External oil cooler

[ricster]

.... too true !!!

[Michael]

So I managed to get a price from UD Samrand, R1,004 incl Vat for this very small piece of metal

I think to have it made will be way cheaper

[ricster]

Greg( juice) on the forum can get it cut and anodized etc, but will need a CAD drawing of it.

Just by looking at it, there is something strange happening with that plate. There are 2 fittings on that plate, I assume one for oil in and one for oil out. There is no exit hole on the flip side of that plate, so that means that there must be a chamber or channel in the plate that connects to each one of the round sections where the recesses are. If I recall there are 2 blue "O" rings that fit into that recess creating a seal between the pressure regulator and the engine block, so that would probably mean that there is an opening somewhere on this plate ( on the inner diameter of the recessed "circle" ) to allow oil to flow into the chamber or channels and out to the external cooler and then back to the plate inlet, back in through the chamber or channel and then on to either the block or the pressure regulator, depending on which way around the oil cycles.

I would think that the size (volume of these chambers would be fairly important to get the max efficiency. Michael, Give this goodie a good going over if possible to see what where when and how. One can reverse engineer a "sandwich" plate to do exactly that but that to me seems like re-inventing the wheel, as one can just buy sandwich plates and an external pressure valve from most turbo shops etc that fit between the 2nd oil filter and engine block ( internal oil cooler ). I don't think that it would be any more cost effective time wise to draw up a CAD model and get he lazer cutting and milling work done plus the 2 extra "O" rings..... but that is just my opinion,

[Michael]

Cedric, yes there are some holes drilled on the side that connect the two. I will try and indicate on the below pic.
The holes that were drilled are just blanked off via small bolts which you can see in the pic.

Oil Filter adaptor.JPG (73.34 KiB) Viewed 3027 times

So the reason why I like this setup more than the sandwich is that it is far away from the water system and it sounds like the oil pressure is higher where this plate sits which means you should get a better flow to the cooler (also I'm not 100% sure of this tho).

See I don't like the standard oil cooler system as the water is mostly warmer than the oil which means the oil is actually been heated by the water and not cooled. Now the sandwich adaptor is so close to this setup that it might influence it in some way.
Also, I have read how some people did not get significant improvement with this setup as the pressure is too low there.....not sure how true this is and know of no one with this setup that measures the oil to confirm that the oil is actually cooler than usual.

Basically, I just wonder why UD has chosen this setup instead of the sandwich?

[ricster]

Just throwing a curve ball into the equation....

One would ultimately want to get the oil to travel at as slow a speed as possible to maximize exposure time to the cooling part of the system. I do understand that the pressure of the oil is not directly proportional to the speed that the oil is traveling at though the system, however due to the oil being bled off at various points and different size chambers that the oil will be traveling through, there will be a speed change if the cross sectional area of the chamber is increased, and visa versa if the cross sectional area reduces in size.

I'm hazarding a guess here, but I would assume that the internal oil cooler will reduce the speed/flow of the oil to allow max heat/cooling absorbtion, and then with the 2 oil filters right there doing their job the oil speed is (I know not accurately ) halved as it splits to the 2 filters. The sandwich plate only operates on one of the filters, so although the pressure in the sandwich plate and external cooling system is the same as elsewhere in the motor, the speed that it is travelling is much slower.

From the internal oil cooler the oil presumably goes first to the pressure regulator ( I may be wrong on this so pleas correct me). Here all the oil from the two filters joins up again ( effectively doubling its volume ) has to travel in a chamber from the internal cooler/filters to the pressure regulator. I assume that the speed that the oil is travelling at will be higher than it was when split between the 2 filters. Now I'm not sure as to how this plate on the UD TD42 motor works but it presumably splits the oil.... half to the rest of the motor, and the balance to the external cooler. What regulates how much oil is moving into the external cooler?..... or does it take the whole amount (volume )of oil out and through the external cooler. If the latter then there is double the volume of oil trying to cool in the external cooler, which in effect would mean that you would need to reduce the speed of the oil by half to achieve efficiency or double the time it has in the cooler by doubling the cooler size. ( the doubling and halving measure I'm using is probably not accurate as there are various coefficients at play but purely for ease of explaining.)

I don't have an oil temp gauge fitted as of yet, but hav not noticed any difference or effect it has had on my water temp since I bypassed my external cooler, due to my exuberant tightening of the nuts .... yeah I know I'm a chop ....hahaha

[Michael]

Valid points Cedric, but I actually have no idea of the pressure it is running at on the two locations and what effect it will have.

I do know on these TD42's if the rate of flow is too slow it will not circulate enough oil in volume to have a successful cooling cycle.
The thing is there is 10L of oil to cool down and if the flow rate is too slow the cooler will only be able to cool a very small amount of oil over a long period and it will not work where if there is more flow it will indeed have less cooling but circulate more of the oil and maybe have a greater effect on the huge amount of oil?

Do you measure your water temps? Would be interesting to know your temps as the onboard heat gauge shows normal temp from 67 deg up to 112 deg where it starts to move higher.
On the Madman both me and Tinus can see the effect of hot oil on the water temp. Once your oil reaches 90 degrees your water temp skyrockets and it's really a challenge to keep the temps down.

