Oil tap solution for add on turbo

[rchalmers3]

I'm working on the details of a future DIY 2H turbo install. I have seen various methods of supplying and draining the oil supply to the turbo, but have not seen this method mentioned: Pegasus - Steel Banjo Bolts

My proposal is to install double banjo bolts in the vacuum pump oil lines (see photo) thus "stacking" the supply and drain connections for the turbo onto the existing vacuum pump taps.

The installation would be simple and less intrusive. These fittings are just below the exhaust manifold, perfect for the intentions!

I am able to easily source the bolts and banjo fittings.

Thoughts? Comments?

Rick

[Jan-78FJ40]

That was the way the previous generation of turboglide turbos tapped into the oil supply. I am running it that way for 40.000km without problems now.
cheers,
J

[Tapage]

It was my first option .. after a second thought decide take the oil line form the better place that I can do, and it was at the same spot that I'm reading my oil press ..

[brownbear]

is there no plug to remove on the side of the block that go into the oil galley like a 3B? I would not put anything remotely near or tapped into the supply for the vacuum pump. It's worth too much to restrict.

[rchalmers3]

Originally Posted by brownbear

is there no plug to remove on the side of the block that go into the oil galley like a 3B? I would not put anything remotely near or tapped into the supply for the vacuum pump. It's worth too much to restrict.

Nah, the exhaust manifold side galley is only tapped at the place shown in the photo. Adding a second line won't cause a restriction. The connection to feed the vacuum pump will be the same as before.

I am relieved to hear Jan-78FJ40 report he has this set-up and its working. That gives me a qualified OK to proceed.

However adding the turbo line will cause an additional pressure drop. I have no idea how much. Feeding the turbo oil is something I need to study further to learn how much is needed without overfeeding the bearing.

Question: Do turbos all come with a restrictor on the oil feed or do I need to prepare for obtaining the correct one?

Rick

[crushers]

remember the oil return is gravity feed so if the return hole is too small for both the vacumm pump oil return and the turbo oil return you will get oil back up. this can lead to oil starvation to either the turbo or the vacumm pump. both a very expensive to replace.
Jan did his because the kit was designed that way. not saying it is right or wrong, just saying i do not agree with the design.
do a return bung to the oil pan and do an oil pickup at the oil pressure sending unit.

you can not "over feed" the turbo as long as the return line is not blocked or restricted.

each to their own.

[Jan-78FJ40]

Originally Posted by crushers

remember the oil return is gravity feed so if the return hole is too small for both the vacumm pump oil return and the turbo oil return you will get oil back up. this can lead to oil starvation to either the turbo or the vacumm pump. both a very expensive to replace.
Jan did his because the kit was designed that way. not saying it is right or wrong, just saying i do not agree with the design.
do a return bung to the oil pan and do an oil pickup at the oil pressure sending unit.

you can not "over feed" the turbo as long as the return line is not blocked or restricted.

each to their own.

Good points Wayne.
The new turbo glide system takes the oil at the pressure sending unit. However, the volume of oil supplied was the same (and a LOT).

cheers,
jan

[rchalmers3]

Originally Posted by crushers

remember the oil return is gravity feed so if the return hole is too small for both the vacumm pump oil return and the turbo oil return you will get oil back up. this can lead to oil starvation to either the turbo or the vacumm pump. both a very expensive to replace.
Jan did his because the kit was designed that way. not saying it is right or wrong, just saying i do not agree with the design.
do a return bung to the oil pan and do an oil pickup at the oil pressure sending unit.

you can not "over feed" the turbo as long as the return line is not blocked or restricted.

each to their own.

I share the same concerns. Not bagging on ya, just trying to understand you:

I don't see why changing the point of tapping into the oil pressure galley makes any difference. It's all at the same pressure in the galley, under the laws of hydraulics, right?

My reasoning is that it's a risk to drape a external line around the engine compartment, from the oil pump location. Why is all that exposed hose and potential for failure a better install?? If the internal oil delivery system was suspect, I'd agree with you.

"if the return hole is too small for both the vacumm pump oil return and the turbo oil return you will get oil back up. this can lead to oil starvation to either the turbo or the vacumm pump. "

Your thinking has me ask how oil backing up would cause starvation. Wouldn't it cause flooding???

On the return side, measuring the flow and assuring adequete sizing for drainage dosen't seem to be too hard to confirm through testing. And I can add another drain if it's questionable.

