If at any time you guys get tired of my questions, please let me know. However, as long as I keep things on topic, I would appreciate it if I could continue to take advantage of your collective experience

In looking things over today, I spent some time fixing what I thought was an alignment problem with the OEM (likely original) radiator on the CRX Si. What I found instead was a broken rad mount on the top/passenger side. Well, considering that I was going to do new hoses and a complete flush anyway, I guess this is the last straw for the radiator (I see no need to repair it, since I have no idea how well it works). So lets look at the radiator first...I see my options as:

1) replace it with an OEM radiator (direct bolt-on, cheap, weak plastic parts, ample cooling for street enviroment, questionalbe for race).

2) replace it with an all metal OEM copy from any radiator shop (should be direct bolt-on, almost as cheap, all metal, and I can get one a little larger for better cooling)

3) replace it with a large, racing radiator like Fluydine (hardly direct bolt-on, not cheap at all, very good build, very good cooling for race time)

Now keep in mind that I race almost exclusively in Arizona where it's not uncommon for the ambient temp to pass 100 for several months out of the year.

For hoses, I figure anything of OEM quality and above is fine, no? 100% water with water wetter is my plan for that. New OEM water pump too.

As for the thermostat, do I even need one? There are a few people in my area that run open thermostats, and only have trouble warming up the motor. Is that a good idea, or should I spend the money on a real thermostat.

I also have a water temp gauge to keep an eye on things.

Anything I'm missing? Are OEM fans okay? Thanks!

 

OEM radiators provide plenty of cooling for the CRX. Here in CenDiv we don't have quite the temps you have in AZ but even in 100+ degree days, I never have a problem. I did have problems with the stock units developing leaks around the tanks so I switched to an all-metal aftermarket copy.

Stock hoses are fine.

I don't even run a fan.

 

Running an engine with out a thermostat is a no no.. Because there is a calculated thermal expansion between the pistons and the cylinder walls.. With out the thermostat the lower part of the cylinder will be over cooled hence a tighter tolerance and abnormal wear..

Maintaining the engine temp at 180°F also keeps the engine oil hot enough (212°F) to burn vapor off water from blow by gasses..

Also the thermostat acts as a restriction to the cooling system hence the coolant behind the thermostat will have a higher pressure than the rest of the system giving it a higher boiling point.

The restriction also increase resident time of coolant in the radiator...

Regards,
Charleston
http://www.geocities.com/chal15

 

Get an all metal repalcement. No need to get a bling-bling high capacity, just more $$$ to waste when somebody drops metal bits in your path or kick sup some rocks.

Use a thermostat. I had trouble getting my RX-7 up to temp without one, so I put it back in. You are fuel injected with an ECU, so probably more sensitve to water temp than my stone-age tech carb.

 

Hmmm, interesting comments about the thermostats. I guess I'll just make sure that mine is working properly. It's not uncommon here in AZ to just "gut" the middle of the thermostat and simply keep it there as a flow restrictor. We'll see how the car does with the OEM thermostat. I ordered an all metal "OEM style" replacement for my busted OEM radiator, and I'll replace the upper and lower hoses at the same time, along with a fresh water pump. I also have a new rad cap on there. I'll finish it up with a good flush, some water/water-wetter, and I hope that cover's it. Anything else?

 

My suggestion is to run with some coolant. Water wetter does not significantly increase the boiling point. Only coolant and pressure will change that.

Warren

 

What do you mean by "coolant"? Best coolant is H20, water wetter makes it even better.

I got an aftermarket metal radiator from 1800radiators after I cracked my original one. Been running H20 and water wetter in it and it never gets hot enough for my fan to come on when driving normally on the street, only after 20+ minutes of racing.

 

The green slippery crap.

If your radiator is oversized, then yeah, water + water wetter is cool. Otherwise, you should run a little coolant to bump up the boiling point.

Warren

 

sorry, the green stuff only lowers boiling point. its called "antifreeze" not coolant, because its job is to prevent freezing of the liquid at the sacrifice of lowering the boiling point. its best not to have the green stuff, but it also has anti corrosion stuff in it as well. thats why its also a good idea to use water wetter even if youre gonna put water in there, because it has anticorrosion stuff in it too.

i live in california, what the heck do i care about freezing...

 

Bad, Warren, Bad! I would feel pretty bad if I dumped coolant on the track & caused someone to crash. I was a event when a RX-7 had a cooling problem. He thought he fixed it (yeah, right!) so he went back out. A CRX & NSX paid the price. Acording to Redlines site, the water wetter/water combo works better than coolant/water.

BTW, I haven't had any problems with the stock radiator cooling enough even in Thunderhill in June/July when it is 100 plus degrees. The stock radiator worked fine for a friend with some head work & slightly higher compression too.


