Firewall coolant expansion tank - stupid idea?

[Okibi]

Here's something i've been contemplating. There's plenty here much smarter than me, is this idea stupid?

Use a vary cowl washer bottle so i can remove the oem washer bottle.

Putting a radiator expansion tank in where the oem washer bottle goes.

Plumbing the hot hose from the back of the engine into a t piece then into the firewall. The top of the T piece plumbed into an expansion tank so any bubbles would collect in the expansion tank.

The final piece would be to place an overflow bottle near the firewall too.

This would truly be the high point in the cooling system and it would make some it easier to do an intercooler setup similar to this with a slightly shorter or angled radiator.



Or for natural aspirated engines more room on the cold side to run a shortie intake and heat shield.

Tell my why this is a stupid idea.

[NitroDann]

Firstly, you cant tee an expansion tank off of anything without a radiator cap. You would need to run the hose from the radiator all the way back to the firewall. Thats for starters. On phone waiting for pics to load..

Dann

[NitroDann]

Also.. Do any mx5s have expansion tanks? Dont they all just have overflow bottles... We certaintly dont have a sealed expansion like a Falcon on any models do we?

So do you mean just an expansion tank with a secondary bottle incase it overflows? It should never require more overflow than stock allows for. And even stock just has a dump hose after it -just in case-.

Theres no reason you couldnt run a sheetmetal overflow/washer combo with a split centre in the firewall area. That would tidy up the engine bay a LOT.

Dann

[NitroDann]

Pics up..

Question only aimed at LHD nb8a owners? :p

Dann

[Okibi]

I guess its more of a header tank rather than expansion tank then.

[Hjt]

You could always put the overflow tank in the drivers side innerguard behind the plastic, many US vehicles use this approach.

[Okibi]

Yeah my people mover has that setup too.

[JBT]

Also.. Do any mx5s have expansion tanks? Dont they all just have overflow bottles... We certaintly dont have a sealed expansion like a Falcon on any model do we?

NC

[NitroDann]

I said MX5s, not mazdas.

Dann

[JBT]

As class clown you should know it's an MX-5 not an MX5...but then again....

[hks_kansei]

Also.. Do any mx5s have expansion tanks? Dont they all just have overflow bottles... We certaintly dont have a sealed expansion like a Falcon on any models do we?

IIRC.

The stock is just a bottle that as the coolant expands it fills the bottle
When it cools, it gets sucked back into the radiator/cooling system.

Correct?



So theoretically, it could work perfectly fine if the stock overflow hose was lengthened and some form of bottle attached to the end (even a coke bottle)
As long as it's uphill of the radiator, and the pipe enters at the bottom of the bottle, it should work.
Yes?/No?

[JBT]

IIRC.

The stock is just a bottle that as the coolant expands it fills the bottle
When it cools, it gets sucked back into the radiator/cooling system.

Correct?

So theoretically, it could work perfectly fine if the stock overflow hose was lengthened and some form of bottle attached to the end (even a coke bottle)
As long as it's uphill of the radiator, and the pipe enters at the bottom of the bottle, it should work.
Yes?/No?

The NA and NB have an overflow tank/bottle as you describe. The NC has a transparent expansion tank which is under pressure (just like a normal radiator) with a pressure cap. It is done that way because the radiator is buried in the engine bay area - as it is in many cars these days - with no pressure cap on the radiator. Mind you, this type of system was also used on the last iteration of the MGB - that factory arrangement was a bit cr@ppy but it worked well with a decent thermo fan(s) and adjustable temp detector setup.

I think Okibi is talking about relocating the overflow bottle as well as incorporating an expansion tank where the overflow bottle used to be. For Okibi, you could run a line from the modified radiator to the expansion tank but I think you need a high point in the pressurised part of the system to bleed it. I don't think an overflow off the expansion tank will achieve anything and is unnecessary.

[NitroDann]

just run 2 bottles in the cowl area and run the overflow line around, maybe hidden in the guard, to the bottle. And the other bottle for washer water.

Dann

[bootz]

I said MX5s, not mazdas.

Dann

[JBT]

Okibi - disregard what I said about your plan to put the expansion tank where the overflow bottle used to be - I misread that part. See attached for a simplified version of a remote expansion tank. Red circle shows the system high point for filling/bleeding and the green circles show where the expansion tank hose connects. Your general expansion tank idea is certainly the way to go to allow a shorter or lower radiator to be fitted.