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Scorpio · Posted: Sun May 11, 2008 3:52 pm Post subject: Straight oil cooler yes or no

I was looking into oil coolers for when i do my engine and turbo upgrade/rebuild. The problem is ive got a radiator, intercooler and air con evaporator all fighting for pole position, and was thinking that this sort of oil cooler might sit nicely along in that lower slot on the GT body kit bumper

http://cgi.ebay.com.au/20-ALUMINIUM-FINNED-OIL-COOLER_W0QQitemZ320248499997QQihZ011QQcategoryZ130664QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
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1979 NA
MS1..EFI..
GARRETT T25 TURBO
BILSTEIN SHOCKS
GT BASED CUSTOM BODYKIT

Brisbane , Australia
Think mean think fast
all youll see is
my Porsches Arse!!!

Rasta Monsta · Joined: 12 Jul 2006 Posts: 11733 Location: PacNW

The smallest Setrab unit would blow that thing away and be in a similar price range.
_________________
Toofah King Bad

WeiBe (1987 924S 2.5t) - 931 S3

Scorpio · Posted: Sun May 11, 2008 10:29 pm Post subject:

fair enough.... theres just so little room and so few good points to have 4 different coolers on the front of the car
_________________
1979 NA
MS1..EFI..
GARRETT T25 TURBO
BILSTEIN SHOCKS
GT BASED CUSTOM BODYKIT

Brisbane , Australia
Think mean think fast
all youll see is
my Porsches Arse!!!

Martijnus · Joined: 29 Dec 2006 Posts: 2019 Location: Netherlands

My guess is that the cooling surface of such a thing is wayyyyyyyy less than from a regular unit... and thus not good at all.
_________________
"Rule: Turbo's make torque, and torque makes fun." (C. Bell)

924 "50-jahre", 1981.
MSII/extra, LPG, ITB's, 5lug.
To be turbo'ed in a while.
Killed her at the Nurburgring, Porscheless at the moment

!tom · Posted: Tue May 13, 2008 2:23 am Post subject:

Looks fine to me if you're not going to run a thermostat. If you're really wanting to manage oil temperatures, you should go for a bigger cooler and a thermostat to regulate temperatures. That thing doesn't look like it'll cool the oil much, so it's not worth putting a thermostat on it.
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78 924 NA
5-lug

Martijnus · Joined: 29 Dec 2006 Posts: 2019 Location: Netherlands

fiat22turbo · Joined: 18 Jan 2006 Posts: 4040 Location: Portland, OR

BTW, whichever way you go (I would suggest going large with a thermostat) spend some time improving the ducting of the air through the radiator, intercooler and evap. A little bit of work with some tin and some rivets and you'll improve the cooling efficiency of the systems. You don't want the air to escape around the sides of the various coolers. Obviously having a place for the hot air to go afterwards is a good idea, but first lets get all of it in the front first!
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Stefan
1979 924 Carrera GTS (clone-ish)
1988 944 Turbo S (Silver Rose)

!tom · Posted: Tue May 13, 2008 4:22 am Post subject:

Rasta Monsta · Joined: 12 Jul 2006 Posts: 11733 Location: PacNW

Off Camber · Joined: 04 Dec 2006 Posts: 12 Location: Brighton MI

How about the BMW E30 Oil Cooler like this one

http://cgi.ebay.com/ebaymotors/BMW-e30-325-i-is-es-Complete-Oil-Cooler-Assembly_W0QQitemZ130220574017QQcmdZViewItem?hash=item130220574017&

Maybe you can adapt it to make it fit.
_________________
"Growing Old is Mandatory"
"Growing Up is Optional"

emoore924 · Joined: 13 Apr 2004 Posts: 2822

Why not consider a stock 931 cooler? They're compact (about 20x30x90cm), the hoses to run to the cooler are available, the conversion methodology is known, and I have one on a shelf in my basement

ideola · Joined: 01 Oct 2004 Posts: 15550 Location: Spring Lake MI

To answer your question (in the topic title): NO.

Now the long winded lecture...understanding of course that I'm no thermal dynamics expert. BUT...as I understand it...

Unless the manufacturer can provided documented and verified data, there is no way I'm going to believe that that design will dissipate enough heat away from the oil passing thru the tube. For any heat exchanger to work, the heated medium has to come into contact with some of the surface in order for the molecules to exchange heat. With that design, I think you'd get nothing more than a boundary layer around the perimeter of the tube with very little conductivity of heat from the hot oil [i]to[/] (and thru) the heat-sink like fins on the exterior of the unit. Just not a good or convincing design, IMO.

On the other hand, if the fins were inversed on the INSIDE of the tube such that the oil flowed past them, you might get more cooling effect. But I wouldn't waste my time on something like this. Just get a conventional cooler that is known to work and not really any more expensive than that unit.

As for space in the front of the car, I think there is PLENTY for you to play with. Here's how. Dropped my oil temps on the NA by 20-30° C.
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erstwhile owner of just about every 924 variant ever made

Scorpio · Posted: Thu May 15, 2008 10:43 am Post subject:

Raceboy · Joined: 01 Mar 2004 Posts: 2327 Location: Estonia, Europe

I use E30 325 oil cooler on my 931 racecar.
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'83 924 2.6 16v Turbo, 470hp
'67 911 2.4S hotrod
'90 944 S2 Cabriolet
'78 924 Carrera GT replica
'84 928 S, sold
'91 944 S2, sold
'82 924S/931 "Gulf", sold

'84 924, turbocharged, sold.
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