oil cooler project
 

this thread is a continuation from my intercooler thread

I'm trying to lower my oil temps. With original intercooler being only 6" tall, I had the oil cooler sitting above it- not in direct flow. In this location oil temp would hit 270f with countless boosted runs, under cruise it would stay around 250f. Now I've got a 12" tall intercooler occupying that space, so the oil cooler was moved to what I thought would be a good location- under the bumper support with an air exit to the mouth. Temps went up- showing 280f at cruise and near 300f after lots of boosting. I added a scoop which dropped the temps but only by 20f - not enough. And it hampered the flow to the rad.

The cooler setup is a Hayden sandwich block with internal 180f tstat, 3/8" ports, to -10 line, 2x3x10 true cool oil cooler with 1/2" npt ports.

So I'm trying to locate the oil cooler in a good spot to lower temps. I'm considering the following or a combination of:

• Enlargement to the lower mouth area with larger oil cooler placed under the intercooler in front of the rad
• Enlargement to the lower mouth area with existing oil cooler in front of rad (difficult because the ports are on the top of the cooler)
• Existing oil cooler in wheel well with air feed from spoiler duct
• Install factory water based oil cooler (or none) to see if there's a problem with the current setup (causing high temps)

Diagram below shows the proposed lower position. The 2nd gen rx7 oil cooler is about 3 times the volume of the current cooler- and it's a double pass with the inlet and outlet on the same ends. My thinking is that the change in the lower section of the mouth piece would compensate for the blockage of the rad face due to increased flow.

Open to any other brilliant ideas. :D - rob

http://i158.photobucket.com/albums/t...erlocation.jpg

Granted the proof is in the pudding of actual water/oil temps, but since flow across the rad is mostly pressure differential based, it probably will reduce radiator flow, but may not make a big enough difference (1-5 degrees) to matter.

I know that you already have the oil cooler, but just an FYI that even though FM does not sell the twin cooler for the 90-97 anymore, doesn't mean that it can not be found elsewhere. ;) Pricey yes, but a nice clean solution.

I could do the same with my existing setup since my rad is narrrow to allow passage of the cold side IC pipe. So the Rx7 oil cooler might work (or something similar) in that vertical space at the price of a "around the rad" cold side pipe. Good suggestion.
Here's the space:
http://i158.photobucket.com/albums/t...G_1533_600.jpg

Instead of blocking what little radiator surface area you still have exposed, what about oil cooler under intake manifold, facing down, with fresh air supply via duct from undertray? Or oil cooler wherever it fits under the hood, with 12v fans providing airflow?

I'm opposed to the fan on the oil cooler thing... tho I don't know why. It's similar to having a pump running for an air:water IC I suppose. IF I stuck the cooler in the wheel well and fed a spoiler duct to it, I'd probably consider the fan for traffic driving. Sticking the oil cooler under the hood makes me think that it's only contribute to the massive amount of heat under hood already. :dunno:

is your car a daily driver?

if not you could put it in the headlight area with a duct leading to it, or the front of one of the wheel wells. FM put a tranny cooler in the back bumper, got the air in it as it came up and over the rear of the car.

Yeah- more or less. Want to try to keep it from being too much of a race car.

Doesn't look like there's enough space to get a decent size oil cooler in the fender well and feed air from the spoiler duct. It might work if I put a hole in the bumper cover- but that's beyond what I want to inflict on the body. The reality is the NB just has a more square nose than the NA and that makes the difference (along with a driving light hole) to making that work. Here's the site that shows the NB install.

Based on the input at this point, I think I'm down to two options.

• Put a larger cooler parallel to the ground, in front of the steer rack and feed the spoiler ducts to it - and a fan on the back side.
• Put a new cooler in the spot where my current cold side IC pipe passes, next to the rad.

Feeding the spoiler ducts will increase the underhood pressure, but I'm definitely putting holes in the hood so it should make that big of difference. The duct feed might be overkill - I could just put a smallish scoop at the base of the cooler to catch air under the car- though I don't know exactly what the flow is like. I still don't have the under tray on since the swap is going to require some alterations to it to get it installed. Don't know how that would play in to the equation either... probably an asset for flow, especially if introducing air post rad.

Mounting the oil cooler next the rad requires fab'ing a new IC pipe setup (pita because of the bov and tb hose). There's no way to get a fan on the back either (funky size - 14x4x2) unless I fab up a rear shroud and place the fan further back which might even be space limited.

