Dirty Howie

(Posted also in TECH Forum)

I have major oil temp issues when I track my car. Temps quickly go over 300* ........ they are around 210-220 normal driving.

I have tried using the Engine Oil Cooler (EOC) in my Dewitts. I have tried using an external cooler (11x8 B&M) with the same results. The external cooler is located behind the driver front wheel well (wheel well liner is cut to access fresh air)

Here are the possible changes I am considering and would like input on these or any other suggestions would be great. Keep in mind that I alread have a very large cooler for my tranny sitting in front of my radiator condensor.....this is obviously the best place but my car is an A4 and must have this cooler here.

1. Move the cooler (or one that fits) to the front bumper area. Where the Z06 fog shrouds are open. Or open the front license plate area.

2. Stack another cooler in front of the radiator possibly affecting air flow to my Calloway Honker or the tranny cooler and radiator.

3. Run another cooler in series

4. Run same or other cooler from bumper area in series with the EOC in the Dewitts radiator.

If running two coolers causes an oil pressure issue is there a remmedy such as larger oil pump.

Thanks,


DH

robvuk

I have to ask the obvious. Have you checked to make sure the radiator is clear all the way at the top?

robvuk

You have a lot of mods though. AND an automatic. All adds up to more heat. You might just need a bigger radiator.

varkwso

A healthy motor with a Dewitt OC should not get that hot.

Check and make sure the temp is "real" - it could be the sending unit is off.

Yours is not boosted is it?

RAFTRACER

I love my DeWitts radiator , and I have one with the EOC which I am no longer using (EOC). I foudn when I finally got my oil pressure issues solved that when running my car that I was far too easily getting the 300+ oil temperatures. I have since stopped using the radiator mounted EOC , and have bought a Fluidyne air to oil cooler that is mounted in front of the radiator in the lower duct. I believe it is also an 11x8x2 plate-type cooler like the B&M unit. The first time I ran with thsi was in August in 90+ ambient temperatures, and I was still getting 300+ degrees , but it would take longer to get there and would stabilize lower than the water to oil cooler. I am concerned with this higher than normal oil temperature , because as the oil gets hotter, the oil pressure gets lower. Since I struggled with oil pressure too long earlier this year this makes me nervous. I have bought another identical cooler to install in addition, but instead of installing them in series, I was going to install them in parallel. This will knock the pressure drop from the single cooler in half, instead of doubling the pressure drop in series. Pressure drop makes me nervous also and my DeWitts cooler had significantly more pressure drop than the plate-type Fluidyne. I picked up 5 or so PSI when I went from the water to oil cooler to the oil to air, FWIW.

Additonally I firmly believe that you need to relocate your cooler , because it is not subject to as much, or as cool air. You are pulling air from the engine compartment and probably additionally soaking brake heat. If I were you I would try to move them to the nose somewhere in as clear of air as possible. Possibly installing two will help ( I would do this in parallel ). I am not sure what your engine combination is but with power and engine speed comes oil temperature. Last year with the stock , tired LS6 and the DeWitts EOC my oil temperature never exceeded 280 deg.....With the new engine I could do 320 deg in 4 laps....

Hope some of this helps......If not call Randy @ DRM, he has a wealth of knowledge on this subject. He and I talked ALOT about this over the summer.

StArrow68

Just for comparison, Howie, I'm running stock engine in two C5's. The
wife's runs around town at 202-208 oil temp with stock set up. My car
with Setrab external cooler and all else stock runs 170's to low 190's
with 175 thermostat until I get on track. Then it gets up into 270's if
I push pretty hard. Only hit 250s to low 260s today at Sears Point with
short NASA 20 min sessions and temps in the 70's. I'm betting on mods
needing lots more starting at the radiator.
Randy

Dirty Howie

Thanks guys for the replies......

robvuc: I have no idea what you mean by "clear radiator to the top". I have a Dewitts radiator already.

varkwso: Very good point. I will have it checked.

