Hello all, looking to get your opinions on winging oil coolers. I'm getting high temps at my HPDE's that I'm not comfortable with. I'd like to get some advice on what others have done to combat this issue.

My car is completely stock. So I'm wondering if an integrated radiator/oil cooler unit is preferred or a separate DeWitt's or comparable unit is suggested.

Thanks,
Tad

 

There are two schools of thought:

1)

Get a fat racing radiator with integrated oil cooler, with hard lines for your oil port on the side, and SPAL fans. One and done, you should probably be okay forever.

DeWitts should sell all of this. Probably $1100-1200 ish.

Instead of the hardline adapter, you may choose to instead use a thermostatic adapter with manufactured flexible lines. This would probably add a fair bit of money to the build (an extra $200 for the improvedracing adapter, probably an extra hundred or two for lines and fittings and all that). The upside is that you would never worry about oil getting too cold. And, you avoid any possible issue of the hard lines not quite being right due to some unforeseen weird fitment issue.

2)

Integrated oil coolers are always going to be worse than external oil coolers for a few reasons:
- You are cooling your oil with airflow, yes, but you're also keeping it adjacent to coolant, which isn't much cooler.
- You are tying together systems that should be as mechanically unrelated as reasonably possible, and risking cascade failures.
- You are not going to have nearly as much cooling capacity as a big standalone cooler.
- You are not going to have as much water cooling capacity as the standalone radiator.
- You are not going to be able to easily change up your oil cooling system ... want more oil cooling? well now you're gonna basically have to redo some of the above work.

So instead, your parts list should be a bit more complicated and expensive:
- Standalone cooler (I like my DeWitts setup)
- SPAL fans (again, DeWitts)
- Thermostat adapter (ImprovedRacing)
- Lines and fittings and misc stuff
- Bigger, better cooler in the right spot




Your choice. Do you go cheap and simple and hope, or do you go bigger and better?


Here's my advice:

You have a stock car, and based on your location, you are probably not racing a lot in 110F days. You're also building up your skills and speeds, you're probably not going all out 10/10 all the time.

Start with the simple upgrade: radiator and fans. Thousand bucks plus any labor, and you're going to be really happy. This alone is likely to knock back your coolant temps significantly. This alone is likely to keep your oil temps to 250F or below for now. Try it and see. Add oil cooling later, and go big, when it's necessary, if it's necessary.

I have a positive displacement supercharger on my car and I am, as a novice, below 250F for now ... with just the aforementioned setup. I am gonna add an oil cooler in the next couple months though.

 

Gimp, thank you. I understand what you're saying. I'm not going for cheap and easy. I want a healthy and protected motor.

Tad

 

Cool. In that case, I recommend you start with a radiator and fans now, take a look at your temps after that install, and if necessary add on the thermostat adapter, hoses, and cooler with bracket.

On the street - in CA and with a supercharger heat-soaking the place up - just the radiator and fans dropped my oil temps about 20-25F, and pegged my coolant right at 190 -- it pretty much never goes higher anymore except the track, where I get a few degrees over 200F on a nice day. I haven't yet tried it on a brutally hot day.

Also the fans sound a little like a jet engine. At hot idle, they're about as loud as my exhaust. Fun times.

ImprovedRacing tells me they currently have a C5 in the shop that they're using as a mule for a plug and play oil cooling kit for stock setups.

 

I purchased a Satrab 925 oil cooler from Doug Rippie Motorsports and my oil temps went from 300 degrees to 260.
I recently purchased a Dewitt's radiator, but since it is thicker I had to drill a bunch of holes in the shroud so I can blow out the debris that collects. I have a thermastat attached to the oil filter housing. Street driving tops out at 200 degrees.
Good luck.
Spaggs

 

Thanks. I'll look into the improved racing set up.

 

Hi Spraggs, thanks for the input. At this point, I know I have to do something. It seems as though there are many different possibilities and whatever I do will help.

Tad

 

Same here. I talked with Micheal last month about their soon to be announced C5 kit.

BTW, have you made sure there isn't any debris blocking air flow thought the radiator?

 

JHrinsin, good question. Checking coolant flow is now on my to-do list. A friend of mine mentioned that.

Tad

 

I was hitting 275* oil temps in Nov at VIR. After my stand alone oil cooler, I was around 250* in Aug/Sept at VIR. (big difference in ambient air temps between Aug and Nov).