Underside shot- this definitely looks like the easier job. Essentially the price of another larger oil cooler ($50), some hose shortening, connectors and duct hose. (no hydraulics used in creating this photo ;) )
http://i158.photobucket.com/albums/t...G_1687_640.jpg

Area where coldside pipe passes
http://i158.photobucket.com/albums/t...G_1690_640.jpg

curiosity
 

I removed the entire oil cooler arrangement and installed just mazda oil filter. Went out and thrashed the car. After numerous 1st-4th and 4th low to high rpm runs at full throttle the temp peaked at 290f and didn't go any higher. That's VERY similar to what I was seeing with the oil cooler- and the oil capacity was reduced by about 3/4 qt. :confused:

I've got a mercedes oe cooler that will fit next to the rad. It's about 2.5x the capacity but a tube design. Need to weld on some AN fittings and maybe brackets, shorten hoses, add fittings to install.

Maybe it was a combination of way too small cooler and no airflow?

Is there a fluid flow path that should be followed from the sandwich plate? In other words, inlet and outlet at the plate and inlet and outlet at the oil cooler?

I've been watching the developments with your oil cooler optimization...I'm in the process of doing the same with mine, though mainly due to borderline-uncomfortable oil pressures. Without getting into my rationale, methinks I need 1) a thermostatic sandwich plate, 2) shorter lines, and 3) 90-deg full-port hose ends to route shorter lines.

Just verified I can use 90-deg hose ends today (my cooler is mounted behind the mouth on the passenger side, most of the cooler is exposed to rushing air), so depending on bracketry, I might be flipping the cooler upside down to run my non-straight-end hoses. Hard to explain without a pic...and I certainly wish I had an oil temp gauge. :\

Do it Bosozuka-style ON the front bumper!

http://tanetane92.web.infoseek.co.jp/053111.jpg
http://tanetane92.web.infoseek.co.jp/052731.jpg

j/k.

I like the parallel/ in front of rack idea. Many OEMs use that location for PS coolers. My SRT4's PS cooler is in that spot and has a simple 1"x (Length of cooler) piece of plastic to catch some air.

beer- I hope you're right. We'll see soon- the new IC will sit right next to the rad in direct flow of oncoming air.

Cooler doesn't care where the oil comes in/out... or at least mine doesn't.

I'm considering an upgrade to the mocal Tstat because it has the larger 1/2" npt ports, whereas my hayden has 3/8" and no room for overbore and rethread.

koto - :rofl: - that first pic is too appropriate - my d-side headlight is missing (lowpro lights) so it would work. Or I could get some of those flares and mount a cooler in one with a duct? ;)

when the t-stat is closed, what happens to the oil? does it simply bypass the path to the cooler and flow to the pan? if so, is there a possibility your t stat simply failed to open?

The tstat opens. When my oil temp gauge got near 200f, I pulled over and the lines were hot. It doesn't make a whole lot of sense to me. And it's easier for me to just change a bunch of shit rather than going thru one piece at a time, just because I don't have a lot of time to do the pinpoint troubleshooting.

The merc cooler was $35, plus the mocal tstat sandwhich plate $90 and whatever I spend on fittings. I could drive on the street all day like this (apparently) but IF (when) I track this car, I don't want to have to look at the oil temp gauge all the time. Most turbo'd street miatas are fine (even in the SE heat) but put them on the track and that all changes.

I'm probably being overly cautious. For example - CSR did his DIY extractor hood because of water temps - he doesn't have an oil temp gauge. I think he's tracked his 95 for five years now, turbocharged at 12psi. :dunno:

Just wondering how your project is coming along ?
I have the Mocal sandwich plate, 1/2" lines and a small-ish 7 row cooler.
My cooler is mounted off the steering rack, between the ARB and the crank pulley, then ducted from the undertray. Cruise temps are 195F, track temps get up to 230F max. It works pretty well, but i always worry about it on the track, its kind of exposed being on the bottom of the engine should i take a trip into a gravel trap....or worse, the scenery.

I am sure you know what you are doing (and I am a newbie on the forum :bowdown: but...

