Why would a big B&B oil cooler simply not work?

[Formerly Steve Wilkinson]

I have a two-foot-wide B&B oil cooler behind an IROC-style bumper/air dam, with a nice big dump chute behind it to evacuate the airflow through it under the car.

Doesn't work. Hasn't worked for two years.

Yes, my thermostat opens just fine, at 180 degrees, as confirmed by a hot outflow tube and oil line to the cooler and a warm (not hot) return line from the cooler.

Yes, I know that B&B had a brief run of coolers with badly welded diverter plates between the inlet and outlet fittings, allowing hot oil to simply immediately seek the easiest return path to the oil tank and skip flow through the cooler, but my diverter plate is just fine, as confirmed by several different tests.

Yes, My bronze oil lines are in excellent shape, not a single crimp.

Yes, I sent the thing back to B&B two years ago, when I first realized it wasn't working, and they sent it back and said it flows just fine.

Okay, so today I go out for a spirited half-hour drive with the bumper/air dam totally off, just a naked cooler out in front. Taped up the entire front of the cooler so there was zero airflow through it. Got the temperature up to 205 degrees F (numerical gauge) and drove that way for 10 minutes, pulled off, jumped out (engine idling) and felt the oil cooler.

Stone cold. Exactly as cold as you'd expect a lump of aluminum sitting out in a 70-mph slipstream on a 78-degree day to be. Oil line to the cooler was hot, oil line exiting the cooler was warm. Cooler was cold.

Any ideas?

[DRACO A5OG]

Sorry for my ignorance, but is hot oil going into the B&B Cooler? From what you described it appears not to flow in or am I reading incorrectly?

The thermostat you mentioned is the one at the rear of the car, correct?

[Formerly Steve Wilkinson]

Hot oil is going _to_ the cooler, but not through it, though a small amount might be trickling from inlet to outlet inside the cooler, but the entire body of the cooler is cold. And yes, the thermostat I'm referring to is the one in the right rear wheelwell. Works fine, and in fact the internals were all replaced a year or two ago.

[DRACO A5OG]

OK I re-read.

Could it be that the cooler is clogged/pinched? Logic dictates the cooler should be extremely hot, i.e. our OEM carrera coolers.

Maybe if you took it off and measure the flow of the cooler with compressed air or water?

I know it is ridiculous but it just seems natural step of deduction.

[dad911]

Originally Posted by Formerly Steve Wilkinson

..... as confirmed by a hot outflow tube and oil line to the cooler and a warm (not hot) return line from the cooler.
......
Oil line to the cooler was hot, oil line exiting the cooler was warm. Cooler was cold
.......

If it's hot going to the cooler, and warm coming out, it must be working, right?

I had a 3.6 track car, with the B&B also. I used to block most of the front air grill with duct tape, even at track events in the middle of summer. I think it works 'too well'

[DRACO A5OG]

Dad911,

Did you ever test like Steve?

I'm think the outlet side is just emitting heat from it being connected to the engine, Just a crazy brain fart

[pete3799]

Sounds to me like it's working.
hot in - warm out. I would think the Cooler would be warm.
Air bound? Cooler made of kryptonite?

[Formerly Steve Wilkinson]

I tested it with boiling water poured into the top fitting with the cooler sitting horizontal (normal position), the hot water pretty quickly came out the bottom (outlet) fitting and none of the cooler got the slightest bit warm. I then tested the cooler sitting on the ground vertical, inlet and outlet fittings pointing straight up, and again poured boiling water into the inlet fitting. The heat quickly percolated about 2/3 of the way down the cooler--gravity feed only, remember, no pressure--so the tubes are not clogged.

If it's hot going to the cooler and warm coming out does not necessarily mean the cooler is working. It just means the oil is going through some small part of the cooler and getting some cooling effect from that.

What I'd love to hear is that other people who have big B&B coolers and run them hard enough to get 205-210 degrees of oil temp and then touch the cooler find that they're cold even though they're fully passing the oil.

[Formerly Steve Wilkinson]

Pete3799, the problem is hot in, warm out, cooler cold.

[Bill Verburg]

I have a 5 1/2" X 2 1/4" X 20" B&B valance mount, oil tmps rarely exceed ~190F. Both inlet and outlet lines are hot as is the whole cooler, intemp > out

[tctnd]

Are you sure all the oil is passing through the cooler and not being bypassed by, say, a faulty thermostat or t'stat housing? Are you sure all the cooler tubes are open and not blocked? Is the cooler outlet at the upper edge so scavenged air isn't trapped and rendering two thirds of the cooler useless?

regards,
Phil

[dad911]

Originally Posted by DRACO A5OG

Dad911,

Did you ever test like Steve?

I'm think the outlet side is just emitting heat from it being connected to the engine, Just a crazy brain fart

No. Car long gone.

[TimT]

Is it air bound?

Which fitting is used for the inlet?

I'll have to check my cars tomorrow, I think hot oil in the bottom, cooled oil out the top

[TimT]

oops noticed someone else mentions in may be airbound

[Formerly Steve Wilkinson]

The way the 911 oil system works, it is not possible for it to be "air-bound." You could put a tuba in the loop and it wouldn't get air-bound. There is no such thing, so that's a non-starter, unfortunately.

Also, it doesn't matter a bit whether the oil goes into the cooler at the top or the bottom fitting. My problem lies elsewhere.

And tctnd needs to read the original post, not just the title...

[TimT]

Well never mind then..

But if the cooler is plumber incorrectly you will have a big block of air preventing the oil from transiting the cooler..

So is the hot oil entering the top or the bottom of the cooler? It does make a difference. You really may want to check this

Why not reverse the hoses on one of your water cooled cars radiators and see how well that works..

[78P930]

Sounds like you are not getting adequate oil flow to the cooler for it to work. I don't know what adequate is, but you might want to check that the system is pumping enough oil to the cooler and not bypassing it somehow.

[Formerly Steve Wilkinson]

Everybody who understands the 911 oil-circulation system has told me that an air blockage is impossible and that it is irrelevant which way the oil flows through the cooler. Everybody. And this includes at least one person who manufactures oil coolers. It has nothing to do with how your water-cooled car operates.

I'm not trying to resist good advice, I'm just saying that this advice has already been processed.

[TimT]

Steve...

Your cooler is divided into a top half, and a bottom half... That is what the diverter does...



If the oil enters the cooler from the top fitting... the liquid will follow the path of least resistance.. and flow down along the divider, leaving a number of unused cooling rows above..

The when the oil enters the bottom half of the cooler the same thing happens. the oil will flow along the lower portion of the cooler, not filling the cooling passages between the bottom of cooler and divider...

In this scenario, you are using very little of the coolers potential...


Now imagine this...

The oil enters the cooler from the lower fitting...

Since a liquid seeks its own level.....

The oil will fill each cooling passage from the bottom to the top..

This will continue, displacing the air from the cooler, and eventually all rows of the cooler are filled with oil...

All of the coolers surface will be cooling the oil... not just the bottom portions..

The way the cooler is plumbed does make a difference

[Gogar]

Well, I know it's not here or there but if I could keep my SC at 205 I'd jump for joy.

I know you're waaaay beyond this, but is it possible you have the send/return lines backwards? Hot oil should fill the whole front loop, and then when the T-stat opens only then it returns. (In my understanding; all apologies if I'm wrong.)