Replacing Fan DMC Part 100415 - Crossover

[OutOfTime]

Looks like I need a new fan, at least one.... I checked the crossover list and did not see any listed, am I stuck ordering from DMC @ $185 each, or has anyone found a part that crosses over?

Also need the inline temp sensor for the switch... can anyone point me in the right direction? Here is an updated pic of the project:

24062

Mark

[DMC5180]

You might consider these from DPNW.

http://www.delorean-parts.com/Merchant2/merchant.mvc?Screen=PROD&Store_Code=DPNW&Product_Code=K4001DP-A&Category_Code=9475

Better Performance and Half the electrical load. The price includes 2 FANS.

[OutOfTime]

That may be exactly what Im looking for. Thank you

[Rich]

Options are NOS/OEM as you mention from DMC, used OE fans or upgraded fans/mounts, one type of which is mentioned already.

Lots of threads/posts about cooling fans, including non-OE types, are in the forum already.

About used OE fans: Looks like there is still a pair of them listed on this forum, still available as of 26-Nov., latest post:

LINK: http://dmctalk.org/showthread.php?8617-MISC-OEM-parts.....-Cooling-Fans-ETC (http://dmctalk.org/showthread.php?8617-MISC-OEM-parts-Exhaust-Tie-Rod-Ends-Alternator-Cooling-Fans-Shroud-ETC)


If no luck there you can post up a request in the Parts Wanted section. LINK: http://dmctalk.org/forumdisplay.php?11-DeLorean-Parts (http://dmctalk.org/forumdisplay.php?11-DeLorean-Parts)

[Rich]

...Also need the inline temp sensor for the switch... can anyone point me in the right direction?:

That would be the cooling fan temp switch, popularly referred to as the Otterstat:

http://store.delorean.com/p-6348-cooling-fan-switch-otterstat.aspx

[DeLorean03]

This is extremely biased from me, but do NOT install NOS fans. Those things demand 22A - practically a house circuit. Do your electrical system a MASSIVE favor and buy Toby's fans. They cycle way more air and demand about half the current at 11A or so.

Trust me, this is an area of the car you want to alleviate any stress you can. Not trying to spend your money for you, just trying to help!

[Delorean Industries]

Delorean Performance fan upgrade with stainless shroud.
http://delorean.gostorego.com/new-products/high-flow-fan-stainless-fan-shroud-upgrade.html

[DeLorean03]

^^^ another awesome solution - my bad Josh!

[DMCMW Dave]

This is extremely biased from me, but do NOT install NOS fans. Those things demand 22A - practically a house circuit. !

It's physics. Electric motors are inherently pretty efficient. If you see fans taking half the current to run them, they are quite likely moving about half the air. This will probably start a %$&-storm but I have not seen any properly metered and loaded air flow testing that convinces me otherwise.

I think the reason people get away with this is that the OEM setup will actually cool the car quite well (to a point) with only one fan working. The low-current fans will not.

Keep in mind that most of the wiring for the fans (from the electrical compartment to the fans) is individual, only carrying half the current. The only components exposed to the full 22A are the initial foot or so of wire, the relay, and the breaker. If the wiring is maintained (i.e. not rusty or covered in mouse crap) it will carry that load fine.

I've installed most of the variants, and while they all cool the car when installed and functioning correctly I really think the factory knew what they were doing in terms of redundancy when they sized the original fan motors.

[NightFlyer]

It's physics. Electric motors are inherently pretty efficient. If you see fans taking half the current to run them, they are quite likely moving about half the air. This will probably start a %$&-storm but I have not seen any properly metered and loaded air flow testing that convinces me otherwise.

I think the reason people get away with this is that the OEM setup will actually cool the car quite well (to a point) with only one fan working. The low-current fans will not.

Keep in mind that most of the wiring for the fans (from the electrical compartment to the fans) is individual, only carrying half the current. The only components exposed to the full 22A are the initial foot or so of wire, the relay, and the breaker. If the wiring is maintained (i.e. not rusty or covered in mouse crap) it will carry that load fine.

I've installed most of the variants, and while they all cool the car when installed and functioning correctly I really think the factory knew what they were doing in terms of redundancy when they sized the original fan motors.

+1

I concur 100%.

[DeLorean03]

So, are you basically saying that if the DeLorean's stock wiring was a bigger gauge and the car had come with a stronger stock alternator, we'd be fine with those fans?

When I see my headlights dim due to cooling fans coming on, that tells me the electrical system is stressed to nearly its limit.

Just asking - honestly am curious on your answer, Dave. No poopoo storms being started here - at least by me ;).

[Bitsyncmaster]

I did do some fan testing a year or two ago. Of course we can always find accuracy faults but doing side by side testing I posted results somewhere.

[ALEXAKOS]

I have upgraded to the newer era of fans.
If you are living in a hotter climate and are thinking of driving your car at 100F / 40C hot days with the A/C giving all it has got, I'd say stick with the heavy duty NOS parts.

The newer ones simply have a slow start until they reach full RPMs and will work fine keeping your wiring cool but the car hot at a sizzling day.

I am partly with Dave's safe way.... Even though I upgraded.

