Looking for suggestions for engine cooling
07-01-2019, 11:07 AM
#1
Race Car
Thread Starter
Looking for suggestions for engine cooling
The 944 I converted to turbo runs REALLY WELL but runs hot. I'm looking for creative solutions.
A contributing factor might be that I angled the rad on about a 45 degree slant and I'm running a front mounted inter cooler & AC condenser.
The more boost I run the hotter it gets (duh!), so I can start using the meth-water injection kit I installed for when boost is on.
I don't need to bring temps down a lot but a bit would help.
Things I've done to help:
-AFR 11.5-12.5:1
-Running 2 oem fans simultaneously
-Ducting or Air Dam in effect
-70/30 coolant/water ratio
Things I haven't done yet that I think will help: add batwing and seal up headlights with clear covers.
Am also considering cutting off the back ends of the factory fog light pockets & extending the air dam to those backsides.
Any suggestions would help, thank you.
07-01-2019, 02:49 PM
#4
that is too high a percentage of coolant....way too high. the water is what carries the heat away and the highest percentage one would need is 63-64% of coolant to water if its -40F.
dump it and go with a 50-50 mix and your temps will drop.
wetters, like red line and royal purple stuff, decreases the surface tension of the molecules. most of the engine heat is around the exhaust port. heat transfer from the metal of the head to the liquid coolant is reduced when bubbles occur on the surface (nucleate boiling. heat a pan of water on the stove and you'll visualize it). the purpose of the wetter is to make the bubbles smaller, thus carry away more heat. note, some say the redline water wetter isn't compatible with g-11 or the blue coolant.
put a 20-21 psi (149kPa) cap on the overflow. a 100kPa isn't enough to keep it from boiling. same principle as above. small bubbles.
dump it and go with a 50-50 mix and your temps will drop.
wetters, like red line and royal purple stuff, decreases the surface tension of the molecules. most of the engine heat is around the exhaust port. heat transfer from the metal of the head to the liquid coolant is reduced when bubbles occur on the surface (nucleate boiling. heat a pan of water on the stove and you'll visualize it). the purpose of the wetter is to make the bubbles smaller, thus carry away more heat. note, some say the redline water wetter isn't compatible with g-11 or the blue coolant.
put a 20-21 psi (149kPa) cap on the overflow. a 100kPa isn't enough to keep it from boiling. same principle as above. small bubbles.
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Stevieporsche (07-02-2019)
07-01-2019, 03:30 PM
#5
that is too high a percentage of coolant....way too high. the water is what carries the heat away and the highest percentage one would need is 63-64% of coolant to water if its -40F.
dump it and go with a 50-50 mix and your temps will drop.
wetters, like red line and royal purple stuff, decreases the surface tension of the molecules. most of the engine heat is around the exhaust port. heat transfer from the metal of the head to the liquid coolant is reduced when bubbles occur on the surface (nucleate boiling. heat a pan of water on the stove and you'll visualize it). the purpose of the wetter is to make the bubbles smaller, thus carry away more heat. note, some say the redline water wetter isn't compatible with g-11 or the blue coolant.
put a 20-21 psi (149kPa) cap on the overflow. a 100kPa isn't enough to keep it from boiling. same principle as above. small bubbles.
dump it and go with a 50-50 mix and your temps will drop.
wetters, like red line and royal purple stuff, decreases the surface tension of the molecules. most of the engine heat is around the exhaust port. heat transfer from the metal of the head to the liquid coolant is reduced when bubbles occur on the surface (nucleate boiling. heat a pan of water on the stove and you'll visualize it). the purpose of the wetter is to make the bubbles smaller, thus carry away more heat. note, some say the redline water wetter isn't compatible with g-11 or the blue coolant.
put a 20-21 psi (149kPa) cap on the overflow. a 100kPa isn't enough to keep it from boiling. same principle as above. small bubbles.
Increasing the proportion of antifreeze (e.g. 30:70) does not lower the freezing point any further. On the contrary, undiluted antifreeze freezes at around –13°C and no longer dissipates sufficient engine heat at temperatures above 0°C. This would cause engine overheating
https://www.hella.com/techworld/uk/T...-coolant-2708/
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Noahs944 (07-02-2019)
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07-01-2019, 06:50 PM
#8
Rainman
Rennlist Member
Rennlist Member
Late model 944 after 85 or 86 got the 21psi cap stock.
951 rad is about 3cm taller than NA and thicker too iirc.
You shouldn't need an aux rad in a climate like Alberta.
951 rad is about 3cm taller than NA and thicker too iirc.
You shouldn't need an aux rad in a climate like Alberta.
07-01-2019, 06:59 PM
#9
I typo'ed 149kPa..i meant 140. its what's on the 968 and most mid 90 Mercedes use them. pretty sure the 951 uses the higher pressure rating also.
less is more. try 50/50 but it might get slushy at -15C. mix the junk up before you pour it in. add a few liters of water then pour the antifreeze into the water jug and shake it up. keep the process up until you have a gallon(3.78L) of each in the system. premix another gallon for the bleeding and future leakage.
imho....air can get sucked into the system as the car cools through the fittings. I pump the system up with air with the system dry. if a hose fitting leaks/bubbles after misting it with soapy water, I seal it with hylomar until it holds air pressure. BUT, it always blows the head gaskets on my kids cars...lol
less is more. try 50/50 but it might get slushy at -15C. mix the junk up before you pour it in. add a few liters of water then pour the antifreeze into the water jug and shake it up. keep the process up until you have a gallon(3.78L) of each in the system. premix another gallon for the bleeding and future leakage.
imho....air can get sucked into the system as the car cools through the fittings. I pump the system up with air with the system dry. if a hose fitting leaks/bubbles after misting it with soapy water, I seal it with hylomar until it holds air pressure. BUT, it always blows the head gaskets on my kids cars...lol
07-02-2019, 02:52 PM
#12
Get the exact psi oem radiator cap. They are different psi ratings on different years and models. Bleed the air out. Bleed the air out and Bleed the air out again. Sometimes I drive a few days and bleed air out and drive a few days and do it again. And on and on. Til needle stays on white mark. These cars just wont bleed even at angle. It is a crazy mess to do it right.
Hours and hours spent on this through the years!
Also dont always (ever) trust the needle. Haha
Hours and hours spent on this through the years!
Also dont always (ever) trust the needle. Haha
07-02-2019, 04:13 PM
#13
Race Car
Thread Starter
Jay W,
The thermostat I'm using seems okay, it worked great as a NA but I think if it opened a bit sooner would help. It came with the 944online waterpump package (full kit) I bought some time ago.
Regarding the overflow cap, correct me if I'm wrong, but if I'm not experiencing a problem with the car puking coolant, then there's no need to change psi rating, right? It was puking coolant until I made the aid dam & wired up both fans to turn on together.
The thermostat I'm using seems okay, it worked great as a NA but I think if it opened a bit sooner would help. It came with the 944online waterpump package (full kit) I bought some time ago.
Regarding the overflow cap, correct me if I'm wrong, but if I'm not experiencing a problem with the car puking coolant, then there's no need to change psi rating, right? It was puking coolant until I made the aid dam & wired up both fans to turn on together.
