2019 plastic expansion tank options

[FABombjoy]

I'd like to revert back to a plastic expansion tank, but it looks like the modern repros plastic tanks are no longer available. I head they had issues so I'm OK with not using an original style.

Why do I not want a metal tank? I'm looking to control radiant heat in the engine bay.

I've seen a few cars with tanks repurposed from other cars but a few searches are coming up empty. Does anyone know offhand what these might have been from?

[David T]

Even if you can figure out what the cross/over is, you will probably wind up with something over 30 years old even if you can find an NOS tank. The design life was not 30 + years. Get the metal tank. I doubt the difference in radiated heat between a metal tank and a plastic tank is going to make a difference.

[FABombjoy]

Yeah it makes a big difference when you have an air/air intercooler less than 1" away.

There was an owner at DCS16 from the Southwest that had to field replace his tank with a nearly bolt-on, modern plastic part. I can't remember what he said it was from though.

[vwdmc16]

Early BMW e30 (82-86) 3 series and some 5 series have a simular looking plastic tank. They are still available, good quality (never seen one burst) and even have a built in level sensor bung.

https://cdn1.pelicanparts.com/catalog/images/SuperStock-Priority/17-11-1-707-540-M9.jpg

https://www.pelicanparts.com/More_Info/17111707540.htm?pn=17-11-1-707-540-M9&gclid=CjwKCAjwtO7qBRBQEiwAl5WC2w9yxl-Y8VdoetV06ki2OHeAtsqKwAfpsdoq39Eo-KnSRYSsRMD9ahoCsKYQAvD_BwE

As you can see the mounting bracket is different so that's another issue too.
That said I know these radiate alot of heat too. Maybe building a heat shield is the best solution

[FABombjoy]

That said I know these radiate alot of heat too. Maybe building a heat shield is the best solution
Thanks for the lead! Matt D is running a Volvo tank, so it looks like there should be a few different options out there to test. I'd like a tank I can check the level on more easily so now seemed the time.

Reviewing data from a couple of cars it's amazing how little time it takes for heat soak to set in. The side of the IC neares the tank feels hotter. IATs get to a certain point and never really ever come back down, even with extended highway speed driving. Slowly working on a duct / pusher fan setup but wanted to make a few smaller changes and study efficacy.

I do have a roll of magic gold tape too but I was saving that for last :D

[dodint]

It's a bad time when you're looking up to plastic BMW cooling components. They're the universally acknowledged weak link in BMWs for decades.

If I had the same concern I would use something like exhaust wrap and line the outside of an SS overflow tank with it.

[vwdmc16]

It's a bad time when you're looking up to plastic BMW cooling components. They're the universally acknowledged weak link in BMWs for decades.


That's true of the generations after the e30. These older ones last a very long time.

[vwdmc16]

... Slowly working on a duct / pusher fan setup.....

So do you have any active airflow through the intercooler? No wonder it heatsoaks.

[valdez]

Nothing beats homemade.

[FABombjoy]

So do you have any active airflow through the intercooler? No wonder it heatsoaks.
The data suggests there is airflow through the IC but not enough (MATs that rise then fall). Active cooling was always in the plan but MATs aren't super duper high, so it's been pushed back.
MATs approach +40F over ambient.
Patrick's car with a plastic airbox is much better in this regard. The spread is probably 10-20F less under similar load. My piping is insulated from turbo to intercooler, but I have lot more air-path metal near coolant-path metal than stock. The IC to kjet housing adapter is also metal. Plus, you know, turbo (with a blanket on the hot side)

MAT is correlated with CLT more than load.
EGO is not MAT correlated suggesting air density measurement is accurate.

I want to get as many passive strategies going as I can before bringing in the IC fan. I have some experiments that I plan to run with both cars on a driving tour we're having next month.

[FABombjoy]

Nothing beats homemade.
Haha, is there a particular flavor of gatoraid that comes in a 20psi-rated bottle? :D

[Timeless]

Haha, is there a particular flavor of gatoraid that comes in a 20psi-rated bottle? :D
Maybe the 'G ZERO' iteration. :nana1:

[Drive Stainless]

Where is your IAT sensor located currently? I need to relocate mine. I was thinking inside of one of the pontoons.


Thanks for the lead! Matt D is running a Volvo tank, so it looks like there should be a few different options out there to test. I'd like a tank I can check the level on more easily so now seemed the time.

Reviewing data from a couple of cars it's amazing how little time it takes for heat soak to set in. The side of the IC neares the tank feels hotter. IATs get to a certain point and never really ever come back down, even with extended highway speed driving. Slowly working on a duct / pusher fan setup but wanted to make a few smaller changes and study efficacy.

I do have a roll of magic gold tape too but I was saving that for last :D

[FABombjoy]

Mine is is a separate, small pipe post-IC. It's relatively thermally isolated from the intake manifold.