RAFTRACER: You can see my setup in my Sig (402, 224/228 cam and torque converter). Have you done the two coolers in series?? Is this what Randy suggested?? What is your setup and are you saying you are still running hot? What do you think of EOC in the Dewitts in parrallel with external EOC ??? I also am getting 320 temps so probably both are temp senders are good....would be nice if they were wrong.....did you check yours??

Randy: How's it going??? My temps definately went up when I got when I got the 402. Now I am getting a 416 .......


DH

0Randy@DRM

Danny,
Remember we also talked about oil pressure and some black magic crap happening. We found it and I am willing to share because it sounds like you may have simular issues.

Randy

davidfarmer

you need to make absolutely sure the radiator is sealed completely around the sides/top. ALL available air needs to go throught the radiator.

Sounds like you may have a friction issue in your engine.

Dirty Howie

So Randy, do you have a solution to allow two coolers to be run in series or parallel.........................

Also, I am wondering wether the adapter plate from DeWitts may not flow as well as others. Or that I need to go to larger diameter lines???


DH

Dirty Howie

David

I'm going to get the radiator sealed up good. But I don't understand how this will change oil temps ?????????????

I'm hoping that some of the heat may be from ring blowby......is that what you mean by friction issues ?????? I am hoping the new 416 shortblock and properly seated rings is going to help in this regard.

Thanks


DH

Bill Dearborn

I have the DRM Ron Davis radiator with EOC and am running 265 when its hot. There shouldn't be that much difference between the DeWitts and the DRM setup. Make sure the A/C condenser is clean at the top and the foam seals between the A/C condenser and the radiator shroud are in the correct position. Typically they tend to blow out near the top of the shroud. You should also make sure your center air dam is duct taped so it will not blow back at high speed. Once speeds hit triple digits the wind pressure starts to overcome the springs holding the spoiler in place. You don't hit that many things on a track that you need to worry about damaging the spoiler because it won't flip back.

Bill

Dirty Howie

Bill

Good tip on duct taping the center spoiler ..... never heard of that before

Will check on foam seals between condensor and radiator when shroud is sealed good. What/How is this accomplished.....duct tape or expensive fabrication......

When you see 265 what is the ambient temps .... ever run when its 90+ outside. Is your motor stock.......

Thanks,


DH

John Shiels

water temp is? Does the motor really feel/get hot?

0Randy@DRM

The two huge coolers is what Danny had to do. I don't think any normal motor should need that much cooling. But I guess Danny runs the living crap out of them, RPM wise. What size lines are you running??? Do you have some oil pressure to spare???

Randy

see5

I run 11x7" cooler mounted in front of radiator, plumed with -10.
Runs very nicely till on track where temps get >300 after about 5 minutes.
No noticeable oil pressure difference before/after cooler.
Running mate has same cooler, same results, with built LS7.

We are scared as well. Is it possible we are overflowing the cooler as not enough time in the cooler elements?
Water temp is fine.

bowmanized

When you have the EOC integrated into the radiator and you aren't using it are you giving up water temp cooling capacity? In other words will a radiator with no EOC cool as well as one not using it's EOC?

see5

My experience with the Dewitts is that it has tons of cooling capacity (2x). I fact with a 160 thermo it was too cool with a 195 Thermo it runs mostly <200. If there is a problem with a Dewitts with EOC it is heat transfer FROM the oil cooler

vms4evr

Bill,

Hadn't heard that one before it makes sense, I think... How and where are you taping it? Got pics?

Graham

AU N EGL

My understanding is the radiator without the EOC will cool better do to the larger volume. Plus I dont know which side the EOC is located on? Would that make a difference?

I have the standard GM T1 set up and run with no problems.

Oil temp 240-255, water 200-215.

trans cooler left, AC condenser & radiator, Oil cooler on right of picture.



I also have a 3 qt accu-sump which helps keep the oil pressure up.

I run 15-w50 M1
and for coolant use water, 10% dex and two bottles of Water Wetter.