The pressure drop in a engine oil cooler (eoc) doesn't come from the hose or the fitting. It comes from the internals of the cooler itself. many of the oil coolers out there are actually trans oil coolers (toc) and they have a totally different internal design. With a trans cooler you actually want some back pressure and turbulance inside. The engine oil coolers should have less internal fins (turbulators) which will minimize the pressure drop.

Our EOC is supplied with a "female" #6 SAE o'ring port. This allows you to install any size hose fitting you desire because these fittings are available with one end #6 SAE and the other end 8AN, 10AN, or 12AN.

I spent 25 years as a hydraulic sales engineer so believe me when I say that a small orifice in the inlet to a cooler is nothing compared to the internal design of the cooler itself. The difference (pressure drop) in using 1/2" hose vs 3/4" might be as low as 2-4 psi. It's really not thing to worry about.

What I worry about more is the fact most EOC's and TOC's have no "offset" and damm near block off the coolant outlet port. What we did was design them with an additional 1/4" offset so there is no restriction to the coolant flow.

As far as a group pruchase, this is what I will do:
First of all, I don't the production coolers yet, only prototypes. They should be in here in about 4-5 weeks. When they get here, we will supply these to C5 members for no additional cost. Same price as the standard radiator with the toc. I also have not tried to install both toc and eoc yet so if someone wants to be a ginny pig on that one, let me know. First check the inlet side of the radiator for clearence for a little bigger inlet tank. Anyway, here's the pics

ok, my website is acting up and I can't upload the photos. Can someone tell me if the forum has a place to upload them to?

 

Tom,

Thanks. Can you explain this offset of which you reference? I've heard it discussed before but am not picture what it actually refers to.

Much thanks, I'm learning alot.

 

Wow! Lots of excellent information - Tom, you can send them to me: Z06Racer@bellsouth.net and I'll post them for you

DT

 

Ok, I think my webmaster has it fixed.



In the top photo you the stock toc (4 plate) and our new eoc (7 plate) The "offset" as we call it is the distance that it sits away from the inside of the tank. You can see the toc is only about 1/8 away from the edge and the eoc is about 3/8 away. This is to minimize the flow restriction of the coolant. We also have to very careful when installing the welded in tube fitting because you could insert it too far and plug it off completely.

The middle photo shows the ports of both a standard toc and our new eoc. You can see that the toc has smaller ID and if you look real close you can even see the turbs (fins) inside the hole. This is not good for engine oil cooling as it creates higher pressure drops. The eoc to the left side has a female o'ring port which is much larger than the toc and no turbs to block flow.

The last photo has a manual trans radiator (no cooler) with two views of the automatic tank with toc. Here you can see just how close the cooler comes to the edge and blocks the outlet.

 

Wow,

Tom, much thanks for taking the time with the writeup. I certainly would not have figured that out in my head by myself .

Many thanks again, I just learned a ton.
Jon

 

Thanks so much Tom for the info!!

One more question, how much does your radiator weigh and is it more/less than stock. Just curious.

 

Tom,

Regarding production units available in 4 - 5 weeks,
do you want to formalize the list for the corvetteforum members, i.e. GP?

If so, please put me down - I will PM you my details.

Thanks
Jason

 

The weight is 9lbs for the original and 13 lbs for the Direct Fit

As far as ordering goes, I'll create a new part number for this and put them on our website. You can then just place the order "shopping cart" style.

 

Thanks for the update, let me know when the website is updated with the new part number and I will order.

 

I would be interested in a group purchase of Dewitt also. Have stock radiator and thermostat with Procharger d1sc sc in hot Phoenix. Various posts would indicate that unless I can get more air flow across the radiator simply changing to a more efficient radiator isn't going to do much. Should I change to a 160 or 175 thermostat, and retune with different fan temps? I don't believe I have space with the intercooler for an auxillary fan. What are your thoughts.

 

B Taylor,

I've had people report temp drops of 20-40 degrees with the "Direct Fit" double row aluminum radiator. If you use this new oil cooler option (eoc) that will reduce these numbers because the oil heat will be dumped into the radiator.
I think 180 is low enough for a thermostat, too cold and you can have excessive engine wear. A lot of people tell me they dyno higher at 160 temps but I wonder if that extra 10hp is really worth it. I think the first thing to do is increase the radiator capacity, it's really the only device that can "remove" heat, then maybe down the road you get more air flow. We are working on an aftermarket package to replace the GM set up.

 

would be very interested in a group purchase on the RON DAVIS radiator. best price i can get is $750.00 for 1 out the door or $700.00 ea. if you buy 2.

 

Upgrading to the DeWitts radiator was the best upgrade I made to my car. I have a Vortech supercharger and the stock radiator was not cutting it. When California temps reached 100 degrees and I got stuck in stop and go traffic, my temps would rise to "oh oh" statuses. I simply changed my radiator to the DeWitts unit (fans were previously programed to kick in sooner). After almost 6 months, I can honestly say that I can be stuck in stop and go traffic for 10 days with 150 degree temps with NO PROBLEM. The radiator definetely did the trick. If you look at the size of the stock radiator compared to the DeWitts unit, you will laugh your **** off. It is amazing that it is a direct fit. Mine fit like a glove.
As far as quality goes, the welds are simply a work of art as is the rest of the radiator. I can't imagine a nicer unit out there.
You can't go wrong with the DeWitts unit....

 

Tom,
Is it normal for all vendors with EOC's or TOC's in their radiators to have that much of a restriction between the xOC and the radiator hose. From the pictures above it seems that little to no fluid would be circulated through the system.

Can you put the EOC on the other side of the radiator? It would make it much easier to plumb.

I'm in for the GP.

 

Vortech C5 - what temp thermostat do you have? Does your Dewitt also have the oil cooler? I need the level of confidence you have sitting in traffic at 100+ degree temps in Phoenix.

 

Nukecop, what do you like better about the ron davis that you would be willing to spend another $100? Just wondering...

The end tanks are fabricated, not pressed, which has multiple corner welds. The two small connections on top right require some kind of fitting because they didn't weld in nipples. Compare the appearance to the one above.

 

Tom, I'm really space challenged by the sc intercooler. Length and height of the radiator to fit direct I'm assumming are the same as stock, but what about width (depth) for both the standard and oil cooler models? Thanks alot for your help. Brian

 

Yes it is normal for any type of cooler to cover the outlet hole, which we didn't like. You can see it in the ron davis radiator above. That's why we offer the new coolers centered in the tank. No one else does this and no one else has a higher performing cooler.

As far as putting the EOC on the left (inlet) tank, I would like to try it! But I need your help. You can see from the ron davis photo above that inlet tanks are much narrower than outlet tanks and you would have to use outlet tanks on both ends to have the cooler on the left. This would also be required for cars with automatics that wanted two coolers (EOC and TOC). I remember when we prototyped the first C5 car here that a wire harness or something ran by the inlet tank and there was some extra clearance for a larger end tank but I need someone to comfirm just how much space is really there.

 

The stock radiator is only one inch thick and there is a gap between the condensor in front and the fans in back. Our radiator just fills the gap and nothing else moves.

 

Tom, that's exactly what I needed to hear and see. Thanks for the pics. You've been a great help and have earned my business. Thanks for supporting the forum. Brian