improve cooling on a 75

[Alfamania]

Hello,

Just wondering if anyone has a method of improving the cooling of the v6 in the Alfa 75. I was recently recommended I add a hose from the back of engine heater hose junction to the front radiator...adding a t piece on each end. This should improve cooling? ideally in summer the heater should be switched to hot so the coolant flows through the heater core as well, otherwise when on cold, coolant just is less flowing  in the back of engine because the heater core is closed? I was just thinking of adding a bigger thermo fan?

[alfa75gta]

Ceramic coating for my headers made a huge difference to my 75 V6. Others may suggest that it is only beneficial for ultimate performance gains but my average engine temp dropped 10c after i had it done, which was in mid summer..

[Duk]

Hello,

Just wondering if anyone has a method of improving the cooling of the v6 in the Alfa 75. I was recently recommended I add a hose from the back of engine heater hose junction to the front radiator...adding a t piece on each end. This should improve cooling? ideally in summer the heater should be switched to hot so the coolant flows through the heater core as well, otherwise when on cold, coolant just is less flowing  in the back of engine because the heater core is closed? I was just thinking of adding a bigger thermo fan?

How does the Alfa heater work?
Some heaters are constant flow, where the air either flow thru the heater core or past it. But some heaters shut off coolant flow thru the heater core.
Either way, do you really want to have to have the heater dumping heat into the cabin to control engine temperatures during summer??? 

Assumptions are the mother of ALL F@#K UPS!

The cooling systems suck because the radiators are so small that any build up of crap inside them compromises their ability to shed heat.
Putting a larger cooling fan on the radiator will do next to nothing, but if you could make a large shroud that mounts the fan further back and allows the fan to draw air thru all of the radiators available surface area, then I'd expect some improvement. That's how most cars do it.
Four90s once told me that the radiator for the 164 will fit a 75/90 and are available with 490x410x40 cores. That is basically the biggest, thickest core you can get that is a drop in replacement.
After that, there is some real expensive stuff you can get from the U.S. (close to $1000 by the time you pay freight).
From there, it's a custom installation using a radiator from a different car. This is what I'm doing, but it's far from straight forward.

[Alfamania]

Thanks guys. Hey alfa75gta which place did you get your headers coated at? Did you have to relocate your lambda sensor? Thanks

[shiny_car]

Along the lines of Duk, ensure your aircon condenser 'radiator' and coolant radiator are not full of bugs and crap. Optimise air flow through the radiator - rather than around the radiator - by ensuring no large air gaps around the edge. If there's gaps, add closed-cell foam rubber (eg: from Clark Rubber) sandwiched between the radiator and panel work; the larger gap along the top edge can also be filled with some rubber seal stripping (ie: like door seal rubber...from Clark Rubber) if the factory one is gone or perished.

It's also possible your old radiator - presuming it's the original - is clogged with crud. You can try a coolant flush product (drain existing coolant; fill with (tap) water and flush, and follow instructions; if there's a lot of crud, you may want to flush it again. Ultimately, it may be too blocked, and you'd benefit from a new radiator, even OE spec.

[Colin Edwards]

I'm looking at replacing the stock radiator on my 75 3.0 with a custom aluminium unit from PWR in Qld.  PWR list 2 Alfa radiators on their site.  One of these looks similar to the 75 3.0 radiator however the piping is arse about - could this be for the 2.0 engine?

Anyone out there have experience with the PWR product?  They appear to be very well manufactured.

[rowan_bris]

I have had two friends with pwr radiators which failed in the first rally they were used in.  I have one from ARE Radiators the same as those two friends have.  More expensive than pwr but they hold water!

[Colin Edwards]

Hi Rowan,
Thanks for the feedback.  Although I wont be rallying the car, I'd still like a radiator that keeps all the coolant inside it! 

I'll contact ARE Radiators.  I dont mind paying more for a quality product. 

Colin.

[MD]

Apart from the usual reasons of poor radiator heat dissipation due to failing/worn water pumps, sticking thermostats, clogged radiator tubes from minerals out of solution, there is a subtle manufacturing fault that doesn't work in hot climates like OZ.

It is simply too many fins per inch in the structure of the radiator itself. This will usually show itself when the car is in traffic and idling at the lights. The thermo fan will kick in but the temperature will /may rise above 100* causing driver stress and anger

When the same car is taken out on the open road and given a serious flogging, it displays perfect temps followed by much head scratching.

The reason for this mystery is that a dense fin pack doesn't allow enough air movement through the radiator with the fan alone.
Pushing the car hard at speed overcomes that restriction and the radiator works as designed.

If all checks out as it should you have two choices:-

1 Live with it and cane the car where ever you go (bit hard if you are in jail) or
2 Replace the core with one that has about 12 fins per inch.

Job done.