It also occurs to me that I can call the people who make the Turbo Glide kit and ask them why they changed their oiling system connections! Might be interesting to hear their reasoning, huh Jan!!

Rick

[crushers]

actually, you sound about right on the flooding. then the backed up oil has to go somewhere which will be past the rings in the turbo creating a lot of smoke. i will call the turbo shop again and ask for the right term...
i will let you and Dougal work out the flow and volumm rate of oil return.
when i started into turboing these engines i talked to a number of custom turbo shops till i found one that was willing to spend the time with me. the oil return line MUST be free of restrictions.

[rchalmers3]

Thanks crusher, I'll call the manufacturer about these issues today and see what they say.

My thinking is that the turbo and vacuum pump bearings won't know the difference if the return line is flooding. The supply side pressure is high enough to overcome some resistance on the drain side.

What will happen is there will be a pressure rise in the return line as the oil under pressure on one side of the bearing starts to find resistance on the drain side. I forsee leaks at the return side fittings if the return side is not sized correctly and tightly fitted.

What about the pressure line? Why do you not agree with the installation of the pressure tap at the vacuum pump oil tap? Why do you prefer to use a long hose and plumb it all the way around from the pump?

Rick

[crushers]

hummm, because it works... which is why i do most of the things i do.

most of the stuff i do has been based on chatting with those that do certain things for a living, i glean info as to what works and what doesn't... i usually forget WHY something is not recommended though. then that becomes standard practice till someone can show me something better THAT WORKS.

as for the feed line and return line, Toyota runs a seperate lines so there must be a reason...

in the end it is your engine, turbo, vacumm pump, money and time... it makes no difference to me how someone else does their project.
(it is not like a pat on the back from me is needed)

cheers and peace

[rchalmers3]

Originally Posted by crushers

in the end it is your engine, turbo, vacumm pump, money and time... it makes no difference to me how someone else does their project.
(it is not like a pat on the back from me is needed)

cheers and peace

It's not your approval I seek, it's your opinion and the basis thereof.

[Dougal]

Originally Posted by rchalmers3

"if the return hole is too small for both the vacumm pump oil return and the turbo oil return you will get oil back up. this can lead to oil starvation to either the turbo or the vacumm pump. "

Your thinking has me ask how oil backing up would cause starvation. Wouldn't it cause flooding???

Yes it causes flooding and pressure buildup inside the turbo. Your turbo then spits oil out both directions (into your engine intake and into your exhaust.

The result is a car propelled by blue smoke, quite impressive.

Turbo seals are like piston rings, they vent a little. They rely on the pressure being higher on the outside (exhaust housing and compressor housing) than in the bearing core which is vented through the drain tube to your sump.
So the return to your sump has to flow not only oil, but a quantity of air and exhaust gas too.

If you give your turbo too much oil pressure, then you'll have the same flooding problems no matter how good your drain is.

[rchalmers3]

Originally Posted by Dougal

Turbo seals are like piston rings, they vent a little. They rely on the pressure being higher on the outside (exhaust housing and compressor housing) than in the bearing core which is vented through the drain tube to your sump.
So the return to your sump has to flow not only oil, but a quantity of air and exhaust gas too.

If you give your turbo too much oil pressure, then you'll have the same flooding problems no matter how good your drain is.

Question: Do all turbos take a large unrestricted oil flow? Or is there a built in or threaded in restriction added to the oil supply? I can imagine that an unrestricted supply of oil to a turbo has implications on the engine oil pumps excess capacity and ability to build pressure.

Rick

[Dougal]

Originally Posted by rchalmers3

Question: Do all turbos take a large unrestricted oil flow? Or is there a built in or threaded in restriction added to the oil supply? I can imagine that an unrestricted supply of oil to a turbo has implications on the engine oil pumps excess capacity and ability to build pressure.

Rick

Some of them have a restriction built into the oil supply port, others rely on a long and thin supply line to drop the supply pressure down. 20-25psi is a number I've heard, but I imagine each turbo manufacturer has their own specs.

[rchalmers3]

Good to know. As I discover the different sources of older turbo specs online I am seeing modest oil feed requirements (liter/min) that don't necessitate extraordinary measures for hook up.

When I obtain a used turbo I will probably have it's oil feed specs and will need to add a restrictor to the turbo if it does not have one already.

Rick