SL55 AMG, SL63 AMG, SL65 AMG (R230) 2002 - 2011 (2003 US for SL55 and 2004 for the SL65)

SL55/63/65/R230 AMG: SL55 split cooling question

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Old Aug 11, 2018 | 05:16 PM
  #1  
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SL55 split cooling question

Hello all,

I am splitting cooling systems, but with true circulation tank, with bottom outlet, upper inlet tank (currently eyeballing 2015 C class tank, pending verification of size) and not just a BMW compensation bottle, in effort to circulate all fluid, and increase the overall thermal capacity of the low temp coolant circuit.

I was wondering if anyone know off the top of their head, what size is the main coolant bottle hose at the H couplet?






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Old Aug 12, 2018 | 11:19 PM
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Bump!

Anyone?
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Old Aug 13, 2018 | 01:53 PM
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Originally Posted by bayhas
Bump!

Anyone?
3/4"

here is how I split an SL55 ...
https://mbworld.org/forums/sl55-amg-...ml#post7516772

Cheers,
Chris
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Old Aug 13, 2018 | 03:43 PM
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R230 sl55
also see, . link

Have you identified a space for your C class tank ? Ive been surprised how little room there is in the Sl55 for anything extra !
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Old Aug 14, 2018 | 12:37 AM
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Originally Posted by Essell55mb
also see, . link

Have you identified a space for your C class tank ? Ive been surprised how little room there is in the Sl55 for anything extra !
Same vacinity as the BMW tank, but I like the idea of Mercedes PN, that looks more stock with matching cap.

But the main reason I looked into the C class tank is it has the same size inlet and outlet, I am thinking of using straight 3/4" in and out, and make the bottle part of the circuit path, instead a compensation T and breather.

Last edited by bayhas; Aug 14, 2018 at 12:47 AM.
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Old Aug 14, 2018 | 12:46 AM
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This is the C tank

I am thinking to route the intercooler hot exit 3/4" line into the inlet of the bottle, and its outlet to go down straight into the pump.

This way the system will be full self bleeding, and will constantly circulate the entire contents of the bottle, instead of the portion that flows out of the T

But if pump flow fluctuates, and is not regulated, can this design cause the pump to swallow air?

I am not a cooling expert, nor trained on flow calculation, and my knowledge comes from basic thermodynamics training and physics as part of my formal engineering studies, so I could be missing the obvious, input is welcome
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Old Aug 14, 2018 | 08:40 AM
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I just split my cooling system and it's working fine ..... until now that is ... https://mbworld.org/forums/sl55-amg-...ml#post7483536
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Old Aug 14, 2018 | 12:01 PM
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R230 sl55
Originally Posted by bayhas
This is the C tank

I am thinking to route the intercooler hot exit 3/4" line into the inlet of the bottle, and its outlet to go down straight into the pump.

This way the system will be full self bleeding, and will constantly circulate the entire contents of the bottle, instead of the portion that flows out of the T

But if pump flow fluctuates, and is not regulated, can this design cause the pump to swallow air?

I am not a cooling expert, nor trained on flow calculation, and my knowledge comes from basic thermodynamics training and physics as part of my formal engineering studies, so I could be missing the obvious, input is welcome

What do you reckon the rough capacity of that tank is ? Thats quite a good find though for a tank with two large 3/4 connections, most seem to have one 3/4 and then bleed and expansion ports.

I would imagine thats the right way round for the flow, ie in theory there will always be a head of coolant for the pump to draw from. - Unless acceleration / cornering pushes the fluid to one side of the tank and away from the outlet ?

Has this tank got a smaller port for the bleed line from the heat exchanger in the supercharger ?
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Old Aug 14, 2018 | 12:03 PM
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R230 sl55
Originally Posted by amok55amg
I just split my cooling system and it's working fine ..... until now that is ... https://mbworld.org/forums/sl55-amg-...ml#post7483536

oh dear, whats happened with the ' until now that is ' ?

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Old Aug 14, 2018 | 02:32 PM
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Originally Posted by Essell55mb
oh dear, whats happened with the ' until now that is ' ?
Just mean i have only been running it for half an hour .... still breaking it in .... topping fluid and some minor adjustments ..... more pics. and info next week ..... car has been standing for almost 6 years .....
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Old Aug 14, 2018 | 08:08 PM
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Originally Posted by amok55amg
Just mean i have only been running it for half an hour .... still breaking it in .... topping fluid and some minor adjustments ..... more pics. and info next week ..... car has been standing for almost 6 years .....
Your system as designed, is impossible to bleed, you need a vent at the highest point of the circuit.
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Old Aug 14, 2018 | 09:25 PM
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Originally Posted by amok55amg
I just split my cooling system and it's working fine ..... until now that is ... https://mbworld.org/forums/sl55-amg-...ml#post7483536
That is not the question, the question is regarding how to split it.

Compensation tank, Vs flow tank.



Obviously, the second design will cool better, and bleed quicker, but my concern if the fluid capacity in bottle is not enough, fluctuation in pressure, along with driving dynamics, can cause air to make its way into the bottom of the bottle... not to mention the upper hose dumping fluid at full force can cause some bubbling and foaming concerns, again, causing air to circulate in the system

What do you think guys?
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Old Aug 14, 2018 | 10:47 PM
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Put in a trunk tank, split the system, and call it a day.
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Old Aug 14, 2018 | 11:20 PM
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Originally Posted by BlownV8
Put in a trunk tank, split the system, and call it a day.
We've already established splitting the system, we're past that point, the debate now is to do circulation bottle or compensation bottle split (post #12).

Trunk tank is not going to happen, the car is a daily driver, I need the spare and trunk space.
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Old Aug 15, 2018 | 07:21 AM
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I believe you can get a trunk tank that will fit the void of the spare tire.
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Old Aug 17, 2018 | 10:57 AM
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C class bottle came in yesterday, turned out the outlet is 5/8" and inlet is 1/2", so it was too restrictive for circulation setup.

I installed in it conventional compensation setup, and wawa wewa... with side cooler and fan on, I was running as low as 9 above ambient at cruise!

Best part is how factory-ish the setup looks like

Now i just need to find an adapter from 1/2 to 1/4 for return line, and the project will be completed


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