Turbo systems for X1/9's

I just went out and looked at the '79 block. The small hole for the EGR valve is at the same level as the block drain petcock. Which is a little below the freeze plugs. On the picture it would be about here (red arrow):

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I remember when I had the freeze plugs out there wasn't too much distance below them to the bottom of the water jackets. So the EGR feed would have to be at the lowest point of the jacket. Which makes sense because the drain valve also is. That might concern me. All of the SOHC blocks I've stripped had a lot of sediment sitting on the bottom of the water jackets. It looks like sand or gravel. I think that would not be good for the turbo's smallish water passages.

Looking back at the UT diagram that @mkmini posted, the turbo feed appears to also be low in the water jackets (assuming the jackets are the same, which I have no idea). But much more rearward than the EGR spot on the '79 X block. So it obviously works.

This all raises a couple questions regarding the after-run cooling "thermosiphon" effect that @rachaeljf described. How significant are the relative heights of all the water connections (on the engine, turbo, and coolant tank) in terms of functional difference? Also how significant of a functional difference does the temperature differential for various locations of water feed (i.e. block vs head) make? And is one of those factors of greater importance than the other in terms of the overall functional outcome? Basically, what's most important?

Completely non-scientific. Purely ameture armchair guesses. But I imagine the ideal arrangement in terms of thermosiphon would be a cold water supply feed location that is below the the height of the turbos' water inlet. And a hot water return location that is above the turbo's outlet. Because physics tells me hot water (less dense) will rise above cold water (more dense). However I also imagine the ideal arrangement for regular cooling (with the pressurized cooling system) while everything is running is sort of the opposite; a cold feed from above and a hot return below? But that last part may not necessarily be true because radiators flow from top to bottom, which is hot to cold. However their purpose is the opposite, remove heat from the water opposed to absorb heat into the water.

Engineers please help.
 
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I was referring to the size of the nipple; the ones on the return pipe are very small diameter, the one on the head for the heater is large diameter. So a greater flow potential. However I don't know that will make a huge difference, just on of the thoughts in the equation.
As I recall that was the prior consensus, as you and @Bjorn Nilson just said; the head vs the return pipe shouldn't make a huge difference in terms of siphon. Although the return tube is a fraction lower than the heater nipple. The bottom of the block is definitely much lower, but adapting it doesn't seem worth the risk.
The stock 79 (and later) return pipe has a port that is about the same size as the one on the head and connects to the heater. This is because the water pump mounted heater return was eliminated for the 1500s. There are also several other small ports on the return pipe for water choke, etc.
I originally tried to use it since it came with my 1500 but I found the heater return pipe was closer to my header than I was happy with so I went back to the 1300 pump mounted return.
 
Got all my plumbing done for oil today. I connected the oil cooler feed from bottom to top.
Regarding turbo water feed for a 1500 I realized that that the freezing plug is very close to the turbo water feed on UT. Freezing plugs shouldn't differ much on a 1500. @Dr.Jeff I understand that drilling a feed on the block isn't worth the risk for damage, but maybe modifying the left freezing plug is an option. As you see the plug an feed port are very close on the UT engine and almost at the same level.
IMG_20200621_183336.jpg
 
Regarding turbo water feed for a 1500
Bjorn, you might have just opened a huge opportunity for me. First let's confirm a couple things. This picture is a Mk1 UT block? And the fitting (yellow arrow) is the water supply for the turbo?

IMG_20200621_183336.jpg


If those are true then adapting the '79 1500 block might be much easier than I expected. Because that boss (blue box) looks a lot like the one for the EGR valve ('79 Calif smog spec 1500 X engine) that I described previously. Seems to be the same location, and even a very similar shape. I wonder if perhaps it is in fact the same casting but with a larger hole for the water?

I've only seen one actual photo of a UT block on that side, and it wasn't specifically showing the water fitting for the turbo. Otherwise I've seen those factory manual sketches that aren't very accurate. And for some reason the location of the water feed fitting appeared to be much lower on the block and further forward, about where the boss is for the turbo support bracket (green arrow). So I thought the two blocks (1500 vs UT) must be very different as far as the internal water jackets go.

It looks like the water fitting (yellow) aims downward? I think it would have to in order to route under the turbo and loop around the front of it?

I made a turbo support bracket that bolts to the two holes in the EGR boss on my 1500 (same as yellow arrow). So if I convert this boss to a water feed for the turbo then I'll have to come up with another place to mount the support. The 1500 doesn't have the boss where the UT bolts the support (green arrow).

