Rad Top Hose

[Guest mcramsay]

Before I go any further with my build I think I have come across a problem. And ultimately I think I know what the answer is going to be but here goes! I have really struggled to find a radiator that will fit in my marlin without going down having a custom one made. In the end I went for a twin core honda civic rad. A friend of mine runs it in his v8 marlin and has no issues so I figured it would work in an inline 6. The problem is in my mind set of measuring to make sure the rad will actually physically fit I didn't really take much interest in inlet and out let positions on the rad.

 

In the pic below it shows the radiator in its lowest position that it can go. However the top inlet of the rad is still around 5" higher than the outlet of the thermostat. Meaning the pump will be pushing water upwards into the radiator.

 

Asking for problems?

 

The alternative is to go for an alloy 50mm core polo rad. But they are pricey. Plus loosing the cost of the rad I just bought.

 

[Snapperpaul]

That's fine rad header tank needs to be higher than engine head so you can fit without separate header tank

[Guest mcramsay]

I thought I was asking for problems... I was planning on fitting a header tank near the scuttle panel, and fitting a blanking cap onto the rad rather than the pressure cap, and fitting a pressure cap on the expansion tank.

[maccavvy]

just run the rad and don't bother with a header tank. I have that rad on my pinto.

[Guest mcramsay]

As in run a suck and blow set up?

[sj-bradley]

I don't think there would be a problem as the pump is also "sucking" the water from below at the same time.

 

As long as you have a way to release air at the highest point, it should be ok. You also need a way to place the expanded water, a header tank or suck/blow would work otherwise the overpressure in the system would blow the hoses off.

 

Simon.

[Guest mcramsay]

I am just at the moment trying to work out the plumbing. The m3 engine has the following connections: there is one outlet on the rear of the head shown here:

 

Then there is a y piece

 

Which joins into one pipe which runs along into the rear of the water pump / thermostat housing

 

 

As I said I did plan on having an expansion tank and my plan was to plumb the outlet from the rear of the block into one of the pipes on the y piece, and then feed the bottom of the expansion tank into the other y.

 

But now if I'm not going to run an expansion tank. And opt for the suck/blow method then if If I remove the y pipe completely, and plumb the outlet from the rear of the head into the rear of the water pump/thermostat housing?

 

And then use a small non pressurised tank and run a pipe from the rad neck outlet into this, it will spit coolant out when warm, and then suck back in when cooling?

[maccavvy]

Bmw use a very complicated heater system mine has loads of pipes going to it.

Go on realoem.com for loads of Bmw exploded diagrams

[Guest mcramsay]

I'm not planning on using a heater in the car, so I want to reroute the system to exclude the heater. Without blocking off or banking any hoses. Basically all the coolant flowing out of the head and into the thermostat bypass. Rather than out of the head, through the heater and into the thermostat bypass... I am guessing the pipe going into the rear of the thermostat/water pump is a thermostat bypass. Otherwise the heater in the car would never get warm until the thermostat opened.