The specs for airflow for the stock cooler are 800L/sec at 4600 rpm, if I'm recalling that correctly. The stock oil cooler size is 3" x 3" x 8". Multiply that out and you get 72. Its location does no favors for cooling to cyl. #3. I agree that this is a very un-scientific means of determing how much cool you get from the stock cooler, but it'll have to work for now.
Consider this option: Add a GT style full mesh engine lid. One of our members makes these. Remove the factory cooler, machine 2 adaptors to go to some lines, (rubber, braded, whatever) to a thermostat mounted on the firewall behind the passinger. Kerry Hunter makes the adaptors, there may be others as well. From there, mount your new cooler, say a 8" x 8" x 2" to the engine lid. Multiply this out and you get 128. Now add a 1500 CFM 2 speed fan to the back of the cooler. Set the low speed of the fan to come on with the ignition, so you always have a flow of air out of the engine area, not pre-heating the engine cooling air or the intake air. Off of the oil cooler, add a thermo switch to kick the fan to high speed at, say, 200 or 225 degrees. Make a vinyl cover for the rest of the area of the GT engine lid, to wrap around the remaining open area and attach to intself with velcro, to stow behind your seat, and toss over the lid if it rains.
Here's where it gets interesting- an engineer friend of mine did some quick math in his head, and unless the coffee had not fully kicked in that morning, the factory rate of 800 L/sec equals about 1600CFM, or so he said.
Bigger motor? Add a bigger cooler or faster fan.
I'm thinking the additional open area of the GT lid would allow for some better cooling for the motor and intake. I would again think, just from looking things over, that the area behind the window is a lower pressure zone on the car, (I could be totally off on this), and using the fan to promote airflow out of the engine area would also promote cooler air to flow in. And more air exchange, from warner to cooler, in an aircooled engine room can't be a bad thing...
Thoughts?
Full Version: Crazy oil cooler idea #27 (or so)
This has been done many times before in different variations. Problem is, where does the engine get it's cool air from? From the top side of the engine lid. Where does the oil cooler exhaust it's hot air to? To the top side of the engine lid. Unless you have a way to separate the exhaust air from the intake air, you will recirculate much of that exhaust air right back into the engine compartment.
Demick
Demick
I am glad to see people thinking outside of the box, but why. Can you guys stop cheapin' out and looking for the "easy" way out. Run the hardlines up front and install the cooler in the right place. Then you don't have to worry about whether it heats the intake/cooling charge, or get too much heat from the exhaust, or gets hit by rocks from the wheels. I get so frustrated with guys that ghetto engineering things. It would take the same amount of time to do it right and you wouldn't have to band-aid some crappy rigged setup later.
Brett
If you are building a race car, I agree with you 100%
However, for street cars (like most of us have), there are far lesser cooling requirements and other considerations as well. Other solutions can work just fine and are not 'ghetto engineering'. I have an aux cooler under the rear trunk, and it works great. Exactly what I need it to do in terms of cooling. Took 2 hours to install (cant say that about a front mounted cooler), cost hundreds less than a front mounted cooler, I didn't have to cut up the front trunk and still have use of the front trunk for my spare. Also didn't need to pull the engine to install a high volume oil pump (not sure if this is req'd with a front cooler either).
I get frustrated with ghetto engineering - but I also get frustrated with those who say there is only one 'right' solution to a problem. In this case the 'right' solution depends on many factors, so it will vary from case to case.
Demick
If you are building a race car, I agree with you 100%
However, for street cars (like most of us have), there are far lesser cooling requirements and other considerations as well. Other solutions can work just fine and are not 'ghetto engineering'. I have an aux cooler under the rear trunk, and it works great. Exactly what I need it to do in terms of cooling. Took 2 hours to install (cant say that about a front mounted cooler), cost hundreds less than a front mounted cooler, I didn't have to cut up the front trunk and still have use of the front trunk for my spare. Also didn't need to pull the engine to install a high volume oil pump (not sure if this is req'd with a front cooler either).
