Oil Pressure in Different Parts of the Engine

Those of you have been on LZ for a while might remember me rebuilding my engine quite a few years ago now. From day 1 it was pushinh oil through the turbo seals, through the inter-cooler and on in to the engine. It was burning about 1ml of oil to the mile. ie every 200 miles I was having to top up with a tad over 200ml oil. One mistake I made was replacing the oil return pipe with a new one. The new aftermarket ones don't fit properly, kink when you tighten them up, so restrict the outflow of oil. I eventually found a 20 year old original pipe, stick in the LR packet and replaced the aftermarket one. This certainly helped and probably halved the oil consumption.
I bought all the engine parts for the rebuild through Turners. When I opened the cam shaft bearings I noticed the hole in No1 shell was smaller than the original. I called Turners to say they had sent the wrong set and Richard told me they use those shells for their rebuilds as the smaller hole gives higher oil pressure and makes the bearing last longer. Not sure if he meant just the cam shaft or all crank too.
Once the rebuild was done and the oil consumption became apparent I did wonder about this, but thought Turners would know what they were doing and must have used those shells in plenty of engines before I rebuilt mine. I was also thinking that surely the oil pressure relief valve in the sump would be doing it's job. Having tried things like porting the edge of the return pipe and changing the turbo cartridge and buying a brand new genuine turbo I gave up and decided to live with it.
I'm not sure why it's nagging at me again after all this time, perhaps it's seeing the very black and sooty exhaust outlet, or having to lift the bonnet and check the oil levels all the time. Not sure, but it's been on my mind again. I installed an oil pressure gauge during the rebuild and my cold oil pressure is between 3.5 and 4 bar. 3.5bar being 50.7psi. At the time of investigating it someone suggested fitting an oil pressure regulator before the turbo. There were a few comments about them being unreliable and at the time I was thinking the relief valve should sort high pressure and if Turners use those shells they should be ok for me.
I'm wondering about how the oil pressure might vary around the engine and how it might be too high on the line that goes to the turbo, but ok at the relief valve. I've no idea about this.
Now that it's back on my mind, I'm wondering if giving the regulator a go is worth doing. Does anyone know of how the oil pressure might vary around the engine? I've not Googled it yet.

I would be looking at the turbo, new or not.
200 or 300? if so the exhaust will always be dirty in the tailpipe.
If 200 has it got the right dipstick?

lynall said:

I would be looking at the turbo, new or not.
200 or 300? if so the exhaust will always be dirty in the tailpipe.
If 200 has it got the right dipstick?

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It's a 300, Lynall. Initially I suspected the turbo and then for quite a while after that. I bought a reconditioned turbo for the rebuild from a company recommended from an LZ member. When it was passing oil I contacted them and they replaced it. That one did the same so I bought a new CHRA and replaced it myself, so that was three different turbos. That one did the same, which was when I bought the fourth, brand new one, from Turners. I'm wondering if the different bearing shell is not only creating higher oil pressure in the gallery feeder the cam shaft, but the feed to the turbo as well.

Al2O3 said:

It's a 300, Lynall. Initially I suspected the turbo and then for quite a while after that. I bought a reconditioned turbo for the rebuild from a company recommended from an LZ member. When it was passing oil I contacted them and they replaced it. That one did the same so I bought a new CHRA and replaced it myself, so that was three different turbos. That one did the same, which was when I bought the fourth, brand new one, from Turners. I'm wondering if the different bearing shell is not only creating higher oil pressure in the gallery feeder the cam shaft, but the feed to the turbo as well.

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I would not be sure the shells are at fault, if you think about it the oil can only get through the hole as fast as the gap between the cam and the shell will allow it.
Do you still have the breather routed in the factory position? ie right before the turbo intake?
My 90 uses oil if filled to the high mark, but when it reaches the N mark it pretty much stays there, I think only the defender 200 stick has the N mark, hence my question a couple of posts ago.
I know its a pita, but is it worth removing the ex manifold to see if any of the cylinders are passing oil?

Didco left, Defender right.
Disco one is also way longer.

Ps what oil are you running.

