I see a disturbing trend regarding this subject and I feel the need to make a statement for all to read. We (DeWitts) were probably the last company to introduce engine oil cooling. Several other companies came out with them before we did and they created a general perception regarding fluid line size. This perception is that you need really large hoses to minimize oil pressure drop. The fact is, you don't.
What you DO need is the correct cooler. The other companies are using transmission oil coolers (toc) for engine oil cooling. EOC's and TOC's look identical on outside but the insides are totally different. Transmissions pressures are much higher and the internal turbulators in a toc are designed to actually create backpressure. This results in high pressure drop which isn't a real concern with a transmission however, it is which engine oil. So when these companies used the wrong coolers, they try to reduce this pressure drop with a bandaid. A fix that doesn't really work that well. The average oil pump flow is about 2 gpm. The correct conductor (hose or tube) for that flow rate is .38" diameter. So you should use 1/2" steel tube or 3/8" hose. Most of the kits out there consist hoses twice that size and many people have asked us for a larger size. Now the pressure drop difference between 3/8 and 3/4 hose might be 1 psi. The difference in pressure drop between a toc and a true eoc can be 8-10 psi or ten times what you will achive with super large hoses. Smaller hoses are easier to route and they cost less. If that's not enough to convince everyone, let's look at what GM thinks about it. The 2005 C6 offered an option with an internal radiator mounted eoc and factory tube/hose assembly. This system consists of a 3plate stainless steel eoc with 1/2" tubing and hose and that's all you need. Since 3 plate was good enough we decided to go with 7 plate and aluminum for weight. Our cooler is also designed to mount in the center of the tank, which reduces the restriction created by other cooler designs. (see below) This 7 plate eoc cooler has a 4psi drop at 2 gpm. So when you are considering a radiator with an eoc, ask for the pressure drop of the cooler.

 

Tom, this was a good explantion of the EOC situation. Now since I have one of your EOC radiatiors I am for sure one who is waiting the launch of you EOC kit before the summer heat reappears in South Texas

 

DH

 

I don't have one, but looked at this radiator at Carlisle last summer. It is a very very nice unit and well constructed.

 

Good Info thanks

 

Fair enough. Tom, can you please explain why the TOC you make is the barrel style rather than the plate style? What's the benefit.

 

The toc we use for 97-00 is what they call a concentric or as you said, barrel type. This is a brass cooler built with a tube inside tube design. It's equal to what the factory cooler will do but it's really not anything special. The main reason we use this is the port connection. When you go shopping for toc's, the first criteria is the right port size and length. The type become seconday when the choice is limited. We might change in the furture to an aluminum one but that's where it is now.

The toc we use for 01-04 is an aluminum 3 plate and again the main reason is the ports. This one is metric so customers can use the factory quick connect fittings.

 

I am also waiting for the EOC installation kit. I will finally be installing my radiator after the holidays and need the adaptor block and lines.

Is there any chance that you could include a port on the adaptor block for an oil feed for a supercharger?

 

Tom,

Since I have the A97A and can't run an internal eoc, I'll still need an oil cooler for the summer. How much is your oil feed block and hose setup to supply the cooler? I'll just need to use an earls cooler up front. What the smallest external cooler I can use for the engine oil?
Thanks

 

How much extra oil should I add with the oil cooler? When I started the car up I got a low oil level warning. I put in 7 quarts.

 

Tom, a new learning... thanks

 

The oil circuit is in "series" so it runs out of the engine, through the cooler and then back into the engine. We could make an adapter for the supercharger assuming it only needs oil pressure and not flow. You could also just put a tee in the hole the temp sender goes into.

As far as the kit and adapter goes, I am really working on developing the eoc on the left, something IM QUIKR suggested. If this is possible, it makes for a cleaner set up because the hoses do not have to cross over to the passenger side. If that happens, we'll have no use for a package on the right side, which you and a few others here on the forum have. So, what I will do is make up a special kit for you guys at a price you will be very happy with and move on to the left side.

 

The oil cooler package doesn't take much oil at all, maybe a pint, if that. Just enough to fill the hoses. Is this our (DeWitts) internal EOC or something else? Something doesn't sound right there at all.

 

Please don't do this. If you do, I'll have to buy replace my old Dewitts with a new one! Actually, if you make a kit that has lightweight hoses like Aeroquip Startlite, I wouldn't resist much at all.