tsegnit
Contributor
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Loc: NY
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07-18-12 04:21 AM - Post#2249353
...400 sbc, mechanical fan as of now. Thinking of electric fan(s). Is it better to have electric fan(s) pushing or pulling? (if pushing is best, ditch or keep the mechanical fan???).
Thanks,
T
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Super
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Posts: 1
Reg: 01-29-12
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07-18-12 07:22 AM - Post#2249403
In response to tsegnit
I've always been told that pulling is better than pushing but I don't have a detailed explanation why.
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YOUNG57
Contributor
Posts: 479
Loc: Franklin TN
Reg: 12-06-10
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07-18-12 08:41 AM - Post#2249449
In response to Super
I think it has to do with air bouncing off the radiator rather than going through it. With a pusher fan you can get some deflected air bouncing off the radiator and not going through it whereas all the air to a puller fan has to come through the radiator meaning more air through the radiator with equivalent fans, I think!!!.
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vet65te
Senior Member
Posts: 396
Loc: NorCal Now, Prescott AZ S...
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07-18-12 09:09 AM - Post#2249467
In response to YOUNG57
Young57 nailed it. I wanted to add an electric fan in the pusher position because I liked having the clutch fan setup plus shroud on the inside. I heard that it would be less efficient having it as a pusher but still figured it was worth it.
Check out the pic. That's a Derale 'S-Blade' style fan and in that position, it's only 5/8-inch off the face of the radiator. When I turned it on, I was very surprised to find very little air being directed through the core. Most of the air, easily 80% or more) was deflecting out the open sides between the fan and core. I believe that's due to the shape of the curved blades which sends the air radially outward and not at a right angle away from the fan face. I could probably help that issue by either trying a straight blade fan (but they are known to be noisier) or attach this fan right to the core but I prefer to not do it that way.
Mike T.
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Tri5man
Frequent Contributor
Posts: 1538
Loc: Inlet Beach, FL
Reg: 06-26-07
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07-18-12 11:57 AM - Post#2249543
In response to vet65te
An installation of a fan shroud will solve your problem of air not being directed through the radiator. Puller fans are way more efficient then pullers. Pushers actually restrict airflow into the radiator. If you do add a puller, make sure its a Spal.
They will flat out blow your hat off. They don't use them on Ferrari's for nothing.
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vet65te
Senior Member
Posts: 396
Loc: NorCal Now, Prescott AZ S...
Reg: 01-04-05
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07-18-12 12:45 PM - Post#2249555
In response to Tri5man
Any electric fan near the core is going to impede air flow whether it's out front or behind to a certain degree since any cooling air stream has to pass completely through the core to do any good. Unless my pusher fan is making direct contact with the core face, this S-bladed unit will want to sling the air out at an angle and it will deflect off to the sides of the core. THere isn't much of a 'skirt' around the fan assembly to attach an extension to take up that 5/8 inch gap so for now, it's off the car.
Mike T.
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fuzzyff
Forum Newbie
Posts: 45
Loc: CA
Reg: 06-13-12
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07-18-12 04:27 PM - Post#2249626
In response to tsegnit
The pushers have a great supply of air to ingest, but is pushing against a radiator body that severly restricts it's mightiest efforts; the puller has a large radiator that it must "suck" hot air through, but can then blow freely towards the engine. There is no obvious large advantage, either way, engineering wise. Advantages certainly will influence one person to go "pusher", or another man a "puller", based upon certain mechanical restrictions that are peculiar to his personal vehicle. Then, there's the fact that certain individuals will be making their decision with "fan noise" in the equation. I suggest that the mechanical fan first be maximized with regard to efficiency, get a 6-blade 19" high volume Flexalite fan, for instance. Then, base the decision for the electric fan by the clearances available on the particular vehicle.(I'd prefer the electric fan to fit "hidden" behind the radiator, but that depends on "space available".)By the way, speaking about the photo above, look how "small" that fan diameter is, leaving a substantial area "unhelped" by the fan. Better to get a maximum coverage fan. ...400 sbc, mechanical fan as of now. Thinking of electric fan(s). Is it better to have electric fan(s) pushing or pulling? (if pushing is best, ditch or keep the mechanical fan???).
