ok so this week I end up with an automatic radiator for my manual car, no biggie, but has anyone ever thought to use the transmission fluid cooler for an oil cooler? you can use a remote oil filter housing and plate etc , is it even worth it? I mean it isn't hugely expensive https://www.jegs.com/i/Trans-Dapt/969/1020/10002/-1 as an example, but if you had a manual transmission car seems away to keep the oil cooler , which would keep the engine cooler and improve the performance of the oil, ( I am guessing) just thinking out loud and thought it would be an interesting discussion maybe not lol

 

As one Hansen to another, I'll say that your notion "might" have merit. Cooler oil should lubricate better and last longer. I suppose that you should first compare the normal operating temperature of the oil to the coolant temperature. There would need to be a significant difference to justify the plumbing change. Then you'd want to insure that filtration and volume of oil to the engine would not be compromised with the revised plumbing.

 

Engine oil is thicker and higher viscosity that ATF. The ATF cooler in the radiator won't flow enough oil and will become a restriction. The oil cooler in the Olds diesel cars used larger lines and fittings, as an example.

 

I doubt a radiator reservoir is designed to hold 50-60psi of oil pressure. Better off with a good stacked plate unit

 

There is not enough cooling capacity in the radiator to do anything substantial.

 

Diesel cars had the engine oil cooler in the radiator.

 

yes they did,you could grab the oil filter housing off a diesel and be set up,but i don't know if they make lines anymore.your best bet could be to just use the ends and a couple inches of line and flare the ends and try to find hyd hose to fit.a better idea might be like my 92 chevy pickup with diesel,had hoses,with aluminum ends.the ends took little E clips to hold them to the block fitting and rad fittings,the ends were crimped on like a/c hoses.they might be a better choice.and my 94 suburban had a separate oil cooler that sat in front of the rad,hoses came out the bottom and worked around to the drivers fenderwell then down to the filter housing.

 

maybe they had the radiator specially designed? I know it was a goofy idea, but I hate seeing things go to waste as I ended up with an automatic capable radiator I was thinking of someway to make it a positive LOL...

 

You could use the transmission cooler as a power steering fluid cooler. This would be especially handy if you tow often. My 86 Ford F250 has a PSF cooler on it.

 

Just as a reinforcement - I learned the hard way that an engine oil cooler must be extremely low restriction. I used a multi-fluid cooler from a late model car that had 3 circuits, one of them using 1/2" hose bibs, for trans, P/S and engine oil cooling. Used the big one for engine oil. Guess what? Too restrictive, wiped out bearings.
Those spin on adapters are pretty cheezy, plus that leaves the bypass in the oil filter housing. It's better to either directly tap the block for 1/2 npt, or get a block that replaces the filter adapter with AN fittings. There's an old design floating around that sticks the fittings straight out, and Larry is now making some that point the fittings towards the back.
All good fun, but only worthwhile if you're doing something special with the engine that so it needs an oil cooler, or you've actually run into oil temp problems. I started down this path because my 403 would slowly lose oil pressure cruising down the highway. Oil was getting hot and thinning out.

 

Boy, if this all isn't just another fix-what-ain't-broken issue. If oil cooling were helpful, wouldn't the factory have done something like that starting in, oh, I don't know, 1897?

Remember, engines run more efficiently when they are HOT, not cold. This obsession you see on this site with people pushing the panic button the moment the temperature gauge even thinks about touching 200F is beyond understanding. I had a '75 Nova when I was in college, and I put a temperature gauge on it for the hell of it. It routinely showed a temperature around 215F, and I never gave it a second thought. I assumed that the car was running properly at the time I installed the gauge (the car was only 1 year old at the time), so I assumed whatever the gauge reading was when I first installed it was what it should be and went from there.

An oil cooler will, of course, cool the oil, which means cool the overall engine operating temperature, which means make the engine operate LESS efficiently, which leads to incomplete combustion, carbon build-up in the cylinders, and a host of other ills. As Joe Padavano himself has said many times on here when people talk about second-guessing the original design of something, the engineers who designed and built Oldsmobile engines were not stupid. If oil coolers would have helped or made a difference or anything, engines would have included them. But they don't and never have. I'm guessing there's a reason for this.

 

Can we have a few more details here? It's normal for oil pressure to decrease as the oil warms up. It's normal for oil to get "hot." But it won't get any hotter than the engine itself, so if your engine is not overheating, the oil should not be getting too hot and thinning out to the point that it's not effectively lubricating.

To what value did the oil pressure decrease? Multiviscosity oils are designed to withstand the operating temperature of an engine and continue to lubricate effectively. If you have oil "thinning out" problems, then you have the wrong oil.

 

Engine oil is designed to run at high temperature. Around 180-190 degrees I believe.
The engine designers know this and so do the oil companies, So why did Oldsmobile diesel powered cars have engine oil coolers?
My guess - if you know better I'm happy to learn - is the greater reciprocating mass of the diesel pistons, and the rapid contamination of the engine oil made it necessary.
Certainly the extra cost of building it into the system would have to be justified to the bean counters at the production design stage.

