• Hello Guest, welcome to the initial stages of our new platform!
    You can find some additional information about where we are in the process of migrating the board and setting up our new software here

    Thank you for being a part of our community!

Texas 240 sugmotor cooling system

This is the control module he's using in the video:

Gates FCM108
Volvo cross reference: 31338823, 31686808, 31305106
https://www.fcpeuro.com/products/volvo-cooling-fan-control-module-gates-fcm108

GAT-FCM108.jpg


Looks like this guy is used on almost all the P3 volvos. It's meant to drive two fans though.
 
Last edited:
If the 240 radiator is indeed sized big enough, I might just stick with that and mount this spal fan directly to it and call it a day. On the hottest days, the air can get above 110F, humidity well above 80%, the concrete radiating a bunch of heat, and of course I'll be blasting the a/c.
 
I just talked to a spal engineer and he recommended against trying to control a dc brushed fan with pwm. He said I would need a minimum of 15KHz pwm speed and that the reliability could suffer especially if the fan stalls at low duty cycles. He recommended a minimum 50% duty cycle to run the fan.
 
sloopy said:
Can you measure the height of the radiator? I think the most relevant measurement would be the height of the metal crimp connection for the end tanks because I believe that's what the stock 240 radiator is mounted by.
Click to expand...
I have a couple on the shelf, so I grabbed one down and measured it for you. Overall height including the ears on the bottom and the little bit of e-fan shroud over top is 19 in.

nFY9LUL.jpg
 
I wouldn't worry too much about the fan aspect of this yet.

I too am in Texas. My car is stock compression as of now, but I put a 940 efan and a cut down shroud in it. So far I just have my fan on a switch and I watch the temp guage, so I know exactly how much my fan runs! lol. Even so I only have to run the fan when I'm at a standstill. Even in 100+ degree temps. Think drive through, or long traffic light. If I'm moving I don't need to run the fan.

I will shave my head sometime in the future, as well as a cam and other stuff. Sounds like we have the same idea in mind.

I have an all metal Nissens radiator with a temp sensor waiting to go in, but I need to get it cleaned up and checked for leaks first. Then I'll have temp control of my fan for high speed and low speed will be triggered by the AC compressor.
 
What's your A/C setup? If it's the later 240/940 CCOT clutch-cycling-orifice-tube setup, you'll need to monitor the pressure sensor by the orifice tube and turn the fan on when the pressure is too high. You could do this with your ECU, if you have a spare input, or wire it into your fan controller with maybe a diode or two. From my '85 245 with '93 A/C, the over pressure switch will trip pretty easily on a hot day while sitting at a traffic light.

Edit: the factory late model 240s turn the efan on while A/C over pressure is detected, most [or all?] 740/940s disable the A/C compressor clutch while A/C over pressure is detected.
 
Last edited:
FROSTED_BVTTS said:
I have a couple on the shelf, so I grabbed one down and measured it for you. Overall height including the ears on the bottom and the little bit of e-fan shroud over top is 19 in.
Click to expand...
Thanks for the measurements! I got a rough measurement just holding the measuring tape along the radiator in the car. Looks like it's maybe 17.25 or 17.5in tall at the same spot. According to the nissens drawings, the 240 radiator core is 418mm tall and the 940 radiator is 419mm tall. Maybe the ends are bigger on the 940 radiator. My upper radiator brackets are not square with the radiator. The front edge of the mount is snug with the radiator, but there is a lot of slack in the rear. I could make a standoff block to raise the stock brackets a bit to accomodate the 940 radiator. Does the left radiator hose from the 940 work well on a 240?
 
bobxyz said:
What's your A/C setup? If it's the later 240/940 CCOT clutch-cycling-orifice-tube setup, you'll need to monitor the pressure sensor by the orifice tube and turn the fan on when the pressure is too high. You could do this with your ECU, if you have a spare input, or wire it into your fan controller with maybe a diode or two. From my '85 245 with '93 A/C, the over pressure switch will trip pretty easily on a hot day while sitting at a traffic light.

Edit: the factory late model 240s turn the efan on while A/C over pressure is detected, most [or all?] 740/940s disable the A/C compressor clutch while A/C over pressure is detected.
Click to expand...
I'm not sure. It's a 1992. My compressor is dead and I think the refrigerant has migrated to the outside. Are the pressure sensor wires run into the cabin? I have plenty of free io on my ecu.
 
