What electric fans to use on a 620?

[racerx]

the issues that I had with overheating with my 510 was not due to my fan but faulty Tstat and radiator.  I currently run 165 tstat. This is just my opinion but I don't think elect. fans are needed.

[Lockleaf]

All 3 FOMOCO fans have a resistor controller built in to them for the two speeds. Even the dual fan system runs both fans at low and high speeds.

 

All controls are mechanical. Most commonly people use a bmw dual temperature fan switch and a specific relay taken out of a Volvo to wire it all up.

 

Fans are all puller fans.

[distributorguy]

Quick way to over-complicate a simple part if you ask me.  

1 big Spal fan.  

1 big 50A relay

1 simple temp switch in the coolant.  

1 high flow Milodon style thermostat liek this:

http://www.jegs.com/webapp/wcs/stores/servlet/SearchResultsPageCmd?Ntt=high+flow+milodon+thermostat+180&requestYear=&storeId=10001&catalogId=10002&langId=-1&year=&make=&model=&submodel=&engine=&Nrpp=&No=&persistYmm=false

[J's 620]

the issues that I had with overheating with my 510 was not due to my fan but faulty Tstat and radiator.  I currently run 165 tstat. This is just my opinion but I don't think elect. fans are needed.

Likewise. I changed the leaky stock radiator to solid aluminum.

I do like to free up any hp available hence the swap. (The fan clutch was causing a jet like noise under the hood too).

[J's 620]

I think we got off topic however.

Do some research and think it through if you go electric. But keep your parts you remove so you CAN go back if needed

[Scgreen620]

I think we got off topic however.

Do some research and think it through if you go electric. But keep your parts you remove so you CAN go back if needed

 

Very clever idea but how would it devalue the car ?

 

My stock fan works fine as well keeps it nice and cool it's more for the extra hp 5? Lol

[Stoffregen Motorsports]

I agree. Values based on a car's originality get thrown out the window when you make any mods, but that doesn't mean the value goes away. It's just measured on a different scale.

 

If you make mods to a car or truck, just be sure they're done right with attention to detail.

 

But I also agree that a 510 with an L motor almost never needs an electric fan. None of the 510's I've ever owned had one, not even the 220hp street/track car I drove for years. Stock Datsun fans work just fine. If you wanted to push the envelope a bit, try a fan clutch. L20B's came stock with fan clutch water pumps. You could even take it a step further and build your own clutch fan setup using a circle track style fan clutch or one of those custom clutches that disconnect at high RPM's.

 

Every engine swap I do here in the shop is started with the intention of using a stock type engine driven fan. Only if that's not possible do I install electric fans.

 

 

 

 

 

[distributorguy]

That LS swap looks like fun...  :ninja:

[J's 620]

Very clever idea but how would it devalue the car ?

My stock fan works fine as well keeps it nice and cool it's more for the extra hp 5? Lol

It's difference of opinions I guess. I had broken things that needed replacing but I wanted to do the electric fan. Keep it stock if it works,that's always good.

[J's 620]

I've tried to post pics but I don't get it. Again no computer but I do have photo bucket.

[ducky]

Hey guys. It's been 5 years on this, and we're at a slightly different situation now. OEM fans are as good as obsolete, so converting to electric is almost a necessity at this point, which sucks. I like how one of the complaints about the fan clutch sounding like a jet is one of the reasons I really like mechanical fans.

 

Have we gotten any further along on a conversion to electric? I haven't dug through the 720 stuff yet for the Focus fans or anything, but I'm at the point where I HAVE to get a new fan solution to continue driving the truck. I'd really like to find a White electric fan so I can sort of make it look stock.

[datzenmike]

Clutch fans only sound like an F18 taking off if the bearing inside seizes and there is no slip at all. Very rare, usually the clutch friction oil leaks out and there is too much slip.

 

Any fan that is as large as possible will do. No one is going to see or care what it looks like. Some push air through the radiator from the front and some pull air from behind the radiator. Unless you cut the clutch fan off the front of the water pump there isn't much room for an electric fan behind the rad. 

 

 

Here's mine, almost finished. What's left is the inner bearing race being cut off. Don't go within 1/8" of the pulley behind it.

 

 

Definitely get an inline temperature switch for the lower radiator hose and use it to power a relay for the fan(s). On start up they draw a lot of power and thew temperature switch might not handle this for long.

 

 

This is what I did. The sensor is set for 190 ish and was from a later FWD 200sx. Just cut an inch out of bottom radiator return hose and installed. I've see manual switches on the dash but this is just asking for trouble. Anything to do will cooling and over heating cannot be left to chance. It has to be automatic and fail safe.

[ducky]

so with an electric fan, should I be upgrading the alternator? it's still a little 35 amp one as far as I can tell

[datzenmike]

The fan rarely comes on as vehicle speed pushes air through the Radiator. Idling for extended periods will, but it would take a long time to drain a battery. I didn't mean the fan draws a lot of power running it is just a heavy load on the start up. Probably not much more than the heater fan. I put a 40 amp in line fuse on the relay. This is the maximum the wire I used will carry. I didn't want to guess and keep blowing fuses.  

[Stoffregen Motorsports]

Let me say that all fans are not created equal. So many of the fans you find for sale these days are just adequate. They barely pull any CFMs and the motors are dinky which means they won't last long. I try to use SPAL fans whenever possible. They have giant motors, and the CFM ratings are better than most. Giant doesn't mean huge necessarily. Go to their website and poke around a bit to find the technical drawings of the fans which give you all the rated amps and CFM and size measurements you need. Be-cool also has good info on their site and if you talk to them, like on the phone, the tech support there is excellent.

