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Kitch

Xu9J4 Oil Starvation Prevention (Never Heard That Before?!)

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petert

I'm glad I've been on holidays out of 3G range. If mounting vertical and north/south, you'll need to remake the pickup and fit a different sump. Otherwise the pickup will be on a 30º angle. Easiest solution would be to cut the bottom off a steel sump and remake it so the bottom is parallel to the face. This is more difficult with an aluminium sump (but not impossible) as you're more likely to distort the mounting face/holes. Whilst remaking the sump, add baffles/ears etc. There are plenty of ideas on the Moroso website. Accumulator is a wise choice regardless.

Edited by petert

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Cameron

Never had any oil pressure issues with my engine. ^_^

 

I wouldn't be brave enough to say I'd solved the problem, but it definitely seems to have helped.

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Kitch

I'm glad I've been on holidays out of 3G range. If mounting vertical and north/south, you'll need to remake the pickup and fit a different sump. Otherwise the pickup will be on a 30º angle. Easiest solution would be to cut the bottom off a steel sump and remake it so the bottom is parallel to the face. This is more difficult with an aluminium sump (but not impossible) as you're more likely to distort the mounting face/holes. Whilst remaking the sump, add baffles/ears etc. There are plenty of ideas on the Moroso website. Accumulator is a wise choice regardless.

 

I'm not going to be mounting vertical, but the angle is less aggressive. It's dictated by the bell-housing, so in the LDV vans the XUD9 lumps must sit at a slighter angle too. Maybe there's a reason?

I could rotate the gearbox slightly to make the engine mount at the original angle, but it's not ideal and I'll have more fun making the gear linkage. But largerly it seems you've suggested what we're thinking, which is good!

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Cameron

Duratec engines sit upright, just sayin'.. ;)

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welshpug

XUD9 sump from an LDV van it is then!

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brumster

What ratios does the gearbox offer, out of interest?

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Kitch

Duratec engines sit upright, just sayin'.. ;)

 

Haha, Duratecs don't fit this chassis either. Blacktop Zetec is the usual custodian.

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Kitch

XUD9 sump from an LDV van it is then!

 

Well.....you never know. Might be worth looking into. XU and XUD sumps are interchangable aren't they?

 

What does the spacer plate do on the alloy sumps? Just space the sump to the right depth for the pickup?

Edited by Kitch

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Kitch

What ratios does the gearbox offer, out of interest?

 

The R380 box from the LDV van has less than ideal ratios as you can imagine (though with 3:92 Sierra diff the terminal speeds are about right, it's just the gaps in the revs that would be an issue.

 

But......I also have an LT77 box from an SD1 Vitesse, which has far better ratios. The R380 box replaced the LT77 and the bell housing fits both. My only issue is the input shaft, so I will probably need to get a hybrid clutch sorted for it but worse still, it's slightly shorter than the R380 one, meaning it doesn't engage in that s*itty bronze make-shift spigot bearing. So I've got to sort something there if I want to use that box, but otherwise I just need an LDV flywheel/clutch and I could bolt it straight together. Could be a tad on the heavy side, mind.

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Anthony

What does the spacer plate do on the alloy sumps? Just space the sump to the right depth for the pickup?

It is there as a stiffening plate, and the sump is shallower to compensate and keep the pickup depth correct.

 

Some people have removed it to run a normal full depth sum, or you can extend the oil pump pickup downwards and keep the stiffening plate, which has the added bonus of adding another litre of so of oil into the sump and reducing the oil starvation issues. If you do a search for something like "Petert extended pickup" you'll find plenty of info about it.

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kyepan

or you can extend the oil pump pickup downwards and keep the stiffening plate, which has the added bonus of adding another litre of so of oil into the sump and reducing the oil starvation issues. If you do a search for something like "Petert extended pickup" you'll find plenty of info about it.

 

this is what i have..

 

check this page out.

 

Cheers

J

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DRTDVL

think anything like this might be happening?

 

by www.performance928.com

 

 

In hard left turns the oil can be seen to be violently blasted up the oil return passages -- one of which would be to the left of the tappet. There is a delay that is approximately 5 seconds long (give or take) and the aerated oil in the shallow area of the sump and probably that oil which has drained down from heads makes its way to the sump. The highly aerated oil is drawn into the pickup tube and compressed by the pump. Typically oil can hold dissolved air at about 9% per bar pressure. The Porsche pump runs at many bars of pressure. When the oil emerges from the cam bearings (primarily) it releases air from the supersaturated oil like sodawater and this whitish-brown foam is clearly seen to be flung by the cam lobe onto the plexi-glas window.

 

More information: http://www.performance928.com/cgi-bin/page_display.cgi?page_nav_name=oilcontrol7DX&pass_parent=1128

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kyepan

that is very interesting!

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luggy

In hard left turns the oil can be seen to be violently blasted up the oil return passages -- one of which would be to the left of the tappet. There is a delay that is approximately 5 seconds long (give or take) and the aerated oil in the shallow area of the sump and probably that oil which has drained down from heads makes its way to the sump. The highly aerated oil is drawn into the pickup tube and compressed by the pump. Typically oil can hold dissolved air at about 9% per bar pressure. The Porsche pump runs at many bars of pressure. When the oil emerges from the cam bearings (primarily) it releases air from the supersaturated oil like sodawater and this whitish-brown foam is clearly seen to be flung by the cam lobe onto the plexi-glas window.

 

In hard or long left turns could this be possibly down to the oil being returned down the oil gallery on the timing side being delayed on its return to the sump due to coming in contact with the oil pump drive sprocket and chain?.

 

If this is the case then it makes sense to put external drains from the head to sump to reduce the possibility of oil pooling during hard cornering and reducing possible cavitation from contact with oil pump drive?

