Choosing an oil cooler system

It is my intention to fit an oil cooler to my Z in the near future. I have three coolers on the shelf. Two are Long Manufacturing stacked-plate coolers, one is OEM fitment to the 1991 Ford E150 Van Transmission cooler, and the other is OEM fitment to the 1989 Ford E150 Van. Both are 10.5" wide and 1.375 inches thick. The guy I use to clean coolers like this works down at the airfield, and has a big flushing machine for doing aircraft oil coolers...If the FAA lets it fly, it's good enough for my engine too! Those guys have to do some serious maintenance on really short intervals.

The 1991 cooler is slightly larger, and has 5/16" inverted flare fittings.

This cooler has been professionally flushed, and when I removed it from service the ATF in the transmission was clean and metal-free. I removed it from a running, driving, perfectly fine truck that was being scrapped out at my employer due to rust. The cooler was about two years old, having been replaced when I replaced the transmission in that truck.

The 1989 cooler is smaller, and has integral 5/16" hose barb fittings.

This cooler has also been cleaned by the same professional service, and when removed from the junkyard van it had very clean engine oil in it...not transmission fluid. It is possible this was fitted by someone other than the factory...although it was a factory fitted part for that year and model. Who knows? This cooler is the same width, but about two inches shorter top to bottom than the above model.

The third cooler is also a transmission cooler...this time built by Niagra Fabrication, with a Ford part number on it. This was removed from a Taurus SHO. This cooler has 3/8" hose barbs on each end, and is a bar-and-plate type cooler. It is 4.5" tall, and 18" wide, not counting the end tanks.

This cooler has integrated mounting points with clip nuts in it, and I can modify it for any size fitting I want on each end without as much risk of rendering it useless. It is currently filled with lacquer thinner, as I haven't had it flushed yet. It will have to go in the front of the car; but I am running out of room. Not sure if I can use it yet, I'll have to look and see in the daylight.

The two stacked-plate cores I could mount in the fenderwell below the headlight, and duct cool air to them via the brake duct holes in the air dam. The long, thin one I am not sure I could do that with; I could mount it to the front of the core support and blow air down through it, but that seems like a less desirable way to go. I would prefer to mount it in the normal manner, but I don't think I have enough room unless I mount it below the core support and duct in air from the brake ducts on each side.

Thoughts, ideas, Advice? Where was the stock ZXT oil cooler mounted, and how was airflow directed through it?

I am no expert, but I am of the belief a cooler for a performance engine needs to have good flow to reduce the risk of impeding the oil flow. For this reason I would opt for the first option as it seems to have a good sized inlet and outlet to allow good flow.

I thought transmission coolers couldnt be used on engine oil because of the pressure?

Automatic transmissions regularly see 100PSI of line pressure, and all the above have been tested in excess of 150PSI by me. Not sure about the pressure *drop* though...although the bar-and-plate unit seems to have the lowest drop of all the three above.

The first option has the 5/16" inverted flare inlets, but the last option has 3/8" hose barbs. I can modify the last option to have -8AN fittings, as well.

the better option would have been to use a z32 twin turbo oil coiler

Yeah, good luck finding one of those in the yards. I can't even find a Z31 turbo that hasn't been stripped in hours, it's next to impossible to find a Z32 at all in any shape in the yards.

Ford trucks and vans almost all have them...and any of the higher-revving or higher-power cars. RX-7 cooler would be great...but they're rare as hens teeth around here too.

Almost all of my go-fast parts are stock parts from other vehicles...Radiator, A/C condenser, Intercooler core, fuel injectors, oil pump, fuel pressure regulator, complete brake system, wheels, electric fans, A/C compressor, dash gauges, ect....all stripped out of pull-a-part yards for pennies on the dollar. All took a little cleanup work, inspection, and thought...but all work just fine.

i always fit a new oil cooler on every build -10 fittings and at least 13row  , factory oil coolers are not up for a hot engine with double the factory hp , have a look at the earls rang of coolers there not dear and there top quality.

A good oil cooler will make your bearings last so much longer and will keep the water temp down as well , one more thing if you run a aftermarket sump like the Arizona z one the oil will run up to 10c cooler with out a oil cooler there ally construction and fins really rip the temps down

also if the engine has had a blow up throw the cooler out you can never get them clean , no mater how hard you try clean them , every race team has this policy and for good reason

Yep...that's why the FAA requires such strict cleaning procedures every 300 hours of running the engine. It's almost two days on four different flushing machines...and they DO get clean inside. Nothing bigger than 10 microns is allowed to be found at ALL after a flushing, when they inspect the filter. That's any particle 1/3 the size of the smallest particle most normal oil filters will filter out...so that's three times cleaner than it will be after 3000 miles of use in the car.

If the engine has a blowup...the cooler is automatically dead. No amount of flushing will make it airworthy again. I inspect every cooler I pull for any kind of metal in the oil, and then they go to the FAA approved reman center to get cleaned and checked out. It's a good idea to pull your oil cooler every few years or once a season anyway and have it cleaned by one of these places, you'd be amazed at the crap that comes out of one on a good running engine!

