Full Version: Oil Cooler - under engine lid?
Anyone have any good pics (and advice) on an aux. oil cooler (not in the front of the car) but either near the tranny or near the engine lid grill? My battery was relocated to the front so I have room.
Adding a cooler under the decklid will help preheat the fan inlet air and will increase engine bay temps....
These are not good for cooling efficienct, simply because hot air doesn't do a vetu good job of cooling a hot engine..
Get that cooler under the vehicle, in the trunk or up front..
The Setrab cooler from aircooled.net is outstanding..
These are not good for cooling efficienct, simply because hot air doesn't do a vetu good job of cooling a hot engine..
Get that cooler under the vehicle, in the trunk or up front..
The Setrab cooler from aircooled.net is outstanding..
I think your answer depends a lot on what type of motor you're running and how much extra cooling you need.
15 years ago, I ran a stock 1.7 at PCA time trails with a cooler bolted to the underside of the engine lid. Also had a temperature gauge in the car, and while I don't remember what temps it ran now, it wasn't a problem.
I now run a stock 2.0 in my street car with the same cooler mounted to the underside of the trunk on the right side, just behind the axle. Fabricated a bracket to hold it at a +/-60 deg. angle so as to better catch the air swirling around below the engine. That setup has worked great for summer highway cruising, including stop and go traffic. Oil temp gauge in the car is the un-numbered kind, so don't know exact temps, but generally never goes past vertical. Give great pease of mind for summer driving. (Anyone know what the actual temperatures are for those un-numbered guages?)
But this is all with stock motors. Something wilder will take more serious cooling.
As a racer, I've never liked the idea of front mounted coolers. Most don't appreciate that they are big drag components. A fundamental of Nascar and F1 speed these days is minimizing their coolder areas to minimize their drag. I'd much rather put a larger cooler in the back beside the tranny. It will only be cooled by the turbulent and warm air coming around and under the engine, so it will be less efficient and therefore larger, but drag effects should be negligent. Extra weight doesn't increase with the square of your speed like drag does.
My 2 cents.
Andrew
15 years ago, I ran a stock 1.7 at PCA time trails with a cooler bolted to the underside of the engine lid. Also had a temperature gauge in the car, and while I don't remember what temps it ran now, it wasn't a problem.
I now run a stock 2.0 in my street car with the same cooler mounted to the underside of the trunk on the right side, just behind the axle. Fabricated a bracket to hold it at a +/-60 deg. angle so as to better catch the air swirling around below the engine. That setup has worked great for summer highway cruising, including stop and go traffic. Oil temp gauge in the car is the un-numbered kind, so don't know exact temps, but generally never goes past vertical. Give great pease of mind for summer driving. (Anyone know what the actual temperatures are for those un-numbered guages?)
But this is all with stock motors. Something wilder will take more serious cooling.
As a racer, I've never liked the idea of front mounted coolers. Most don't appreciate that they are big drag components. A fundamental of Nascar and F1 speed these days is minimizing their coolder areas to minimize their drag. I'd much rather put a larger cooler in the back beside the tranny. It will only be cooled by the turbulent and warm air coming around and under the engine, so it will be less efficient and therefore larger, but drag effects should be negligent. Extra weight doesn't increase with the square of your speed like drag does.
My 2 cents.
Andrew
Here are some pirated pics
The other
There's and article on Pelicanparts that a guy wrote up about how he did his cooler under the rear trunk. It has pictures so you can get an idea.
You can simplify what he did by using a Mocal thermostatic sandwich adapter between the oil filter and oil filter console. Then you only have to run oil lines directly from it to the cooler and back. If I recall, his setup had a spin-on adapter, remote oil filter mounting, and separate thermostat. That made for lots of extra stuff to mount and plumb.
Like has already been pointed out, don't put the cooler under the engine lid.
Demick
You can simplify what he did by using a Mocal thermostatic sandwich adapter between the oil filter and oil filter console. Then you only have to run oil lines directly from it to the cooler and back. If I recall, his setup had a spin-on adapter, remote oil filter mounting, and separate thermostat. That made for lots of extra stuff to mount and plumb.
Like has already been pointed out, don't put the cooler under the engine lid.
Demick
Some pics of my setup are in this thread http://www.914world.com/bbs2/index.php?act...9874&hl=don9146
The engine is 2.7 with RS pistons and a solex cam. I only need to turn the oil cooler fan on iin stop and go traffic when it is 95°F out or on track days if it is warm.
The engine is 2.7 with RS pistons and a solex cam. I only need to turn the oil cooler fan on iin stop and go traffic when it is 95°F out or on track days if it is warm.
I bought my car like this, so I never questioned it.
I have an oil cooler sandwiched between the engine lid and the drain tray, connected with real braided hoses.
I've driven this car for HOURS on days where it was well over 90 degrees..... highways included. Never got above 1/2 the temp gauge.
