How much cooling does engine oil do?

496BBC

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May 13, 2008
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Deep in the marsh, South Louisiana
I've been trying to increase the cooling capacity of my car for a while now, when cruising on the hwy my temps are around 220* to 230* at around 3000rpm. I'm curious on how much cooling I can gain by adding a LARGE engine oil cooler with a fan and shroud in the rear of the car. Does anyone here have any first hand experiance with adding an engine oil cooler and if so how big of a difference did it make.

I spoke with a member that said it helped alot on his car so I am in the middle of planning to add one. Right now I'm trying to decide what size and what type to buy.

Any ideas on which type works the best?

Neal :)
 
Quite a bit, all the heat from the bearings is dissipated into the oil and the surrounding block. The only sensible way to plumb it however is if you thermostatically control the output to the cooler.

Get a stacked plate cooler, much more durable than a tube & fin model.

Here's some oil cooler stuff for inspiration.

http://www.vettemod.com/forum/showthread.php?t=85
 
thanks for the quick reply TT, I just got off the phone with one of Haydens engineers. He gave me a couple of things to look at, one I feel stupid for not even thinking about (know what the oil temp is right now). I've read so many threads saying that engine oil temp is 20* to 30* higher than water temp that I've not even checked the oil temp to verify what my oil is running at. He indicated that if the oil is not hot than adding an oil cooler will do nothing to help the water temps.

I've ordered an oil temp gauge so I will know what they are when I get the car running again.

Neal :)
 
thanks for the quick reply TT, I just got off the phone with one of Haydens engineers. He gave me a couple of things to look at, one I feel stupid for not even thinking about (know what the oil temp is right now). I've read so many threads saying that engine oil temp is 20* to 30* higher than water temp that I've not even checked the oil temp to verify what my oil is running at. He indicated that if the oil is not hot than adding an oil cooler will do nothing to help the water temps.

I've ordered an oil temp gauge so I will know what they are when I get the car running again.

Neal :)

I just take my temp probe to my DVM and touch it with heat sink compound on the oil pan, OR, my later lazy device, the IR heat gun either way I have verified them both to track accurately.....I would guess the oil is in such a hurry in there being sprayed all over the joint that the temp variation would be less than 10f.....

:eek:
 
Heres were I'm at right now, I've got an adapter installed between the filter and the block, its got a thermostatic controlled bypass built into it were it will bypass the cooler with a little oil while the engine is warming up. I'm also gona install a oil temp controlled thermostat as TT suggested between the adapter and the cooler so 90% of the oil will be bypassed back to the engine until the oil comes up to temp. Then the oil thermostat will control the oil temp by diverting oil to the cooler. The thermostat is designed to divert oil back to the engine until the oil temp reaches 170*, at this point it will start diverting oil to the cooler and at 180* all oil will be diverted to the cooler.

I'm looking at a large Fluidyne cooler, the size of a radiator to mount under the rear of the car. The reason I want a large cooler is to compensate for air fow. I'm going to mount two 12" fans on it and want them to run all the time so heat form the cooler don't effect the fuel tank. I'm going to install an insulated sheild between the cooler and the tank so I don't think it will be an issue. When speaking the member that shared his install with me he did some testing on his install and it had little to no effect on his fuel tank. He also installed a sheild between his cooler and tank.

Neal
 
My 69 ran warmer on the highway (70 MPH +) than it did around town. I took the front license plate and bracket off. More air= better cooling. It still gets warm, 12.5 compression, lots of timing, and 4:11 gears get credit for that, but it's liveable. Maybe you could open up the bumper in the center unless you have to run a front plate.
 
My 69 ran warmer on the highway (70 MPH +) than it did around town. I took the front license plate and bracket off. More air= better cooling. It still gets warm, 12.5 compression, lots of timing, and 4:11 gears get credit for that, but it's liveable. Maybe you could open up the bumper in the center unless you have to run a front plate.

I removed the headlights and ran like that, made no change in temps. I'm running 4:11's, lots of timing and a 3 speed tranny with a stall so we know were the rpms are at hwy speeds.

Neal
 
Are you running the factory trans cooler mounted in the rad core? With a 3 speed auto and a manly converter (2,800+) you are going to be throwing a ton of heat into the radiator going down the highway.
 
You sure mount your coolers in unconventional places. My oil cooler and my tranny cooler is up front where it gets on the average 65-85 mph of air flow. No additional fans needed. I also modded my front bumper for the additional air flow where the front plate used to be. I also use my old AC condensor for my tranny cooler and don't use the tranny cooler in the radiator. What are the weather conditions where you live?
Bee Jay
Edit: Nevermind, I used to spend my summers growing up in Franklin, just south of Lafayette. It sure can get hot and humid there. I don't visit in the summer anymore.
 
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I was able to get the small leaks fixed and take a ride in my car to see if I had done any good with the oil cooler install.

