Over the next few months I'll be installing a new radiator into my 740, when I install the new radiator should I look into installing an e-fan?

If so, what would be a good fan to use? I hope to get better mpg and better cooling around town. The car has a puller e-fan for the non functioning AC if that helps.

 

in 1992, volvo switched the 740/940 turbos from a mechanical fan plus aux e-fan, to a full time 2-speed e-fan with no mechanical fan. along with this switch, they went to a bigger radiator, different intercooler air plumbing, etc.

I doubt a fan would affect your MPG unless your car is overheating. you don't WANT it to run too cool, that will lower your MPG.

 

Thats interesting, would you say its a worthwhile upgrade or should I just throw in a new radiator and leave the fan be?

As it is the cooling works pretty good even in hot temp, assuming the Yazaki cluster is accurate. Did Yazaki ever use compensate-boards?

 

the new/larger radiator requires different sheet metal

1991 Turbo, with mechanical fan...


1992 Turbo with electric fan...

 

Thank you for the pics

If I had a spare later model I'd do this, but I think I'll keep it stock and just freshen up whats there.

Do I remove the radiator from the top or the bottom?

 

I believe it comes out the top, after removing the bars that clamp it down on each side. of course, first you have to disconnect the hoses, as well as the transmission cooler lines, if you have those.

 

Hi, I am about to undertake this swap and wanted to learn a bit more about this (I noticed you can't receive PM's). I have the 940 radiator, intercooler, trans lines and e-fan and electrical. Anything else I might need? Anything you I can learn for your experience would be great!

 

i never did this swap, just had both kinds at different times.

I note the turbo-to-intercooler air hoses are different on the two.

 

I would worry more about the alternator. Did the conversion for my 240 with the original radiator, when all the lights, radio and fan on, the alternator barely make it 13V and I was only using half speed. Did cool down the engine efficiently once its on, you will want to match the temp switch to your thermostat, otherwise fan will not off or on too late. But my main issue was the power supply, swap to a lower power LED headlight didn't save it so I gave up, ends up with a small push fan (Almost never used) at the front and a set of switch/relay to turn that manually.

Engine did quiet down and easier to rev tho, but nothing obvious. If I have a better alternator I would keep the e-fan to free the engine bit, but mechanical fan works great even during heavy pulls.

 

What amperage alternator do you have? Maybe bring that mine is a 740 it can handle more load?

 

standard volvo alternators on these cars as of the mid 80s were at least 100 amp, which is like 1300-1400 watts. If you had low voltage under load, I suspect bad wiring or grounds, or tired/worn regulator brushes.

 

couldn't see what's on my 240(feels like 80amp). If I remember it correctly 740 came with something different like 100 or something, should be better, but if it uses the Bosch it won't feel like what it is rated for(slightly). I pulled mine from a 940(couldn't really remember), shouldn't be that power consuming but did gave some serious load to my alternator, you might want to keep an eye on your voltage(especially when the fan just kicks in) even you got a higher amp alternator. Put a fuse in the line before you actually drive it.

 

one thing, no alternator can generate its rated amperage at idle... easy to see, turn everything on, engine idling at 700-ish RPM, then gently rev it up and note around 1200 RPM or so the headlights get a bit brighter/whiter.

even if the voltage drops to 13V at idle under heavy load, thats still enough to keep the battery from discharging, and when you rev the engine, you should see 13.6-14.2V which will fully charge the battery

 

A mechanical fan consumes energy (and fuel) all of the time, whether or not it's needed.
An electical fan consumes energy only it's needed.
It's a small effect, less than 1 mi/gal, but it's genuine.

 

ya, with fan half speed I can get above 13V when rev, full speed will never. I tested it during idle on purpose as the fan will likely to be on a lot when im stuck in traffic. But after all, that's still some serious load for my little alternator tho, didn't really want to beat it too hard.

 

I doubt that fan motor is over 100 watts on high. if its dropping your voltage that deeply, your alternator wiring or ground is marginal.