After polling Tom and Randy, I went with the DRM/RD with right side EOC. ... Best I can tell, it looks like about 40 degrees difference on track, 20 degrees on street. I'm sure I would have been equally pleased with the DeWitt.
Just wondering if your current and your future are both are same side ... left or right ... and whether you will have a baseline with current to compare what the delta is between them as far as temp reductions.

 

I really won't have a fair baseline.

Going from a 402 to a 416. Heads from 205 to 225. And cam from 224/228 to 228/232.

Plus since this current engine consumes 2/3 qt of oil in 400 easy freeway miles there is definately a ring issue. So some of my heat could be from blow by gasses heating the oil.

But you can bet I will be posting oil temps when I get them.


DH

 

I ran a Ron Davis for a while and ended up coming back to a DeWitt's for my personal car. I thought the Ron Davis would run cooler than the DeWitt's but it did not. At least not for me. So I saw no reason to keep a radiator that cost around twice as much as the DeWitt's in my car.

Also, the RD, while being a fantastic product, just does not fit as well as the DeWitt's.

Note, I went from a DeWitt's with no cooler to a Ron Davis with integrated EOC and back to a DeWitt's, but this time with my own custom oil cooler.

 

My thoughts on this is.
I have sold 100 or so Ron Davis radiators with EOC and our line kits. I have one or two customers that are still having cooling issues, one C5 and one C6. The other 98 or so customers have been running the crap out of them and never have oil cooling issues. I have more problems with our stand alone kits keeping oil temps down, because of the way air is moving across the cooler???

The last 8-10 racecars that we have built have all had Ron Davis standard radiators with EOC and even PS coolers. They all run very cool even under the hottest conditions. The last yellow car that we built runs in the summer down in FL with oil temps under 220 (dry-sump helps too). That is spinning it to 7400 rpm with a ton of power out of a stock size motor.

Leave the front ends alone on the C5's, more cooling issues happen with aftermarket junk.

Randy
PS Twice the cost

 

^^I really like the simplicity of an integrated radiator and EOC. However, the general consensus seems to be that having a separate EOC works better (i.e. cooler temps).

Right now my motor is stock but I plan to add some headers, Ti exhaust, and maybe a better set of heads.

Down the line, I figure I will need to put in a new motor (forged). I am leaning toward and LS3 (not sure if I will go stock or stroked). I want a cooling system that will work with both my current motor and what I might do in the future.

Do you have any large block motors (over 400 cu) running this set-up for HPDEs, and if so, how are they doing temp wise - radiator and oil?

Thanks

 

We have about 15 427 that we have built running track events, many others I have sold. Without any cooling issues. These are strong 500-550 to the wheel motors that get spun to 6500-7000 rpm. If you are planning on spinning them to 8000 rpm or something stupid I think you will run into problems. We have a ton of LS2 based 402-412 cubic inch motors also running our setup without getting into the red zone. I'm not a engineer and never will be, in fact none of us are. But we know what works based on racing and testing. Ask around the forum because I have about 30 guys on here that have our setup.

Randy

 

As Randy will certainly attest to, beware of those offering data on different oil cooler setups. It depends on too many factors. In my opinion, the biggest factor is the driver. I would guess that 90% of people driving on the track will not have any problems with oil temps given any cooling setup. Those of us that struggle with our oil temps continually, find that 100 different factors influence the efficiency of the cooling. Cooler size, airflow, ducting, water temps, RPM range, dry sump etc...

Most of the data on oil cooler setups are false positives, no problems to begin with, and no problems after modifications. Buyer beware.

Internal coolers are a convenient setup (packaging wise) and provide steady oil temps even in street driving. However, if you are having problems with oil temp and coolant temps, its nice to get the two units separated to have access to more airflow. Also, from an engineering standpoint, heat transfer is a function of the temperature differential of the two fluids. In this case, 210* water versus 100* to 150* air. If your oil temps are 250* the delta with your radiator is 40*, the delta with air is between 100* and 150*. The transfer efficiency is better with water, but not enough to make up for the temperature differential.

Again, no one solution is best. Know your issues and talk to those of us building and racing these cars. You'll get a good solution.


-Aaron

 

I really like the looks of that Pfadt stand alone... it doesn't block flow to the radiator, and as said, you can put the stock cover back on for street driving and reduce air flow!

Personally I'm running a dewitts racing radiator w/ left side EOC. The left side is the hotter side of the radiator so it provieds for shorter lines and the car gets up to temp wonderfully in winter driving.

My car is still a dual use car. The car has seen a max of 276 and that was in 95+ degree heat this summer at VIR wringing it out. My last HPDE in early September saw a steady around 260.

I do have a DRM vented hood and have modified my oem radiator fan shroud to allow more air pass through.

My winter project will be fabricating a new shround to take advantage of my Tigershark facia and force the air into the condensor/radiator.

A few pics of my setup:

 

Opening up a high pressure area like the front plate is causing other issues. We have been there done that back in 98. The engineers at the tunnel didn't like the idea at all.

Randy

 

^ Like what? I have a TS facia so that area is all open. Also, the stock Z06 facia has the front screens open to let in all that air.

Oh... and look at a C6.... it's all open... it's a front breather and a bottom breather.

 

Can't say I am having any heat issues at the moment but that is because I have never run the car at the track. Highest oil temp I have ever seen on the road is 223*

What is a good engine oil temp range to shoot for? I know that the owners manual says 320* is the max. I have also read claims that above 220* oil begins to break down. Don't know how valid this last statement is.

The reason I am asking all these questions is that I am going to be doing work on the car this winter with my brother and I figure I will try to tackle all the reliability type issues that I can at the same time.

I should also add that I am not looking for the optimal solution just one that has been proven and works. Have no interest in being a pioneer or doing free R&D. Been there already and did not really care for it.

Thanks again for your time and help.

Definitely appreciated!

 

When it comes to racecar aero. Everyone trys to reduce the amount of openings in the front of the car. It is in every book and on every car running out front.

Randy

 

Thats the first I've seen/heard about opening up the fan shroud. Do you have any data on how benificial this was????

Also it looks pretty flimsy now. Any rattle or vibration issues.

Good idea.....I think


DH

 

Regarding the debat of opening the front to place a cooler.

Common sense says that it is a good source of ambient temp air.

Now at certain speeds there could definatley be an aerodynamic issue.

Personally I will not be going over 150 on the track ..... is that fast enough to be an issue??????


DH

 

I got the picture from DRM... it's not flimsy at all.... functions perfectly, I see no downside.

 

Diynoob, coming from someone that has installed both brands this is important information.

....and I wanted to see it here twice.

 

It is easy to test. Just run some tape over the holes. I have a ram air scoop on mine and just keep forgetting to tape and test.

 

Howie,
I am sending the info to Andy. Make sure he does it. It will help, trust me

Randy

 

It might be a good idea if you are racing 100% of the time but if you cruise around town, the fans are going to suck air. I mean, think of the fans as vacuums, sucking the air through the radiator. What do you think happens when your vacuum cleaner hose has a hole in it?
Getting air to pass through at high speed is a good concept, Spal addresses this with relief flaps that open at highway speeds and they suck closed when cruising.


We incorporate these rubber flaps into some of our other models to allow free flow at high speeds.

 

DH