Electric fans

[zedhead260]

I have a Pacet electric fan to fit to my 260Z. It can be switched for either push or pull into the radiator. I assume they manufacture it like this due to the available space in some cars. In a Zed, there is enough room to have the fan fitted either in front or behind the rad'.
Anyone got any recomendations as to which is best ? Is it more efficient one way or the other ?

 

[Zed2k]

You can fit it either way I have put my fan in front of the rad but am soon going to put a larger fan slightly off set to the nearside of the rad on the inside next to the engine, this way it cools the hotter water as it enters the radiator by the top hose.
If your fitting the automatic control for the fan I think Demon Tweeks has a good fan controller that fits in the top hose rather than a cappilary which goes under the top hose.
This is adjustable so it can be made to cut in and out when you like.

Hope this helps
Nick.

 

[pmac]

I have just had a guided tour of Dominic Fratarolli's rally 240Z recently. It has the fan behind the rad  ie a puller effect,but offset to the carburettor side so it helps keep the fuel cool. It also has a four core rad fitted. I reckon what is good enough for rallying on the Manx National sholud be good enough for kerb crawling round Stevenage.

 

[zedhead260]

Good point about fitting the fan offset so it cools the hotter water entering the rad', should help the carbs too.
Couldn't find the auto control gizmo in DT's - Do you have a page number / part number ??
I suffer from high water temperatures only at high speed. At sustained speeds above 4000rpm I think air flow through the rad' is reduced because the car has hit it's aero-dynamic brick wall. My anti-freeze ratio is good, I use distilled water to keep out the impurities, and treat it with Redline Water Wetter. I have an oil cooler to fit (with termostatic take off plate), which may help things a little.
I have had a 4-core radiator installed already, so low speed kerb crawling doesn't cause me a problem. Oh,..........and Roxy sends her love pmac, she misses you. &nbsp;<img src="http://www.zclub.net/iB_html/non-cgi/emoticons/tounge.gif" border="0" valign="absmiddle" alt=''>

 

[Zed2k]

Hi i've got the 2001 edition Demon Tweeks Cat, the electronic fan control is on page 94 under the Auxiliary engine fans.
Hope this helps
I haven't fitted this yet but it looks a lot better than the capilary type.
Nick

 

[zedhead260]

I see it now, I was looking in the Motorsport edition before.
Thanks.

 

[zedhead260]

Purchased, delivered and fitted !!!!!!!!!!!!
It's a bit of a tight fit to get it in the top hose. I found that butting it up to the thermostat houseing was the best place for it - you will need an extra bit of 35mm ID hose. What you cut off the existing hose doesn't quite give you enough to play with. Be careful not to kink it, measure twice and cut once.
I've wired it up so I have a manual overide switch, and also so a warning lamp comes on when the fan switches on automatically. That way you know when the fan is working and makes tweaking the thermostat more accurate.
Goodbye excessive high speed engine temperatures. &nbsp; <img src="http://www.zclub.net/iB_html/non-cgi/emoticons/biggrin.gif" border="0" valign="absmiddle" alt=''>

 

[Zed2k]

Glad to hear it fit's ok, I think I'll order mine now and fit it up with my new larger Fan.
Stay cool
Nick

 

[zedhead260]

Just thought I'd mention that the relay for the thermostat has failed already. Not impressed, but it could be down to an earthing complication on the overide switch when first installed. This was remedied, but I feel could have shortened the life of said relay.
Good job I did fit the overide switch though, as it prevented a boil over.
Haven't changed the relay yet (lazy), so am keeping an eye on the temp' gauge and manually switching when necessary. Funny thing is, I hardly have to use it. Only really when I am stuck in traffic, which makes me wonder what the problem was in the first place !
I have fitted an oil cooler though, so i guess this is helping matters - particularly at high speed.
Not convinced about fitting the fan carb' side. A 13" Pacet fan is so bloody powerfull I'm sure you could put it anywhere. When the fan is on (usually when stationery), all it's doing is drawing in warm air right into the carb's filters. I think this is the cause of some fuel vapour lock when gunning it from standstill. Admittedly this was at Santa Pod on a very hot day.

 

[pmac]

So what you reckon then? &nbsp;fit the fan central or offset the other way? &nbsp;You could &nbsp;mabye have a cold box fitted over the carbs with an intake coming forward to the rad mount panel cut out section. I have just had a 4 core rad fabricated and the guy who did it expressed concern about the way that the pacet fan uses these plastic ties to secure it to the core.( I cant print his real words) It sounded like " ducking bodge ". I think I might go for a fabricated bracket coming off the rad cowl mounting points. What you reckon??

 

[Mr.F]

The Pacet ties are not going to cause you any problems - they are a simple and elegant way of mounting a fan to a radiator without the need for excess brackets, nuts, bolts and other stuff. I have used them on Ratz up to 160mph on an aluminium radiator and also on my 280ZX turbo (two fans side by side) without any radiator damage or loosening of the fan security. To descibe them as a "bodge" is rude and ill-informed.

 

[zedhead260]

Yeah, there really is no problem in the way Pacet get you to mount their fans. When it is in operation, it sucks itself to the rad' with so much force, if you took the fixings off it would still be in place. I have full confidence in them.
As for the position - I really dont think it would make that much difference to cooling efficiency if it was fitted on the other side. But like I said, it only caused me a problem sitting by the light tree, cos the engine got too hot in the fire up lane. For normal applications, and once the car is moving (with cooler air flowing through) I think it's fine.
I spoke with Dave Jarmen regarding air-boxes poking out the front, in the hope to achieve a RAM-AIR effect. He had his doubts. I can't remember what he said, as it all started to get too complex for me. Dellorto internals are not my strong point.
Would be intersting if anyone else in the forum can give advice on this idea. Perhaps I should start it as a different topic, but we'll see what happens for now.
I notice that Alan Thomas' 240ZG has an air-box hugging his carb's. Doesn't poke out the front though. You out there Alan <img src="http://www.zclub.net/iB_html/non-cgi/emoticons/confused.gif" border="0" valign="absmiddle" alt='???'>

 

[ben240z]

fit an electric water pump and all the problems will be solved &nbsp;my race engine will run all day long on idle at 65 degrees with an electric fan from a metro and when the engine is switched off the pump carries on running till the temp comes down to 55 degrees therefore letting the engine cool evenly. once the car is moving along the road the electric fan does very little in the way of cooling if the flow of air through the grille is not obstructed ,so there might be another problem that you need to look at regarding the temp rising when driving. Whether the fan pulls or pushes is really not that important as long as it rotates the right way for the blades. Rather than trying to get a ram air system to feed cold air to the carbs you would be better off trying to get an increased airflow under the bonnet passed the carbs, this can be achieved by adding louvre vents to the bonnet in the right place. there are other ways but it starts getting a bit scary to let anyone one attempt it email me if you are serious about it though, ben