Track Heat Management

[Petah78]

Originally Posted by ZDan

Are pressures more stable, or just higher in general due to lower temp? My understanding (I haven't logged pressure so I'm going on info from others here) is that the pressure becomes unstable at high rpm due to cavitation rather than from temperature...

I know lower oil temp would equal higher oil pressure because of oil viscosity, but wouldn't the effects of cavitation be less severe because of the lower oil temp?

[NoHaveMSG]

Originally Posted by Petah78

I know lower oil temp would equal higher oil pressure because of oil viscosity, but wouldn't the effects of cavitation be less severe because of the lower oil temp?

That was my initial thought but I was getting more cavitation at higher temps before.

[Petah78]

Originally Posted by NoHaveMSG

That was my initial thought but I was getting more cavitation at higher temps before.

Right. So lower oil temps in theory will produce higher pressure because of

1. Oil viscosity
2. Lower effect of cavitation

Though the question remains: Is low 40's PSI at redline enough for the FA20?

I agree that higher oil pressure/lower oil temps = better safety margin but I am still on the fence about adding an oil cooler. Broken oil lines leading to lost engines are not uncommon. Longer warm up times is also a concern for a street car with the potential of overcooling. For the average user that does maybe 4-5 hours of actual track driving per season, I don't know if it's worth the potential trade off.

[NoHaveMSG]

Originally Posted by Petah78

Right. So lower oil temps in theory will produce higher pressure because of

1. Oil viscosity
2. Lower effect of cavitation

Though the question remains: Is low 40's PSI at redline enough for the FA20?

I agree that higher oil pressure/lower oil temps = better safety margin but I am still on the fence about adding an oil cooler. Broken oil lines leading to lost engines are not uncommon. Longer warm up times is also a concern for a street car with the potential of overcooling. For the average user that does maybe 4-5 hours of actual track driving per season, I don't know if it's worth the potential trade off.

I'm 95k miles NA and no rod knock yet (knock on wood). Running 0-20w 300V 95% of the time with a 613 core. 7500 mile oil change interval. I did blow a spare engine that I ran for about a thousand miles from a rocker arm kicking out, but most of the miles are on my original engine.

[Icecreamtruk]

Does the overflow tank fills up more than usual (or even shoots coolant out the top)? I had a similar setup to you and the only thing that made it overheat was the head gasket that went bad and it was pushing compression and heat into the water. Test your rad water for carbon in it, its the easiest way to tell you you are pushing stuff from the cylinders into the coolant (and hence, a bad head gastket).

[Petah78]

Originally Posted by NoHaveMSG

I'm 95k miles NA and no rod knock yet (knock on wood). Running 0-20w 300V 95% of the time with a 613 core. 7500 mile oil change interval. I did blow a spare engine that I ran for about a thousand miles from a rocker arm kicking out, but most of the miles are on my original engine.

That is 95k with an oil cooler and track abuse, right?

[NoHaveMSG]

Originally Posted by Petah78

That is 95k with an oil cooler and track abuse, right?

About 60K when I started doing some autoX then track day. Probably 45K with oil cooler.

[rice_classic]

I'm not behind cavitation (yet).

I think obvious culprits needs to be looked at like head gasket or thermostat.

I'm racing with 6 degrees advanced over stock on 100 oct (doesn't burn as cool as E85), in a draft on a 90 degree day on an OEM radiator and temps aren't a concern.

Just pulled my data from Portland: 90 degree day, lots of time drafting, 30 minute sprint race. Never saw a water temp above 210.2F on the hottest lap. Oil peaked at 244.4 on that lap as well with center mounted greddy oil cooler. This was with 0w-40 oil.

[NoHaveMSG]

Originally Posted by rice_classic

I'm not behind cavitation (yet).

I think obvious culprits needs to be looked at like head gasket or thermostat.

I'm racing with 6 degrees advanced over stock on 100 oct (doesn't burn as cool as E85), in a draft on a 90 degree day on an OEM radiator and temps aren't a concern.

Just pulled my data from Portland: 90 degree day, lots of time drafting, 30 minute sprint race. Never saw a water temp above 210.2F on the hottest lap. Oil peaked at 244.4 on that lap as well with center mounted greddy oil cooler. This was with 0w-40 oil.

I am pretty sure it is thermostat at this point. I don't know how I glossed that over. Coolant has no oil in it, plugs are clean.

[jflogerzi]

With all that cooling at least it's an easy fix. But it makes sense

Sent from my GM1915 using Tapatalk

[Ultramaroon]

Originally Posted by NoHaveMSG

I am pretty sure it is thermostat at this point. I don't know how I glossed that over. Coolant has no oil in it, plugs are clean.

I jumped right into the mod pit with you.

[Icecreamtruk]

Also kind of unrelated to it but the last post by @rice_classic made me think about it. I have an LS1 under the hood now and kept a stock sized koyo rad. No fans, no shrouds, only ducted in the front (bumper to rad) and vents in the hood. Water temp is at a solid 196F all the time, regardless of outside temp so far. If pushing 3 times the power is still not enough to overload a kind of stock sized radiator, I really doubt any kind of NA power can actually push too much heat into it unless something is wrong (water pump, thermostat stuck closed or head gasket).

[Ultramaroon]

Stock radiator is amazingly effective. Cooling system design and layout are top notch.

[NoHaveMSG]

Originally Posted by Icecreamtruk

Also kind of unrelated to it but the last post by @rice_classic made me think about it. I have an LS1 under the hood now and kept a stock sized koyo rad. No fans, no shrouds, only ducted in the front (bumper to rad) and vents in the hood. Water temp is at a solid 196F all the time, regardless of outside temp so far. If pushing 3 times the power is still not enough to overload a kind of stock sized radiator, I really doubt any kind of NA power can actually push too much heat into it unless something is wrong (water pump, thermostat stuck closed or head gasket).

Yeah, my monkey brain was stuck in "what else" mode and not "what if" mode. I know boosted guys running stock cooling setups with no issues so it kind of left me going WTF and figured I would ask the hive mind. Took the car out for a drive. Still no oil in the coolant or vise versa. On the street water temps sit in the 160's even on a 90F ambient day as long as I am moving. Pretty sure now the thermostat is not opening up all the way when hot. It should be here this week.