Trout

iTrader: (1)

OK - here is an interesting one - any thoughts on locating an oil cooler in the bonnet scoop?

I believe that GTiRs do this - obviously when they use an FMIC - any thoughts on issues of doing this on a Scoob?

Rannoch

Andy.F

I recall a discussion on this once before and the only drawback was that it was considered that the oil may drain back into the engine when switched off. This could then mean a period (albeit brief) where the bearings are not supplied on start up.
Perhaps you could locate the cooler lower down on the passenger side and take a duct to it from the scoop ?

Andy

tweenierob

The scoop has poor airflow at speed.

It works well on GTIR's but obviously the vent design differs, someone on here has one on his STI5, cant remember who..

Rob

DubaiNeil

Rannoch,

Lots of questions in the past, and few definitive answers! Try the search facility with 'oil cooler' as the text
A few guys got carried away with theory, including electric pumps and one way valves all over the shop *), but unless you are seeing extremely high oil temps (105C and above) it seems there are much better parts to 'invest' in first.
I had the same thoughts after fitting the FMIC, and keep toying with the idea of fitting a sport bonnet just so I stop thinking about it!

Andy.F

Neil

Rannoch has a new super dooper engine with enough power to melt unobtainium He needs an oil cooler !

Andy

The Fixer

Certainly is suffiecent space for it but I was under the impression that there isn't really that much air flows into that area once you get moving. I would of thought in the inner wing or behind the FMIC would maybe better.

DubaiNeil

tweenierob,

Do not wish to disagree, but its a bit concerning that the scoop doesn't work at speed! I understand the logic/thought process/aerodynamic principles etc (nothing like a bit of negative pressure to starve the scoop of flow!) but surely the air flow required for an oil cooler to be effective would be far less than the requirement for the original TMIC?
With the oil cooler fitted at least when speeds dropped, so the scoop became effective again, the oil will drop the latent heat built up during a high speed run.
The majority of oil coolers I have seen (mostly OEM fitments - non-Scoob obviously) have been hidden from direct airflow due to large radiators and auto-trans coolers needing the space, with the oil cooler tucked almost out of sight.

DubaiNeil

It seems to take me too long to reply, there are at least two other replies each time I get re-directed!

DubaiNeil

S*d it! Rannoch - please fit one, prove the concept then tell me what parts I need
I may not have a super-dooper engine (...yet)

But I do have summer that lasts 12 months a year!

tweenierob

Lol, no worries Neil.
I do agree that the oil cooler will need less airflow into the scoop than a TMIC. I did write something else but it has dissapeared?? oh well

Rob

Fatman

Apart from needing a monster oil pump, wouldn't this create a permanent airlock in the oil system?

StanS

iTrader: (3)

I asked the same q several months ago and the main concern voiced by one well regarded contributor was about oil draining back.
But I thought the thermostatically controlled take off from the top of the oil filter (in the kit I was considering) would have shut as the oil temp cooled (engine stopped) so that whole loop would be shut off. When the engine started, the cooler would not be in the circuit, so no pressure drops. Unless oil would drain out while valve was cooling until it shut that loop off. But I wonder where the air gets in and whether it could flow in, to allow the oil to flow out of the loop.

(I assume the oil is picked up from the sump, pushed through the filter (oil cooler if fitted) then into bearings etc ??????)

If any oil can drain out of a high cooler through the bearings, I thought it would be replaced as the valve slowly opened as the temp rose so there would be two parallel routes for the oil until the valve fully opened, so minimising any lack of oil due to compressed air pockets. But if there were any hiccups of air in the oil flow, it would be embarrassing engine wise.

Someone brave (with an old engine !!!) needs to try it
(I couldn't fit anything under my scoop - no room - would have to be in the scoop - too tricky - so will try behind FMIC).
Stan

Trout

iTrader: (1)

Thank you for your replies!!

A couple of thoughts...

- I agree with most of the comments - however - isn't what is said true if the cooler is placed anywhere above the level of the oil in the sump? As there if it is there will always be the possibility of drain back.

- Does anyone know how they do it on the GTiR as they regularly do this and they do not have any problems?

May end up with a laminar cooler as they are small - and an uprated rad!

Rannoch

pban

Didn't Falkland Performance fit an oil cooler under the scoop in that lime green scoob they had/have?

Wouldn't the oil cooler have to have a temperature actuated valve so as to only bring the cooler into play when required?

What about a non return valve in the system

[Edited by pban - 9/23/2003 8:41:45 AM]

Cord

Have fitted them to impreza's and GTiR's before, always mounted them on a slight angle, 1 to catch more air, and 2 so that the inlet/outlet is the highest point. Oil won't drain back due to the thermostatic valve you will be fitting, and also if it did drain (which it can't) only the hoses would empty. But there isn't a vast amount of room there anyway once you have accounted for your intercooler piping.

MorayMackenzie

Re oilstat preventing draining of top mounted oil cooler theory...

1. Oil cooler has two hoses to it, whats stopping the other one gravity draining?

2. Oil stat will take time to close... hot oil is less viscous and will probably have drained back way before the stat gets close to closed... assuming it can drain back that route... but then it will take the easiest route of the two available.

I still think the brake duct/foglight areas as good candidated for cooler rads... especially if you don't suffer from stupidly long fmic pipework issues.

Cord

You are probably right on the time taken for the valve to close, but we mounted the cooler on an angle so it couldn't simply drain out. We tested it for draining by taking it off when the engine had been left to stand and getting a full litre, or however much they hold, out of it. We run remote oil filters on a lot of our skylines and they mount upside down (threaded fitting at the bottom) you can take a filter off that has been standing for days and it is full to the brim of oil (again i have tested this). If the air can't find its way into a filter to replace the oil there is no way it's gonna make it's way up pipes to drain or syphon a cooler.

Andy.F

I'd agree with that Cord, if the air can't get in, the oil can't get out so your way of keeping the fittings to the top would work ok.
Not sure if mounted differently that the air may get back up from the engine as the heads/cams drain back ?

Andy

MorayMackenzie

Hi Cord,

The subarus oilfilter screws directly up into the mounting on the bottom of the engine, so it won't drain either.

Good point about the mounting angle. I still suspect that at least one of the hoses will drain and need to refil on startup.

Problem is, there is a significant distance from the OE oilfilter location and the proposed mounting point, and so the hoses connecting a sandwich plate to the cooler will have a not insignificant volume.

rapac

Mounting an oil cooler where tmi was, seems to be MRTs favoured spot.
Spoke to Marcus from MRT and ll be fitting one soon at $800(AU)without thermostat.


Chris