Patrick's car we put it right in the lower airbox.

In the pontoon it might become more of an ambient air temp sensor than intake air temp.

[dmcnc]

I believe Arran from Deloreango might have a used repro if you're still interested.

[DeLoreanGo Arran]

I do, but it isn't suitable for pressurised systems.

Over here there a few people using a Volvo plastic tank, Volvo part 1276040 (replaced by 3547466 ). This requires no drilling as the bracket can use the existing mounts - just a slight modification to the hose.

[David T]

One idea is to move the tank into the pontoon and cut a hole for the pressure cap. Then connect an overflow tank to the overflow and keep the header tank filled and watch the level in the overflow tank. That is what Lotus did and they put the overflow tank in the R/R wheel well. Another thing Lotus did was put a fan in the engine cover controlled by a thermostat to reduce heat soak. On the V-8's they also put an electric recirculating pump in and the ECU controlled it and the rad fans to get rid of heat soak. For more passive solutions use heat shields and heat wrap tape. On old Jaguars they porcelainized the exhaust manifolds to reduce radiated heat.

[FABombjoy]

Over here there a few people using a Volvo plastic tank, Volvo part 1276040 (replaced by 3547466 ). This requires no drilling as the bracket can use the existing mounts - just a slight modification to the hose.
Thanks for that! This tank was actually on my short list as it seemed like it would work for all the above reasons.

Do you know if people are using the green 1.5b cap? I saw a reference to a very uncommon white cap rated at 1b but a quick search came up empty.

[DeLoreanGo Arran]

The cap is 1357776 - which is the correct 15lb / 1 bar one. Obviously you don't want the 1.5 bar one. Colours do vary, but generally it is white, yes - some aftermarket ones are black, I think some are even yellow. Generally the green ones are 22PSI/1.5bar - you don't want that...

Although it is used on the various normal Volvos (the usual ones that we are all familiar with) its main use these days is on a boat engine, and this diagram might help - http://www.marinepartseurope.com/en/volvo-penta-explodedview-7742230-90-15204B.aspx - in some cases you will need to buy the bracket separately - I can't remember off the top of my head how it attaches on the car - as mentioned the only real issue is the hose outlet which just needs a reducer to get to the correct size.

[Drive Stainless]

Thanks for that! This tank was actually on my short list as it seemed like it would work for all the above reasons.

Do you know if people are using the green 1.5b cap? I saw a reference to a very uncommon white cap rated at 1b but a quick search came up empty.

First, I like that tank Arran posted because the mounting would be simplified, at least compared with what I had to fashion to make the Volvo 940 tank work.

Second, I've been running the green cap for about a year now. If you have an original car with original hoses, you may be more likely to burst one, but ideally the cooling system should hold much more pressure than its normal operating pressure. There isn't anything different about the hoses and clamps and radiators used on the green cap-designated cars.

[FABombjoy]

The cap is 1357776 - which is the correct 15lb / 1 bar one. Obviously you don't want the 1.5 bar one. Colours do vary, but generally it is white, yes - some aftermarket ones are black, I think some are even yellow. Generally the green ones are 22PSI/1.5bar - you don't want that...

Although it is used on the various normal Volvos (the usual ones that we are all familiar with) its main use these days is on a boat engine, and this diagram might help - http://www.marinepartseurope.com/en/volvo-penta-explodedview-7742230-90-15204B.aspx - in some cases you will need to buy the bracket separately - I can't remember off the top of my head how it attaches on the car - as mentioned the only real issue is the hose outlet which just needs a reducer to get to the correct size.
Appreciate the help & part numbers! That Looks like fabricating a bracket should be fairly easy. I'll post a follow-up photo once fitted.

[valdez]

Haha, is there a particular flavor of gatoraid that comes in a 20psi-rated bottle? :D

It is the electrolytes that are important!

[FABombjoy]

Took me long enough!

Volvo tank installed:
https://i.imgur.com/mNremji.jpg

Data:
Histogram views, similar samples taken from cold start. The numbers are the coolant temp delta.
Lower intake air temps = number further into the negative.
The more negative the number, the cooler the air temps are compared to coolant temps.

Warm-up log from July 2, approx 3pm.
Stainless coolant tank.
Daily high temp 88F.
A/C enabled.
https://i.imgur.com/4JoAzVI.png

Warm-up log from July 25, approx 5pm.
Plastic coolant tank.
Daily high temp 87F.
A/C enabled.
https://i.imgur.com/57ndT6x.png

My situation is unique with the top-mounted intercooler running parallel to the expansion bottle.
I didn't expect to see such a measurable difference, especially once the engine is warmed up.

I'll continue to collect & compare data but I'm optimistic that this is an effective way to reduce radiated heat in the engine compartment.