Is the Mk1 UT water fitting the same as the Mk2 UT? I vaguely recall the Mk2 has a branch off one of the water hoses or such?

The fitting you added (black arrow) is where the block drain petcock is on the 1500 X block. Was that also a petcock drain on yours? And what are you going to use the "-AN" fitting for?

Sorry, lots of questions but you have given me new hope for a better water feed arrangement. Thanks for any info offered.
 
The coolant supply to the turbo can come from any suitable place on the block, or from the head at a pinch. The important thing is that it gets coolant under positive pressure from the coolant pump. Also important is that the turbo to header tank pipe enters the header tank above the normal coolant level. Note the thermosiphon is not a regular one relying on hot/cold liquid density changes, it only works when the coolant boils in the turbo. When running, the coolant is pumped through the turbo - if you remove the header tank cap you can actually see the little fountain of coolant being pumped in from the turbo. From memory the UT Mk1 and Mk2 turbo coolant feed comes the flywheel end of the block. I will have to have a look when I get a chance.
 
Bjorn, you might have just opened a huge opportunity for me. First let's confirm a couple things.
Yes it is an UT Mk1 1.3l block and I don't think it differs much from Mk2. -See illustrations in the UT Service Manual. Actually it seems to be very small differences between UT Mk1 and FI X engines in general.
The yellow arrow is the turbo water feed. It is a barb with 12mm outer diameter and it is aiming a little bit downwards.
Your green arrow is pointing to one of the two turbo supporting bolts. Normally there's a steel plate between the block and manifold here. My engine came with this tube/bracket instead and I didn't bother to replace it as I think it will handle vibrations as is.
The black arrow is the turbo oil feed. Stock setup is a banjo bolt and a steel tube but it didn't fit on the TD04 Turbo so I replaced it with an AN connector and hose. (I took the photo before fitting the hose). It was NOT a petcock drain.
The original IHI turbo had steel/copper tubes with barbs for water feed/return.
IMG_20200621_222123.jpg

I am going for AN hoses for both oil and water on the TD04 turbo as nothing else would fit.
I didn't know about the EGR boss on your block. Hopefully you can use it for turbo water feed. If not, welding a push on barb on to the freezing plug would be an easy thing?
 
Yes it is an UT Mk1 1.3l block and I don't think it differs much from Mk2. -See illustrations in the UT Service Manual. Actually it seems to be very small differences between UT Mk1 and FI X engines in general.
The yellow arrow is the turbo water feed. It is a barb with 12mm outer diameter and it is aiming a little bit downwards.
Your green arrow is pointing to one of the two turbo supporting bolts. Normally there's a steel plate between the block and manifold here. My engine came with this tube/bracket instead and I didn't bother to replace it as I think it will handle vibrations as is.
The black arrow is the turbo oil feed. Stock setup is a banjo bolt and a steel tube but it didn't fit on the TD04 Turbo so I replaced it with an AN connector and hose. (I took the photo before fitting the hose). It was NOT a petcock drain.
The original IHI turbo had steel/copper tubes with barbs for water feed/return.
View attachment 33544
I am going for AN hoses for both oil and water on the TD04 turbo as nothing else would fit.
I didn't know about the EGR boss on your block. Hopefully you can use it for turbo water feed. If not, welding a push on barb on to the freezing plug would be an easy thing?


You are using (silver -soldered, not sweated, I hope) copper fittings for the coolant feed (we are looking at the underside, correct? - I assume it can't be the drain since it's pointing back uphill) - I would suggets that is not a great idea. I made many version of drains using copper, as it was easiest to work with at the time I did it - and the heat cycling of the CHRA is gonna really not play well with the copper, in my experience. Best case for me it lasted one year.

EDIT - re-read the info under the pic - I see that that you are deleting whatever that mess was :)
 
You are using (silver -soldered, not sweated, I hope) copper fittings for the coolant feed (we are looking at the underside, correct? - I assume it can't be the drain since it's pointing back uphill) - I would suggets that is not a great idea. I made many version of drains using copper, as it was easiest to work with at the time I did it - and the heat cycling of the CHRA is gonna really not play well with the copper, in my experience. Best case for me it lasted one year.
Yes we are looking at the underside. Water feed pipe is made of steel, return pipe is soldered copper. Could be that the return pipe has been replaced, as your comment makes sense.
I am using none of it. -Not even the turbo. The new TD04 got AN connectors/hoses.
 