[Modified by civicrr, 5:40 PM 4/26/2002]

 

COOLANT also raises the boiling point of water. No way I'd run my car w/o some coolant in there. Water wetter + water is not enough to keep it from boiling in my car(s).

Warren

 

Forgive me, I was mispoken. Antifreeze, glycol, green stuff, whatever, does in fact raise the boiling point compared to water. I was confusing that for the reduced thermal transfer ability of antifreeze compared to water. Which makes water a better radiator coolant fluid. I hate when I stick my foot in my mouth...

To be honest, if the water is continually circulating as it does when the engine runs and thermostat is open, water is the better fluid because of its better heat transfer property. If it can transfer the heat better, and still maintain a safe boiling point, then it makes it the better "coolant" strictly speaking. But then again, antifreeze has anticorrosion properties that are important as well.

 

While it is true that added impurities (which is all anti-freeze is, really) will lower the freezing point and raise the boiling point, it is my understanding that water does in fact have a better thermal transfer ability. Regardless, the local NASA group prohibits the use of glycol based additives, so I don't really have any decision to make there.

 

YOu can increase the boiling point and lower the freezing point of water by adding impurities. Anything from salt, sand, sugar, glycol, alcohol, etc, etc will affect the boiling/freezing points of water. I wont go into the chemistry aspect of this, but you get the idea.

Water has better thermal conductivity properties than most substances out there - adding impurities will decrease its thermal conductivity coefficient, however it will raise the boiling point. There's a happy medium in there, but 50/50 works just fine for the street, and pure water is ok if your temps will never see freezing or boiling.

Water wetter works by improving the thermal conductivity of pure water - it does this by decreasing surface tension across the water molecules, thus reducing intermolecular forces (hydrogen bonds, van der waals) and increasing its effectiveness to transfer heat.

 

All of you that don't use 50/50 a/f better put in a can of that milky pump lube / antirust stuff, unless you like replacing waterpump seals.

Gary

 

Coolant also acts as a lubricant for the water pump and it keeps your cooling system from rusting out.

 

Have you thought about replacing your heater hoses, and other miscellaneous coolant hoses? When I swapped engines in my car I replaced the heater hoses and all of the 5/16" hoses because most of those lines had around 165,000 miles on them and I didn't want to risk it in the future. Something I haven't heard mentioned which is prudent to keeping the needle on the blue side of the temp guage.

EDIT: It's probably not as much of a problem for you, but also check your hose clamps too. Some of mine were rusted out and on their last leg, but I can't foresee you having that problem in Arizona with zero salt and zero snow.


[Modified by mojoGSR92, 1:59 AM 4/27/2002]

 

As I remove the AC system, I'm just giving everything the once-over and so far it looks pretty good. Rust hasn't really been an issue, but in this heat older hoses can dry and crack. I guess I should have some on hand, huh?

 

I don't know about you, but giving some of those heater hoses the "once over" wouldn't work for me. Most of those attach right between the firewall and obscure parts of the block/intake manifold or underneath a bunch of things. It's difficult to check the condition of those particular hoses on my vehicle. I think I paid around $50 for new heater hoses from Honda. As far as the 5/16" hoses, you may just want to buy in bulk and carry some extra around with you in case something happens. Most of those preformed 5/16" hoses are over-priced from Honda.

Jonathan - Who enjoys giving suggestions when the end result is not his money being spent.

 

If you are going to buy new hoses to have on hand, they will be WAY more handy installed on the car, than they will in the truck... Particularly since you need to be concerned about finishing races for licensing purposes, use the better safe than sorry approach.

All good advice so far but be sure that you don't mount the radiator rigidly - that will cause cracks. I also have a hard time understanding how an electric fan will slow you down and it will sure as heck save you in the pits. And leave it on the thermo switch because you WILL eventually forget to turn it on manually...

As a general rule (I love 'em!), assume that the engineers who designed the system were at LEAST as clever as all of the folks at the track or on this forum - maybe even more so. Seriously - Hondas are great cars because they are well engineered and have lots of excess capacity built in. If I had a nickle for every time a club racer (me included) thought that he or she could engineer a solution better than that achieved by a bunch of people with all of the resources of a huge corporation behind them, I would use the budget to run WC Touring this season...

Keep having fun!

Kirk

 

ITR231, I have no fan on the CRX, I have, from appearances, a slight amount of Coolant in the system (my understanding is that you want it lubrication/protection above the cooling/freezing properties - I wouldnt' swear to that). I too have "no" problems sitting for a good while at idle without the fan, even at CMP this past weekend and RR two weekends ago (I don't remember it ever going above 180 in the fasle grid at idle). A factor that might be contributing is the oil cooler and remote filter - I don't know if or how much it does, just don't want to mislead about what I am running.

 

Koyo Just got one on my EG and the damn thing won't warm up!


[Modified by Solo2Vtec, 9:16 PM 4/29/2002]

 

Leaky thermostat?