Cooling

[toyman]

I've been having cooling issues since installing the KB when in traffic with high ambient air temperatures and under high load conditions (temps in the 220*- 230+ range). As I'm running a cobra crank pulley (5.85") vs the stock pulley (6.875") it occurs to me that perhaps I should install an overdrive pulley on the water pump. Has this worked for anyone else who had cooling issues? The only other solution I can think of is to change to a higher flowing water pump but it seems to me that I'll still have a problem with the smaller than stock crank pulley. I've turned off the low speed rad fan and have the fan running on high speed from 180*. The T-stat is 160*. At highway speeds and light throttle the temps are in an acceptable 195* - 205* range.

Or, is the problem in the tune? AFR at idle and light throttle between 13.8 - 14.7 and WOT at 11.6 in the higher rpm range. Good mpg at cruise (20+ mpg)but sucks a lot of fuel around town (10 mpg).

 

[HISSIN50]

Is your radiator pretty new and/or in good shape? Because it runs hot while at speed (with some RPM), I'm not sure that getting your water pump spinning faster will help (it might at idle, but since the issue occurs while not at idle..........).

There are enough restrictions in the system that more coolant flow isn't always helpful anyhow. My test for this is to simply let a car warm up good and hot at idle. Then hold the throttle at about 1K RPM and see if the temps drop. Then you have to decide if they dropped because of the increase in coolant flow or the extra power going to the cooling fan.

Are you sure your stat opens all the way? Is it a balanced stat of some sort (balanced stats open a bit more than cheaper ones).

Otherwise, going back to the radiator, do you have a good seal around it (so the fan shroud, rad, condenser, etc are all all relatively sealed between one another)? I bet you have a fat trans cooler in front of your condenser, which isn't helping any. The stock coils have rubber and plastic side slats to seal things up (so the fan pulls air through all the coils instead of around them).

If necessary, I'd seal things up around the rad (I use thick weatherstripping with adhesive on one side) and blow out the coils with compressed air if you haven't.

I find that a lot of little tiny crap adds up on cooling systems, but that it's hard to find one thing that makes a gonga difference if the system is in good shape already.

 

[toyman]

I'll address each of the points.

Is your radiator pretty new and/or in good shape?

New Be Cool Aluminum rad last year to address very high temps with the OEM unit.

Because it runs hot while at speed (with some RPM), I'm not sure that getting your water pump spinning faster will help (it might at idle, but since the issue occurs while not at idle..........).

If you mean 195* - 205* being hot at speed then, yes. However, I am specifically referring to temp readings when the ambient air temps are in the 90* range. Otherwise temps are in the 190* range at speed and light throttle. Always climbs quickly if I put my foot in it. That's why I was thinking the tune may be a factor.

There are enough restrictions in the system that more coolant flow isn't always helpful anyhow. My test for this is to simply let a car warm up good and hot at idle. Then hold the throttle at about 1K RPM and see if the temps drop. Then you have to decide if they dropped because of the increase in coolant flow or the extra power going to the cooling fan.

My idle is set at 850 and while I haven't just sat in the car and idled at 1000 rpm to see if it drops I'm not sure what the outcome will be. I did hook up a battery charger and with KOEO fan on high it cooled the engine from 240* to 190* (hood open) in about 10 minutes.

Are you sure your stat opens all the way? Is it a balanced stat of some sort (balanced stats open a bit more than cheaper ones).

I haven't tested the stat to confirm that it's opening all the way. I don't recall what was installed but the shop that did the engine rebuild would have put in a quality piece, that I'm certain of. Of course that doesn't mean that the stat is working as expected. That can be changed again if needed.

Otherwise, going back to the radiator, do you have a good seal around it (so the fan shroud, rad, condenser, etc are all all relatively sealed between one another)?

I'll check. Mounting will be as if stock without any attempt to restrict air from coming in from the sides. While I haven't measured the air temp coming through the rad I can tell you that you can't keep your hand in the flow long as it is hot.

I bet you have a fat trans cooler in front of your condenser, which isn't helping any. The stock coils have rubber and plastic side slats to seal things up (so the fan pulls air through all the coils instead of around them).

There is a tranny cooler. And if it's significant the tranny temp runs between 160* - 170* with not a lot of variation.

If necessary, I'd seal things up around the rad (I use thick weatherstripping with adhesive on one side) and blow out the coils with compressed air if you haven't.

I'll try blowing out the coils.

I find that a lot of little tiny crap adds up on cooling systems, but that it's hard to find one thing that makes a gonga difference if the system is in good shape already.

As noted there is always lots of little stuff caught in the fins.