 

Also, if you want a cleaner installation, build a fan shroud that mounts the fan, instead of using those through-the-core sip tie things. And have a bung soldered or welded into your radiator so you don't have to have one of those in-line hose coupler switches. Summit Racing, Jegs and Speedway Motors all sell DIY fan shroud kits, so if you can TIG weld, it's an easy way to go.

[Stoffregen Motorsports]

There's also a radiator company building custom aluminum radiators with the fan motor imbedded into the radiator core. Major space saving, but they are like $800. I forget the brand name.

 

Here it is - https://www.proformparts.com/slim-fit

Edited April 7, 2022 by Stoffregen Motorsports

[ducky]

19 hours ago, datzenmike said:

Clutch fans only sound like an F18 taking off if the bearing inside seizes and there is no slip at all. Very rare, usually the clutch friction oil leaks out and there is too much slip.

 

Any fan that is as large as possible will do. No one is going to see or care what it looks like. Some push air through the radiator from the front and some pull air from behind the radiator. Unless you cut the clutch fan off the front of the water pump there isn't much room for an electric fan behind the rad.

 

Here's mine, almost finished. What's left is the inner bearing race being cut off. Don't go within 1/8" of the pulley behind it.

 

 

Definitely get an inline temperature switch for the lower radiator hose and use it to power a relay for the fan(s). On start up they draw a lot of power and thew temperature switch might not handle this for long.

 

This is what I did. The sensor is set for 190 ish and was from a later FWD 200sx. Just cut an inch out of bottom radiator return hose and installed. I've see manual switches on the dash but this is just asking for trouble. Anything to do will cooling and over heating cannot be left to chance. It has to be automatic and fail safe.

 

So this is interesting. Back when I first got my truck and knew nothing about it, I bought as many replacement parts as I figured I may need. I got a water pump as one of those. The pump I got does not have a pulley as part of it. Just a spot for one to bolt up. Is there any possibility that some years had a two piece pump and clutch fan? If not, I wonder what I have...

 

For the temp switch, I know there's one in the thermostat housing. Does that not work the same? Is it ONLY a sender for the gauge?

 

24 minutes ago, Stoffregen Motorsports said:

Let me say that all fans are not created equal. So many of the fans you find for sale these days are just adequate. They barely pull any CFMs and the motors are dinky which means they won't last long. I try to use SPAL fans whenever possible. They have giant motors, and the CFM ratings are better than most. Giant doesn't mean huge necessarily. Go to their website and poke around a bit to find the technical drawings of the fans which give you all the rated amps and CFM and size measurements you need. Be-cool also has good info on their site and if you talk to them, like on the phone, the tech support there is excellent.

 

Also, if you want a cleaner installation, build a fan shroud that mounts the fan, instead of using those through-the-core sip tie things. And have a bung soldered or welded into your radiator so you don't have to have one of those in-line hose coupler switches. Summit Racing, Jegs and Speedway Motors all sell DIY fan shroud kits, so if you can TIG weld, it's an easy way to go.

 

This is a lot more good info. I'd gleaned about as much from the previous posts. Are we trying to hit around 2,000 CFM with whatever route we're taking on these conversions, or is there even a magic number?

 

As far as the custom radiator assemblies go, as much as I'd love to move that route, one of the things I want to take OFF my truck is the ugly (IMO) aluminum radiator. I really want my truck to just look as stock as possible, as any old vehicle should. I might be able to deal with it if they'd powder coat it black...

[Stoffregen Motorsports]

42 minutes ago, ducky said:

 

So this is interesting. Back when I first got my truck and knew nothing about it, I bought as many replacement parts as I figured I may need. I got a water pump as one of those. The pump I got does not have a pulley as part of it. Just a spot for one to bolt up. Is there any possibility that some years had a two piece pump and clutch fan? If not, I wonder what I have...

 

For the temp switch, I know there's one in the thermostat housing. Does that not work the same? Is it ONLY a sender for the gauge?

 

 

This is a lot more good info. I'd gleaned about as much from the previous posts. Are we trying to hit around 2,000 CFM with whatever route we're taking on these conversions, or is there even a magic number?

 

As far as the custom radiator assemblies go, as much as I'd love to move that route, one of the things I want to take OFF my truck is the ugly (IMO) aluminum radiator. I really want my truck to just look as stock as possible, as any old vehicle should. I might be able to deal with it if they'd powder coat it black...

Some thermostat housings had two threaded bungs, one of which you could use for a temp switch (a sender is different than a switch).

 

There isn't really a magic CFM number. Just find the biggest fan that fits the radiator, with enough clearance to the water pump and other accessory drive parts. Ideally, the fan would cover the entire core, but if it doesn't, build a shroud that sits a half inch (minimum) off the core, so the fan can suck the air from the entire core.

 

I agree about the look, which is why I powder coat aluminum radiators for my engine swaps. Welded aluminum radiators can be powder coated, and if you do a satin (10-30%) black, it will look nice.

 

Here are a couple pics of radiators and fans I use in my Land Cruiser LS swaps. The fans are SPAL and you can see the giant motors. The radiators come from Champion and I have them powder coated 10% black, after I weld in the bung required for LS steam port venting. I make the fan "bracket" out of 16ga steel. It's not really a shroud because the fans have it built in.

 

[Stoffregen Motorsports]

Another thing about shrouds is that you want to have passive flaps or openings in the dead areas of the shroud so air doesn't bounce back off the back of the shroud and confuse the air flow. You can see the flaps in the SPAL fan module.

 

I powder coat everything 10% black, for a bit of a modern look. It matches the plastic intake of the LS3 crate motors. But for a more vintage look, 30% gloss would be great.

 

[EDM620]

Very nice & clean setup you have there 👍