard thermostats hold the water in the block until the thermostat setting is reached, there is a thermostat from BMW that is a three way configuration and it recirculates the block water until its setting is reached and then it opens to the cooling source. The advantage is that with a standard thermostat the water around the exhaust valves can be a lot hotter than the water at the thermostat before it opens, the three way style assures water circulation through the complete engine and reduces hot spots. Just a thought.

Rex

Rex, Can you give us more info on this three way thermostat. We have built our own using two connect opposed thermostats with one of the springs removed in the past to keep recirculation speed up in the block but if we could buy a more professional unit, that would be great.

[Rex Schimmer]

Rob,
See my last reply it has a web site with the thermostat info. You may want to consider going with a pair of these as I would expect that you are going to have some pretty high flow rates for the water. If you want an extremely good engine water pump contact Stu Van Dyne, Van Dyne Engineering, 714-847-4417. Stu has a water pump based upon the Offy engine design that I am sure will provide sufficient water for your big turbo motor.

Rex

[jimmy six]

We run a Van Dyne water pump on our dirt car and are very satisfied. Charlie Reno runs a remote (belt drive) on his 1471 blown big Chev and it works................Good Luck

Van Dyne is also one of our advertisers..................