The Mark's Cooling Fan Mods

But you are not having temp issues from running at max power levels, you are having them from just cruising around, no? To me it seems it should not matter how much HP that thing is making cause it aint making it at 45 MPH in 4th gear.

You have a larger then stock radiator, no? With the multiple fans you should have more CFM then a stock Mark too. There is NO reason for the car to be running as hot as it is unless:

1. Severe air flow restriction. Prolly not though because of the fans total CFM.
2. Too much timing at low loads.
3. Running lean. What is your A/F at normal cruise?
4. Water pump is not functioning properly. (Cobra pumps designed for higher RPM plus they have a smaller pulley so with a Mark pulley its spining way too slow)
5. Cracked block/heads/gasket. Not likely cause you say it does not spit out any coolant.


The car is just too damn hot and I hate to see such a fine ass ride having issues like this. It has to be something simple. If my old Mark with a completly stock cooling system and underdrive crank also pushing a non-intercooled positive displacement supercharger can run 208* all day long in traffic then thats why I keep thinking water pump.
 
I'd also go for #4 but that Evan's would still come out regardless. Heard a lot of bad stories about that stuff when the engine has to be opened up for any reason. It can be messy and hard to deal with. I really would like to see what that water pump looks like right now with the Evan's in there.
 
He was talking earlier about the radiator upgrade, and that the multiple coolers are aligned back to back, which in my eyes is reducing the amount of cool air coming in. I t would seem to me that a draw fan is only rated to a certain cfm, but if it is pulling from the nose and having to pull that air thru most likely different coolers, the effectiveness of that fan has to decrease. I would say at least a 3 roll radiator an maybe a bigger double cfm fan set or a larger single, this is if he is using electric fans. I doubt the waterpump is the issue and a cracked block or head, I think that would of been first check point.
 
As I said, just giving things that would cause the issue. Not that they ARE causing the issue.

My understanding was that the three fans he has are the strongest available.
 
Here is where I am at. The car heats up the most when not moving. That is when I see the highest temps, usually parking the car in the garage after driving it. When I am moving, the temp will cool and will recover some after sitting in traffic, but not completely back to 200 or so.

The car ran fine with the green coolant. The temp would climb when I turned the a/c on, and it was upper 80's outside, and I was in stop and go type traffic. Turn the a/c off, and the temp would eventually recover back to the middle of the gauge.

Here is the updated test results:

Initial test drive - 50/50 mix of water/green coolant with max a/c on - 160* t-stat, push fans turn on when a/c turns on

54* outside temp: ECT - 194*

After swap to Evans NPG+ Coolant, same conditions with max a/c on - 160* t-stat, push fans turn on when a/c turns on.

52* outside temp: ECT - 230*


Evans coolant, with t-stat removed, and turn push fans on with pull fan. a/c was off during test.

80* outside temp: ECT - 250*


The builder/tuner says more air is needed to move across the radiator.

Evans says to use a bigger radiator for higher hp motors.

I can be back to normal operating temps with a coolant flush back to green. Just would have to be careful not to run the a/c on the real hot days until I get the right combination figured out.
 
What kind of cooling fans or fan are you running, rate wise? And many different coolers for other drive-line parts are you stacking in front of the radiator that could possibly be limiting the amount of fresh air to the radiator? I would definitely consider a 3 row or better radiator to help with cooling naturally, and if you are multi stacked with other coolers in front of the radiator, it may be wise to relocate the others elsewhere, and have you looked into electric flow water pumps too? Just some ideas throwing out there. The stacking of coolers adn or 2 row radiator may explain the parked or stopped in drive temp elevations. Because you are only drawing what the fan can pull, but if it is pulling thru multiple cooloers before it actually reaches the radiator, then it is used air by that time which equates to higher temp air in the radiator.
 
Back in the day, you could turn the dizzy a bit to pick up timing and HP but almost always would cause the engine to run hotter as well.

Load is increased over stock with a built motor with a tune, regardless of speed. I have a flip chip and ran different tunes on my '93 and I would always notice higher highway temps with the "hotter" tune(s). I would simply switch back to "stock" tune for extended street driving in warm weather.

Is the transmission cooler separated from the stock cooler or in series? On my car I eventually ran the after-market cooler by itself and noticed a significant drop in normal engine temperature with the same transmission temps.

Many cars run 210 plus temps from the factory.

I think Evans is correct that more radiator is needed. I think Aric is correct that more airflow is needed. I also will go out on a limb and say you could do better in a waterpump. But with the t-stat removed you could also be pumping coolant too fast through the radiator before it has a chance to be cooled. Been there, done that.
 
The fans combined are around the same cfm as a Mark fan - around 4k cfm.

There are 3 coolers in front of the radiator - condenser, intercooler, and trans cooler. IAT is usually 10* above ambient. Not bad since the intercooler is sandwiched between the trans cooler and the condenser.

The radiator is for a manual trans Cobra, so there are no side tanks on it. Evans recommends to remove the t-stat on higher hp motors. That is the reason why it was removed.

I think the key here is to increase air flow through the radiator first, because just putting a bigger radiator in there with the same air flow it has now does not seem like a solution. I think the first step is to move the trans cooler, because that would be the easiest one to move.
 
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