34 replies to this topic

[Brandon]

Had me a bit of a cooling issue this past weekend at Summit Point and wanted to get some feedback.

Car is a previously-built one that I'm in my second race season on with a JDavis Racing AL radiator.
Unfortunately after swapping out the AL model for a stock one, the temps still didn't drop.

With the stock radiator I was running 220+ in traffic and while in clean air managed to drop it to 210- (wavered between 205 & 210).
This was no change from while running the AL radiator. Temps were gathered via an aftermarket gauge & upper-radiator hose sensor mount (Advanced Auto's).

Some possible next steps are:

• Test the thermostat (it's new this season but ensure it's not faulty & opens at the spec'd temp)
• Bypass the heater core & monitor temps (possibly plugged)
• Scrub/flush/backflush the cooling system (commercial product or DIY formulation - I'm doing a flush without the thermostat installed regardless)
• Replace the water pump (not my idea of a good time)

A close inspection of the AL radiator reveals one that's lived a fairly hard life and purchasing a new one isn't out of the question. My time spent straightening that number of fins would be worth buying 2 of the eBay AL models...however, before I jump into the parts replacement process (never the optimal solution) I was hoping to review the other options to ensure I'm not tilting at windmills and all that.

Some questions:

• Commercial cooling system cleaning/flushing solutions - are there any still available that are worth a damn?
• Is there a DIY version of these solutions that should give me a similar result? I've heard white vinegar is a decently acidic solution that would be effective in this scenario as well as oxalic acid (wood bleach). Though the wood bleach strikes me as potentially deleterious to any AL parts and our engines are nearly all AL.
• What's the nominal flow rate of a properly functioning water pump? How do you tell if yours is failing/has failed without tearing into the front of the engine?

I'm hoping a flush/backflush would remove any sediments that may have collected down low in the block on this crate engine over the years (it's perhaps 4-5 years old) but I'd like to do whatever possible to get as much of that out as I could so I'm taking suggestions for any commercially available solutions. I've heard the GM or Ford coolant system cleaners do a generally good job but those may have been designed with an iron block & head in mind and would be too aggressive for our engines.

Suggestions/alternatives/known fixes appreciated!

Thanks,
Brandon

[Mike Collins]

Just stick a garden hose in the bottom of it and let it run for a few minutes.

[davew]

Take out the thermostat and throw it away. Solves 99% of all cooling issues

[Tom Hampton]

Yup. 53mm koyo, no Thermo, 106 in the shade (god knows what on the track).... temp guage still below normal last weekend at msrc.

[Jim Drago]

Had me a bit of a cooling issue this past weekend at Summit Point and wanted to get some feedback.

Car is a previously-built one that I'm in my second race season on with a JDavis Racing AL radiator.
Unfortunately after swapping out the AL model for a stock one, the temps still didn't drop.

With the stock radiator I was running 220+ in traffic and while in clean air managed to drop it to 210- (wavered between 205 & 210).
This was no change from while running the AL radiator. Temps were gathered via an aftermarket gauge & upper-radiator hose sensor mount (Advanced Auto's).

Some possible next steps are:

• Test the thermostat (it's new this season but ensure it's not faulty & opens at the spec'd temp)
• Bypass the heater core & monitor temps (possibly plugged)
• Scrub/flush/backflush the cooling system (commercial product or DIY formulation - I'm doing a flush without the thermostat installed regardless)
• Replace the water pump (not my idea of a good time)

A close inspection of the AL radiator reveals one that's lived a fairly hard life and purchasing a new one isn't out of the question. My time spent straightening that number of fins would be worth buying 2 of the eBay AL models...however, before I jump into the parts replacement process (never the optimal solution) I was hoping to review the other options to ensure I'm not tilting at windmills and all that.

Some questions:

• Commercial cooling system cleaning/flushing solutions - are there any still available that are worth a damn?
• Is there a DIY version of these solutions that should give me a similar result? I've heard white vinegar is a decently acidic solution that would be effective in this scenario as well as oxalic acid (wood bleach). Though the wood bleach strikes me as potentially deleterious to any AL parts and our engines are nearly all AL.
• What's the nominal flow rate of a properly functioning water pump? How do you tell if yours is failing/has failed without tearing into the front of the engine?

I'm hoping a flush/backflush would remove any sediments that may have collected down low in the block on this crate engine over the years (it's perhaps 4-5 years old) but I'd like to do whatever possible to get as much of that out as I could so I'm taking suggestions for any commercially available solutions. I've heard the GM or Ford coolant system cleaners do a generally good job but those may have been designed with an iron block & head in mind and would be too aggressive for our engines.

Suggestions/alternatives/known fixes appreciated!