The first ride wasn't good, I had let the battery go dead while the car was sitting there being worked on. This caused the fan controller to lose its settings so on the first drive I had no fans running. The hwy is close to the house so the temps stayed down till after I was cruising. At 2800 rpm the temps slowly climbed to 215* and hung there tile I had to stop and turn around, they climbed to 230*, once back on the hwy and the rpm up to 2500 the temps came back down to around 220*. This had me scratching my head till I got home and realized the fans weren't running.

After setting the low and high temp trips I started the car again and waited for the fans to kick on. Nothing, so I had to start troubleshooting, the low speed light indicator came on but the fan did not. After a closer look I found the issue, it was a weatherpack plug that had gotten hot and was not making a good connection. I removed the connector and connected the wires straight to each other. Then gave it another try, bingo the fans came on and ran as before. I have an override switch wired into the circuit so I can run both fans when needed.

It was late so another drive would have to wait. The next day it was raining so no drive, there is rain forecasted for the next 4 days here so it wasn't looking good for a test drive.

Today the rain had been light early with no rain this afternoon so I decided to take the car for a drive. With the car sitting running for a good while to warm up and to make sure the fans would run, the temp stayed right at 167* (temp gun) so things were looking ok.

Took my time getting to the hwy to let the engine bay warm up, once on the hwy I got up to about 2800 rpm and held there. The water temp held at about 175* while the oil temp was at about 180* to 190*on the inlet of the oil cooler and around 110* to 120* at the outlet. Now keep in mind that the oil is not diverted to the cooler totally until it gets to 190*so the oil is being split between the cooler and being bypassed to the engine. I have a third gauge in place to get the oil pan temp but I don't have it connected right now so the temps I see are at the inlet and outlet of the oil cooler. I'm sure the temp of the oil will be higher in the pan than at the cooler.

After being on the hwy for around 10 minutes I pulled into a drive and turned around to head back home. The water temp stayed right at 175* so I decided to kick the rpm up and see what would happen. Brought them up to 3500 (about 70 mph) and held them there, right away the temp dropped down to about 170*(by the gauge), slowed to about 3000 and the temp held to right at 170/175*. This is without a T-stat and with both 11" Spal fans running. Also the outside temp was around 78* compared to 98* back when I was running at 220* to 230*without the oil cooler. The real test will be when the rain stops and the temps come back up to the 90's.

One other thing I did was to rout the bypass hose from the intake through two small heater cores that I mounted up front right behind the grills in the bumper back to the water pump. This should add some cooling capacity while driving. Prior to this I had tried to remove the bypass hose and plug it off but the temps would swing wildly, I think the stage IV pump was cavitating with out the hose connected.

I'm going to install the T-stat in hopes to stabilize the temps although they didn't swing much from the hwy to in town driving.

More updates to come after more test drives
 
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Bee Jay,

my thoughts on where I mounted the coolers were to get them out of the air flow stream of the radiator. I am looking for the greatest air temp gradient for maximum cooling at the radiator. The heat added form the oil coolers and the trans cooler would add heat to the incoming air and reduce the temp gradient. The engine is making a lot of heat and the air flow through the engine compartment may not be very good.

The engine compartment is packed with engine and accessories; the serp drive doesn't leave much room on the front of the engine for air flow. With the electric fans being angled down right into the cross member the air flow is restricted. The air flow across the engine is reduced due to the angle of the fans and no shroud.

I've been looking for ways to increase air flow through the engine compartment I've just not come up with any that will make an appreciable increase.

Any ideas?

Neal
 
Bee Jay,

my thoughts on where I mounted the coolers were to get them out of the air flow stream of the radiator. I am looking for the greatest air temp gradient for maximum cooling at the radiator. The heat added form the oil coolers and the trans cooler would add heat to the incoming air and reduce the temp gradient. The engine is making a lot of heat and the air flow through the engine compartment may not be very good.

The engine compartment is packed with engine and accessories; the serp drive doesn't leave much room on the front of the engine for air flow. With the electric fans being angled down right into the cross member the air flow is restricted. The air flow across the engine is reduced due to the angle of the fans and no shroud.

I've been looking for ways to increase air flow through the engine compartment I've just not come up with any that will make an appreciable increase.

Any ideas?

Neal
It looks like you've added an 80-82 front bumper. What is behind that, a 74-77 Vette? Have you removed the battering ram/air reservoir tank. It will remove a major obstruction in front of your radiator and lighten your car about 60 lbs. Also, the Big Block chrome bumper guys remove their front license plates to significantly reduce water temps. I modified my '79 front bumper to do the same thing. It made a big difference in my water temps. If you look up at the middle opening in my bottom pan in front of the spoiler you will see where I mounted my oil cooler. It lays flat in the air stream, but the spoiler forces air up thru it. It's a plate oil cooler and my oil temp is usually 20 degrees lower or the same temp as the water temp. My water temp is down 15-20 degrees also with the front plate gone.
Bee Jay
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I've been thinking about cutting the battering ram off to open the area were the front plate would go. The reservoir is another story; it has the core support lower brackets mounted to it. On my car these brackets help support the nose of the car. I've had to adjust them to make the nose sit level.