I also have a cyl head temp gauge in my car, and that never got too hot either.
I have an oil cooler sandwiched between the engine lid and the drain tray, connected with real braided hoses.
I've driven this car for HOURS on days where it was well over 90 degrees..... highways included. Never got above 1/2 the temp gauge.
I also have a cyl head temp gauge in my car, and that never got too hot either.
My whole system is in the trunk..
Accusump, Setrab cooler, and two canton filters. I duct air through the cooler with outside air as the cooler is fully encapsulated in a shroud fed with two hoses. The air is roted out the rear and under the car..
Accusump, Setrab cooler, and two canton filters. I duct air through the cooler with outside air as the cooler is fully encapsulated in a shroud fed with two hoses. The air is roted out the rear and under the car..
Somewhat OT, but related.. That's where I plan to put my AC condenser (with fans). I'll use a GT style lid too. Won't affect cooling much as I'm going V8.
What about a NACA duct in the rear decklid plumbed through the trunk floor to a cooler mounted below? Might not be too bad. Hmm. Trekkor, you listening? As a bonus, when it's raining, you have water cooling! 
The hardest part would be making it so you can still open the trunk lid and even moreso, making it so you could still stow the top. 
hmmm. hmmm. hmmm.
The hardest part would be making it so you can still open the trunk lid and even moreso, making it so you could still stow the top. hmmm. hmmm. hmmm.
Ratheer than the NACA duct through the rear trunk lid idea, here is what I would do:
Mount the cooler to the underside of the rear trunk with a hole in the rear trunk above the cooler. Put a fan under the cooler sucking air through it. Then cut a hole in the firewall between the engine compartment and rear trunk, and build a duct to get fresh air directly from the engine compartment to the fan. I'd guess the duct would be about 1" to 2" high and 8" or 10" wide.
Then run the fan at low speed anytime the engine is on to prevent air from being sucked backward through the cooler into the engine compartment. When the oil temp hits 180 or 200 or whatever, the fan goes to full speed.
Demick
Mount the cooler to the underside of the rear trunk with a hole in the rear trunk above the cooler. Put a fan under the cooler sucking air through it. Then cut a hole in the firewall between the engine compartment and rear trunk, and build a duct to get fresh air directly from the engine compartment to the fan. I'd guess the duct would be about 1" to 2" high and 8" or 10" wide.
Then run the fan at low speed anytime the engine is on to prevent air from being sucked backward through the cooler into the engine compartment. When the oil temp hits 180 or 200 or whatever, the fan goes to full speed.
Demick
Any chance you could post some pics of your cooler setup Jake? 
| QUOTE (Demick @ Jan 19 2005, 06:32 PM) |
| Ratheer than the NACA duct through the rear trunk lid idea, here is what I would do: Mount the cooler to the underside of the rear trunk with a hole in the rear trunk above the cooler. Put a fan under the cooler sucking air through it. Then cut a hole in the firewall between the engine compartment and rear trunk, and build a duct to get fresh air directly from the engine compartment to the fan. I'd guess the duct would be about 1" to 2" high and 8" or 10" wide. Then run the fan at low speed anytime the engine is on to prevent air from being sucked backward through the cooler into the engine compartment. When the oil temp hits 180 or 200 or whatever, the fan goes to full speed. Demick |
that might help lower the engine compartment temps as well???
I beileve it was either Bern Bomb, or Bern Bros that did this set up
pdsa
oh ya
wf
| QUOTE (don9146 @ Jan 19 2005, 10:46 AM) |
| Some pics of my setup are in this thread http://www.914world.com/bbs2/index.php?act...9874&hl=don9146 |
What kind of cooler is that?
Anyone tried putting it in the front hood with a NACA duct?
when 924 GTS hood scoops attack...
when 924 GTS hood scoops attack...
| QUOTE (Jake Raby @ Jan 19 2005, 02:42 PM) |
| My whole system is in the trunk.. Accusump, Setrab cooler, and two canton filters. I duct air through the cooler with outside air as the cooler is fully encapsulated in a shroud fed with two hoses. The air is roted out the rear and under the car.. |
Jake....I'd like to see a pic of that set-up (if it's not top secret
)Still got room to put the top in there?
The top still fits..
I don't want to give out pics just yet because I have not finished testing it...
And I wanna sell the entire kit if it works well on the updated engine..
I don't want to give out pics just yet because I have not finished testing it...
And I wanna sell the entire kit if it works well on the updated engine..
Has anyone tried mounting in the front trunk where the a/c condensor would go? You could pop the plastic discs out from behind the front bumper on the 73-74's, duct that into a box over the cooler, and also add a small scoop under the car to pull air up and over the cooler, venting the air back below the car, as the a/c system did. I have a front mount a/c box and have been thinking about this. Might help on the corner balancing as well, given that our cars are a little rear heavy anyway.