Thanks,
T
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fuzzyff
Forum Newbie
Posts: 45
Loc: CA
Reg: 06-13-12
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07-18-12 04:34 PM - Post#2249628
In response to fuzzyff
oh, and there's a good reason that my old 58 Nomad (4-door, obviously) had a huge, max. coverage Fan/Radiator Shroud.....it Worked. It made the flow of air through the radiator Cool that 283 w/TurboGlide Better than without it. Simple. Basic.
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vet65te
Senior Member
Posts: 396
Loc: NorCal Now, Prescott AZ S...
Reg: 01-04-05
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07-18-12 04:44 PM - Post#2249632
In response to fuzzyff
I prefer to keep the fan clutch unit on the water pump snout and use the electric fan as a backup for extreme situations so in my case, I don't need the electric fan to handle all the cooling needs. For those who are using an electric fan for all their cooling, there are more efficient setups available such as the SPAL fans and as recently mentioned in Car Craft (or Pop Hot Rodding), the use of the mid 90's Lincoln Mark VII and Ford Taurus fans that are built with a good sized shroud. Not a simple instalation but one to consider if you've got serious cooling needs. Those fans do draw some serious amps so an alternator upgrade is warranted.
Mike T.
Edited by vet65te on 07-18-12 04:46 PM. Reason for edit: No reason given.
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fuzzyff
Forum Newbie
Posts: 45
Loc: CA
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07-18-12 07:18 PM - Post#2249693
In response to vet65te
hmmm, using the electric fan as a "backup" is exactly like putting a big, dead, Blob in front of the radiator, when driving the car. Wouldn't work for me, neighbor. Looks like it works for you, and that's so nice. I prefer to keep the fan clutch unit on the water pump snout and use the electric fan as a backup for extreme situations so in my case, I don't need the electric fan to handle all the cooling needs. For those who are using an electric fan for all their cooling, there are more efficient setups available such as the SPAL fans and as recently mentioned in Car Craft (or Pop Hot Rodding), the use of the mid 90's Lincoln Mark VII and Ford Taurus fans that are built with a good sized shroud. Not a simple instalation but one to consider if you've got serious cooling needs. Those fans do draw some serious amps so an alternator upgrade is warranted.
Mike T.
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vet65te
Senior Member
Posts: 396
Loc: NorCal Now, Prescott AZ S...
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07-18-12 08:10 PM - Post#2249710
In response to fuzzyff
Touch a nerve did I? No need to be shy 'friend', why not tell us how you really feel.
Edited by vet65te on 07-18-12 08:16 PM. Reason for edit: No reason given.
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fuzzyff
Forum Newbie
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Loc: CA
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07-18-12 09:02 PM - Post#2249726
In response to vet65te
No, you didn't touch any nerve at all, mister "friend", I just don't understand driving around with a cold, dead, air-block in front of a perfectly good radiator. And, then running 15-20 amps of hard-bitten current into the mess to fight a black wall of defeat, just because the air temp went up a bit. Cooling systems have been designed by the best experts in their field, and it is highly unlikely that amateur "hobbyists" can outthink the pros.Opinions are one thing, and God Bless them all. But an opinion in the face of a contraverting fact is.....absolutely worthless. Touch a nerve did I? No need to be shy 'friend', why not tell us how you really feel.
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vet65te
Senior Member
Posts: 396
Loc: NorCal Now, Prescott AZ S...
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07-19-12 06:11 AM - Post#2249824
In response to fuzzyff
Seems to be a bit of a contradiction in your replies. Earlier you said there is no large advantage either way, engineering-wise but now describe pusher fans as a 'cold, dead-air block' and (this is my particular favorite) 'Black Wall of Defeat'.
I'm sure the folks at Be-Cool, DeRale and Flex-a-Lite will be relieved to hear that they can stop production of their pusher fans (aka: Black Wall of Defeat).
Mike T.
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 57tim
"11th Year" Silver Supporting Member
Posts: 2490
Loc: Cameron, Wi, USA
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07-19-12 06:51 AM - Post#2249840
In response to vet65te
I have used a pusher fan for a number of years only when my temp rose above 195 during slow cruising situation with VERY GOOD results and no problems of the fan effecting normal cooling at speed when its switched off.
I have since replaced my radiator with a new aluminum radiator with a pusher fan(no room for a puller) and at20mph and higher at 90 degrees temps, the pusher is turned off and my car stays at 180 degrees or less. I only turn the fan on when the temp goes over 195 and it comes back down in a hurry. Its a Spall straight blade high performance and is loud as h#$$ so its off most of the time.