If you ARE considering an upgrade then make sure that your shroud does a good job tunneling the hot air through he fans. The SS shroud offered by josh@DPI seems like a very professional replacement.

[DMCMW Dave]

When I see my headlights dim due to cooling fans coming on, that tells me the electrical system is stressed to nearly its limit.
.

Agreed, but in what way? Bad grounds, dirty connections, high-resistance breaker, bad sockets, weak alternator? Fix the electrical system, don't compromise the cooling system.

This will be an even bigger deal for you when you put that 250HP engine in your car.

Explain how you take an electric motor that is 80-90% efficient, cut the current in half, and move the same amount of air. TANSTAAFL:thumbup:.

[David T]

Agreed, but in what way? Bad grounds, dirty connections, high-resistance breaker, bad sockets, weak alternator? Fix the electrical system, don't compromise the cooling system.

This will be an even bigger deal for you when you put that 250HP engine in your car.

Explain how you take an electric motor that is 80-90% efficient, cut the current in half, and move the same amount of air. TANSTAAFL:thumbup:.

The newer type fans like Spaal have much higher magnetism magnets inside and a better fan design. They are more efficient. While it is true there is little to be gained by improving the efficiency of the motor, the fans are a lot more efficient. The duct design and shroud also has a lot to do with overall efficiency. The main reason you see the lights dim at idle when the fans kick on is because the alternator is not outputting enough at those low RPM's. Even at high RPM's you can feel it in the gas pedal when both of those fans suddenly kick on. They may "only" draw 22 amps but on starting they can draw 2 1/2 to 3 times that for a second or two. That is where a "soft start" relay like the Fanzilla is great. It also sequences them so they both don't start at the same time. Keeps the instantaneous load lower so it is much easier on the electrical system. When a large inductive load like a motor kicks on it causes all kinds of havoc to the wiring, switches, relays and power source. Almost the same thing happens when they stop. There is an inertia to the electric (inductance) and the motors now act like generators. It can get complicated and we are only discussing simple DC. Suffice it to say the general practice is to oversize things to deal with these issues and the wiring system when it was NEW was borderline. Good thing we rarely need the rear window defroster!

[DMCMW Dave]

The newer type fans like Spaal have much higher magnetism magnets inside and a better fan design. They are more efficient. While it is true there is little to be gained by improving the efficiency of the motor, the fans are a lot more efficient. The duct design and shroud also has a lot to do with overall efficiency. !

Numbers please?

[Bitsyncmaster]

Agreed, but in what way? Bad grounds, dirty connections, high-resistance breaker, bad sockets, weak alternator? Fix the electrical system, don't compromise the cooling system.

This will be an even bigger deal for you when you put that 250HP engine in your car.

Explain how you take an electric motor that is 80-90% efficient, cut the current in half, and move the same amount of air. TANSTAAFL:thumbup:.

By the way, get rid of that Breaker and it's 6 foot of wire if you have fused fan fail jumpers. Replace it with a 4 inch 12 AWG jumper (two 12 AWG relay pins required).

There are electric motors which give more efficiency but priced way to high for what you gain. Cobalt magnets are used for efficiency for model air plane motors.

[Bikercmbc]

Numbers please?

This is what I found on DMC NW site, I purchased these just for low current and higher volume of air:

These quality high performance fans utilize the latest state-of-the-art electric motors, each delivering 1248 cubic feet per minute (CFM) of air flow per the manufacturers data sheet while demanding only 7.0 amps maximum power each at full motor load. For comparison, the stock fans taken out of our personal car were measured at a total CFM of 1100 for BOTH fans

[DMCMW Dave]

These quality high performance fans utilize the latest state-of-the-art electric motors, each delivering 1248 cubic feet per minute (CFM) of air flow per the manufacturers data sheet while demanding only 7.0 amps maximum power each at full motor load. For comparison, the stock fans taken out of our personal car were measured at a total CFM of 1100 for BOTH fans

Still not necessarily measured under the same circumstances. Ducted or free space? Loaded with a radiator/condenser or open air? At a specific voltage? What does "state-of-the-art" mean? Brushless? Cobalt magnets? Made of unobtanium? etc.? Marketing poop.

If both were measured, at the same time by the same person under the same installation standards using the same method of measurement, (i.e. not comparing a manufacturer's data sheet to an undefined method of measurement) we'd have something. Engineering data.

I've installed those fans several times and, while definitely a high-quality product, there is no way on earth, compared to stock, that they are moving twice the air through the radiator/condenser, much less doing it at 2/3 the electrical current load.

IMO the best one could hope for is an increase in motor and fan efficiency over time of maybe 20%. That would be a huge efficiency gain in electric motor design, especially at 1/4 the cost. This would drop the current from 11 amps to just under 9 amps at the same air flow. That would be a reasonable claim. I just have never seen it proven.

[DMC5180]

TANSTAAFL:thumbup:.

Geez, and I thought Aviation Acronyms were confusing. :hmm:


I wonder what the running RPM is for the stock motors vs. Spal high performance motors AKA the DPNW setup?