I'm keen to try this one and see what effect it has.

[Tinus lotz]

I am hooked on this ud tipe one ....we can build the cooler any size to suit but if ud thinks its a good idea i think it will be a good way forward.
Sure we can make it for a steal ....Piet is picking his stuff up that Michael painted for him he can take that one and make a cad drawing so we can check will not be more than 100 bucks or so

[ricster]

Michael, the speed of the oil inside the engine will be at various speeds because the pump is pressurizing it to a certain pressure at a certain rev range ( higher revs higher pressure ) the pressure valve will regulate that pressure into a reasonably constant pressure ( probably within a certain psi range ). The pressure of the oil remains a constant throughout the system, due to the fact that you cannot compress a liquid, and therefore the forces on any surface within the path that the oil takes will always be equal. So there will be "X" bar pressure all the way along, until it reaches its final destination, where it then either is forced out through the oil squirters under the pistons, or work their way through the crank journal bearings etc.

So going back to the beginning of the oils journey, the oil pump and regulator will pressurize the oil to "X" bar pressure. The oil is forced into a tube of "A" diameter ( I'm just going to pick a speed for information purposes, so these are in no way accurate ), at "X" pressure causing the oil to flow at say 10m/sec. The tube then widens to "B" diameter, lets say into a tube 5 times the original diameter. The pressure in this tube will still be exactly "X" bar, but the speed that it is moving through will be reduced to 2m/sec while in this section of tube ( for arguments sake lets say it is the internal or external oil cooler ). At the end of this bigger tube the diameter of pipe reduces to "C" diameter which is a quarter of Diameter "B". The pressure inside tube "C" will again still be at "X" pressure, but the speed will increase to 8m/sec. This 8m/sec ( hypothetically will be the oil pressure required to efficiently perform it purpose.

So in a nutshell, one needs to slow the oil down dramatically when inside the intercooler to allow maximum transfer of heat away from the oil, and then by restricting the diameter of the pathway for the oil, one increases the speed of the oil to its destination.

In principal this is VERY similar as to how our intercoolers work with the major difference being that air can be compresses so your pressure, as well as the airspeed differs from point A to point B. There are weird things that go on when working with fluid dymamics and air in a tube, but the one thing that is hard and fast is that with liquid the pressure throughout the tube will equal at all and any point, whereas it will vary with air under pressure as it can be compressed.

quote " do know on these TD42's if the rate of flow is too slow it will not circulate enough oil in volume to have a successful cooling cycle.
The thing is there is 10L of oil to cool down and if the flow rate is too slow the cooler will only be able to cool a very small amount of oil over a long period and it will not work where if there is more flow it will indeed have less cooling but circulate more of the oil and maybe have a greater effect on the huge amount of oil? "..... the volume of oil at the destination point will still be identical to what it was prior to fitting an extra external oil cooler, and the 10L of oil will slow down once in the internal oil cooler , speed up as it leaves the internal cooler and again slow down in the external oil cooler, speed up on exiting the external cooler, and land up at the destination at the same original volume and pressure that it was at before

[Peter Connan]

Cedric is correct in that the oil pressure will be a constant throughout the engine.

The more oil you get through the cooler the better. Lower velocity will mean better cooler efficiency, but can be achieved by increasing the bore of the cooling circuit or compensated for by using a larger cooler.

The fact that in the early stages of engine operation the water-based cooler heats up the oil is beneficial because it reduces the length of the high-wear cycle, so the ideal may well be to run both systems?

I will collect the plate tomorrow afternoon and draw it up, then we'll see who can make it cheapest?

[ChristoSlang]

Cedric is correct in that the oil pressure will be a constant throughout the engine.

The more oil you get through the cooler the better. Lower velocity will mean better cooler efficiency, but can be achieved by increasing the bore of the cooling circuit or compensated for by using a larger cooler.

The fact that in the early stages of engine operation the water-based cooler heats up the oil is beneficial because it reduces the length of the high-wear cycle, so the ideal may well be to run both systems?

I will collect the plate tomorrow afternoon and draw it up, then we'll see who can make it cheapest?

Great stuff - I'll definitely buy one!

Gents, consider the following info from the Garrett website:
"Garrett ball bearing turbochargers require less oil than journal bearing turbos. Therefore an oil inlet restrictor is recommended to achieve an oil pressure of 40-45psi entering the turbocharger for optimal performance. The oil outlet should be plumbed to the oil pan above the oil level (for wet sump systems). Since the oil drain is gravity fed, it is important that the oil outlet points downward, and that the drain tube does not become horizontal or go "uphill" at any point." On the 350z, I indeed had to go that route to lower the pressure going to the turbos...

Furthermore, when trying to find a suitable spot for the Madman's oil pressure pickup on my TD42, I initially fitted it to a spot on the exhaust side of the engine where it read almost no pressure whatsoever. There was oil alright, just not properly pressurised. Now it's fitted on the oil filter side and reads a decent amount of pressure.

Lastly, I read recently that local city council intends fitting pressure regulators to the water supply to try and lower water consumption.

Are all of us & them confusing flow & pressure?