Good news for all those fan builders, they can stay in business.
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5Larry7
"11th Year" Silver Supporting Member
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07-19-12 10:00 AM - Post#2249889
In response to tsegnit
FWIW, I tried the mechanical puller with a clutch and electric pusher in front of the condenser. Worked ok but I now have dual Spal puller fans only, works much better. I can slow drive in a parade and the car says at 180 on a 100 degree day.
'57 210, Blown 327 cid, Holley HP TBI, 700R4, A/C
'51 Studebaker Starlite coupe, 350, TH400, GV OD.
'08 Corvette Jetstream Blue coupe.
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Edited by 5Larry7 on 07-19-12 10:00 AM. Reason for edit: No reason given.
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MikeB
Senior Member
Posts: 9389
Loc: Plano, TX
Reg: 08-28-03
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07-19-12 11:42 AM - Post#2249915
In response to 5Larry7
OK, so we have vet65te telling us what works for him (part-time pusher) and fuzzyff essentially calling him nuts.
You know, if you have a recommendation or want to say what works for you, that's great. But if your main mission here is to criticize others, then please go find another website.
BTW, I'm convinced that all you need to keep a small block cool is a good quality radiator that's new or recently cleaned, along with a 6-7 blade mechanical puller fan. Heck, all my car has is a Derale large blade flex-fan with a Griffin down flow radiator. I have zero cooling problems, even here in North Texas. Coolant temp usually hangs around 180-190, and MIGHT approach 200 on a 100 degree day at a long traffic light.
That said, I've been meaning to try a clutch fan setup someday. An electric fan is added complexity that I'd personally rather stay away from. But I also have a mechanical fuel pump and manual brakes, so you can see where I'm coming from. However, I will admit to power steering and A/C. 
Real Hot Rods have a Clutch!
1955 210 2dr: 327, Brodix IK180 heads, Jones cam, Muncie M20, Wilwood front brakes
1969 C-10 pickup: 350, TH350
My car pictures
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 abyars
"6th Year" Silver Supporting Member
Posts: 627
Age: 40
Loc: Decatur, Alabama
Reg: 06-01-04
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07-19-12 12:47 PM - Post#2249931
In response to MikeB
I have a similar setup to MikeB.
Stock 350, griffin downflow radiator, smaller tubes not the large one, 5 blade clutch fan, auto trans. fluid going through radiator. On 100 degree days while waiting in line at my kids favorite fast food joint it gets just past 190. I have a fan shroud but it's not adjusted properly. The fan blade is too far inside it, needs to be half in half out. One day I will adjust it.
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vet65te
Senior Member
Posts: 396
Loc: NorCal Now, Prescott AZ S...
Reg: 01-04-05
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07-20-12 12:33 PM - Post#2250285
In response to abyars
Hey Guys, you all bring up valid points starting with a decent radiator being totally capable of handling a run-of-the-mill smallblock like I have currently in my 56. The Griffin downflow, on days with temps not exceeding 75 has the temp gauge hovering right around the thermostat rating of 160. On hot days (90+) it will climb up towards 200 when in slow moving traffic but so far I haven't actually been stuck in a situation where I had to find out just how high it might reach so in the end, my reasoning for wanting to have an electric fan in place (whether pusher or puller) is really due to me just not wanting to find out the hard way that the Griffin and fan clutch unit just aren't going to be enough. On my 64 GTO, I have a 16-inch Derale in front as a pusher but it's mounted right on the face of the Brass/Copper radiator. On the Nomad, with the aluminum radiator, I tried to avoid hanging the fan right on the core so I came up with that aluminum mount setup you saw in the earlier post of mine. Problem is that 'S' blade fan just wants to throw the air out at an angle and with any gap between the fan and core face it just bounces off, hence the reason it's not on the car right now. So, in my case where I've decided to keep the fan clutch/5-blade GM fan and Danchuk shroud on the inside, I'm either going to try a straight bladed fan (though I expect the fan noise to be much worse than the S-blade setup) or just mount the S-Blade Derale tight to the core face. The other reason for me wanting to have the electric fan is due to us eventually relocating to Prescott Arizona and while Prescott is at the 5400 foot elevation and has mostly cool temps, a trip to the Phoenix/Scottsdale valley might require a safety net electric fan.
Mike T.