I also have to agree to certain extent, that One OEM fan will be sufficient for operating under light load conditions. I ran my car a for couple years on one fan without realizing it back when I first acquired it. The Fan blade for the RH had separated from the motor and was just lying in the shroud. The motor worked though. I also did not have an operating A/C the first 5 years I owned it. It helps living in a more northern climate. The cooling demand was low because of it.

[Bitsyncmaster]

There are more in my photos page but the first 8 shown here.

[Bikercmbc]

Looks like I need a new fan, at least one.... I checked the crossover list and did not see any listed, am I stuck ordering from DMC @ $185 each, or has anyone found a part that crosses over?

Also need the inline temp sensor for the switch... can anyone point me in the right direction? Here is an updated pic of the project:

24062

Mark

*** OutOfTime if you are interested in a good used fan, PM me I have a couple of sets laying around in my stock pile of parts ***

[DMCMW Dave]

There are more in my photos page but the first 8 shown here.

Looks like the most methodical test I've seen published, I'm trying to digest this and have some questions:

It appears that you are measuring the air velocity at various points behind the fan. Any idea how this would relate to overall air volume, i.e. in cubic feet of air per minute (CFM) as the fan makers tend to specify things? It seems to me that the trick is getting the air to flow uniformly through a measured opening (a square foot would be handy!) and then measuring the speed. All without restricting the flow and impacting the measurements. As you noted it is hard to get an accurate measurement as air flow through the fan blade is not uniform right at the blade.

Why do the numbers look so very different from test to test, i.e. at a constant 13 volts the air movement (speed?) varies from 2150 to 710 on the OEM fans all with the radiator in play, depending on which report you look at.

If nothing else this shows how hard it is to do comparison tests on things like this, and in turn verify manufacturers' claims.

I'm more impressed with the aftermarket fans than I expected to be. Someday I'd really like to repeat this test using the OEM fans (which at this point are pretty old old), the current Bosch fans that we use, and the various others that are out there. Would be a bit of a pain to set up.

[refugeefromcalif]

I've never had a problem the the OEM fans in my D.
Here in Alabama it gets Hot in the summer and A/C is always on when I'm driving. They do a Great job at keeping the radiator temps cool.
The only problem that I've had is having to replace the 40 amp. breaker every 4-6 months.
I have to go back through my wiring and see what's causing the problem.

George

[Bitsyncmaster]

Looks like the most methodical test I've seen published, I'm trying to digest this and have some questions:

It appears that you are measuring the air velocity at various points behind the fan. Any idea how this would relate to overall air volume, i.e. in cubic feet of air per minute (CFM) as the fan makers tend to specify things? It seems to me that the trick is getting the air to flow uniformly through a measured opening (a square foot would be handy!) and then measuring the speed. All without restricting the flow and impacting the measurements. As you noted it is hard to get an accurate measurement as air flow through the fan blade is not uniform right at the blade.

Why do the numbers look so very different from test to test, i.e. at a constant 13 volts the air movement (speed?) varies from 2150 to 710 on the OEM fans all with the radiator in play, depending on which report you look at.

If nothing else this shows how hard it is to do comparison tests on things like this, and in turn verify manufacturers' claims.

I'm more impressed with the aftermarket fans than I expected to be. Someday I'd really like to repeat this test using the OEM fans (which at this point are pretty old old), the current Bosch fans that we use, and the various others that are out there. Would be a bit of a pain to set up.

Some of those early numbers were done with a cheap blade type anemometer. I attached a photo of the nice hot wire unit I bought (back when I had money to spend). Willing to sell this unit to anyone willing to do more fan testing (it's brand new only used for those fan tests). They use these for AC work in homes and business.

To get CFM you just take the blade area (remove the motor area) times the feet/min flow.

[Rich]

I've never had a problem the the OEM fans in my D......They do a Great job at keeping the radiator temps cool.
The only problem that I've had is having to replace the 40 amp. breaker every 4-6 months....

Nor have we ever had problems with the OEM fans doing the job on our D here in California.

In reference to the earlier postings the headlights on our car (with 90A Motorola alt.) do not dim at idle when the fans kick in. Evidence against the notion that "they all do that". Dave's list of things to check is a good one. Post #14 here.

For those 40A breaker failures quoted above are you running a Fanzilla or a Joe Cool fan sequencer module? Installing one will likely keep your breaker happy. And Dave's list may also be useful for this symptom as well.

[DeLorean03]

Agreed, but in what way? Bad grounds, dirty connections, high-resistance breaker, bad sockets, weak alternator? Fix the electrical system, don't compromise the cooling system.

This will be an even bigger deal for you when you put that 250HP engine in your car.

Explain how you take an electric motor that is 80-90% efficient, cut the current in half, and move the same amount of air. TANSTAAFL:thumbup:.

No criticisms there. Thankfully when Casey and I met, we did both the electrical system and the cooling system ;). After all, I started doing things like installing Fuse #18A (fuel pump dedicated circuit) for a reason ;).

As far as efficiency, and this is more of a tongue-in-cheek comment, Dave, sometimes as time goes along things get smaller but more efficient. Take computers or cell phones for example ...... ;).