I have a kit from Moss, with the filter on the firewall and the cooler in the driver side wheel well (my car is a -99, so far without boost). The thermostat in my kit (and I assume in other kits) is always a little bit open, to make sure the cooler stays filled with oil and no air gaps are created in the system. When it “opens”, it actually just opens more, flowing more of the oil thru the cooler. Therefore, my oil cooler and oil lines actually gets hot before the thermostat is open, just from the slow base flow thru it.

torkel, you may have a point. I know there's a gap behind the tstate blade- you can see it when the fitting is off the car. It looks fine, but it's not too complex either being the cheapie flat coil type vs. the true mocal type tstat. That said, the coiled blade works, has worked forever, which is why it's still used.

My merc cooler now as -10 bungs on it, just need to install it. Haven't had ANY free time, and when I do get some I've got to do the tbelt on the RX300.

lloydie- you could build a shroud/housing around the cooler and run some ducts from the front (spoiler vents). That would protect it and channel some direct air. That's what I'm planning to do.

Man, i like this guys setup. Might just have to copy the oil cooler portion. Found this on someone's cardomain as you can tell.
http://memimage.cardomain.net/member...91_54_full.jpg http://memimage.cardomain.net/member...91_55_full.jpg http://memimage.cardomain.net/member...91_60_full.jpg

yeah, I've got that marked. Perfect for an NB, but no room on an NA w/o sticking some stoooopid holes in the bumper skin.

I've seen those coolers come up on ebay as trans coolers (still have 1/2" npt fittings) for cheap. No mention of oil cooler, so it might be a way to pick up one cheap. AND ebay is a good place to find all kinds of hose and AN fittings - second hand nascar stuff if you don't mind washing it out.

cutting holes is fun and you know it:

http://memimage.cardomain.net/member...67_14_full.jpg

http://memimage.cardomain.net/member...67_13_full.jpg

BTW, what size AN hose is good for the cooler system? 8, 10? Used to run 12 on the Mustang that saw some open track duty.

no way I'm doing that shit to my car :nono:
I think running some tubes from the OE spoiler vent holes to the cooler mounted at the rack will work. Though it my seriously increase the need for a hole in the hood to vent some of the pressure.

-10 is the usual recommendation for "our" application

IDK i was going to put one on the shelf of the firewall a nice thin design should work just fine and get alot of flow. :dunno:

I think all depends on how much you're looking to lower your temps- and that'll dictate size and exposure. I need to drop them a lot if I'm going to track this car in the summer... one day.

Hey Rob, just ran across this from my holsets manual and thought i'd post it here for you.

I guess that proves that your temps are quite a bit too high.

fred.

or maybe it shows why holsets are such a bargain ;)
yes- it's still a project.

apologies for my inability to take your tease/joke :-p

garrett are a pain in the arse for finding info "please refer to your authorised distributor" etc etc

but i found this for one of their aviation products :

rgl.faa.gov/Regulatory_and_Guidance_Library/rgMakeModel.nsf/0/c5724721927d08cd862568f6004c3de6/$FILE/E3WE.pdf

this page lists nominal operating temps at 90C :

http://www.turbotech.com.au/garrett2.htm

also, all the oil temp guages have max around 300 - 320F

i know its still a project, i just remember you discussing what was and wasnt too high, so thought i'd post up what a reputable open company that i respect has to say on the matter.

the "normal" companies (cough-garrett-cough) website is so packed with marketing garbage that its impossible to find anything useful if indeed it is available.

fred.

I don't know what my temps are post cooler, but I can only hope they're cooler than the oil in pan post combustion at ~275f or so. My oil feed leaves the block immediately after returning from the cooler, which IMO is ideal. Another reason those sandwich plates or the T at the pressure gauge are good idea.

I don't have a condenser to worry about anymore, but here is where I put the cooler in my car.
Gotta love cell phone pics.
http://www.systemstrategies.com/miat...112707_003.jpg

That's nice. I've got an large IC, condenser and extra large rad stacked in there. I had the little oil cooler floating out front (after the big IC install) and there was insufficient exposure AND it's just too small (smaller than yours for sure- smallest trucool).

Sometimes if it weren't cell phone pics, we'd have no pics at all. :D

a little progress
 

Got the new Mocal plate installed. The main diff between Mocal and the Hayden:

• Mocal 1/2" ports
• Hayden 3/8" ports
• Mocal true coil spring tstat
• Hayden flat coiled steel that covers bypass hole when hot
• Mocal is about 1/2 the thickness of the Hayden

As mentioned before, the Mocal does well with some porting on the internals. The larger 1/2" ports leave some very hard edges and extra metal hanging out at the transition. Dremel with small carbide tip will clean it up in minutes.