If it's good enough to fly, it's good enough for my car...That said, the Earls coolers are the same as what ford installs on the trucks OEM, but the ford coolers usually are set up for 5/16" lines instead of the larger lines that the Earls units are. The big stacked plate cooler is rated by Long (the manufacturer) at being able to dissapate 30,000BTU's of heat...that should be plenty.

I am still trying to figure out how to mount the bar-and-plate core...those things are dead simple to get clean inside once you cut the tanks off the ends. It's just a little too long to mount the way I want, but I can't cut the endplates off, have to keep those so I have something to weld tanks on.

Hey XNKE

I used to work for Long Manufacturing...I was their Australian agent, so I know a bit about their products.

The stacked plate cooler has the lowest performance of their product range. It's appeal for OEM's is its low manufacturing cost and relative robustness compared with fin and plate coolers. Fin and plate is higher performance however. The reason is that the limiting constraint of all air to oil coolers is the air side heat rejection....due to oil's higher density, it's relatively easy to get the heat from the oil into the aluminium, but much harder to get the heat from the aluminium into the air at the same rate. As fin and plate has a greater air-side surface area, it's performance is superior. The downside (for OEM's), is that they are more expensive and more prone to damage and fouling from insects etc.

My personal preference is for oil-water heat exchangers. The appeal of this configuration is that both the fluids in question have higher density than air, hence heat exchanger efficiency (and therefore power density) is superior to air-oil. Additionally, the exchanger also warms the oil up which is good for the engine during starting and cold weather. Also, the exchanger does not require radiator packaging space (assuming you use a donut cooler or matrix cooler which you can locate wherever you want), and hence does not obstruct air flow to the radiator. Finally, as the oil cooler needs to do its best work at speed when the oil is hottest, you don't compromise radiator performance at lower speeds when air flow is limited due to vehicle speed, and when the speeds are high and the oil hottest, the radiator is working at its best. The design constraints you need to consider are choosing a water to oil exchanger that has an adequate rating to transfer the heat you need to reject, and of course configuring your radiator to reject the additional heat the oil will put into the engine coolant.

If you get the design right, it works very well.

Cheers

Jamo

And that level of performance vs durability is a good thing for me. I have a largeish cooler installed in a low point on the car...it will need to be a little more durable. It's not exactly going in a damage prone area but it's not shielded much either.

Going to be ducting it in behind the brake-cooling-duct on the air dam, exhausting air to the wheel well. Will be mounted below the right-side headlight bucket.

This question is for Peter Mc and/or Jamo

So oil-water heat exchangers what size would one use on a L28 with a large Datsun Competition winged sump making over 250 rwhp to keep temps under/around 210F. Currently car has a 16 row setrab unit installed which works but temps on hot days can go to 240-250F which is not ideal.

Cheers Mike

...........................................

 

Going to be ducting it in behind the brake-cooling-duct on the air dam, exhausting air to the wheel well. Will be mounted below the right-side headlight bucket.

That is exactly how mine is done on the S130, works well too. Can't understand why more are not done that way instead of mounting them in front of the radiator so they cause more hot air to go into the engine bay.

or in the wheel arch itself, the tyres turning at anything above 30kp develops quite the turbulence of dynamic air.

Just need to deflect any rocks flicking up into the wheel arch away from the cooler.

Nat0

My M3 engine has a pretty big oil-air cooler from the factory which I would happily use if I could make it fit but it has quirky O ring fittings that make this not practical so Ive bought some -10AN adapters for the oil filter housing and I'm intending to use one of these form Earls http://www.summitracing.com/parts/ear-83410erl/overview/

Setrab look to be a good alternative but a bit pricey and you still need to buy the AN adapters.

What do you thinks Jamo/Pete?

Lads...sorry for the slow response, I haven't been on for a while.

NZeder: I would aim for about a 5kW heat exchanger (HXr). A large 'donut' cooler can go close, or a 'matrix' style cooler certainly can. You can buy one already done that may suit, but if not, you can make one up from the HXr that's in many diesel engines (Cummins have a beautiful one made in stainless steel), that can be enclosed in a casing so the oil goes inside the matrix, and the coolant flows through the casing you made for it. You can locate it anywhere, and just plumb the oil and coolant to it. That way you use the radiator to cool the coolant that cools ALL the engine fluids, rather than using separate radiators for each fluid, and run into all the packaging problems that result.

Dave: I am not really a fan of the plate type cooler....as I said in an earlier post, they are relatively low performance, and are exist because they are cheap to make and work ok for many OEM applications, where low performance is acceptable.

If you must go air-oil, then go tube/fin...easily the highest performance out there. Setrab do make good HXr's.

Cheers

Jamo

Thanks Jamo...too late though...Earls already on the way from Summit!