Radiator in tank sizing question

[Tman]

Good luck and keep us posted with your progress!

[Rex Schimmer]

Andy,
Good thinking about using a "real" water to water heat exchanger. If you know your heat load then the manufactures application engineering data and calculations can get the right size for you plus show you what the required fluid flows need to be to be efficient. Also "tube an shell" heat exchangers are typically fairly small and can be integrated into tight spaces in your car. Also look into the newer "plate" style exchangers as they are even smaller. Most of the "radiator in a box" coolers that you see at Bonneville have way to large of a radiator in them, a typical water to water exchanger is 7-10 times more efficient than an air to water radiator for equal surface area.

Regarding the "boil off" safety net, if you used a closed system with a water reservoir that can be pressurized then you can still have the protection of the additional energy required to phase change water to steam when it boils. But you need to be pressurized so it takes a strong container.

A little test that you might try is to use one of your electric pumps, I assume that you have one for each side of the flat motor, and have it pump through the engine and monitor the outlet pressure of the pump, this would be the pressure required to pump through the engine and you might even consider running the out let water into a 5 gallon bucket and time how long it take to fill which will then give you the actual flow rate through the engine. I'll bet you a beer it won't be 37 gpm.

Rex

[Sumner]

... As you can see from the pictures of Buddy's system and the system that Sum built for Hooley's Studi they are not small. When Hooley was running a supercharged small block Chevy they ran a pressurized closed system using a 15 or 20 gallon air bottle that carried the cooling water and that was on an engine that made at least 800-900 horse power. ...

Realizing that some people base their builds on what others have done (we have) I just wanted to clarify Rex's comments above.  We did run the first year or two with a smaller tank that I think was about 16-18 gallons but then with the blown motor we ended up with the 30 gallon tank that we still use in the car.  We also ran a 2-3 lb. radiator cap and circulated the water through the engine from the tank with a Meziere pump that I believe is about 25 gallons per minute and not their largest pump.  The engine never had a heating problem except when we forgot to turn the pump on  .  I'd still like to put a second "on" switch on the the shift linkage just in case the driver forgot to turn the pumps on.  Now we have to remember to turn the water pump and the intercooler pump on.  Ran out of time to do this but  might have time before World Finals.

We didn't like even the low pressure in the tank with the 2-3 lb. cap as the tank is in there with the driver.  I feel much safer now that there is no pressure in that tank.  Also cooling should be better with less chance of steam pockets in the motor with the 18 lb. cap we can now run with the rad-in-a-box.

Also like Rex said I'm sure we probably could run with a smaller radiator than what we have now, but if we get this motor up in the 1400-1600 HP range I'll feel better having it but also as he mentioned these radiators were designed in the first place as air to water coolers so more efficient water/water ones are probably out there.  If money matters you can get a double pass like we are using for under $200 though. 

I'm double passing the cooling water through the double pass radiator.  If you just have the radiator in a box and aren't running water through it from another tank then I'm not sure you gain much with using a double pass radiator.  Rex maybe you could comment on that.

For most of us that can't do all of the calculations and there are a lot of variables to consider maybe going oversize from the beginning if you have room is safer.  That way you also have the potential to cover your butt if you do engine or power-added changes down the road,

Sum

[SPARKY]

Sum I think that there still would be an advantage  heat rises so the water going back would still be coolest available/

[Sumner]

Sum I think that there still would be an advantage  heat rises so the water going back would still be coolest available/

I guess I see that in that the final pass through the radiator would be down in the cooler water.  Makes sense and since the 2 pass are easy to obtain why not use one.  They are even better with the same temp air going through the top and the bottom vs. a single pass in a more normal car use since the water in the rad sees the air twice,

Sum

[Jon]

One advantage of a double pass radiator is that the water is higher velocity in the tubes as it is forced through 1/2 at a time.
Turbulent flow is your friend for heat exchange.

jon

[Skip Pipes]

Here is my finished system. Double pass radiator and I use a pump/spray bar to circulate water inside the box. As yet untested in competition, so copy at your own risk

Skip Pipes

[Dynoroom]

What a great idea!!   

Here is my finished system. Double pass radiator and I use a pump/spray bar to circulate water inside the box. As yet untested in competition, so copy at your own risk

Skip Pipes

[Skip Pipes]

Oh crap - busted again

OK, my system is entirely based from what I spied off Dynoroom's car! Or a stolen design might be more accurate. Nonetheless, it's a really effective way to cool the engine.

