Cooling an L28

[74zzz]

Looking for a good cooling setup for my 180rwhp l28. Before I bought it the previous owner had swapped in 200b radiator with 2 12inch fans, pulled out the water pump and replaced with a electric davis craig unit. Has never stayed cool while driving and I have to leave the fans on constantly and even with them on it simply over heats sitting for any length of time. I was told by my mechanic (who has since retired) that he used the stock water pump and radiator with 2 bmw fans upfront on his race 240s but Im not sure if I remember correctly. He also stated that CD electric setups are rubbish and he would never touch them. What would you suggest as the car doesnt stay cool under 80kmh

 

cheers!

[Whittie]

I had a lot of trouble getting mine to stay cool and I took the easy option: ally radiator.

 

However, that just solves the symptoms, not the underlying cause: Not enough air through the radiator flowing at the proper speed for efficient heat transfer. You do this by getting air OUT of the engine bay and/or restricting the air opening into the radiator. However, that takes a lot of effort because the inherent problem with zeds is that the radiator opening is too big and air just piles up in front of the car and doesn't flow into or out of the engine bay. 2 options: less air in or more air out. Both require a lot of fabrication.

 

The right middle ground in my opinion is to check to make sure that the radiator is working properly. If it's fouled on the inside or the out, it will not work. First step is to get some of that radiator cleaning chemical from your local super crap auto or similar and run that through a couple times to clean out the inside of the radiator.

 

I would think that the water circulation is not the issue with your setup, so next step if the chemicals don't do the trick would be to make sure the outside of the radiator is transferring heat to the air efficiently. Make sure there are not too many bent, blocked, damaged fins.

 

your next option would be to try a different radiator. I had a 3-core holden radiator for the longest time and that with a 14" fan worked awesome, however when it started getting old and fouled it stopped working, with exactly the same symptoms you have now..

 

I now have a PWR radiator and 2x12" davies craig fans. It's an awesome setup, low power draw, low weight, but rather exxy and I wouldn't recommend it unless you really want it or can't get other options working first.

[Mr Camouflage]

I've also read that electric water pumps are rubbish.

[dat2kman]

Ditch the EWP, go back to std pump. Fit an undertray, the standard thing is fine, something to create neg air pressure in engine bay to help suck air in through rad. Cover over all holes in rad support panel cept for intake air holes, and use plumbers insulating tube foam stuff to seal rad fully to rad support panel.

Do ypu get below zero temps where you live?

No!

Dont use anti freeze ethylene glycol, use redline eater wetter, or penrite sin coolant, but thourighly flush clean entire system. Eth glycol acts as an insulator between the eater and the metal, water wetter does not. Temps are 7 to 10 deg lower in my race car, running all stock rad, water pump no fan, just a electric fan BHIND the rad.

 

You could try some ally sheet to ducy air as a funnel arrangement from behind grill to rad opening

25 lap races at eastern creek are no issue

[be-zed]

All previous comments are correct . However I run about 160 to 170 rwhp with a 3 core z radiator and a Z31 electric fan . It stays cool under racing conditions on the hottest QLD days . So I feel you may have a water leak some where as our cars are old . First establish that it is not losing water with a visual inspection of the whole motor. All hoses and if you have a heater that needs to be checked. If this is all fine do a compression test . If a cylinder is down it may be showing a leaking head gasket or cracked cylinder bore. There are many things that it could be . But if it is losing water and you can not see or fine any leaks then it is finding its way into the combustion chamber. I know that I may not be full of good news but this is all I can offer.

Best of luck   

[DatPilot]

Ive seen big improvements on other cars by adding a shroud to surround the fan, otherwise its just sucking air from the circular section instead of the whole radiator surface area...

 

But its probably easier to go back to factory.... much easier

[74zzz]

THanks for all your help!

 

I am thinking of going the orig option and some thermos......... Be zed you now have me concerned........Its not losing water and there is nothing in the coolant eg. oil! hopefully its just a matter of a shitty radiator as the fins are damaged in some areas......also it was doing the same thing when i had the head and cam done and webbers rejetted which is when the mech told me he'd go back to the orig set up.. so hopefully if there was damage to the bottom end then he would have picked it up.......Ill give it a real go over and pull everything out on the wknd

 

Thanks again guys a number of good ideas........

[be-zed]

If your not losing water it sounds like it may be just something little you may have over looked .If you use a thermostat it could be broken.

If your radiator looks a bit second hand then there is agood chance some of the vanes may be blocked . Easy way to check this is to run the engine up to temp and feel the outside of the radiator (do not put your hand near any fans they hurt) it should be hot all over . If it is not then you have found your problem . If that is the case you need to replace it . Z radiators are expensive no matter how you look at it. So if you plan to have the car for some time ,spoil your self and get something good .  If your like most of us and need to go to the Minister of finance. Tell her X dollars for a new radiator or 10 x X dollars for a new engine. Works for me