ok, i was just wonderin.....i have a mark8 on my truck and have heard pretty good stuff about them, but dont know if half of its true or not

 

Most of the recommendations I've seen across all the sites is 2500 cfm for any small block. That's at their '0' airflow fans which puts 'actual' airflow at closer to 2k. If you are using a junk yard fan, and it's off a small block v8 vehicle, what really decides if it will work is the differences in the radiator sizing (thickness and fin spacing) between 2 vehicles.

It's my GUESS without testing anything, that if you looked at the ram radiator, and it was thicker then the lincoln, and the fin spacing across the front seemed closer together, you could have issues. I know that fan is a popular and have seen it across many forum sites as the used fan of choice, but it's never appealed to me because it seems to pull a lot of amps.

But in fairness, I don't know what my aftermarket fan of choice will pull so it may not be that much worse.

 

Just going to post another email exchange with a product rep. I'm being intentinonally naive in the exchanges because I'm curious what the response will be. Again start from the bottom to follow the initial question and back and forth. Not going to reply to this, they've answered my question.


"Mike.

They will decrease in airflow depending on the thickness and fin count of
the radiator core.

-----Original Message-----
From: hutch1973@msn.com [mailto:hutch1973@msn.com]
Sent: Thursday, June 04, 2009 3:41 PM
To: xxxxxxxx@flex-a-lite.com
Subject: Re: Comments from Website


Do you have any idea what the fans will move for airflow when attached to a
radiator? My understanding of '0' static is the fans are basically
pulling/pushing against nothing? Will they decrease in flow when installed?

--------------------------------------------------
From: xxxxx <xxxxxx@flex-a-lite.com>
Sent: Thursday, June 04, 2009 5:36 PM
To: <hutch1973@msn.com>
Subject: RE: Comments from Website

> Mike.
>
> Not really, usually everything is tested at 0 static due to all the
> different radiator configurations and such.
>
> xxxx
>
> -----Original Message-----
> From: xxxxxx[mailto:xxxxxx@flex-a-lite.com]
> Sent: Thursday, June 04, 2009 1:57 PM
> To: xxxxxx
> Subject: Fw: Comments from Website
> Importance: High
>
>
>
> ----- Original Message -----
> From: "Mike " <hutch1973@msn.com>
> To: <fxxxxxx@flex-a-lite.com>
> Sent: Wednesday, June 03, 2009 6:13 PM
> Subject: Comments from Website
>
>
>>
>> The following are form results from your web site:
>>
>> Name: Mike
>>
>> Email: hutch1973@msn.com
>>
>> Comments: Do you have any fan specs that are not at '0' static
>> pressure?
>>"

 

This is my attempt to explain what 0" S.P. is, and why a fan rating of 0" s.p. is fraudulent. I'm not attacking any individual fan manufacturer by stating this, since they all advertise these numbers. Since I've been able to track down 1 published number stating 2100 cfm is the airflow requirements on our trucks, I want to show why buying a 2100 cfm fan rated at 0" s.p. may not work. Hopefully this fully explains why the fan of choice on here that moves "3300-3500" cfm is not at all moving that amount.

First off, an explanation of resistance as related to airflow and fan performance. A simple explanation of this is to open your mouth a bit and exhale. As you are exhaling, let's assume the air you are moving is 100 cfm. Now, take your hand and push your fingers together, not tightly, but just so you can see hint of light through your fingers. Put that up against your mouth as you are exhaling. That resistance obviously affects the air flow you are pushing out, and reduces it. The 100 cfm might be reduced to 50 cfm because of the restriction/resistance of your hand. From a design standpoint we would have to assign a resitance factor to your hand, which is what a s.p. number is. In this instance, we could say your hand had a pressure drop across it of .3" s.p.

Now, at 0" s.p, or no resistance, your 'fan' (mouth) had a performance rating of 100 cfm, but at .3" s.p., you only have 50 cfm of 'fan' performance. Make sense?

So, when you see a fan rating at 0" s.p., this is basically how they obtained that airflow.