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abyars
"6th Year" Silver Supporting Member
Posts: 627
Age: 40
Loc: Decatur, Alabama
Reg: 06-01-04
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07-20-12 01:39 PM - Post#2250302
In response to vet65te
I think you have a good reason. The straight blade should do the trick. It want be on all the time so who cares about the noise.
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inline0_0
"10th Year" Silver Supporting Member
Posts: 1396
Loc: Arizona desert
Reg: 03-10-04
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07-20-12 03:49 PM - Post#2250349
In response to vet65te
Do you think you could put a strip of 1" square foam rubber between the elect fan housing & the rad. fins? The kind like a hardware store sells for sealing around window A/C's in a house. I used some of that where my fabbed up shroud didn't fit as close as I'd like.
Doug
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MikeB
Senior Member
Posts: 9389
Loc: Plano, TX
Reg: 08-28-03
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07-20-12 04:54 PM - Post#2250373
In response to vet65te
temp gauge hovering right around the thermostat rating of 160.
You might want to do some reading on that. From the articles I have read, 185-190 is optimum for efficiency and lubrication. Just something to think about.
Real Hot Rods have a Clutch!
1955 210 2dr: 327, Brodix IK180 heads, Jones cam, Muncie M20, Wilwood front brakes
1969 C-10 pickup: 350, TH350
My car pictures
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wagonman100
Super Senior Member
Posts: 12996
Loc: Baltimore, MD
Reg: 11-27-04
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07-20-12 05:36 PM - Post#2250388
In response to MikeB
Actually, you get better combustion at around 205-210. Somehow people have gotten the idea that 160-180 is the optimum temp for cars to run. I guess people get uncomfortable with having a smaller margin of error with the engine running 205-210 and overheating being in the 230-240 range.
I had a copper/brass radiator with a 2500 cfm (manufacturers rating) dual puller fans. It cooled the engine just fine. When I did some work to the car (added EFI, 9" w/rear discs and a 700R4) I also changed to a Griffen aluminum radiator. The fans didn't cool the car worth a darn after that. It would regularly get to 230 plus on the electric gauge (I switched from a mechanical one during the changes and I kind of doubted the accuracy a bit). When the control unit gave up the ghost, I ran for years with no fans at all with no appreciable difference from having the fans.
I finally confiscated a fan from a Dodge minivan with a V6 we were replacing at work and installed it in the car. I let the temp run up to 240 on the gauge and switched on the fan. It cooled the car down to 180 on a 180 thermostat in a matter of a couple of minutes. That fans pulls a lot of air and is pretty quiet.
Jay
Some days it's not worth chewing through the restraints.
1999 Silverado Z71 4X4 extra-cab short bed
1983 Malibu Fauxmad - tubbed
1978 El Camino Kustomized
1972 Monte Carlo
1957 210 handyman wagon
1957 Nomad sport wagon |
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vet65te
Senior Member
Posts: 396
Loc: NorCal Now, Prescott AZ S...
Reg: 01-04-05
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07-20-12 06:00 PM - Post#2250400
In response to inline0_0
Doug - I thought about trying to attach some sort of skirt to the existing Derale fan frame but as you'll see in the pic, (a) it's at an angle and (b) there's only about a 1/16th worth of material in thickness to deal with.
 Still haven't figured out how to use my aluminum support frame to get the fan closer to the core but I'm working on it.
Mike B & Jay - Couldn't agree more. I know that on cool days the engine temp is barely hovering around the thermostat opening point and that's definitely below what it should be running. I did move up to a 180 thermostat but only for a brief period. The reason I reinstalled the 160 was due to seeing the mechanical temp gauge (verified by the IR gun) reading in the 195/205 range on hotter days and while I know that is better for the engine, I have to admit, I get this nervous 'twitch' any time I see the needle get anywhere around 200 or more. My issue is not seeing the temp gauge 'at' 200 but crossing my fingers that it doesn't continue higher. I will be putting back the 180 thermostat shortly and hope I don't sweat too much afterwards ;-).
Mike T.
Edited by vet65te on 07-20-12 06:19 PM. Reason for edit: No reason given.
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65_Impala
Very Senior Member
Posts: 1607
Reg: 12-29-02
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07-21-12 11:02 AM - Post#2250606
In response to vet65te
I'm thinking tuning really helps with the cooling too. I just put a LT1 with some head porting and a bigger cam in my Impala and it will cool down and kick back off using the stock rad and a 16" pusher fan attached right to the core. Before, I had another 350 with TBI that had less power and it needed both the pusher and mechanical fan at idle to {barely} hold the temperature from rising.
