More Rear Mount Oil Cooler Questions, Setrab Setup Options

[BeatNavy]

I'm trying to nail down why I'm having oil cooler issues. Specifically, I've blown two sandwich plate adapter seals in the same place / manner. In addition, during my test drives I wasn't necessarily thrilled with the temp drop I was seeing.

First, I'm running the Setrab oil cooler and Setrab sandwich plate adapter. Anyone else running the Setrab sandwich plate adapter without any issues? I know I'm not the ONLY one, but how many people run this as opposed to something like the Mocal setup?

Second, when I contacted Pegasus Racing to order more seals, I spoke to the tech guy who gave me some food for thought. The most interesting thing was he said the oil cooler needs to be mounted with the inlet and outlet ports facing up, otherwise the cooler won't fill up all the way and you won't get ideal (or any) cooling.

Here's my setup with it angled somewhat down for what I hoped was good airflow: http://www.914world.com/bbs2/index.php?s=&...t&p=2826235

Essentially he says the oil takes "the path of least resistance" which could largely be from the inlet port to the outlet port using few of the cooling rows. I assumed the pressure would fill the cooler, but I can see what he's saying. Any thoughts on that? If that's the case, I really need to completely redo my mounting setup and plumbing.

[GregAmy]

Aren't the heat exchangers already a heat shield for the headers? If air is running through them, the exterior should stay pretty cool.

Mine are horribly hot, you can't even get your hands near them.

There's a TON of heat stagnating under the backside of these cars.

This is on mine. It's now covered in adhesive-backed reflective insulation.

It's finally stabilizing the temps around 215-220 (in the line exiting the cooler) on 80+ days.

[Olympic 914]

Aren't the heat exchangers already a heat shield for the headers? If air is running through them, the exterior should stay pretty cool.

Mine are horribly hot, you can't even get your hands near them.

There's a TON of heat stagnating under the backside of these cars.

This is on mine. It's now covered in adhesive-backed reflective insulation.

It's finally stabilizing the temps around 215-220 (in the line exiting the cooler) on 80+ days.

Do you still have the original oil cooler in place? No gauge sender in the taco plate?

I guess it depends where you are reading the temp.

As I understand the oil flow -

(1) its picked up from the sump,

(2) through oil pump then to the oil filter


(3) through the stock oil cooler

(4) on to the bearings etc. through the oil galley.

If you are reading the temp inline after the aux cooler your oil temp should drop some more after going through the stock cooler, before going into the engine.

Using a sandwich adapter, after the oil filter the oil goes to the aux cooler then back through the stock cooler to dissipate more heat before going to the bearings etc.

By having the sender for the temp gauge in the taco plate you are reading the oil temp after it has gone through the engine and lubricated/cooled it.

[GregAmy]

As I understand the oil flow -

At the risk of diverting Rob's thread...you got me to thinking more about this.

My combo gauge and Mainely dipstick agree on temperature, so I'm pretty confident of that. I've rechecked the calibration on the R-T sensor and I have a long history of their sensors in my race cars, so I'm confident of it as well.

But here's the thing I cannot explain.

As noted I'm using the Tangerine block/thermostat and external oil cooler, and measuring the oil temperature on the outlet line of the cooler.

And yet...the temperature is the same or very similar as that in the sump.

Chris Foley and I have gone back and forth on this, and I'm very very confident that we actually have it in the cooler exit line.

But this makes no sense.

I've checked and rechecked the oil cooler lines, and rechecked the sensor calibration.

So this means that either my temp sensor is wrong, the cooler is doing nothing, and/or the ports on the thermostat block aren't what we think they are (but Chris built the block so I'm pretty sure he knows which way they go).

One thing for sure is that between adding the cooler, adding a fan to it, and ducting air to it, my oil temps are stabilizing around 215F on the Mainely dipstick at highway cruise with the fan on 100% of the time.

Everything else is up for grabs.

[jd74914]

And yet...the temperature is the same or very similar as that in the sump.

...

One thing for sure is that between adding the cooler, adding a fan to it, and ducting air to it, my oil temps are stabilizing around 215F on the Mainely dipstick at highway cruise with the fan on 100% of the time.

When you say highway cruise, what do you mean? Flat road, 65 mph is probably only using 30 hp, so your thermal load is pretty low and the cooler may be taking just enough energy out to keep the oil cool, but not show any crazy temperature difference.

If you really load the thing up (say 65 mph cruising up the hills on 84 near exit 68), do you see any temperature differences?

[GregAmy]

If you really load the thing up (say 65 mph cruising up the hills on 84 near exit 68), do you see any temperature differences?

Jim, I live just off I-91 in Middletown off exit 20 so my "test track" for each of these changes has been south on 91 down to around exit 8, then back up. As you know, the land slowly descends toward the Sound. I try to keep the speeds consistent both directions, around 3400/72mph.

With just the cooler, no fan, and Tangerine's surround/mount I was into the red coming north, somewhere around 250F+ and it was 245F when I stopped to check the dipstick. I did not like that at all and baby'd it home.

Removed the cooler surround and it went down about 10-15 degrees but it was still touching the red when I stopped and it was 235 on the dipstick.

I added a fan and had it on 100% of the time and it made very little difference, maybe 5F.

At this point I wanted to get some hard info so I added the temperature sensor into the cooler line and input it into the Microsquirt to log. That seemed to confirm the other numbers. At the same time I also leveraged an output of the 'Squirt to control the fan relay, coming on at 220 and off at 190.

I am figuring I have some strange aero going on under there, stagnant air along with exhaust heat, heat from the engine cooling, heat from the transaxle (I do have new air diverters inder the firewall). I stick my hand under there behind the right axle after pulling off and it's friggin *broiling* under there. That's when I built the ducting (it's just roof flashing riveted into box structures...I call it my monococque). That dropped the temps down to my current level of roughly 215-220 doing the long climb from North Haven to Middletown. I added adhesive-backed insulation to the box later, didn't seem to make much difference.

I'd also like to note that last couple of years with the stock cooler (and stock D-Jet) I was having a very similar oil temp problems this time of year with increased ambient temps. That's why I installed the cooler over the winter (the stock one was not blocked or leaking). So I'm fully aware that I may have some other issues with the engine resulting in this problem.

I'd really like to get enough spare BTU capability to be able to take it to a track day, but I don't think I can do it in the current config.

I'm way open to ideas.