GTJordan said:
Thanks for that link. I had been thinking of using a Volvo control module. Nice to see a video of it in use with the Maxx. Answers a couple questions I had.
Click to expand...
The spal engineer really stressed that trying to drive a brushed fan with pwm is very likely to be unreliable. The solid-state relays eventually fail. If the fan stalls, the solid-state relay will rapidly fail. It can also kill the fan. He warned against any duty cycle below 50% and said you would need at least 15KHz frequency. His advice was that if you want speed control, either use a dual-speed fan with relays or use a brushless fan.
 
Wizard cooling sells the spal 30207125 brushless fan (https://wizardcooling.com/i-30500771-16-brushless-fan-300-watt-flush-mount.html). They also offer a "diy" shroud kit. I'm gonna call them to see how that works. I need to decide which radiator I'm gonna use first. The volvo engineers certainly decided the 240 radiator was adequate for Texas even for the turbocharged cars. They even used it on the 740 turbo which is a heavier car. But then I have to wonder why they decided to upgrade the radiator on the 940 n/a (1992+) when the old one was doing fine. And then they gave the 940 turbo an even bigger radiator than that. I'd really like some help deciding between the 240 radiator and the 940 n/a radiator.
 
sloopy said:
Can you measure the height of the radiator? I think the most relevant measurement would be the height of the metal crimp connection for the end tanks because I believe that's what the stock 240 radiator is mounted by.
Click to expand...

core height 16.5"
core width 23.25"
core thickness 1.5"

total width 28"
total height 18"
total thickness 2.25"
(measured at the tank crimps)

so same as the other data :lol:

prepare yourself for a musty engine bay




I bet if you cut down the stiffening angle aluminum on the top of the core you could make the stock bracket height work maybe. I'd probably just stick with stock 240 radiator though. You can also see the hacked up 240 airbox, I really need a solution for that. I'm thinking p2 turbo airbox.
 
I bet it sounds good with that air box :^) Yeah if the 240 radiator is well-suited for my car and its climate, I want to keep it. I haven't noticed any issues with temperature sitting in traffic, but then again I haven't used the a/c and I think my heater core is getting some circulation even with the heater valve shut. I have noticed something strange though. There's a nice 4 mile stretch of road on my way to work where the lights are actually timed well and you don't have to stop. I usually go around 60-70 mph. I remember a few cool mornings around September when I got to the end of that stretch of road and my temps were a bit elevated. The needle was sitting a little above horizontal whereas it normally sits a little below (I have an 82C thermostat). When I came to a brief stop at the light and continued on, the fan clutch was really putting some power into the fan. I couldn't explain why it happened because I don't remember it doing that during the summer.
 
I'm gonna stick with the stock 240 radiator. Gonna get a fresh one when I build the new motor though. I'm going with the 300W brushless spal fan. Just gotta figure out what I'm doing about the shroud. If I go with a full shroud, I probably need to add the flaps. Or I could go with a narrow shroud which leaves the left side of the radiator exposed.
 
sloopy said:
I'm gonna stick with the stock 240 radiator. Gonna get a fresh one when I build the new motor though. I'm going with the 300W brushless spal fan. Just gotta figure out what I'm doing about the shroud. If I go with a full shroud, I probably need to add the flaps. Or I could go with a narrow shroud which leaves the left side of the radiator exposed.
Click to expand...
Find a 940 setup in the yard and then cut the shroud down to fit the 240 radiator, if it fits the spal fan. Then you could tweak from there. I also recall looking at mounting an electric fan in a 740 turbo fan shroud.
 
I have the short, full width 940 radiator so I could also use the 940 electric fan. It took a bit of fettling but no real problems. I hated having to remove the viscous fan/shroud to work at the front of the engine.
Following an old post from Stealthfti, I connected the heater output connector on the head to the pipe going from the thermostat housing to the radiator.
I retained function of the heater by using the pipe that went from the block (under the exhaust manifold) to the old oil cooler/heater thing on the oil filter extension. This was turned upwards and twisted a bit so that it followed the path of the original pipe and connected to the heater inlet on the bulkhead ( a brass 90 degree fitting was necessary to fit).
The effect of this was to reduce engine temps by about 20 degrees celsius. Obviously too much, so I fitted a heater control valve in the pipe. Now I can control the amount of coolling from inside the car.
This won't stop your car over heating while stationary - the electric fan still kicks in, but on a high speed run or prolonged acceleration it is very effective.
I don't know how much difference it makes but I have the "Group A" holes in the head.
I would also add that a new radiator can make a difference over a 30+ year old one.
Tim
 
You must log in or register to reply here.
Back
Top