TWO B&M 70268 Coolers In Series? (1 Viewer)

[LCnAZ]

The B&M 70268 tranny cooler is popular partly because it's 3/4" depth is friendly to installation (due to that annoying condenser line). Numerous members have felt like the 70268 didn't measure up, though. For example, @BlackCat swapped to a Derale Atomic cooler (model 15950 with a fan) for this reason. He gives it rave reviews with a 30+ degree drop in AT operating temp. He had to make some structural modifications to install that cooler...that I'm not willing to make.

How about this idea? How about two 70268 coolers in front of the condenser connected in series? That would double the BTU capacity to 26,000 BTU. Other than doubling the investment, can anybody think of a downside to that approach?

 

[toyotaspeed90]

Yeah, you'll be blocking quite a it more of the radiator/condenser, plus possible additional heat soak.

Have you considered a heat sink style cooler mounted elsewhere?

 

[LCnAZ]

Yeah, you'll be blocking quite a it more of the radiator/condenser, plus possible additional heat soak.

Have you considered a heat sink style cooler mounted elsewhere?

I'll consider anything, but I haven't thought of that yet. There's not a ton of space on our Cruisers for such...unless I'm not understanding the type of cooler your mean.

Another variation I'm going to consider is trying to fit a 70266 on the passenger side. A fellow at Summit Racing had an interesting suggestion. He said if we knew the pitch on the output at the transmission, a change to 1/2" hose could be affected and run to the 70266. His reasoning was that the steel braided 1/2" hose on that run to the cooler would dissipate heat quicker.

 

[toyotaspeed90]

You could run a larger hose, but could cause pressure drops (someone more in tune with transmissions would need to add, or take away, from that thought).

This is what I was talking about...

Summit Racing® Heat Sink Transmission Coolers SUM-331000

You could also look for an external coolant based system... but the radiator/cooling system would need to be able to handle the additional needs.

 

[tmxmotorsports]

Why do you need two or think you need two have you installed one of them and its not helping. There maybe another issue or maybe its hot af where you live

 

[hygge]

@LCnAZ i am pretty sure that you could get one of the larger coolers from BM.

Also the 3/4” is nice but you could use a little larger spacer between the hardline and the connector to the Compressor Line.

I took pictures in my thread. It’s totally doable.

 

[OSS]

To put things into perspective, Toyota designed the 62 as a Heavy Duty vehicle. It's a Land Cruiser, not a car and they overbuilt everything. A lot of thought and careful consideration went into designing the transmission AND the cooler by a team of engineers. The vehicle design (and transmission) was then torture tested prior to getting signed off for manufacturing.
The resulting ATF cooler design (via the heat exchanger at the bottom of the radiator) was deemed sufficient for a heavy duty Land Cruiser in the harshest conditions.

Everything about the cruiser is overbuilt. Nothing was skimped on. Whenever there's doubt as to whether a certain component is up to the task, just look at the steering components or transfer case.
Everything on the cruiser is built to the same degree of robustness as those things. Although ATF temps on the 62 might get above 200° on hot days, and that seems hot to those of us who aren't lubrication engineers, ATF and the transmission can handle much hotter temperatures just fine.

Personally I wouldn't try to outsmart the engineering team at Toyota. None of us will win at that game. I say leave it as designed. It's a Land Cruiser, not a RAV4.

 

[hygge]

@OSS I tend to agree with you for the most part.

But, I can only speculate that they were not throwing 33” plus size tires with roof racks and Roof top tents and expeditions with Old Man Emu lifts on the LCs back 30 years ago.

The usage we see today is not stock. Also I would argue that most of our trucks and transmissions are not in the same condition as say they were a quarter of a century ago (even if they were rebuilt).

Then again, like you said, I am NOT an engineer. I also don’t know what type of stress testing they did back in the day.

 

[tmxmotorsports]

Good points above i say screw the second transmission cooler and put an ls in it and be done...lol

 

[cruisermatt]

I'll consider anything, but I haven't thought of that yet. There's not a ton of space on our Cruisers for such...unless I'm not understanding the type of cooler your mean.

You need to be more creative. There is a TON of room to mount coolers. You can use scoops, ducting, all to your advantage. Look at lots of different racecar coolers and radiators for inspiration.

The two coolers in series in front is not great for the reasons @toyotaspeed90 stated.

Cooler transmission fluid is good. No question. Same with power steering fluid.

 

[LCnAZ]

You could run a larger hose, but could cause pressure drops (someone more in tune with transmissions would need to add, or take away, from that thought).

This is what I was talking about...

Summit Racing® Heat Sink Transmission Coolers SUM-331000

You could also look for an external coolant based system... but the radiator/cooling system would need to be able to handle the additional needs.