The first setup didn't have room between the pump and rad to mount a puller and I just left the pusher when I stuck the LT1 in. I could have pulled the core support to rad spacer out and made room but I didn't and once it was there I wasn't moving it unless I had to.
At any rate, a pusher can work.
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57dood
Contributor
Posts: 219
Loc: Ontario
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07-22-12 08:22 PM - Post#2251033
In response to vet65te
Been runnin a 16 inch single spiral,thermostat controlled pusher fan on its own,surface tight fit,aluminum 3 core rad,190 deg. all day long,no probs at idle,350 motor.Get a good brand name fan as i experienced theres some crap out there.
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fuzzyff
Forum Newbie
Posts: 45
Loc: CA
Reg: 06-13-12
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07-23-12 03:29 PM - Post#2251297
In response to vet65te
well, then, "Mike T", let me consolidate and organize your precision analysis of my "contradictive" stuff, you have HALF of it in your previous comment, the OTHER half would be that which is FULLY DESCRIBED in my previous statement that the "puller's" job is to "Suck" hot air and push it freely. So, mister half-wound, half-articulate pal, get the entire story against me straight, or don't mess with me at all. I have fully explained myself in 3 previous salutations. Seems to be a bit of a contradiction in your replies. Earlier you said there is no large advantage either way, engineering-wise but now describe pusher fans as a 'cold, dead-air block' and (this is my particular favorite) 'Black Wall of Defeat'.
I'm sure the folks at Be-Cool, DeRale and Flex-a-Lite will be relieved to hear that they can stop production of their pusher fans (aka: Black Wall of Defeat).
Mike T.
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fuzzyff
Forum Newbie
Posts: 45
Loc: CA
Reg: 06-13-12
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07-23-12 03:35 PM - Post#2251301
In response to 57dood
what an interesting entry, dude, does Not address the issue of the mechanical fan, at all. So, you have chosen to depart from the Original question, and just jump off into a parallel world, where your rig is, and......that's fine, sir. Just, that it does not address the situation that the person who started the thread was persuing. Do you get the point? Been runnin a 16 inch single spiral,thermostat controlled pusher fan on its own,surface tight fit,aluminum 3 core rad,190 deg. all day long,no probs at idle,350 motor.Get a good brand name fan as i experienced theres some crap out there.
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fuzzyff
Forum Newbie
Posts: 45
Loc: CA
Reg: 06-13-12
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07-23-12 03:46 PM - Post#2251310
In response to 65_Impala
At Any Rate, a man needs to see to the Cooling System, and be sure that it is clean, and doesn't leak, and then to know that the original factory engineers were NOT idiots, and that their Cooling Systems work GREAT, unless compromised by dirt, age, and bad components, or mis-understandings by amateur parts-replacers. They do NOT overheat, unless subjected to errors by the maintanence persons. SO, adding hundreds of dollars of Compensative Add-ons will often cover up problems that are preventable, by professional-quality maintainance.Blah Blah Blah, as to " a pusher can work" I'm thinking tuning really helps with the cooling too. I just put a LT1 with some head porting and a bigger cam in my Impala and it will cool down and kick back off using the stock rad and a 16" pusher fan attached right to the core. Before, I had another 350 with TBI that had less power and it needed both the pusher and mechanical fan at idle to {barely} hold the temperature from rising.
The first setup didn't have room between the pump and rad to mount a puller and I just left the pusher when I stuck the LT1 in. I could have pulled the core support to rad spacer out and made room but I didn't and once it was there I wasn't moving it unless I had to.
At any rate, a pusher can work.
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inline0_0
"10th Year" Silver Supporting Member
Posts: 1396
Loc: Arizona desert
Reg: 03-10-04
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07-23-12 03:49 PM - Post#2251312
In response to fuzzyff
fuzzy - There is a good exchange of information going on here. How about you just back off.
Doug
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fuzzyff
Forum Newbie
Posts: 45
Loc: CA
Reg: 06-13-12
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07-23-12 04:17 PM - Post#2251336
In response to inline0_0
frankly, mister, my input of constructive information is an integral part of that "good exchange" (and your omission of that fact is noted) Oh, I will, certainly back-off, having been chastised by the Master-At-Arms, guns raised in threat. fuzzy - There is a good exchange of information going on here. How about you just back off.
Doug
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