Now if we're gonna start talking NACA ducts, I have a fantasy about that topic. I've been thinking how to get a well integrated AC system into a 914 for vacation crusing. Don't want to give up the front trunk space as is done in the usual dealer installed version. I was think a NACA duct in the rear quarter panel just behind the rear edge of the door, similar to the Boxster air intake location. Mount the AC condenser in the generous and unused space between the engine bay side wall and the outer fender. Screen the backside to keep rocks spinning off the tires from doing damage. AC condenser could be on one side, oil cooler on the other.
Andrew
Andrew
When I had my engine rebuilt I had them mount an oil cooler under the car, damn thing didn't do anything about the hot temps. Finally mounted the cooler where it should be. I've had this cooler installed now for almost 3 years without any problems. Also have a mocal thermostat for this setup.
This is where I mounted the thermostat
Not as pretty as others but worth maybe 10 to 15F oil temp on a hot summer day... diff: with 195/210 without 210/220.
Some interesting locations for coolers seen here. The ones mounted directly above the headers, or heat exchangers might do more harm than good, ecspecially in stop and go traffic, little air flow, and a big heat source right under them.
An extra cooler in the engine bay is not the ticket either, It will preheat the air needed to cool the heads by the fan.
It would be very interseting to see some data on before and after oil temp, AND head temps with some of these installations. Some installations may lower oil temps, at expense of head temps. maybe not a good trade off?
As per VW experience, that is well documented, for Bug, and Busses, one should not run an extra cooler int he engine bay, as they have learned it will preheat the cooling air. It is generally considered a no-no.
Porsche when they decided they needed extra cooling placed a cooler up front, away from the engine bay, in a good air stream, and near no hot exhaust components. It took more piping to do it, I bet they had a good reason doing it that way rather than an engine bay mounting, or over the headers.
Unless I see before and after temp readings of both oil and heads to the otherwise, i will believe that engine bay mounting is harmful, as is mounting a cooler right over a header.
A front mount is the best beat, however Porsche did for a year or so have a copper pipe "loop" cooler on the 911, basically a pair of metal oil lines that went along the rockers and intot he front fender area. The pipe was coiled a couple times, and routed back to the engine, it was later replaced with a "real" cooler, however it must have helped some, and might be an option if one does not want to cut the front bumper for the correct factory front cooler. perhaps a loop of pipe could be routed behind the fog light grill(s) to get good air flow? Or maybe just mount a pair of small coolers behind the fog light grills (you won't have stock fog light then).
the 914 has a sealed lower engine bay for a reason, to assure that only cool air gets to the fan, run a cooler on the engine lid, and oil might be cooler (depending on air flow) but you will increase head temps. I have found thru testing on a Bug motor that head temps track fan inlet temp, so a 50F rise in fan inlet air temp (engine bay temp) will give about an equal rise in head temp.
An extra cooler in the engine bay is not the ticket either, It will preheat the air needed to cool the heads by the fan.
It would be very interseting to see some data on before and after oil temp, AND head temps with some of these installations. Some installations may lower oil temps, at expense of head temps. maybe not a good trade off?
As per VW experience, that is well documented, for Bug, and Busses, one should not run an extra cooler int he engine bay, as they have learned it will preheat the cooling air. It is generally considered a no-no.
Porsche when they decided they needed extra cooling placed a cooler up front, away from the engine bay, in a good air stream, and near no hot exhaust components. It took more piping to do it, I bet they had a good reason doing it that way rather than an engine bay mounting, or over the headers.
Unless I see before and after temp readings of both oil and heads to the otherwise, i will believe that engine bay mounting is harmful, as is mounting a cooler right over a header.
A front mount is the best beat, however Porsche did for a year or so have a copper pipe "loop" cooler on the 911, basically a pair of metal oil lines that went along the rockers and intot he front fender area. The pipe was coiled a couple times, and routed back to the engine, it was later replaced with a "real" cooler, however it must have helped some, and might be an option if one does not want to cut the front bumper for the correct factory front cooler. perhaps a loop of pipe could be routed behind the fog light grill(s) to get good air flow? Or maybe just mount a pair of small coolers behind the fog light grills (you won't have stock fog light then).
the 914 has a sealed lower engine bay for a reason, to assure that only cool air gets to the fan, run a cooler on the engine lid, and oil might be cooler (depending on air flow) but you will increase head temps. I have found thru testing on a Bug motor that head temps track fan inlet temp, so a 50F rise in fan inlet air temp (engine bay temp) will give about an equal rise in head temp.
Adding a cooler close to the exhaust is not going to be as effective as mounting it up front. Yea, it might get you 5 degrees cooler, but the majority of race cars have the cooler up front, and it is there for a reason. I guess that it could cause a bit of drag, (look at the intake on F1 cars right above the drivers head) but I think that is something they just deal with, as it is guaranteed to keep the temps where they should be. IMHO, your best and most effective bet is to mount it up front.
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