However, it obviously can't perform the same way when you install it, because the looks more like this.



What I'm going to be building is 'test chamber' similar to the first picture where I can measure a fan's performance at 0" s.p., but I will also be building it so I can install a Radiator/a.c. coil/a.t. trans cooler (from future junk yard visit) like below so I can determine what the s.p. drop of our trucks is, and determine how a fans perform at that pressure.



If the aftermarket were to advertise fans honestly, they would say a fan would move 2000 cfm@.3" s.p. Part of the reason they don't do this is because most don't know what the s.p. of the vehicle is, and most companies won't admit how poorly the fan will perform when they have a restriction.

In the industry, we have what is called a 'fan curve', which plots how much air the same fan, moving at the same rpm, will move against different s.p. readings. As the S.P. number (resistance) increases, airflow decreases. Here is a sample of a fan curve.



It's labeled wrong, but it shows airflow on the left hand column, s.p. numbers across the bottom. (static pressure numbers on bottom should have a decimal point in front of them) Ideally, you'd know your truck had a .5" s.p. resistance, and you could then chart that this fan would move 2300 cfm. Although the box would say 2700 cfm.

If you have questions, ask away. Hoping this clears things up as to why I'm doing this. I'm not trying to trash on the guys who've said 3300 to 3500 cfm is required for our trucks, because that's what the box probably said on the fan you bought, it works, so why would you think any different?

I'll test 3 new fans, and decided this a.m., should I be able to find the Lincoln Mark fan that's the 'used' fan of choice in a local scrap yard, I'll test that too. They'll all be tested in the same manor in the same 'chamber' I'm going to be building in the next couple weeks, so if my numbers are not a 'true' reflection of our in vehicle performance (I believe I won't be more then 3% off) it will still give you an idea of how each individual fan will perform.

 

Theres too many numbers in this to make sense to me lol. My with E fans so far are

1. No professional clean way to install
2. No where to mount your bottles

I will eventually work on these issues. i have a few buddies in the towing business I need to go raid some cars for fans



Hutch posted before I was done this reply so maybe it will make more sense. Sadly i doubt it haha

 

I also read on DT just a bit ago Crown vic fans work as well. At least on the newer rams.

Like I said i wanna go try and find a couple myself. maybe I'll be a good sport if I find a couple and ship them out to be tested as well if you would like.

 

Sure, once I get my chamber built, if anyone has a fan they want tested, send it up. It'll take an hour or so to do the testing once everything is built.

New fans I'm going to test are as follows:

Proform 67016 rated at 2100 cfm @ '0' s.p., ($66 at summit)
Perma-Cool 19115 Rated at 2950 cfm at '0' s.p. ($126.95 at summit)
To Be Determined Flex-a-lite.... haven't decided which one yet, they are pricey and I don't believe they will perform very well, so hoping to find a used one. (If anyone has one laying around I could borrow for a week-10 days, pm me)

Going into this, I believe the best performing fan will be the Perma-cool, based on 'picture' studies on the designs. (That's based area and rpm of a fan, but more important is pitch of the blade.) My gut feeling is the Perma-cool will perform the best against a resistance. I suspect the proform will drop a solid 400-500 cfm upon installation, and the Flex-A-Lite I'll reserve judgement on until I test it.

Looking at pics of the Lincoln fan, I suspect it is going to move a solid 2000 cfm across the radiator, and should be sufficient. I suspect the Lincoln/Crown vic fans are fairly similar. For junk yard fans, let me see what's around here locally before anyone sends anything, since the shipping costs will probably outweigh a pick n pull yard price.

 

Works for me. It will be a while before I'm ready to mess around with install ideas anyway.

 

I am also going for a single fan install, behind the factory shroud. (Won't get into the engineering end of it, but factory shroud should aid airflow.) So if the whatever you are mounting bolts up in the factory config, it'll work here too. I don't believe a dual fan set up is required for our trucks, and the manufacturers pushing them are only doing so because they can't get the right amount of airflow out of a single fan.

 

the shround thing is good to know. I was pondering options about that. If it will help maybe I will keep it