Thanks,
Brandon

Order a Springfield radiator from Saferacer, throw the t-stat away and your problems are solved, you will be 170/180 in those conditions
Jim

[Keith Novak]

I run a 53mm Koyo in my '95 and aside from waiting for the scales, I usually don't get much over 160 without a stat. I rarely hit 175 with one. I think the 1.8 must run a lot cooler than the 1.6. If you decide the water pump might be an issue, it's not really a big deal to change.

[HoneyBadger - BrianW]

I run a 53mm Koyo in my '95 and aside from waiting for the scales, I usually don't get much over 160 without a stat. I rarely hit 175 with one. I think the 1.8 must run a lot cooler than the 1.6. If you decide the water pump might be an issue, it's not really a big deal to change.

I was running this past weekend in 103 degree heat in Texas and my car was 210-215, I have a 53mm Koyo. My buddy who has a SpringField was running about 7-10 degrees cooler. At the end of the session he was running 207. Neither of us have thermostats.

[Tom Hampton]

Where were you running Brian?

[HoneyBadger - BrianW]

Where were you running Brian?

MSRC on Sunday. I presume you were running the Apex day on Saturday? I was out on Sunday with Brett Gabriel, we were doing some setup testing.

[luckymiata76]

High 80's at GingerMan last weekend. 53 mm Koyo, no thermostat, ran 206 F in my '99.

[Tom Hampton]

MSRC on Sunday. I presume you were running the Apex day on Saturday? I was out on Sunday with Brett Gabriel, we were doing some setup testing.

Yeah. Apex. A good day.

[Brandon]

Those who have bought the CX model radiator, is this the same one?

eBay CX Radiator

I couldn't complain for $130 all-in considering what mine is doing right now.

[Ken Wilkinson]

There are a lot of different numbers above...what is the optimum number for performance?

[Johnny D]

High 80's at GingerMan last weekend. 53 mm Koyo, no thermostat, ran 206 F in my '99.

+1

There are a lot of different numbers above...what is the optimum number for performance?

I've heard 195~205.

Brandon,
If your on a budget and there's nothing wrong with your racing AL Rad, put it back and take the thermostat out.
J~

[dstevens]

Those who have bought the CX model radiator, is this the same one?

eBay CX Radiator

I couldn't complain for $130 all-in considering what mine is doing right now.

That's the one. The downsides I hear are spotty welding on some of them and some of the beads aren't too clean. If you've got an AC tig it might not be an issue to maintain. It's not going to have the cooling capacity that a Koyo or Springfield due to the core but I'd say it's better than stock.

[steveracer]

I have one of those CX Racing radiators and a stock, MAZDA thermostat in my car.

It ALWAYS runs 192 even in 100+ degree heat here in central Texas.

It's not the prettiest thing I've ever seen, but it sure seems to do the job.

[davew]

A properly working thermostat will do you no harm. The problem is, they go bad very often.

When they go bad they can stick open. At which point you will not even know about it.

Or they can stick closed, causing the car to run hot or overheat.

Unless you are running below 50* air temps, the thermostat has no beneficail use. But it sure can cause problems, so why take the chance?

It always amazes me that we have this same conversation every few months. And the result is always the same. Definition of insanity: doing the same thing twice and expecting different results

Dave

[Ken Wilkinson]

A properly working thermostat will do you no harm. The problem is, they go bad very often.

When they go bad they can stick open. At which point you will not even know about it.

Or they can stick closed, causing the car to run hot or overheat.

Unless you are running below 50* air temps, the thermostat has no beneficail use. But it sure can cause problems, so why take the chance?

It always amazes me that we have this same conversation every few months. And the result is always the same. Definition of insanity: doing the same thing twice and expecting different results

Dave

Dave, thanks for your advice. I am curious to know what is the optimal water temperature range for performance and at what point (high and low) should alert you to a problem?

[Johnny D]

Here's a tip.
Point the overflow tube from your expansion tank out under the side of the hood. Then, if the car overheats to the point that the expansion tank is full, it will start spraying water on to the passenger side of your windshield. It's easy to miss a temp gauge reading but it's almost impossible to miss water spraying all over your windshield.

Keep going after that, Safety will be putting down speedy dry and/or picking up pieces from your engine.

220 isn't good.
J~

[Brandon]

Thanks to everyone who offered up specific details/data on their setups. I did forget one tidbit regarding my AL radiator: it managed to bear the edge of a jack saddle when I was trying to move around the front end while elevated on the jack. This caused one of the fan mounts to tear & bend in the radiator and, of course, destroy the fan (shroud, mount, & blades). The radiator was repaired but perhaps there's more than just the hole that's impacted.

Looking at the radiator now I can see a slight bend "upwards" which to me indicates possible compromised flow - especially problematic if it's a downflow type (or crossflow, I don't recall exactly) as you could effectively lose half the cooling capacity flow based upon where the bend is located (near the middle).

Dumping the damaged one, a thorough cleaning of the cooling system, gutting the t-stat and going with the cheap-y CX Racing model should work well for me.

Thanks again!
Brandon