The more shallow Mocal caused the fittings to interfere with some bosses on the block so it was far more difficult to install the lines. All adjusting had to be done off the block, then reinstalled to test fit. Bending -10 braided lines is a bitch in such a tight spot- inevitable the lines don't watch to thread straight, so patience is imperative.

I just left the small cooler installed since the larger cooler is going to require custom lines and maybe fittings. I'll just keep an eye on the ebay nascar surplus for deals. Anyway, this will give a direct comparison between the two plates for performance.

I played around with positioning the new big cooler in front of the steering rack and getting air from the spoiler ducts is going to require some serious plastic fabricating. The ducts are definitely design to go right to the brakes- which means I'll probably end up hacking the back side of the spoiler ducts up to get them over to the cooler.

http://i158.photobucket.com/albums/t...x5t/mocal4.jpg
http://i158.photobucket.com/albums/t...x5t/MOCAL1.jpg

Mine's around the size of the larger photo above. I don't have a condenser anymore to get in the way. I don't have a thermostat, but the OEM water/oil cooler, so the oil temps are still being adjusted by the coolant temps. The lines are -8. The adapter on the block and remote adapter were touched up with a die grinder and cartridge rolls to enhance flow. The 90º fittings were also kept to a minimum.

You don't need a tstat in the everglades. :D
It was 22f the last time I drove my car, that's the only reason I have it. I really want to keep the a/c and have gone to great lengths towards that effort up to this point. There's room for everything up to this point, so that should be the last item after the go-fast stuff is sorted out.

IMO you won't need to cut any holes in the bumper. There is so much turbulence and air moving around there because of the tire so most likely all you'll need is a fan to force circulate air through the cooler and the tire will take care of the rest ...

I hope so. Plan was to install it first and see what the temps do. If they're still too high, then run ducts.

I've done some driving and the oil temps are nearly identical as before with the Hayden sandwich plate.

So the next step is installing the big mercedes cooler. And I've decided at this point to install it next to the radiator in place of the cold side IC pipe, and then run the cold side IC pipe around the rad and up to the TB. Just makes sense to do it this way since that really is the optimum spot on my car- direct air flow and better access to add a fan.

son of bitch
 

Day off and I'd planned to get the coldside IC pipe rerouted around the rad and get the oil cooler mounted. Looked to be a perfect fit until I slid it up and it came to a stop on the rad filler neck. :vash: Few pics to show the old IC pipe routing, oil cooler "almost" where it will go and the interference. I guess at this point I've got to cut my filler neck off and move it... somewhere. I might do a remote like splitime/dave. :dunno:

http://i158.photobucket.com/albums/t...fillerhump.jpg
http://i158.photobucket.com/albums/t...coolerspot.jpg
http://i158.photobucket.com/albums/t...olermount2.jpg
http://i158.photobucket.com/albums/t...olermount1.jpg

That's gonne be pretty nice when it's done. You could keep the filler neck on that side. Cut the neck and that hump off and move the whole thing back towards the motor. So it's offset closer to the throttlebody. That would give the cooler room and keep things simple. Just more aluminum welding.

:eek: I'm gonna need about 6 hours of practice before I put the mig to my rad... or I'll just wuss out and pay. But that puts the car outta commission. If I mig it right, it's done and I can reassemble.

I think it will be a good solution when it's done. Essentially a "twin" cooler with far more capacity and double pass cross flow rad for ~$300. When I'm done with this shit, I better have some oil temps in check. :cool:

Where's the radiator coolant inlet? Inlet and outlet both on driver side? Get rid of the AC and you'll have room and drop a good 30 or so lbs.

so close. that's just painful to see. :mad:

The inlet and outlet are both on the exhaust- it's a double pass rad. AC is NOT going, no way, never. :D Even if the compressor did try to fall off. :gay:

I think the easiest thing to do is put the cap on the front crossover coolant pipe (in front of the cam gears) and remove the filler on the rad tank sealing it shut. I've actually got an aluminum filler neck from a KL v6 that I could cut and weld on and get the similar result.
http://www.nfauto.co.uk/images/july2...iller_neck.jpg

Nice placement for the merc. oil cooler though. Thing is big! I think if I come to find I need one I might put it in the shroud between the firewall and windsheild. If oil temps get hot, you can open up the cabin vents to outside air for increased pull across the cooler. It only requires drilling holes for the oil lines to pass through the rad.

Where are you measuring oil temps from?