I get frustrated with ghetto engineering - but I also get frustrated with those who say there is only one 'right' solution to a problem. In this case the 'right' solution depends on many factors, so it will vary from case to case.
Demick
Brett- I agree, but can't do it that way due to... vanity. I just like the look of a stock front end 914, and have a 9/10 quality chrome bumper with a great rubber top, and I just can't bring myself to hack it up and pay the re-chrome the deal. Another thought I had, was to use the factory A/C unit for the front trunk and put a big cooler in there, knock out the round plugs at the front of the trunk, and duct that into the cooler enclosure. I'd probably put a cooler in there about 1/2 the size of the enclosure, to try to use the front 1/2 to "scoop" air out from under the car, and run it up and over the cooler in addition to the ducted air from the round knock outs. This would preserve the bumper/valance look I like in the front now, but I ? if enough cooling air can be sourced for the oil radiator this way. I'd also like to loose the factory cooler if I can to allow more engine cooling to #3. Is this any more crazy than the other plan?
Demick- how big is your cooler, with fan or without, and any picts to post or links to picts? I expect this is in addition to, and not instead of, the factory cooler. I'd considered a mount under the back as well, but was letting my mind go farther outside the box to see what was out there.
Demick- how big is your cooler, with fan or without, and any picts to post or links to picts? I expect this is in addition to, and not instead of, the factory cooler. I'd considered a mount under the back as well, but was letting my mind go farther outside the box to see what was out there.
Is the #3 cylinder really "that" much of a problem in a 914 as it is in a bug to warrent this much thought into this???
figure the 914 has been out for 30+ years.....
...almost everything has been done or tried in order to improve upon the car, I think this idea for the engine lid mounted cooler has been asked at least 5 times in the last year
...some ideas work better than others and those are the ones we see the most, such as the front mounted cooler....of course others have done what Demick has done with fine results, "except", he kept the stock cooler which might be the best and easiest way unless you need or really just want the additional cooling..which is fine...
figure the 914 has been out for 30+ years.....
...almost everything has been done or tried in order to improve upon the car, I think this idea for the engine lid mounted cooler has been asked at least 5 times in the last year
...some ideas work better than others and those are the ones we see the most, such as the front mounted cooler....of course others have done what Demick has done with fine results, "except", he kept the stock cooler which might be the best and easiest way unless you need or really just want the additional cooling..which is fine...| QUOTE (ottox914 @ Apr 19 2005, 09:35 AM) |
| Demick- how big is your cooler, with fan or without, and any picts to post or links to picts? I expect this is in addition to, and not instead of, the factory cooler. I'd considered a mount under the back as well, but was letting my mind go farther outside the box to see what was out there. |
Do a search for something along the lines of '2 hour oil cooler installation' and you'll find it. From about 3 months ago.
Demick
Here is the cooler I sell for mounting on the engine lid, at 22x12 It has plenty of cooling.
By using this cooler and the bypass that mounts up in line with the stock oil cooler you engine will run nice and cool.
And is plumbed just like the factory did it.
By using this cooler and the bypass that mounts up in line with the stock oil cooler you engine will run nice and cool.
And is plumbed just like the factory did it.
| QUOTE (Type 4 @ Apr 19 2005, 11:12 AM) |
| Here is the cooler I sell for mounting on the engine lid, at 22x12 It has plenty of cooling. By using this cooler and the bypass that mounts up in line with the stock oil cooler you engine will run nice and cool. And is plumbed just like the factory did it. |
Steve,
got data?? before and after oil temps??
I think I'll be just adding another cooler just like Demicks setup...seems the easiest and most cost effective...
There are a host of oil cooler ideas out thre. Some good, some not. Brett, you're right about runnign the lines to the front, if you're racing... Otherwise, putting around at 30 mph is not going to get much air through a cooler in the nose unless there's a fan attached to it.