I brought up the question of pressure, too. Interesting on the sink cooler. Our late model Sequoia has this type, I believe.

Why do you need two or think you need two have you installed one of them and its not helping. There maybe another issue or maybe its hot af where you live

Primarily preventative. I'm the original owner, and over it's life I've seen the tranny want to get a bit hot in mountainous terrain. It was rebuilt about 35K miles ago. It runs terrific in the occasional drives in my area, but I want to take it up to the mountains occasionally. It's time to make this restored LC last. It's not hot now. It's southern Arizona.

Personally I wouldn't try to outsmart the engineering team at Toyota. None of us will win at that game. I say leave it as designed. It's a Land Cruiser, not a RAV4.

Thanks for that info, but @hygge makes a point I tell the local dealer from time to time; they are not new vehicles any more. As the original owner, our LC has taken us on great adventures in it's younger years. They are not the same vehicles they were when younger. If so, we all wouldn't be here discussing all manner of work. They are not new or even like-new. We can only maintain and sustain. Even Rodney of down-under points out that this tranny always had overheating issues. He adds that to a great degree the AT in the 80 series overcame this, but not ours. Hence, we try to protect it from heat.

You need to be more creative. There is a TON of room to mount coolers. You can use scoops, ducting, all to your advantage. Look at lots of different racecar coolers and radiators for inspiration.

Good point as long as you don't mind your rig looking quite a bit different from OEM. I'm at my limit on visual mods with the OME, ARB front bumper, and 31x10.5 tires.

To the gallery...there are a lot of paths to research and analyze. I am not insensitive to the issue of too much in front of the condenser. I already have a 12" fan I added there a few months ago. @hygge, the spacer you describe is what I had to do to fit that fan in there. I'm going to measure and study to see if I can fit a B&M 70266 on the passenger side where that 12" fan is now. The 1.5" depth won't permit it on the driver side due to the condenser line...same for the 12" fan. If the 70266 will fit on the driver's side, I can add a smaller fan below the condenser line on the driver side to keep the a/c cool at stops in the summer.

Another possibility is to use create a custom bracket for a combo 70268 (3/4" depth) and the smaller fan. This would be much like the Derale Atomic and similar coolers. But with the 20268 being more shallow than those, I might be able to fit both it and a fan in there behind the grille on the driver side. In that case, I leave the 12" fan on the passenger side of the condenser. I know. Lot's of electrical.

If all of these fail...then it's H55 conversion time sooner than later.

Thank you all for you inputs. Ours is the mother of all sites for brainstorming solutions.

 

[FJ60Cam]

You can grind the back side of the grill to fit a deeper cooler.

 

[LCnAZ]

@hygge @toyotaspeed90 @tmxmotorsports @cruisermatt @BlackCat @CenTXFJ60 ...and all...How about this idea?

I have exhausted the various installation approaches. Series won't work. The only thing that appears will work (with me keeping the 12" condenser fan), is installing the 70268 in front of the passenger side of the condenser. But as cruisermatt mentioned, maybe there is a nontraditional/creative approach to this.

I really like the approach like BlackCat's with the Derale Atomic cooler, but I cannot find a fit that will work for me. But maybe I've thought of a unique way. I suddenly remembered this morning that there is significant space between the back of the condenser and the front of the radiator. My idea for consideration is mounting the 70268 between the condenser and radiator directly in the flow of the 12" condenser fan (as it passes through the condenser). That fan comes on as soon as the EGR hose reaches 140 degrees. That tends to correspond to the engine reaching normal warm up operating temperature. Of course the fan clutch keeps a flow until the 12" fan kicks on. Below is a photo of the installed 12" condenser fan?

What one gives up in such a scenario is direct flow across the transcooler from clear ambient air pulled by the fan clutch and by relative wind when moving. What it gains is high velocity active air across the transcooler after passing through the condenser...at all times after the engine is up to operating temperature. What I don't know is how warm the condenser gets in summer time. Obviously it doesn't get hot like the radiator.

The obvious in this scenario is that efficiency of the transcooler depends mightily on the fan operating/not failing unexpectedly.

Give this some thought and share what you think.

 

[LCnAZ]

I wonder if heat soak after shutdown could be a greater concern in that installation.

 

[hygge]

@hygge @toyotaspeed90 @tmxmotorsports @cruisermatt @BlackCat @CenTXFJ60 ...and all...How about this idea?

I have exhausted the various installation approaches. Series won't work. The only thing that appears will work (with me keeping the 12" condenser fan), is installing the 70268 in front of the passenger side of the condenser. But as cruisermatt mentioned, maybe there is a nontraditional/creative approach to this.