Eva- I think you meant "pass through the firewall". I'm not convinced that's the best place for the cooler. It's been my experience up to this point that putting the cooler in the easy to install spot is going to get you less for your effort. Of course that all depends on what your after in the end. I want acceptable oil temps after an absolute pounding on the track.

Temp is measured post everything- in the pan. Oil only turbo with total capacity of almost 5 qts. (4-1/2 in the sump plus the lines and small cooler). Ben and I were talking about the lack of oil capacity on most jap cars compared to the europeans- especially when turbos are added. I checked around for oil temps on some other cars - for example the turbo volvo 5 cylinders see around 260f peak with a hard track beating and 7 quarts of oil. Right now I see that and then some on a hot day with a some street boosted runs on my tiny oil cooler. That merc cooler is supposedly 1-1/2 qts - I'll check for sure.

I run the ISC remote filter/cooler kit. I am using a huge oil filter, generic SAE thread on the filter mount. With the smallish cooler and remote filter I have about an extra quart in the system. Hoses are -8. Probably be well over a quart once the whole turbo setup is installed. 347 Mustang I used to run had a 7 quart pan, remote cooler, and required 8 quarts to fill it just below the full line on the dipstick.

http://memimage.cardomain.net/member...70_77_full.jpg

http://memimage.cardomain.net/member...70_80_full.jpg

http://memimage.cardomain.net/member...70_78_full.jpg

I'm considering something like this

I think that'd be a lot more efficient if the sides were closed up (maybe it is?). I was going to try my cooler there next, but realized it would (based on my observations at the time) taken the same amount of work and wasn't up for another "try it and see".

I've seen a bunch of X nascar oil coolers that are about 4" tall, 4" thick and 28" wide. I bet they'd work fine under a FMIC in the front. There's a lot of vertical space up there w/o breaking the lower plane of the subframe.

Check this one out- that's a $2-300 oil cooler.

Have you considered a oil-to-coolant heat exchanger approach? This is used on several sportbikes and is a very compact system. It could be a viable approach especially if you have an oversized radiator.

This is used for biodiesel to coolant heat exchange to preheat the fuel before injection. Could work...
http://cgi.ebay.com/FPHE-20-Plate-He...QQcmdZViewItem

No - it might work on sport bikes, but it doesn't on race cars. I'm not sure if it's displacement or the fact that a sportbike cooling system see less duty. What I do know is that every race car out there that uses exchangers for both uses isolated systems.

I'm not to far from resolving this - the crossover now has a filler neck on it, I just need to pull the rad. Though I'm working on the EBC issue right now.

Well, every '94+ Miata has that oil cooler stock. It can't deal with the extra heat at track events, that's why people around are adding a second cooler inline (in addition to the stock one)

Maybe a lower duty cycle on the street, but for endurance racing we run them as hard as we can for hours at a time. :bigtu: Most everyone uses the stock cooling system.

At any rate, just a suggestion. Sounds like you are almost there with the oil-to-air approach.

i wish i could sort out all my MS crap and move on to real problems, like boost control and coolant re-routes, oil coolers, ducting and undertrays, etc. lol
props to you for being FI man, thats all i can say

How many years do you have in the project at this point? Your day will come. :D

Got the peace pipe (coolant crossover with filler neck) completed and pressure tested to 50 psi. :cool:
http://i158.photobucket.com/albums/t...fillerneck.jpg

Is that some of your aluminum welding skills? (looks like an AL filler neck)

Yes.... actually that's my grinder skills you're looking at. There's a lot of aluminum wire in there :gay: I had a big gap to fill.
excuse 2: the most retarded thing about this Clarke MIG spool gun is the fact that the wire speed dial (at the base of the gun) does NOT lock. So if you bump it, guess what? Surprise new wire speed. That got me a couple of times. I practiced a couple of runs but needless to say, this was not as good. That said, "pressure tested to 50psi". :D

Hey I've got a quick question about the mocal plate, I've got one myself. Do you remember the threads on it, I need to get an adapter to the an fittings?

thanks

1/2 NPT

Has anybody ever tried adding an exchanged to cool the water that goes through the OEM oil cooler, rather than hanging a second oil cooler in series with it? The coolant passing through that thing is typically 180° or so to begin with. If you were to mount a small water-air radiator up front and pass the water through this prior to the OEM oil cooler, it would increase the effectiveness. Plus it means you'd be running lines with a relatively low volume of low-pressure, non flammable water in them, rather than a high volume of high-pressure, flammable oil.