Did you add another bracket to support the lower core support?

Did you do this work while you had the bumper off for re-painting?

Do you think the battering ram can be removed without removing the bumper?

I may cut the battering ram off and open the bumper to give that a try. I should be able to do this without removing the bumper.

I've done some low buck air flow tests with a blower on the front of the car to see how the spoiler directs air flow and the vacuum reservoir is right in the way. The air flow has to go around the reservoir creating a void on the back side of it. This may have a negative effect on the lower section of the radiator.

I thought the idea was there is a high pressure area in front of the radiator and a low pressure area on the engine side. I was not too concerned with flow but more about pressure (packing as much air in front of the radiator).

Thanks for your input, Neal

I've been through Franklin a few times, allot of southern heritage there.
 
Yes, you can remove the battering ram/air reservoir without removing the front bumper cover. See how here:
http://forums.corvetteforum.com/c3-...servoir-bumper-support-removal-questions.html
The brackets on the air reservoir that holds the front end together can be cut off. That is what I did, then place it back in it's spot. It's as if the ram is still there. You will have ot remove the bumer cover to modify the license plate area for additional air flow. See how I did it here:
http://www.vettemod.com/forum/showthread.php?t=4274
Bee Jay
 
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Yes, you can remove the battering ram/air reservoir without removing the front bumper cover. See how here:
http://forums.corvetteforum.com/c3-...servoir-bumper-support-removal-questions.html
The brackets on the air reservoir that holds the front end together can be cut off. That is what I did, then place it back in it's spot. It's as of the ram is still there. You will have ot remove the bumer cover to modify the license plate area for additional air flow. See how I did it here:
http://www.vettemod.com/forum/showthread.php?t=4274
Bee Jay

Thanks, I'll take a look at those threads and see what I can do

Neal
 
Yes, you can remove the battering ram/air reservoir without removing the front bumper cover. See how here:
http://forums.corvetteforum.com/c3-...servoir-bumper-support-removal-questions.html
The brackets on the air reservoir that holds the front end together can be cut off. That is what I did, then place it back in it's spot. It's as of the ram is still there. You will have ot remove the bumer cover to modify the license plate area for additional air flow. See how I did it here:
http://www.vettemod.com/forum/showthread.php?t=4274
Bee Jay

Thanks, I'll take a look at those threads and see what I can do

Neal

I just looked at your pictures. There isn't a clear picture of your spoiler/bumper from underneath, so I assume you have it all there and the spoiler is forcing air up into the radiator. Something else to consider, where are your headlights? I sealed my radiator up really good. So much that at 140 mph, with the additional air being forced thru the license plate grill, the headlights pop up because of 0" manifold pressure at wot. You have to have some positive pressure in front of the radiator, and that forces air to flow thru the radiator. With no headlight covers, that air may be escaping thru the headlight openings instead of going thru the radiator. This is only a Bee Jay theory.
Bee Jay
 
Everything that is suppose to be there is there, minus the honey comb that was in the front bumper and the stock spoiler.

The headlights are fixed buckets without covers. I had covers on but they would fog over in the morning blocking a good bit of light from the headlughts. I didn't think about the possibilty of air escaping form the headlights, I'll look into sealing them up.

Thanks Neal
 
After taking a closer look at the frontal area of my 80 style bumper it appears that the open area is a good bit smaller than the original 77 bumper. The instructions that I got with the 80 style bumper re-used the original grills. The grills are at the wrong angle for the bumper and the area that they are installed in is a good bit less. There appears to be a good bit of room to enlarge the openings for the grills and also open the area were the plate would go.

Once I get in there I'll look a little closer at the reservoir.

Neal
 
After taking a closer look at the frontal area of my 80 style bumper it appears that the open area is a good bit smaller than the original 77 bumper. The instructions that I got with the 80 style bumper re-used the original grills. The grills are at the wrong angle for the bumper and the area that they are installed in is a good bit less. There appears to be a good bit of room to enlarge the openings for the grills and also open the area were the plate would go.

Once I get in there I'll look a little closer at the reservoir.

Neal

To each his own, but I bet a '73 style bumper would look better and cool better. Just my humble opinion. I like the C5 Z06 wheels. I think I remember when you bolted them on. I would love to see under your bumper to see the size of the bottom openings. Sometimes when you bolt on an 80-82 bumper, you have to bolt on a bumper extension. Did you? You sure don't need that reservoir with non-pop up headlights.
Bee Jay
 
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