Setrab oil cooler, Can two small ones be run in series? Options

[rtalich]

Ordered the smaller setrab unit with fan to replace the oil cooler that was installed when I bought the car (pictures). The new setrab unit is way smaller than I thought it would be. In fact, it's about half the size of what's installed now. I'm pretty sure the bigger setrab unit with the double fans is too big for this space. Anyone see issues if I run two of these smaller units in series? That way I can install them staggered and will fit in that space quite nicely.

[jim_hoyland]

Interesting.. would a space between the trunk and cooler benefit air circulation ?

[McMark]

Yes, but running them in parallel is better.

[Porschef]

I'm very pleased with the performance of the single small unit I installed a month ago. While I see you're running a much more potent plant, it's worked great for my application. I think Zach is running a dual setup twinned. Your idea may work better, but will require more plumbing.

[rtalich]

Yes, but running them in parallel is better.

Cool. Thanks Mark! I think I'll install this one and see how it does then decide if I want to put in another one. Right now it gets pretty hot. As expected I guess. It really hasn't been terribly hot yet weather wise here. But never really does for that matter. The hottest it's been while driving the car is about 75?? It does ok (so so) temperature wise on the freeway while moving. But once I get stuck in traffic or driving around town the temps get into the 200's pretty quick. In traffic I've seen 215-220 pretty regular. The hottest oil temp I've seen is 230!! I live in a hilly neighborhood and it got that high right before I got home.

[Porschef]

If 220 is the highest temp your seeing, one of these units (I'm assuming it has the fan) may be enough to keep your engine where you'd like the temps to be. They're pretty efficient.

[patssle]

It keeps my six cool with just one. (not braced in this photo)

[screenguy914]

Yes, but running them in parallel is better.

You sure? Running coolers in parallel, oil will take the path of least resistance. I suggest running in series, and maybe at least one in a better location for air flow, like in front. What size is the AN hose? Should be at least -12.

Sherwood

[stugray]

Yes, but running them in parallel is better.

You sure? Running coolers in parallel, oil will take the path of least resistance. I suggest running in series, and maybe at least one in a better location for air flow, like in front. What size is the AN hose? Should be at least -12.

Sherwood

I thought about this very issue.
I put two of the smallest setrabs you can buy below the headlight buckets and vented through the foglamp holes.

I put them in series. I considered the parallel idea, but decided that there would be no way to know if you had even flow through both that way.
And I used 12AN for the full run to the front & back.

[aircooledtechguy]

Those coolers work so well, I doubt you will need a second. Especially since you'll have a fan on it.

[McMark]

Oil cooling works best when there is a large differential between the oil temp and the air temp. So the first cooler, with the hottest oil, will drop more temp, and the second cooler will be underperforming. Coolers in parallel will keep the differential high and will slow down the oil so it will Cool down more.

Plus, that path of least resistance thing is a little too idealistic. Yes, one will probably have more flow than the other, but I expect its negligible since the resistance to flow is fairly equal. It's like taking a garden hose, hooking up a y-adapter, and expecting that the flow between the two nozzles will be drastically different.

[bdstone914]

Yes, but running them in parallel is better.

(IMG:style_emoticons/default/agree.gif)

Running two units in series doubles the pressure drop. Running them in parallel cur the pressure drop in half but you should run identical units or oil will take the path of least resistance which is the larger cooler. You end up with reduced flow and cooling with a series installation. Sometimes less than a single cooler depending on the coolers used. Will not affect main engine oil pressure as the loi cooler circuit has a pressure bypass.
Question is how much cooling do you need? I have never liked the under body cooler installations fue to hot and low air flow. Adding a fan only provides air flow on part of the cooler due to the motor center and the area covered with a circle on a square. They are more effective in the airflow path with cool air.

[SLITS]

If Jim Lamonica (six here) would post, he runs two small coolers in series on his 3.6l 914/6. They are installed in the front horn/fog light areas. He's happy with the setup.

[Jake Raby]

For a good oil, 230 isn't hot and some oils prefer to run hotter.

As long as you are maintaining oil pressure with a minimum of 1 bar at 1K RPM and 3 bar at 4,000 RPM when hot, I'd not be concerned with it.

Are you using Brad Penn? If so, a swap to JGR DT50 would probably drop the temps 10 degrees alone.

I have cooled a 3 liter 250HP twin plug T4 engine with a single Setrab cooler before and driven that car 14,000 miles in a single year, with ambient temps over 95F while running air conditioning. The highest OT it was was 225.

This post has been edited by Jake Raby: May 23 2015, 09:14 AM

[VaccaRabite]

Dual SETRAB unit DOES fit in the same location that you want to put yours.

Proof:
(IMG:http://www.914world.com/bbs2/uploads_offsite/farm5.staticflickr.com-1435-1432508090.1.jpg)

In this pic I have headers, but they also fit just fine here with SSI heat exchangers and a muffler. Also keeps oil temps low. Mine went from ~240 to 205. Mine is themostat controlled, with the stat opening and the fans turning on at 180.

Zach

[rtalich]

Thanks for all the comments and suggestions! I will install the single (with fan) and see how it does. I will report back when I do.

[Andyrew]

Yes, but running them in parallel is better.

You sure? Running coolers in parallel, oil will take the path of least resistance. I suggest running in series, and maybe at least one in a better location for air flow, like in front. What size is the AN hose? Should be at least -12.

Sherwood

I thought about this very issue.
I put two of the smallest setrabs you can buy below the headlight buckets and vented through the foglamp holes.

I put them in series. I considered the parallel idea, but decided that there would be no way to know if you had even flow through both that way.
And I used 12AN for the full run to the front & back.

Stu,

You got pics of this? I am curious of the fit (IMG:style_emoticons/default/smile.gif)

[rtalich]

Just a quick update. I finally installed the setrab cooler but have not driven it yet. Here is a pic of the old cooler. Not sure how it even worked at all. Air can't even get thru it!!

[Mike Bellis]

That's a cross flow cooler. Supposed to have more surface area and better oil mixing than a standard cooler.

[Andyrew]

/\ I agree, turn the cooler so you can see it at an angle, You'll see it actually flows fairly well.