I'm developing a setup for my 914 that will use a 22 row Mocal oil cooler w/fan (and thermo switch) in place of the factory oil cooler. It's mounted to the engine, not the lid, so the exhaust heat goes under the motor, not into it. I'm doing this for very specific reasons. The biggest reason is -the rules-. I'm building a car for Street prepared autox class in SCCA. And there are a number things that I'd like to do but can't. I can't cut sheet metal for ducting to an oil cooler. So, unless I want to hang my oil cooler in front of the bumber (making it the first thing to break should I hit a cone), I can't do it. Second, oil lines (and oil) add weight. I'll be in a class where I'll be light, but also underpowered, weight is everything. If I can shed 10 lbs off the car, I'll do it.
When the engine comes together later this spring, I'll post pictures.
-Josh2
I'm developing a setup for my 914 that will use a 22 row Mocal oil cooler w/fan (and thermo switch) in place of the factory oil cooler. It's mounted to the engine, not the lid, so the exhaust heat goes under the motor, not into it. I'm doing this for very specific reasons. The biggest reason is -the rules-. I'm building a car for Street prepared autox class in SCCA. And there are a number things that I'd like to do but can't. I can't cut sheet metal for ducting to an oil cooler. So, unless I want to hang my oil cooler in front of the bumber (making it the first thing to break should I hit a cone), I can't do it. Second, oil lines (and oil) add weight. I'll be in a class where I'll be light, but also underpowered, weight is everything. If I can shed 10 lbs off the car, I'll do it.
When the engine comes together later this spring, I'll post pictures.
-Josh2
Installing a cooler in the engine lid is like pissing in the wind..
The heat coming from the cooler increases fan inlet temp- Hot air doesn't cool.
Hotter air entering the engine bay also means hotter carb inlet temps, hotter air also doesn't promote HP.
Every 10 degrees of added carb inlet temp can drop power by 5% or so from what I have seen on my dyno when supplying cool air Vs hotter air to the intake system. This is why newer cars use ducting to scavenge inlet air from outside the engine bay.
Keep that engine bay as cool as possible and keep that cooler off the engine lid.
In my 914 with the DTM test engine I have a 48 plate mesa cooler mounted in the confines of the re4ar trunk with ducted air in and out of the cooler and with no stock cooler at all the oil will not get over 210 degrees. Of course part a huge part of this puzzle is the fact that the DTM is keeping the heads and cylinders cooler .
The DTM should absolutely allow for the removal of most of the external coolers on many engines out there, my test engine is a 2316.
All I lack is the final data from the datalogger that should be here in a week or so so I can publish the results effectively and accurately.
I avoid front mounted coolers at all costs on street cars.
The heat coming from the cooler increases fan inlet temp- Hot air doesn't cool.
Hotter air entering the engine bay also means hotter carb inlet temps, hotter air also doesn't promote HP.
Every 10 degrees of added carb inlet temp can drop power by 5% or so from what I have seen on my dyno when supplying cool air Vs hotter air to the intake system. This is why newer cars use ducting to scavenge inlet air from outside the engine bay.
Keep that engine bay as cool as possible and keep that cooler off the engine lid.
In my 914 with the DTM test engine I have a 48 plate mesa cooler mounted in the confines of the re4ar trunk with ducted air in and out of the cooler and with no stock cooler at all the oil will not get over 210 degrees. Of course part a huge part of this puzzle is the fact that the DTM is keeping the heads and cylinders cooler .
The DTM should absolutely allow for the removal of most of the external coolers on many engines out there, my test engine is a 2316.
All I lack is the final data from the datalogger that should be here in a week or so so I can publish the results effectively and accurately.
I avoid front mounted coolers at all costs on street cars.
| QUOTE (jhadler @ Apr 19 2005, 12:54 PM) |
| -Josh2 |
DAAAMMMMMNNNNN! Josh2 is back! Haven't heard from you in what, 5 or 6 years?
Josh...
Very good to see you posting here sir!
brant
Very good to see you posting here sir!
brant
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