The coolant supply to the turbo can come from any suitable place on the block, or from the head at a pinch. The important thing is that it gets coolant under positive pressure from the coolant pump. Also important is that the turbo to header tank pipe enters the header tank above the normal coolant level. Note the thermosiphon is not a regular one relying on hot/cold liquid density changes, it only works when the coolant boils in the turbo. When running, the coolant is pumped through the turbo - if you remove the header tank cap you can actually see the little fountain of coolant being pumped in from the turbo. From memory the UT Mk1 and Mk2 turbo coolant feed comes the flywheel end of the block. I will have to have a look when I get a chance.
Thank you Rachael. I know we've covered a little of this previously, but as I keep learning more and more about all of it I come up with additional questions. Really appreciate your engineering perspective. ;)

At one point I even thought about adding a auxiliary coolant circuit to the turbo for after-run cooling, like some of the modern factory systems have. Basically a small electric pump that switches on after the engine is shut down, to circulate coolant through the turbo until it cools. But the logistics of it, and not interfering with the regular cooling circuits, wasn't worth the benefit.
 
Yes it is an UT Mk1 1.3l block and I don't think it differs much from Mk2. -See illustrations in the UT Service Manual. Actually it seems to be very small differences between UT Mk1 and FI X engines in general.
The yellow arrow is the turbo water feed. It is a barb with 12mm outer diameter and it is aiming a little bit downwards.
Your green arrow is pointing to one of the two turbo supporting bolts. Normally there's a steel plate between the block and manifold here. My engine came with this tube/bracket instead and I didn't bother to replace it as I think it will handle vibrations as is.
The black arrow is the turbo oil feed. Stock setup is a banjo bolt and a steel tube but it didn't fit on the TD04 Turbo so I replaced it with an AN connector and hose. (I took the photo before fitting the hose). It was NOT a petcock drain.
The original IHI turbo had steel/copper tubes with barbs for water feed/return.
View attachment 33544
I am going for AN hoses for both oil and water on the TD04 turbo as nothing else would fit.
I didn't know about the EGR boss on your block. Hopefully you can use it for turbo water feed. If not, welding a push on barb on to the freezing plug would be an easy thing?
Bjorn, thanks for all of the answers. This offers another good option for how I might plumb the turbo cooling circuit. ;)

Interesting that the oil supply for the UT's turbo is exactly where the block coolant drain petcock is on the 1500. That's another difference between these blocks. I've seen on the factory sketches that there is a perpendicular passage from the main oil galley that travels up the middle of the block, and goes over to that spot on the rear side of the block. I just didn't realize that was also the location of the coolant drain on our 1500's (I guess the UT block doesn't have a coolant drain, but that's not a big deal).

I decided to take the turbo oil feed from the oil filter adaptor plate. It has four ports, two outlet and two inlet. One of each goes to/from the oil cooler and remote filter circuit. The other outlet feeds the turbo. And the extra inlet is used to mount a oil temp sensor/sender. Makes for neat and easy installation of everything. But that's one reason the adaptor plate isn't a thermostat type, the choice was either or but not both. And as stated previously the oil (and coolant) will be heated very quickly due to the turbo.
 
Bjorn, you might have just opened a huge opportunity for me. First let's confirm a couple things. This picture is a Mk1 UT block? And the fitting (yellow arrow) is the water supply for the turbo?

View attachment 33538

If those are true then adapting the '79 1500 block might be much easier than I expected. Because that boss (blue box) looks a lot like the one for the EGR valve ('79 Calif smog spec 1500 X engine) that I described previously. Seems to be the same location, and even a very similar shape. I wonder if perhaps it is in fact the same casting but with a larger hole for the water?

I've only seen one actual photo of a UT block on that side, and it wasn't specifically showing the water fitting for the turbo. Otherwise I've seen those factory manual sketches that aren't very accurate. And for some reason the location of the water feed fitting appeared to be much lower on the block and further forward, about where the boss is for the turbo support bracket (green arrow). So I thought the two blocks (1500 vs UT) must be very different as far as the internal water jackets go.

It looks like the water fitting (yellow) aims downward? I think it would have to in order to route under the turbo and loop around the front of it?

I made a turbo support bracket that bolts to the two holes in the EGR boss on my 1500 (same as yellow arrow). So if I convert this boss to a water feed for the turbo then I'll have to come up with another place to mount the support. The 1500 doesn't have the boss where the UT bolts the support (green arrow).

Is the Mk1 UT water fitting the same as the Mk2 UT? I vaguely recall the Mk2 has a branch off one of the water hoses or such?

The fitting you added (black arrow) is where the block drain petcock is on the 1500 X block. Was that also a petcock drain on yours? And what are you going to use the "-AN" fitting for?