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Cameron

That's a Porsche engine so not representative of what's happening in an XU.

 

Very important not to draw conclusions by comparing two completely dissimilar things - I seem to be saying this an awful lot recently!

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Baz
:lol:

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Kitch

Noticed something interesting on that link to Taylor Engineering.....the XU10J4 head has an extra oil return outlet for a vacuum pump. I wonder if I could modify this into an extra external oil return :excl:

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petert

Yes there is a hole in the XU10J4 head, but it's high. You really need to drain from the exhaust area, back of the head. If you do this, it would be wise to add an inlet spray bar on the exhaust side, as the std exhaust spray bar doesn't actually spray. The exhaust cam is in a bath of oil.

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DRTDVL

That's a Porsche engine so not representative of what's happening in an XU.

 

Very important not to draw conclusions by comparing two completely dissimilar things - I seem to be saying this an awful lot recently!

 

I didn't suggest that what is happening to the Porsche engine is 'The PROBLEM", it was more something i found very interesting and wondered if it could be a contrubiting factor or something that is also occuring on the XU engines. Not knowing the answer to that is the reason why i asked - hence the first line of "think anything like this might be happening?"

 

Is there anyway without cutting a hole in the head that you can state that it's not happening?

 

Is there a list of theroies, suggested solutions, and tested results?

 

Whats the likely hood that it's not just one problem but a collection of problems all contributing to the overall issue?

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NNN

Would a low pressure electrical scavenge pump not be a solution? I can´t help but thinking that they are worth a try... and they are nowhere near as expensive as an oil failure...

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wicked

If you take closer look to the XU9j4 head, you'll see that the drain on timing belt side, is a lot smaller than on the gearbox side. It also seems that it's not a the lowest point in the head. So a (significant) drain on that side of the block should be enough.

 

The gti-6 has much wider drains and the EW10J4 has enormous drains on the back side of the block and is tilted at 15 degrees iso 30 degrees.

Think they didn't do that without reason...

 

Did anyone mount the XU9J4 at less than 30 degrees angle?

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Cameron

I didn't suggest that what is happening to the Porsche engine is 'The PROBLEM", it was more something i found very interesting and wondered if it could be a contrubiting factor or something that is also occuring on the XU engines. Not knowing the answer to that is the reason why i asked - hence the first line of "think anything like this might be happening?"

 

You seem to be mistaken, my post was aimed at the one above it (surprisingly).

 

I don't know or care for engine oil theory tbh, it's not my thing. My point still stands though, while it's an interesting video it can't be used to solve any of the problems being discussed here.

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rodionski

Questions re two extremely interesting ideas on draining oil from the head:

 

1. Fitting an electric pump to pump oil from the head to the sump:

- will the external electric water pump cope with the oil temperature as it will surely be higher than that of coolant?

- will it cope with the viscosity of oil, much more dense than coolant?

- where to drill and which diameter of hole(s)? Cruicial to avoid the coolant jacket! Theoretically the best way would be to drill into the back of the head in 4 places where the respective cavities in the head are located?

- where do the plugs on the back of the head lead? Oil pressure galleries or water jacket?

2. Where would the drain pipe be fitted in the sump? Assuming it would need to be close to the oil pickup, eg in the center of sump and after the baffles.

3. Has anyone actually went through with widening the stock drains in the head/block?

4. Has anyone actually physically confirmed that the exhaust cam bathes in an oil lake, or is it just a reasonable theoretic conclusion?

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James504

Has anyone got any photos of a head/engine with an external drain fitted? I guess BTCC 405s or group A GTi16's?

 

I would drill the head just above the exhaust manifold ( I can't see how you could put an external drain behind the timing belt) and route them to the oil level sensor plug (having to delete this sensor, which is only used on the 405 anyway). However the problem in my mind is space. The diameter of fittings and pipe+ only using gravity to drain the oil nullifies the cost/ effort required to fabricate such a system. If you could enlarge the timing side drain it would be helpfull, but its proxcimity to the waterjacket and freeze plug don't allow it. The next problem is where the drains in the block go. They both dump the oil onto the top of the crank which im sure flicks it around abit before it drains down the walls of the block to the sump.

 

I have made up an oil restrictor to go into my head. Based on my experiences with nissan RB engines, which have similar oil control problems as the xu. I am slightly worried to use it, but I am willing to risk it. I have also focused my efforts into a new sump design and pump modifactions.

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James504

Snip

 

I'll have a shot, but I admit to my word not being gospel just my individual opinion.

 

1. I don't think so, these pumps draw about just under 5amp pumping coolant, I have blown up a few bosch units at 10amp. I think the current draw on the motor would be too great with oil. A small fuel pump would be better suited. Motorcycle electric scavenge pumps are really expensive! The three plugs on the back of the head are water jacket freeze (welsh) plugs. As is the one on the timing side of the head.

 

2. You could put it where ever you like really. As above I would try and make use of the level sensor plug on the back of the block.

 

3. I have smoothed the drains in the head and block on my engine, most people call it a part of blue printing an engine. You want the oil to flow as best as possible to the sump, removing and sharp edges will help. Imo I wouldnt pay someone to do it, as the reality of it is its not worth doing if it is going to cost $$(cost vs gain).

 

4. My xu9j4 exhaust cam spray bar has holes in it. But given the design of the head (it helps if you can strip your head down so you can get a good look around/behind the valve springs) there will be quite a pool of oil on that side. There are lots of little areas where oil will pool before it reaches a level that is the same or greater than the height of the drains.

 

Alot of these threads end up on narrowing in on finding the sole cause of Xu oil starvation. Don't get carried away on just one area. As stated by others many times, the xu oil surge problem is a combination of many little factors.

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