Add turbo

[Oil pan 4]

I have ran oil returns to valve covers before.
My diesel suburban has been that way since 2009, oil return dumps to the valve cover.
I have pulled oil returns and dumped them into an oil bottle to test flow and the oil just looks like oil.
Since I run oil restrictors to make the turbo more responsive I have to test flow.

 

[NHSleddog]

I have ran oil returns to valve covers before.
My diesel suburban has been that way since 2009, oil return dumps to the valve cover.
I have pulled oil returns and dumped them into an oil bottle to test flow and the oil just looks like oil.
Since I run oil restrictors to make the turbo more responsive I have to test flow.

Someone needs to get you a B2650! I love the sound of a turbo.

 

[SidecarFlip]

I have ran oil returns to valve covers before.
My diesel suburban has been that way since 2009, oil return dumps to the valve cover.
I have pulled oil returns and dumped them into an oil bottle to test flow and the oil just looks like oil.
Since I run oil restrictors to make the turbo more responsive I have to test flow.

+1. I was going to comment about some of his wacko ideas, but decided not to. Turbine oil is pressurized, don't matter where it discharges so long as it gets back into the lube oil and there is no 'jelloing' of the oil, the bearings do't whip it at all. Most turbo's have plain ceramic bearings anyway.

 

[Oil pan 4]

I would love a new tractor but would hate the payments.

Went to go look at the suburban because I thought I remembered that the valve cover cracked and leaked some oil. I ended up relocating the drain to the timing cover, but I ran it for a year or 2 going into the valve cover, it just cracked because the metal is paper thin GM steel.
The kubota has a more substantial cast valve cover.

I'm sure this little cheap turbo just has non roller brass sleeve bearings and a brass non roller thrust bearing.

If the oil was foamy from the turbo wouldn't giving it more complex surfaces to run over and a few different pathways to get back to the sump give the oil more time to defoam?

 

[Oil pan 4]

I did a static pneumatic test on the waste gate.
It starts to open about 11 to 12psi. In a dynamic situation with drive pressure trying to push the waste gate open that would be more like 8 to 10psi.
That's plenty. If I get out there with the brush shredder and romp on it never then hit above 6 to 8 psi there's no need for the WG.

 

[JeffL]

"If the oil was foamy from the turbo wouldn't giving it more complex surfaces to run over and a few different pathways to get back to the sump give the oil more time to defoam?"

You might be right with a small turbo and oil flow. Also might put a lot of extra heat onto the valves and springs. All this really depends on how much the turbo is spooled up. You will not see the foam at idle or moderate reving of the engine. Need the turbo at boost and high rpm.
If it becomes a problem you can use a catch can arrangement to allow the oil to loose the air and then drain back to rocker cover. Worked with a project that wanted to place the turbos below and behind the engine. I recommended the can and electric pump to return to crankcase. Worked not sure where they went with it, racing or aftermarket kit.

 

[JeffL]

Diesels can take a lot more boost than the gas engines. Largely due to the more robust design but also form the lack of need to control a A/F ratio. You will not see the exhaust temps as you would in a gasser.
Now if you get power greedy go back and read NIW's posts.

 

[SidecarFlip]

The hairdryers on both my M9's are pretty small. In fact tiny but I know when they are spooled up they make positive pressure (no boost gauge), I can tell by the expanding air to air plumbing. The rubber hoses grow in size a bit when it's 'on the turbo'. Both my M's are waste gated. I prefer charge air cooled myself. Cooling the incoming compressed air charge goes a long way to producing better power.

 

[Oil pan 4]

I had a T76 draining into the valve cover on my diesel suburban. The T76 is just about the biggest turbo you will see used on a highway driven vehicle.

 

[North Idaho Wolfman]

The only real issue I can see with draining to the valve cover on these little dudes is that they are really slow at returning it's normal amount of oil to the pan, if you add too much it might just end up coming out the breather pipe.