I used a Setrab 625 cooler. I.R. block adapter w/thermostat. 10AN braided line with Raceflux heat sheathing (the lines run very close to the headers; can't be too careful). And I fabricated my own mounting bracket and located the cooler in front of the radiator.

I bought all of my parts from Improved Racing. Great guys, highly recommend them. And if they're working on a plug-n-play kit for the C5... then even better! Overall, I'm very happy with my cooler setup, even when I'm street driving. The thermostat allows the oil to warm up normally so the engine gets up to temp in a reasonable period of time.


I did a video of my install. Might be useful for you. Since then, I've also upgraded to a DeWitt's radiator (while I had the engine out).

 

Hey bigmackloud, this is coincidence. I found your video prior to my postand saved the link for future reference. I watched about ten minutes. Very thorough!

Thanks,
Tad

 

I like the DRM set up.

 

93polo, that's good to know.

Thanks,
Tad

 

Friend and I installed one on his car, I have a radiator with integrated oil cooler which came with the car. He has been very happy with the DRM running HPDEs in the Georgia summer.

Given the choice I'd take the oil cooler separate rather than integrated with the radiator for the reasons gimp stated. Further if you have a motor failure, the trash in the oil will be in the cooler which is easier to ship to have cleaned or cheaper to just replace if it is a stand alone component.

 

I've heard this a lot. People are liking these units separate. A good friend of mine who I run with at the track swears by the Ron Davis integrated radiator and oil cooler unit.

One guy earlier said to start with a fresh new radiator. I like that advice too.

 

Also make sure the foam is still in place around the shrouding. This helps to force all the high pressure air through the radiator and keeps it from spilling out the sides where it does no good

 

The integrated works, and I'm not changing just because. However, if I am building from the ground up I am going separate.

 

Not sure about the specifics on your particular C5, but here is one more bit of info concerning the cooling system in the C5. GM switched to the LS6 intake manifold in '01 one both the LS1 and the then new LS6, The LS6 manifold has a deeper plenum area and due to clearance issues, they removed the LS1 style 4-corner steam tubing/coolant crossover setup and simply plugged the rear corners of the cylinder heads. This can cause an issue with hot spots developing in the rear of the cylinder heads when the engine is being pushed hard at the track. As a result has been that numerous LS6 engines with stock short blocks that have failed due to overheating issues on the track typically with #7 cylinder. This can also be exasperated by the fact that these engine came from the factory with what amounts to fairly tight piston ring gaps. You can help to prevent hot spots in the back of the cylinders by either - modifying the bottom of the LS6 intake manifold (remove the webbing) so there is clearance to install the LS1 style 4-corner tubing setup, or install the front LS2 crossover tube in the rear, or install the rear tube from a LS Vortec truck engine in the rear. Then tie the LS2 or Vortec rear crossover tubes into the hose going from the front crossover tube to the radiator or you can install an aftermarket four corner tubing setup.

 

Coolant flow is one thing, but this is actually referring to airflow. The C5 is a bottom breather and loves to get all sorts of crud in the radiator. Even a small handful of dirt can bring your coolant temps up 10+ degrees. In my experience, a good blasting of compressed air (back to front) that had clearly been neglected, brought my coolant temps down about 30 degrees (yes! 30!) when driving in hot weather at lower speeds. That alone basically made my car go from being nearly undriveable in the hot CA summer except on the highway, to completely driveable anywhere in any condition. (Of course it wasn't enough for, yknow, track days.)

So yeah. Compressed air, blast the radiator fins clean if you haven't done so recently.

 

I think you'll get a wide range of answers and experiences because it really depends. Stock car with street tires and more casual hpde driver will be way different than a guy on slicks/aero doing time trial... and climate plays a big role too.

Big radiator with integrated EOC is ultimately a compromise setup, but it's still nice because you'll keep your coolant temp in normal range (which reduces oil temp) and cool some of the oil in the radiator end tank. It's also a great street setup.... I have the dewitts with C6 hardlines / stock fans, and oil actually comes up to temp faster than stock. I was new to HPDE when I changed mine, so it's hard for me to give stock vs my setup now comparison because I was constantly getting faster. But stock cooler on a cold day, I reached 260F after about a lap (oil temp). With the Rad w/ EOC highest I saw in a louisiana summer day was 260 and water around 200. This is on 200tw summer tires.

If this is going to be a mostly track car or you're fast and/or going to use sticky tires.... then do it right and get a separate oil cooler from the start, along with radiator.

So, just be honest with yourself and intended usage and go from there