The V8 Owners Forum -

Hi All,

Having a re-think of the cooling system for one of my MGB V8 race cars.

This particular car is soon to be fitted with one of our 4.0ltr FPC engines, which produce just north of 400bhp and see constant high RPMs. The general tradition in our series is to fit an aftermarket aluminium radiator (not the cheap chinese stuff!) along with a DC electric water pump. The temps are always marginal, and realistically on a hot day, they run too hot.

From recent reading it appears that the DC water pumps are not really up to the job and flow significantly less than the stock pump, so I am toying with running the stock pump, although I suspect that cavitation may occur at high revs, and if i play with the pulley sizes then there will not be enough flow at idle. So the option on the pump front is to run the biggest 12v pump I can find, like the Stewart Components inline pump (55gpm) or to run the standard pump slower, with an electric booster pump for idle.

I also think I can get another 2" of length on the radiator, which due to the restricted width of the body of the car is a bit undersized.

I welcome everyone's thoughts and experiences on this?

Do you have a cabin heater?
If so remove it and block the circuit other than a 1/16 hole to allow air bleeding.

Basically you are now forcing all the coolant through the radiator.

In the GT40 arena we run radiators with a 60 by30 cm core in aluminium and 5 rows.

Some run up to 600 hp and they keep cool, with a standard water pump even with the 7 foot long pipes back and forward from engine to rad.

Airflow wise rule of thumb is free air in area 1/3 of core area and 2/3 for air exit. And the second one may be the problem as you have a tight engine bay., bonnet fins will help greatly to clear air and heat out.

Ian

Have you reviewed Pierberg?
https://www.tecomotive.com/en/products/CWA400.html

Ian

They only list that CWA400 against 2.oL BMW engines, I think one from the BMW 3.0L engines may be more suitable although I can't find any pressure/flow/current specs vs the CWA400.

It costs more so it has to be better right!
Only spec I can see is 0.8bar and 9M3/h which looks similar to the CW400 - but without a curve you can't really tell:
http://www.easycarparts.nl/Controls/Cus ... 607_DS.PDF

https://www.turnermotorsport.com/BMW-E9 ... ater-pumps

For what its worth the M3 uses a mechanical pump...

Tom.

Thanks Guys, I purchased the CWA400 and the controller. The way I see it, it's several times better than the biggest DC pump so can only be an improvement. I am hoping to get the engine back together over the next few months so will let you know the outcome.

36A....

Make sure your wiring and alternator are up to running that, and everything else full time !

On paper at least it does flow a sensible about.

Although the simplicity and reliability of mechanical pumps are hard to beat...plus their cheap cost !