[Tman]

Oh crap - busted again

OK, my system is entirely based from what I spied off Dynoroom's car! Or a stolen design might be more accurate. Nonetheless, it's a really effective way to cool the engine.

So who do I say I stole mine off of?!

[Rex Schimmer]

With this interest in the "radiator in a tank" cooling concept I still have one 15x15x4 double pass radiator left. See my add in the "For Sale" section, http://www.landracing.com/forum/index.php/topic,10946.0.html. In a properly designed system this radiator should be good for at least 800 - 1000 hp with a good circulation pump and a stout water pump. Price is $150 plus shipping. Radiator is pro built by Ron Davis.

Rex

[Sumner]

With this interest in the "radiator in a tank" cooling concept I still have one 15x15x4 double pass radiator left. See my add in the "For Sale" section, http://www.landracing.com/forum/index.php/topic,10946.0.html. In a properly designed system this radiator should be good for at least 800 - 1000 hp with a good circulation pump and a stout water pump. Price is $150 plus shipping. Radiator is pro built by Ron Davis.

Rex

With this interest in the "radiator in a tank" cooling concept I still have one 15x15x4 double pass radiator left. See my add in the "For Sale" section, http://www.landracing.com/forum/index.php/topic,10946.0.html. In a properly designed system this radiator should be good for at least 800 - 1000 hp with a good circulation pump and a stout water pump. Price is $150 plus shipping. Radiator is pro built by Ron Davis.

Rex

That is a good price.  I'm wondering about how it flows.



Do the inlets/outlets have two possible connections...front or side?  Does it come in at the middle one and flow up and across and then down and back out the the other one or is that where the tank fill is also?  Can't tell from the picture and I"m confused as it looks like the side tank...



..is divided at two places (near side of the picture above)

Are the two protrusions to the left of the tank mounts or to an inside transmission cooler or something?

Thanks and hope you find a home for it as it could be a good tank for someone.  Are you still building a lakester?  I've been gone from here so have been out of the loop,

Sum

[Rex Schimmer]

These coolers, I had 3 at one time, were made for a Porsche race car and, as I understand, they mounted two of them in the front air damn area, and they were interconnected which explains the extra water connections. they are double pass, the connection that is toward the center is connected to the core on the right side. I think that the welds on the bottom of the tank are just welds to complete the tank and are not "dams" to prevent water flow. I have ran water through it to confirm the double pass configuration.

Regarding my lakester, Sum, I have started up again and I am  doing some design to finalize the configuration of the final drive and also am planning to start building the buck for the body when I get back from the World Finals and a couple of weeks of hunting in Arizona next month. If I actually get some steam up on the build I will start a build thread.

Rex

[Sumner]

These coolers, I had 3 at one time, were made for a Porsche race car and, as I understand, they mounted two of them in the front air Dodge area, and they were interconnected which explains the extra water connections. they are double pass, the connection that is toward the center is connected to the core on the right side. I think that the welds on the bottom of the tank are just welds to complete the tank and are not "dams" to prevent water flow. I have ran water through it to confirm the double pass configuration.

Regarding my lakester, Sum, I have started up again and I am  doing some design to finalize the configuration of the final drive and also am planning to start building the buck for the body when I get back from the World Finals and a couple of weeks of hunting in Arizona next month. If I actually get some steam up on the build I will start a build thread.

Rex

Thanks for the added info on the radiator and I'll be looking forward to the build pictures.  Considering what you accomplished with your roadster they will be well worth viewing,

Sum

[CTX-SLPR]

The other recommendation that I would have is to use a BMW 320 I three way thermostat. These are really cheap, about $20, and what they allow you to do is to have full pump volume water flow through the engine while the engine is warming up as opposed to "normal" thermostats that "lock" the water in the engine until their set temperature is reached and then open which can cause temperature fluctuations. Also adding some ice to the water will provide additional cooling capacity as ice requires additional energy to do the phase conversion from ice to water.

Rex

Rex,

I've seen this recommended a few times and I've looked it up as far as what it looks like and it's original usage.  I've never seen how someone has used it in an actual application though.  Can anyone show a picture of the housing or mount they used with the above BMW thermostat?

Thanks,