 

[JeffL]

reminded me of a childhood experience where oil flow into cover far exceeded drain rate on a OHC gasser. Happened after working to increase upper RPM by 1500. Looked like a blown NASCAR engine. It wasn't a maybe situation.
Something to look out for, all engines designs are different and have their quirks.

 

[Oil pan 4]

Well then I can watch it run and make sure it's going to drain fast enough.

 

[JeffL]

OP4, sounds like a plan.

Changing the subject: How do you select the correct oil feed orifice or restrictor?

 

[Oil pan 4]

Easy, look up the technical specs for the turbo and guess.
One that I remember looking up was a he351ve, the manual called for 1 quart of oil at idle and 3 running per minute.
Just pick a size orifice and go up from there.
On my T76 I started with a 1mm restrictor, it definitely wasn't big enough so I drilled it out to 0.05''. Flow was a little low for what it called for but the next size up drill bit I had was 0.062'' and that would have been way more than enough.

For this tiny turbo I can't find any oil flow specs I will assume half of what a T76 uses should be sufficient.

 

[greenacresnorth]

oil pan, dont let anyone tell you it wont work, also the intercooler is a wast of time, these little motors will never drive a RHB near its map and make any appreciable heat, I see a 1.9 degree rise in temp at 4psi between inlet and outlet. my L2501 really woke up above 5500', made such a large difference that I have done 3 more since and looking at adding a GT15 to a 3301 and keep the DPF some how.

https://www.orangetractortalks.com/forums/showthread.php?t=42951

 

[Oil pan 4]

oil pan, dont let anyone tell you it wont work, also the intercooler is a wast of time, these little motors will never drive a RHB near its map and make any appreciable heat, I see a 1.9 degree rise in temp at 4psi between inlet and outlet. my L2501 really woke up above 5500', made such a large difference that I have done 3 more since and looking at adding a GT15 to a 3301 and keep the DPF some how.

https://www.orangetractortalks.com/forums/showthread.php?t=42951

I was planning to hook it up and run hot boost for a bit until I figure out how hot its going to get.

 

[greenacresnorth]

I was planning to hook it up and run hot boost for a bit until I figure out how hot it a going to get.

i saw a drop in exhaust temp by 200 degrees of NA and no appreciable rise in water temp. PTO dyno states 31hp at 2500RPM and 4psi boost

 

[JeffL]

"Easy, look up the technical specs for the turbo and guess."

Educated guessing based on fact! Have to admire that.
Probably a lot faster than calculating and plotting a flow graph for several orifices until a good match is found!

If you find the turbo is over sized you can always add an afterburner to spool it up. Of course fuel economy just went out the window. and you would be a little closer to needing to reread NIW's initial posts.

 

[Oil pan 4]

No plotting flow graphs. Waste of time.
Put a restrictor that's about the right size, start the engine catch the oil that drains out of the turbo and measure it in both volume and time. Drill it out if you need more flow, smash it with a punch or solder over it and redrill for less.
It's not rocket science.

I don't need to read anyone else's posts.

I put a T76 on my little 6.5L diesel and fuel economy went up about 20%. The rhb31 appears to be sized for an absolute maximum around 120hp. Not worried about it being too big.

When I first moved here and my diesel suburban was non turbo the EGT gauge lived at 900F when on the highway.
Now it barely sees 700F unless I floor it. The ball bearing T76 loves cramming air into that engine.

 

[Oil pan 4]

I'm wondering if the air cleaner is sufficient for the turbo.
At 3,000 rpm with no turbo the little 700cc kubota sucks down about 32 cubic feet per minute.
At 3,000rpm running 1.5 atmospheres of absolute pressure it should be more like 56cfm. I expect to see 1.5 atmospheres of absolute pressure, that's totally realistic.
If I hit 2 atmospheres assuming the engine doesn't blow it would be sucking down 74cfm. But the waste gate should be opening before that.

I can test the original filter see how much it sucks at full power, if it's not big enough bump it up to something like a Donaldson G057512.