Hey,
I'm finally into final tuning stages on the 20B FD. Just wondering how many have had cooling problems with their project and whether it's been resolved or still an issue. In short, I have the typical FMIC then AC cooler then radiator sandwiched. The radiator is a 2.5 inch width with fairly good end tank size. I have fabed a cowling on it with dual fans. I also have dual oil cooler with fans. The hood is a scoot type for cooling. We have even tried the standard thermostat in normal function and also tried taking the spring and valve out for freeflow. It has the 13B water pump with plenty of rpms to it. I've also fabbed a stainless steel belly pan to for all the air up front through the radiator. Despite all this, I'm still seeing temps to 220-230 degrees. Are you guys seeing this on your machines and if not what's a normal temp and how are you getting it? Do I need wider end tanks and a half inch thicker core on the radiator (I understand that after 3 inches you lose cooling efficiency)? A different thermostat option? Switch back to the 20B water pump? Surround the block in dry ice!?!?!?!?! Any input is greatly appreciated. We're also running a fat A:F in tuning stage, so I don't think it's leaning out heat.

Aaron

 

Under what conditions do you see those temps? Though you have a belly pan, you need to make sure the air isn't going over the radiator and out your vented Scoot hood. Air will always take the path of least resistance. If the air is actually going through the radiator, you shouldn't be seeing temps that high. I don't even think the stock Cosmo runs that hot (and it has a much thinner radiator).

 

try a double flow rad with two heavy duty electric fans, like at least 1500 cfm each. buy a rad air buble kit to make sure you have all the air out.

 

When I was ordering from SPAL, they recommended 2000 cfm for a 500 hp motor. I've been getting by with 1700 cfm (due to space limitations), but I really have to avoid getting caught in stop-and-go traffic.

 

I was seeing temps of upwards of 220 degrees on a low 80 degree day running boost up to 10 pounds. The overheat with coolant spill was in the shop on computer tuning with a fan blowing into the IC inlet. The belly pan was off temporarily in both cases for further engine tinkering, so I wonder if that is part of the problem in not forcing the air through the radiator. I need to double check the CFM's on the two fans. I have good capture of the air on topside with a stainless steel cover that completely caps of the top of the radiator, AC cooler, and IC. Maybe I'm leaking air under the units or I wonder if the air is bypassing easier into the scoot hood inlet? We even put a pulley in place of the air pump to guarantee enough backride pressure on the waterpump pulley for enough spin. I've also considered Evans coolant as an anhydrous coolant option to negate the boil off effect, but am concerned that if I get too hot, that a may hot spot the rotor housing and end up with detonation risk. Keep the recommendations coming! Thanks.

Aaron

 

Vintage air sells a efan for a 68 camaro with a shroud that pulls 2200 CFM. And the price is right as well.

 

You just answered your own original question. No radiator can do it's job unless it has the proper amounts of air flow through it. Again air will always take the path of least resistance. Think about it, why would the air go through some small thin fins when it can easily and smoothly travel under the air? This is one of those situations where it would be nice to have a wind tunnel.

 

I hope you're right about the belly pan. I'll get it on Monday for another trial. Would you recommend going with the stock thermostat instead of the wide open flow we've made by taking out the spring and valve? Thanks again for all of the feed back.

Aaron

 

I don't have any overheating problems currently. Even on those 90+ days with the humidity last week. I am using a Koyo, REW water pump, 99+fans, and evans coolent.
Glad to hear you have it up and running.

Jered

 

Jered,

What kind of temps do you see with the Evans coolant? I'm going to take some aluminum sheet metal and wrap it around the undersurface of the radiator, AC cooler, and IC and up the sides to try to force the air focused even more through these units in addition to getting the belly pan back on. We're also hoping that as the tuning tigntens up, we'll have less lean time and cooler temps. Thanks again for all the responses. Hope to have the beast fully operational by end of this month.

Aaron