Radiator & A/C core positioning

[jonchai]

Who needs a/c?

i removed mine!!

[thechuckster]

That AC core does sound rather large (thos this is for a wagon)?

Given that you rarely use it, i'd talk to a AC shop about using a smaller or different-shaped core placed elsewhere in the front of the car - perhaps with some subtle ducting to help it do its job. it might cost you a bit.

i'ev seen thin thermo fans on Merc's - perhaps a walk around a euro wrecking yard might find you some thin fans

Also, i bought a cheap and thin 12" thermo fan from supacrap a while back - seemed to push more air than my 12" Davies Craig fan. It's under the house but i could check it (for height) during daylight hours.

[BigWorm]

Hmmm, that doesn't look much like a toyota motor!

I was always led to believe that a push through fan setup was more efficient, maybe I'll dig out my various thermo fan installation instructions tomorrow, as I'm sure this is where I got that idea from.....
And just for interests sake, AU thermofans are not really what I would call "slimline".

[ProjectSleeper]

....Also, i bought a cheap and thin 12" thermo fan from supacrap a while back - seemed to push more air than my 12" Davies Craig fan......

Remember to check the flow rates at about 40 pascals minimum..

That is about the resitance of a average unblocked radiator...

A lot of companies list their flow rates at ZERO pascals (ie, free air)... whilst this sounds impressive, it is not "real world" and as soon as they are offered any sort of resitance (ie, mounted to a radiator), They lose LOTS of flow very rapidly....

For example, there is a 12" slimline fan on the market that claims that it flows 1600cfm - (for a 12" thermo fan, that is sensational), and I was going to buy two of them because they flow more than what my 14" Davies Craig one does (about 1050cfm for the 14" and about 850cfm for the 12").. anyway.

It wasn't until I checked around and asked questions that I discovered that this other brand (when given some load/resistence (ie, 40 pascals, the real world cfm was actually heaps lower.. see below

Other 12"
0 Pascals - 1580 cfm
40 Pascals - 790 cfm
80 pascals - 430 cfm
120 pascals - 110cfm

Davies Craig 12"
0 Pascals - 860 cfm
40 Pascals - 750 cfm
80 pascals - 620 cfm
120 pascals - 190 cfm

Davies Craig 14"
0 Pascals - 1060 cfm
40 Pascals - 840 cfm
80 pascals - 650 cfm
120 pascals - 440 cfm

Davies Craig 16"
0 Pascals - 2120 cfm
40 Pascals - 1750 cfm
80 pascals - 1400 cfm
120 pascals - 1100 cfm
(This big mother draws 19.5 amps and it 10cm thick)


so, make sure you check the REAL WORLD cfm ratings, because once they are loaded up, they ALL drop dramatically..

[wagonist]

Joel: hahahaha SHHHH!
It jsut goes to show what kind of a tech resource this place is. I've asked this q on the other forum relating to my car, and the conversion I'm doing isn't uncommon, but 99% of others remove the A/C because they're often dedicated cars, not daily drivers.

The A/C is big & it is in a wagon, but it's the standard part for these cars (its the "other" link in my sig)
Doing a combined rad/air con core wouldn't be a good idea. The standard single core rad in these has trouble keeping the 1.8 SOHC carb motor cool, let alone the 2.0 DOHC turbo motor that's in there now.

Getting airflow into the front of the car isn't a prob, so I may look into a different shaped core. That way I could fit the A/C & intercooler rad beside each other, which would free up a crap load of space.

["Z" UTE]

Hiya Steve, have you thought about a couple of 10 inch fans, mounted between the A/C condensor, and the radiator. One pulling through the A/C condensor, and the other pushing through the radiator.

With regard to your water cooled I/C, have you considered 2 smaller heat exchangers, and the different mount solutions available?

FWIW, I fitted 2x 10" Davis Craig fans as pushers on the front of the radiator in the 1JZ-GTE '77 Celica, no probs with cooling .

cheers Chuck

[wagonist]

I couldn't fit 2 fans like that back to back, only side by side, & considering the close proximity of the 2 cores to each other, whether one was pushing through the rad & the other pulling through the A/C, or both just pushing through the rad (which would be my preference anyway), wouldn't make much of a diff.

Though reading from the opinions here, I think I'm going to try with my first thought on this & that is to move the rad back as far as possible & then squeeze the fans on the front of the rad between it & the factory position of the A/C.

Plus the other hitch I've realised is that if I have the A/C core between the rad & the engine, it means that the engine couldn't be moved much without having to degas the Air con.
Not really a good solution when you've got to pretty much remove the engine any time a bit of maintenance is required (like change spark plugs or clutch)

["Z" UTE]

Hi Steve, yes side by side is what I should have mentioned. I moved my radiator back to within 10mm of the front of the engine. That was the only way I could fit the 2 fans between the I/C and the radiator. Most A/C that I have come across have a dedicated fan on the condesor.

cheers Chuck.

[wagonist]

You haven't had any issues with getting the air past the engine then? Because that's what I'm thinking about doing myself.
though as you can see from the pic, it's not an inline motor, so there's a fair chunk of cross-sectional area taken up by it & I'm a bit worried about the air not being able to escape from behind the core (though there'll be a good 50mm from the back of the core to the cam covers by the time you include the space taken up by the pulleys.

I'd really love to be able to change the way the power steer pulley is mounted. There's a splined shaft which the pulley pushes onto & then a thread. this sticks out a good 15-20mm from the pulley face & is the furthest forward thing on the motor.
If I could find a way to have a countersunk bolt or something instead, I'd gain a bit more room.

["Z" UTE]

If you can retain the engine bay under trays, you will not have a problem. These trays help to guide the air through the bay and out the back at the firewall. Have you looked at other power steering pumps?


cheers Chuck

[thechuckster]

quick check of my supacrap fan - 3.5 fingers high making it about 35-40mm - sorry, too big.

southo : i ended dumping the twin 12" fans for a single Davies Craig 16" and an air-tight shroud behind the radiator (air has to exit via the fan). Seems to work quite well so far.

[ProjectSleeper]

Chuckster - Awesome,
The 16" is a mother of a fan and i reckon if you had 3 of them running at the smae time, the gravitational pull of the earth would be thrown out of whack

On a side note, I just had my Air con regassed and checked today and it appears I need a larger front condensor fan as the "push through" of the single "no name" 12" thermo I have is useless when trying to cool the condensor - thankfully the twin 14's when they kick in rapidly bring the temps down, but it's not the ideal situation.....

[M.J.H]

They might be able to do the job but have you had a look at what is avalible on some bikes?

Might be smaller but if they are thin enough then surely using a few wouldn't matter would it?