Diablo roadster cooling system

[jdinner]

Jim, that is a very "Cool" idea! Why get rid of the zero pressure tank?

That is an antiquated system in my opinion. We are doing things that are not normal. Nobody can tell me that our cooling systems will work just like any other car.
Our air flow is restricted in so many ways and at speed we are creating a vacuum behind the car which also restricts air flow.
A zero pressure tank only collects fluid while the coolant is heated and expanding.
Steam is created in our cars. Where does the steam go? It travels to the highest points. A water pump will never be more powerful than stream.
How do we get rid of the steam at the top of the engine and radiators?
We install vents. Where do the vents vent to? They could go anywhere but we want to collect the liquid that goes with it.
So, if it went to a zero pressure tank we would need a really large tank because all the coolant would spill into it eventually.
If we had a zero pressure tank that sent coolant back to the engine as it was expelled it would no longer be a zero pressure tank, it would be a pressure tank.
The pressure tank does not need to be filled to the top. It should be down a little to allow for expansion when hot.
Most people don't have a zero pressure tank attached to the 2nd, 3rd or 4th radiator cap vent port because no coolant spills out of there normally.
If you have more than one radiator cap in the system picture this....
When a hot engine cools it creates a vacuum in the system. A "vented" or "closed" radiator cap is typically used with a zero pressure tank. This allows for coolant to be sucked into the system during the cool down period. It there is no tank on one of the caps necks then it will only suck in air. Air is then going to become steam.
This is why I am recommending a pressure tank with only ONE radiator cap in the system. This cap should be a "non-vented or open" cap.
https://jimdinner.wordpress.com/2012/07/09/radiator-caps-explained/

[★Murci-Me★]

Radiators hooked up in series???Not a good idea IMO.

[eddie]

I know nothing about mechanicals stuff ,but why are the rads side ways ? does it  matter? 

[01Lambiero]

 

[mhotmarkx1]

Hi Jim, can you look at my sketch and modify it. I am uncertain.Thanks

[eddie]

I do not have a termostat on 3.8 runs good
Yesterday we had over 30c heat and I had it run for good half hour in side the garage with out any air flow . & 195f spal  kicked in and 3 min was down to 180. And again in and out.

[76mx]

Jim, that is a very "Cool" idea! Why get rid of the zero pressure tank?

[mhotmarkx1]

Thanks Jim, always appreciated, can you draw a diagram or modify my sketch so i am certain. Greatly appreciated.

[jdinner]

My suggestions:
Add in vent tubes at the top of each radiator. 1/4" NPT ports will work.
Run these two ports to a new pressure reservoir. Get rid of your zero pressure reservoir tank.
By adding in the pressure reservoir you will stop all air build up in the system (steam).
The pressure reservoir MUST have a drain port (large bottom port going to a low spot in the cooling system)
The pressure reservoir MUST have a upper port (or 2) (these run to the top of each rad - 1/4"NPT)
The pressure reservoir MUST have a upper port venting the thermostat housing as well.

By doing this you will ensure that any air in the system vents back to the pressure tank creating steam on the top side of the tank. This allows clean liquid to be forced back into the system through the large bottom port.

Now, get the correct system radiator cap.

https://jimdinner.wordpress.com/2012/07/09/radiator-caps-explained/

If you have another rad cap in the system, be sure to plug the vent port.

https://www.youtube.com/watch?v=Z-dqqhWQo_8

https://jimdinner.wordpress.com/2012/07/07/coolant-expansion-tank-revisited/




Good luck.

[tonypaul]

Tonypaul. thanks for the diagram. Does it really matter where the elect pump is? yes i have one on the engine and an electric one. see diagram.
how about the heater core hoses? i appreciate your help. thanks.
I also found earls bead roll tool online and will remove the 3 pipes and add a bead to prevent hose slippage. any other suggestions?

I had my electric water pump right between the 2 radiators, about 1/2 way within the cooling flow. I bet your problem is just needing to get the air out of the system. Can you see the upper side of the radiator tanks if there is a little plug to take out? If you either have little ports at the top of your radiators or radiator caps on each radiator or just take off the upper hose (1 at a time starting with the radiator closest to the water pump on the motor.) Jack up the rear of the car as high as you can get it. Fill slowly at the radiator till coolant starts coming out the 1st radiator bleed port or put upper hose back on. Fill at the second radiator till coolant comes out the top put in the plug or put the upper hose back on. Make sure you have a small hole drilled into the flat part of your thermostat. Below is what the bleed ports look like on my radiators.

[eddie]

don't spend money on bead tool, since you have to take them off, take a Mig and weld bead on it.  that's what i did . Workie good.

[mhotmarkx1]

Tonypaul. thanks for the diagram. Does it really matter where the elect pump is? yes i have one on the engine and an electric one. see diagram.
how about the heater core hoses? i appreciate your help. thanks.
I also found earls bead roll tool online and will remove the 3 pipes and add a bead to prevent hose slippage. any other suggestions?

[CCIE]

Very Nice!!!!

Is this a IFG kit based? Please post interior pic too

Congrats again

[mhotmarkx1]

I purchased Dwights Lambo

[tonypaul]

so you have a waterpump mounted on the motor and a inline electric water pump also? If so put the electric water pump between the two radiators. That might help, thats how I had mine when I had a sbc. But I never had any cooling problems once all the air pockets was burped out of the system. Personally I think you have way too many overflow hoses. You really just need one good working recovery/overflow tank. here is a diagram I found-