Al2O3 said:

Those of you have been on LZ for a while might remember me rebuilding my engine quite a few years ago now. From day 1 it was pushinh oil through the turbo seals, through the inter-cooler and on in to the engine. It was burning about 1ml of oil to the mile. ie every 200 miles I was having to top up with a tad over 200ml oil. One mistake I made was replacing the oil return pipe with a new one. The new aftermarket ones don't fit properly, kink when you tighten them up, so restrict the outflow of oil. I eventually found a 20 year old original pipe, stick in the LR packet and replaced the aftermarket one. This certainly helped and probably halved the oil consumption.
I bought all the engine parts for the rebuild through Turners. When I opened the cam shaft bearings I noticed the hole in No1 shell was smaller than the original. I called Turners to say they had sent the wrong set and Richard told me they use those shells for their rebuilds as the smaller hole gives higher oil pressure and makes the bearing last longer. Not sure if he meant just the cam shaft or all crank too.
Once the rebuild was done and the oil consumption became apparent I did wonder about this, but thought Turners would know what they were doing and must have used those shells in plenty of engines before I rebuilt mine. I was also thinking that surely the oil pressure relief valve in the sump would be doing it's job. Having tried things like porting the edge of the return pipe and changing the turbo cartridge and buying a brand new genuine turbo I gave up and decided to live with it.
I'm not sure why it's nagging at me again after all this time, perhaps it's seeing the very black and sooty exhaust outlet, or having to lift the bonnet and check the oil levels all the time. Not sure, but it's been on my mind again. I installed an oil pressure gauge during the rebuild and my cold oil pressure is between 3.5 and 4 bar. 3.5bar being 50.7psi. At the time of investigating it someone suggested fitting an oil pressure regulator before the turbo. There were a few comments about them being unreliable and at the time I was thinking the relief valve should sort high pressure and if Turners use those shells they should be ok for me.
I'm wondering about how the oil pressure might vary around the engine and how it might be too high on the line that goes to the turbo, but ok at the relief valve. I've no idea about this.
Now that it's back on my mind, I'm wondering if giving the regulator a go is worth doing. Does anyone know of how the oil pressure might vary around the engine? I've not Googled it yet.

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I think the pressure around the engine should be fairly constant, because the oil pump delivers more oil than the engine can use.

Bit of a long shot, but have you ever replaced the wax stat in the oil filter adaptor, which controls the flow of oil to the oil cooler.
If that never opens, the oil system with the engine hot and running is much smaller than intended. And the oil will be hotter.
I am not absolutely sure if this could be causing the problem, but it is good to have the oil cooler working anyway.

lynall said:

I would not be sure the shells are at fault, if you think about it the oil can only get through the hole as fast as the gap between the cam and the shell will allow it.

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I can see what you're saying. I think Richard Turner's theory was that forcing the oil through the smaller hole in the shell would up the pressure within the shell. Not sure if he was meaning just that fron shell or it would do the same to all of them.

lynall said:

Do you still have the breather routed in the factory position? ie right before the turbo intake?

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Yes, it's still in place. At the time I ran the breather in to a catch can for a while and absolutely nothing came out of it.

lynall said:

My 90 uses oil if filled to the high mark, but when it reaches the N mark it pretty much stays there, I think only the defender 200 stick has the N mark, hence my question a couple of posts ago.

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Mine is the original dipstick, like the one on the left of your picture.

lynall said:

I know its a pita, but is it worth removing the ex manifold to see if any of the cylinders are passing oil?

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I haven't done a compression test since after the original rebuild and trying different things to solve the oil problem. It was excellent at the time. After about 15k-20k miles I took the head off. All four crowns and valves were thick of carbon build up. I took the sump off to check the relief valve was working. I'd used a genuine LR spring in the relief valve, which was much longer than the one I took out. However, the new one had already compressed quite a bit. I just put it back, thinking the easier that releases the oil pressure the better!

At the time of first trying to solve the problem I tried different oils and viscosities, as recommended by James Martin and others. The problem remained the same.

Turboman said:

I think the pressure around the engine should be fairly constant, because the oil pump delivers more oil than the engine can use.

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I was hoping not

Turboman said:

Bit of a long shot, but have you ever replaced the wax stat in the oil filter adaptor, which controls the flow of oil to the oil cooler.
If that never opens, the oil system with the engine hot and running is much smaller than intended. And the oil will be hotter.
I am not absolutely sure if this could be causing the problem, but it is good to have the oil cooler working anyway.

Click to expand...

Yes, I replaced that at the time too. Can't remember who suggested it back then, to be honest I didn't know about it being in the system at the time, so got really excited about it as a possible solution.