Roger.

 

From what I've read, engine oil cooling is used most often as another means of cooling the engine, not specifically to cool the oil. Motorcycle engines use oil cooling because they don't have liquid cooling. When the motorcycle is cruising down the highway, the wind blowing over the engine is enough to cool it. But when it's stopped in traffic, with no fan, there is no air blowing over the engine at all, and oil cooling is used to prevent the engine from overheating. This is also the case for some aircraft engines that don't use water cooling. When in flight, there is plenty of air flow to cool the engine, but when idling on the runway or taxiing, when the air flow is much less, oil cooling keeps the engine cool.

Wankel rotary engines used oil coolers for this same reason as those engines run hot.

Oil is nowhere near as efficient as water when it comes to cooling as it has only about half the heat capacity.

 

Oil temperature in my 2010 Challenger SRT8 would quickly reach 260° when driving at my usual (excessive) speed in the mountains. I had to cut my speed in half to keep the oil from exceeding 260°. If I didn't slow, I'm not sure how high the temperature would have reached.

Some research revealed that the Gen III Hemi used oil squirters under the pistons to minimize temperature-induced detonation. That was the source of the excessive temperature under high load.

I put in a purpose-built stacked-plate Engine Oil Cooler and plumbed it into the engine oil system using a sandwich between the oil filter and oil filter mount. Now the max oil temperature I've seen in the last 9 years and 80,000 mi of road trips has been 230°.

From my experience, there are two additional things you need to consider here:

• measure your oil temperature before you decide to put in a cooler. The oil temperature in our (non-diesel) Olds engines may not get hot enough to warrant using a cooler.
• if you use a cooler, install an oil thermostat that only allows oil cooling when the oil exceeds 215° or so. The oil needs to get hot enough to boil off water from blowby and needs to reach a high enough temperature so that it can flow freely to deliver adequate oil to the engine.

If you decide to put in a cooler, let me know and I can help you with detail design information. You absolutely don't want the cooler to be a restriction in the oil system.

 

The first, and biggest issue, you will introduce is by using the radiator as a cooler is excessive differential pressure drop across the cooler. With the tiny lines used, I suspect that differential between you outlet and inlet ports will be substantial and would probably damage the engine due to restriction if the oil is forced through the cooler path.

Oil cooler line sizing should be a minimum of AN10 and preferably AN12 in size to minimize restrictions. Then, you need to look at the cooler specs itself. I wouldn't use anything that has more than a 3 - 5 psi drop across the cooler. If you need to run multiple coolers in series, then the total differential drop still needs to be in that range - which means more expensive coolers because now they need to each be sub 3 psi.

Liquid to liquid oil coolers are extremely efficient - a lot more so than air to oil coolers. But, you need a system specifically designed for this type of application and they are expensive. Expect a radiator with a good liquid to liquid oil cooler designed to work together to run upward of $1,000.

Building a good air to oil cooler system for your car would be easier, but still expensive using decent components such as Setrab. Expect that to cost $500 - $800 depending on the size and type of cooler needed to meet application needs as a starting point.

In a street driven application, you should also add an oil thermostat that bypasses the cooler until the oil temperature hits a minimum of 180 degrees.

Bottom line, a poorly designed system will cause more harm than good. And, today's synthetics can be routinely run at 230 - 250 degrees with little impact. A lot of modern performance cars will not go into limp mode until oil temps approach 300 degrees. Of course, I prefer to keep oil in the 200 - 215 degree range during normal driving.

 

Thank you will do "If" I go that route. much appreciated

 

I hear what your saying, Jaunty, but many cars did have factory oil coolers, MG, rover, jaguar, modern camaros and corvettes all had original engine oil coolers, and they may not have been put in not due to better performance etc, but because in the design requirements there is, assembly line considerations , budget considerations, maintenance considerations and as you rightfully say what is the return and IF its really necessary. but I do see where you are coming from :-)

 

External oil coolers and plumbing are a common modification on air cooled VW engines, especially if they're being used offroad.

 

For what it’s worth, I did a fair amount of research before deciding to disable the engine oil cooler on my Tbi k1500. The only time the oil cooler was considered a requirement for that vehicle was extended time driving at very slow speed in low range with the a/c on. Otherwise the indirect cooling system ( radiator, water pump, coolant )was sufficient. Any one who has owned a mid 90 ‘s GM truck will jump at the chance to eliminate the possibility of oil leaks from hoses, lines and fittings that are required for a direct, oil cooling system.

 

I'm no expert but I've heard 75% of engine cooling is from the oil system. Maybe an aluminum pan would dissipate heat better. Ford had oil coolers on Drag-Pack cars, Talladega's, maybe some others. I recall seeing big tubes also. I think I would sump mine separately with it's own pump so as not to interfere with the main system. I'm sure there's and optimal temperature for best oil lubrication.