Sorry, lots of questions but you have given me new hope for a better water feed arrangement. Thanks for any info offered.
For what it is worth, the EGR water passage on my block was slightly smaller than an M8. I drilled and tapped it for an M8 plug. Not sure how big the hole is on a UT Turbo block but I recall there being a fair amount of material to play with around the hole. If the EGR boss is the same as it is for the turbo water connection, it might be possible to enlarge it without too much risk.
 
If the EGR boss is the same as it is for the turbo water connection, it might be possible to enlarge it without too much risk.
That's exactly what I'm thinking now. Previously I was mistaken about the UT's water supply and didn't want to risk damaging my best engine by experimenting. But the more info I'm receiving, and the more I think back to when I had the expansion plugs and water jacket plates off the block, I think it can be modified accordingly. In fact it may even be possible the UT water fitting will bolt onto the same mounting holes as the EGR valve did.
 
I decided to take the turbo oil feed from the oil filter adaptor plate.
I thought about another thing... As per my understanding the oil pressure is quite low on the turbo to reduce oil consumption and smoke. If the oil pressure reduction is happening on the turbo itself, it would be ok to feed it from the adaptor plate.
 
I thought about another thing... As per my understanding the oil pressure is quite low on the turbo to reduce oil consumption and smoke. If the oil pressure reduction is happening on the turbo itself, it would be ok to feed it from the adaptor plate.

That is ususally accomplished by the restrictor port within the turbo - on Mitsubishi TD04 series, anyway. Volvo feeds the turbo off the main galley close to the oil pump. Many aftermarket setups require restrictors added to the inlet. The pressure isn't that low - after all, the impeller shaft has to float in the pressurized oil film coming through the bearings at either end, at extremely high rpm's. Also that pressure is fed through the thrust plate, to keep the axial load from pushing the compressor wheel into the plate and/or housing

V70XR_0847.jpg


the tiny hole the arrow points to is the pressure restriction in this TD04HL I was rebuilding. Also, the Oil feed banjo bolt has much smaller holes than the water jacket banjos, for example.
V70XR_0987.jpg


This is what happens when the oil pressure drops or there is improper drainage (possibly caused by excessive blowby = high CC pressures). Axial load forces the compressor side into the thrust plate - no/reduced oil flim to act as buffer.

V70-XR-0846.jpg


Once axial play develops - the oil rings can 'eat' the impeller shaft

V70-XR-0892.jpg


V70-XR-0893.jpg


This can all happen in the blink of an eye under high load conditions.

So, it is essential that oil delivery and oil drainage is properly managed. Draining at the wrong level, or excessive boost will creat CC pressures in that backfeed the drain tube & prevent the oil from draining, and the above it the direct result.

Internal layout of parts:

Screen-Shot-2020-06-21-at-5-55-18-PM.png
 
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The oil feed volume and pressure also depend on the type of bearing the turbo uses. Roller bearing turbos require MUCH lower pressure than journal bearing turbos. Has to do with the description @lookforjoe gave. So the internal restrictor in the turbo is designed according to the bearing type. In addition some turbos require external restrictors, such as a special type fitting that feeds the oil inlet on the turbo. The turbo manufacturer will specify what that restriction should be.

For the most part the primary risk of too much oil pressure is it makes its way past the seals and gets burned, causing carbon buildup and the smoke that @Bjorn Nilson referred to. Relatively speaking that is less critical (at least initially) than too little oil as @lookforjoe explained.

On the oil filter adaptor plate I'm using, the turbo oil feed is on the return side - after going to the oil filter and cooler. I like that the turbo is getting cool clean oil. The basic oil pressure coming off that point on the adaptor plate will be pretty much the same as that of the main oil feed galley in the block, where the UT gets it. The filter adaptor plate just happens to be a convenient source on a block not designed for a turbo oil feed, without robbing oil supply from another area (as can happen with some solutions to getting turbo oil feed elsewhere).
 
Photo of the Punto GT engine's turbo connections. Coolant feed adjacent to flywheel, oil feed from between cylinders 2 and 3, oil return to sump.
2020-06-30 21.09.45.jpg
 
Excellent picture @rachaeljf , thanks for posting. Looks like some evolution for the Punto GT compared to the Uno Turbo. I believe the coolant feed is in a slightly different location (though nearby), and it is cast into the block rather than a bolt on fitting. ;)
 
Thank you all. I also believe that an oil temp gauge is a must for racing. I also had a small fan that I turned on when needed and it did make a difference that I could see in the oil pressure. Here's the set up on my 'new' 1000TC Abarth. Also added ducting to direct more air through the cooler. I'll add a fan if needed. Now, hope to find a good X19...
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