I really like the approach like BlackCat's with the Derale Atomic cooler, but I cannot find a fit that will work for me. But maybe I've thought of a unique way. I suddenly remembered this morning that there is significant space between the back of the condenser and the front of the radiator. My idea for consideration is mounting the 70268 between the condenser and radiator directly in the flow of the 12" condenser fan (as it passes through the condenser). That fan comes on as soon as the EGR hose reaches 140 degrees. That tends to correspond to the engine reaching normal warm up operating temperature. Of course the fan clutch keeps a flow until the 12" fan kicks on. Below is a photo of the installed 12" condenser fan?

What one gives up in such a scenario is direct flow across the transcooler from clear ambient air pulled by the fan clutch and by relative wind when moving. What it gains is high velocity active air across the transcooler after passing through the condenser...at all times after the engine is up to operating temperature. What I don't know is how warm the condenser gets in summer time. Obviously it doesn't get hot like the radiator.

The obvious in this scenario is that efficiency of the transcooler depends mightily on the fan operating/not failing unexpectedly.

Give this some thought and share what you think.

View attachment 1895077

I was able to fit my power steering cooler on the drivers side. Even though it’s a small space it’s worked.

But who knows, maybe I am suffocating my condenser and radiator. I guess we will find out this summer.

Yeah, you could totally go in between the condenser and radiator. It’s less efficient, but then again everything is a compromise.

 

[FJ60Cam]

Put it on the driver side & grind the grill. There’s a lot of meat that can come off.

Anything you do at this point is better than the stock setup.

 

[OSS]

Re: blocking air flow-

A few years ago I took a long trip for many months to Baja MX and brought a 2nd new tire with me along with the mounted spare. I didn't want to carry the extra tire (31") on the roof rack because the rack was already packed.... So I strapped it to the front ARB bumper. Fit great.

It looked like it wouldn't block any significant airflow to the radiator because the open 15" center of the tire was centered in the middle with a direct line straight to the radiator.

But it did.

While I drove it like that, the fan clutch would regularly lock up from the extra heat caused by reduced airflow going through the radiator.

So this story has a point: If something is mounted in front of the radiator but the fan clutch doesn't seem to lock up more often than usual, the thing in front of the radiator isn't significantly blocking the air flow.
But if you hear the fan clutch lock up more than usual, that thing is making things worse.

The roar of the fan clutch is an audible signal that the coolant temperature inside the radiator is getting hot.

 

[LCnAZ]

@hygge @toyotaspeed90 @tmxmotorsports @cruisermatt @BlackCat @CenTXFJ60
@FJ60Cam

Hey guys...unique solution found and executed today that provides the best of all installation scenarios. See post on my build thread. Builds - Sentimental Restoration of Family 1990 FJ62

 

[toyotaspeed90]

There's a problem with your solutuon....

Electric fans can be set up as a pusher or a puller - you might have issues with what the fan was meant to help cool. Electric fans tend to be better (CFM) set up as a pusher than a puller, but I would bet with it set up as a pusher it won't only not push air well for your condenser but also wont pull air through the cooler.

 

[LCnAZ]

There's a problem with your solutuon....

Electric fans can be set up as a pusher or a puller - you might have issues with what the fan was meant to help cool. Electric fans tend to be better (CFM) set up as a pusher than a puller, but I would bet with it set up as a pusher it won't only not push air well for your condenser but also wont pull air through the cooler.

I can bring more to your concerns than one might expect. There are numerous structural and aerodynamic variables. The most obvious/predictable factor is the direction of the fan. It is tempting to just swap the polarity of the power to change pusher/puller, but with this fan that will not have nominal results if that is done. The reason is that the fan blades are designed to be most efficient turning in the direction of the blade sweep (not pitch). This is a common design now in advance turboprops like the A400 and latest C-130 mod. This fan's direction (push or pull) must be done by flipping the rotor.

Structurally, this type of fan will benefit most whatever device its shroud is flush against; as a pusher against the condenser, or a puller on the back side of a radiator. In my installation, the fan is being tasked to do double duty. It will be most efficient at a pusher through the condenser. But its effectiveness as a "puller" for the transcooler is proportional to the cooler's distance from the fan; the closer the better. There is a happy medium, though, to be found in this installation. As a pusher for the condenser it needs to have some ambient temperature air draw. The transcooler is designed to benefit from ambient air flowing through AND around it. The 12" fan does just this, but providing more velocity at all times. The fan is also not pulling strictly transmission-heated air from the cooler; plenty of ambient temperature air flows around the transcooler. Hence my prediction that this will be a very effective configuration.

By the way, my background on airflow is from my background as a military pilot (retired). I refered to those "heavies," but that's not what I flew. With one exception (the A-10), what I flew was faster than a scalded-ass ape.