 

One of the better ways, if you have room for it, to cool the oil a bit, is to add more capacity to the system. A 7 or 8 quart oil pan, with the proper pickup is a good modification, with several benefits, including less chance of high rpm oil starvation, if properly baffled. I had no need to do this on my 350 Olds, but my Pontiac 455 runs a bit cooler with the 8 quart Milodon pan I have on there. If I ever had to replace the pan on my 350, for any reason, I wouldn't hesitate to purchase a bigger pan and pickup for that as well. I am not a fan of any more plumbing under the hood than necessary, especially when it involves the oil system. I have seen more than a few late model vehilces ruined with a remote oil cooler, simply by having leaking lines.

 

I bought a "stock" mylodon pan for my 455 it holds 5 quarts, and the filter makes 6 looks completely stock

 

I’m betting the Olds diesel used a oil cooler simply due to the added compression increases heat transfer to bearings, crank, etc. You can bet your last dollar that if the added expense of the oil cooler wasn’t needed, Olds wouldn’t have spent the money to design a oil cooler.


As for the oil temp of the SRT, 260 degrees oil temp is no big deal. Chrysler worked those engine far harder than anybody ever would on the street. The Chrysler transmission plant I work at use to have every current engine and transmission model in the test garage, mounted on engine dynos. Those engine ran 24 hours a day, 7 days a week, nonstop. Each one would make several full throttle up shifts, downshifts, forward and reverse, extended idle times, then back to full throttle tests. The only time they were shut down was for extended holiday vacation or routine maintenance. After a certain tome, the transmissions were torn down for inspection. I assume the engines get the same treatment.

I don’t think a oil cooler is a bad idea, but only if it can flow enough oil to keep things lubricated. I have never bothered to study the Olds diesel oil cooler system, is it a full flow system, with all the oil going thru the cooler? Or did it pump a little thru to take some of the heat out?

 

Oil Cooler

 

I want to reiterate that oil temps in the 250 or so range aren’t a big deal only if you are running high quality full synthetic oils. If your running conventional oils, you are asking for trouble with the first issue being a breakdown in viscosity.

Even with full synthetics, if you routinely have high oil temps you should shorten your change intervals. For example, Ford’s factory built race cars such as the Boss 302S, 302R, and FP350 have a 4 hour change interval. These cars run 260 - 280 oil temps depending on where they are raced during the spring through fall.

For a street car, I agree that before you invest in a good cooler system, you need to baseline your temps. If you only occasionally have high temps, just run a good synthetic. If you routinely gave high temps, consider a cooler; but you should also try to determine why you have high temps.

For example, if you have high oil temps at highway speeds in mild engine build and a 2.70 rear, you probably have an underlying issue. If the car has a set of 4.11s, yea, the oil temps will probably be a bit high after an hour long cruise at 60 mph.

 

[QUOTE=matt69olds;1245450]I’m betting the Olds diesel used a oil cooler simply due to the added compression increases heat transfer to bearings, crank, etc. You can bet your last dollar that if the added expense of the oil cooler wasn’t needed, Olds wouldn’t have spent the money to design an oil cooler.

The oil cooler on all TBI and vortech trucks was standard equipment on four wheel drive trucks. The two wheel drive versions of the same trucks did not have them. Also, oil coolers add more time to achieve proper oil pressure on start up. That was reason enough for me.

 

Huh? My 1999 Crewcab Dually 4x4 with 454 has a factory oil cooler. I've owned it since new and it currently has just under 300K miles on it. The engine has never been apart. There's never been an issue with time to oil pressure.

 

That’s awesome! My 93 K1500 5.7 has 320k plus and never been apart. It has knocked on start up until pressure builds since I bought it at 124k(thrust bearing issue but sounds like a rod knock). My point was why add the time to pressurize the Olds motor on start up when it is most likely not needed.

 

Liquids are incompressible, so there should be no delay in pressure build-up. Perhaps flow direction or cooler orientation was not correct. This could have trapped air in the cooler system. Air in the cooler would cause delay of pressure build.

With a stacked plate cooler, connections should be at the top.

 

The original post was about using the cooler in the radiator because it was there. With the oil cooler mounted higher than the filter and and the anti drain back valves that fail inevitably in the oil filter along with the help of gravity, make a space in the line that will need to be charged with engine oil every time it is started. Not a huge issue, especially in carbureted applications but why invite a problem by adding equipment that was not used by the factory in this application ,or the vast majority of enthusiasts with these engines that are especially known for their longevity as well as their performance?

 

OK, I understand. That would cause a problem after every oil change. If there were no drain-back valve, it would cause a problem on every cold start.

 

A quite common practice with European diesel engines, for the most part gasoline engines either had a squirt hole in the rod to send oil to the piston underside or relied on oil escaping the rod journals to do this. A good reason not to use a higher viscosity oil than the makers recommend imo.

Roger.

 

The bottom portion of the water jacket along the cylinders IS an oil cooler. Any oil that gets flung onto the bottom of the water jacket transfers heat to the engine coolant.

Thus the need for an oil cooler when the block has had the bottom portion of the water jacket "filled" with concrete or epoxy or whatever is the hot ticket this year.