Fan - Suck or Blow?

I noticed something about my SA 200 that I found a little odd. The fan blows air through the radiator rather than pulling it through and blowing it over the engine. That's counter to (I think) every engine I've seen. Maybe I just didn't notice on some of the big pumps and stuff. I was going to use the side table to do some welding, and thought the blow from the fan would be a problem. Then I fired it up and found out it blows the air the other direction.

When I rebuilt this, I didn't take the fan off, nor any of the pulleys. So this is the way it came or someone else before me changed it. Everything seems to run fine, just seems a little odd.

Steve

"...the man who really counts in the world is the doer, not the mere critic-the man who actually does the work, even if roughly and imperfectly, not the man who only talks or writes about how it ought to be done." Theodore Roosevelt 1891

Reply to
SteveB
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Check your car Steve, I think that it is doing the same thing.

i
Reply to
Ignoramus4557

A lot of industrial engines and heavy equipment engines are set up this way to keep the hot air off the engine and the operator station. You would have to install a different fan than the "pusher" fan to change this.

Russ

Reply to
Russ

Reply to
RoyJ

Probably the reason they don't do this in a car is that the car is usually moving in a way that would "fight" the push-type radiator fan.

Grant

Reply to
Grant Erwin

Yes. You are right. I have a stomach bug and am not thinking well at all. Sorry. I just used up my one "dumb answer of the month" coupon.

Reply to
Ignoramus17662

And if you look at new cars with electric fans they usually put them on the front of the engine, or in a shroud, or both.

Note that most cars don't need to have a fan running when they're under way -- it's only when the car is stopped that the fan is necessary to keep the air moving.

Reply to
Tim Wescott

Most Caterpillar equipment has fans rigged to blow out the front. If you are in a car helling down the highway you want the air to come in the front and go out the back, but when you are just sitting there it doesn't make any difference.

Bruce-in-Bangkok (correct Address is bpaige125atgmaildotcom)

Reply to
Bruce in Bangkok

No, Ig. When I stand in front of my car, the air is being sucked in, not blown out. There is no wind in front of my car. It goes INTO the engine compartment through the radiator first. This exhausts through the radiator. If a car pushed air in front of it, the forward travel of the car would cause the cooling effect to be cancelled at some point. Think about it.

Steve

Reply to
SteveB

The fan doesnt perform any additional cooling of engine bits and components in a "in from the fan and over the engine" configuration?

Gunner

Reply to
Gunner

Blow for summer, suck for winter.

A suck fan with closed side doors combined with head down and large rods can actually boil the gas in the tank. Some heavy industrial machinery have (manually) reversible fans and some weldors change their fans seasonally. A suck fan can help to prevent moisture freezing at the bottom of the crankcase ventilation (road draft) tube and also to prevent carb icing on cool humid days. Most of us solve the freezing crankcase vent tube problem by punching a small hole just above the bend, (I bet your machine already has a hole) and the air intake has an adjustable collar to allow the engine to pull its intake air from the exhaust manifold stove/shroud.

I liked a suck fan in the winter as it would melt the snow and dry the deck of my rig, but I do not bother to seasonally change from a blow fan as I try not to work in severe cold. I like a blow fan for cool weather as I have a hook on the front of my rad which is used to hang my welding helmet which keeps it warm and prevents it from frosting up from my breath. Front hooks also work well for drying gloves.

A blow fan can be problematic it you have oil leaks as it will cause the rad to be coated with oil and dust and this will require maintenance cleaning to preventing overheating. A suck fan will just blow this oil all over the generator and the side doors.

Most generator cooling fans pull air from the rear of the generator and exhaust it from the engine end, a blow fan will help to pull this warm air over the engine and out of the housing.

Good luck, YMMV

Reply to
Private

Ignoramus17662 wrote in news:S7- dnbejlYSqwLXVnZ2dnUVZ snipped-for-privacy@giganews.com:

Don't sweat it, Iggy - you can use mine.

I've got a large stockpile of them.

Reply to
Eregon

Gunner wrote in news: snipped-for-privacy@4ax.com:

Did a VW or a Corvair have a fan?

I thought not.

Reply to
RAM³

What did that VW fan do keep the driver cool?

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Reply to
Up North

IIRC, the Corvair had an enclosed fan with a belt that was early serpentine in nature. It ran in both vertical and horizontal directions. You could see the fan through a hole in the top of the engine. VeeDubs, no.

Steve

Reply to
SteveB

My SA 200 is minus the two side panels. The manual says to be sure they are closed, as this is important for optimum engine performance and life.

Page 3 of manual: Operate the welder with the doors closed. Leaving the doors open changes the designed air flow and can cause overheating.

Hmmm. May have to make some doors. I've seen them with and without doors.

Steve

Reply to
SteveB

I saw a Cat generator with a 3306 that would overheat the generator because the hood side panels were missing. It was mounted inside a van trailer and the side panels were removed because you couldn't access the engine with them in place. The problem occured when the temp was over 90F. Steve

Reply to
Up North

I must admit to some skepticism, but I would (almost) always accept the manufacturer's operating manual as the best authority. My rig has run for years with only one door in the summer, (it makes it easier to service the engine). I do often use both doors in the winter, never any problems with overheating. The doors are a great place for signage.

Buying new doors could cost more than you paid for the whole welder, I suggest you contact the previous owner as he may still have them or know where to look for some. Check at the local welder dealers first. A WTB post here or on EBay or Craig'slist may help?

Good luck, YMMV

Reply to
Private

Did this unit overheat the engine or the generator with the side panels removed?

Reply to
Private

The generator not the engine.

Reply to
Up North

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