Jump to content

Suck or blow?


FridgeFreezer
 Share

Recommended Posts

Suck is always more efficient.

Engine driven fans are also always far more effective than electric ones from a cooling point of view.

I've have very good results with the flexi fans that the americans make. Got one on my series funnily enough. Far more efficient than the 16" kenlowe I've got on the front of the rad!

Jon

Link to comment
Share on other sites

I've have very good results with the flexi fans that the americans make. Got one on my series funnily enough. Far more efficient than the 16" kenlowe I've got on the front of the rad!

Jon

What are these 'Flexi Fans' of which you speak?

Si

Link to comment
Share on other sites

What are these 'Flexi Fans' of which you speak?

Si

My Webpage

Basically very very slimline (ideal for tight V8 installations) and the blades are made of sping steel, such that at higher RPM they flex so offering less air resistance.

Made a hell of a difference on my series, as I only had 20mm from front of waterpump to rad, this was the only fan I could get to fit - I dont half shift some air!

Jon

Link to comment
Share on other sites

Apparently it's more efficient to push on air than to pull on it. The usual reason for mounting a fan behind the engine is so that you have an easy mechanical drive. Electric fans are usually front mounted so that they can blow.

and if you think cowling on the front is worse then on the back, then that can be discussed in pt II.

Link to comment
Share on other sites

Suck or blow is ok if the temp outsite is cool, but when its 30-40oC then its not as effecient as water cooled intercoolers.

Or better still do as Im planning......... Down both sides of the Intercooler tubes that are sealed at the bollom but open at the top....just add dry ice :)

Link to comment
Share on other sites

Push should be able to shift more air than pull.

Pulling, you can generate a max pressure differential between the front & back of the rad of 1 atmosphere (14psi or so). Pushing there is no limit.

In practice, it may not be that simple though - and I doubt any fan is going to generate anything near 14psi (a 12" fan at 14 psi would give 1500lb of thrust - so we are in to jet engine terratory)

Si

Link to comment
Share on other sites

Push should be able to shift more air than pull.

Pulling, you can generate a max pressure differential between the front & back of the rad of 1 atmosphere (14psi or so). Pushing there is no limit.

In practice, it may not be that simple though - and I doubt any fan is going to generate anything near 14psi (a 12" fan at 14 psi would give 1500lb of thrust - so we are in to jet engine terratory)

Si

Yes, but we are not just looking at the fan, but it is the fan and the rad togetther you have to look at. I know from experience that the greater effective surface you have at the front of the rad with the fan behind it, works better in high speed situations. I am not entirely sure where this leaves us at 5 MPH offroad, But I think it is still better.

Daan

Link to comment
Share on other sites

My personel preference is suck I have 2 fans one for the rad and one for the intercooler in my D90 have plenty of room for them as taken out cowling and disco 200TDI .............. as noted less prone to mud getting on blades and IMHO better than mechanical one as less risk of water being sprayed over engine mor e of a problem for petrol I suppose

Steve

Link to comment
Share on other sites

Yes, but we are not just looking at the fan, but it is the fan and the rad togetther you have to look at. I know from experience that the greater effective surface you have at the front of the rad with the fan behind it, works better in high speed situations. I am not entirely sure where this leaves us at 5 MPH offroad, But I think it is still better.

Daan

whoah!!!! Let's go back and look at the question:

is it better to have cooling fans that suck or blow?
Suck or blow?, What's your preference? Options

The first is objective, the one that I responded to, not having seen the second one, which is purely subjective.

... but ofcourse if you want to discuss the merits of both types of fan even to restart the electric vs viscous debate then continue.... B)

Link to comment
Share on other sites

whoah!!!! Let's go back and look at the question:

The first is objective, the one that I responded to, not having seen the second one, which is purely subjective.

... but ofcourse if you want to discuss the merits of both types of fan even to restart the electric vs viscous debate then continue.... B)

blow from the inside our suck from the outside. That way when you are standing around in the cold you get a nice blast of warm air to stand in front of. :)

Link to comment
Share on other sites

Did you find someone in the UK to buy them from? I've been trying to contact Flexalite about something else - and they have proved elusive!

Si

No - I simply picked one up at an NSRA swap meet. You can get them from the various american car type speed shops. Moroso also do one you can get via Real Steel.

I've found trying to deal with american based manufacturers in general is hopeless - they never seem to have UK based outlets etc.

Jon

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...

Important Information

We use cookies to ensure you get the best experience. By using our website you agree to our Cookie Policy