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Holset Turbos Oiling

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Boostdriven

10+ Year Contributor
622
14
Jan 7, 2010
Pasco, Washington
I posted this in Mike1992's thread (holset HX35 oiling) but since it was on page 6 with already over populated thread, I figured it might be a good idea to start a new thread so more people can see what I would consider valuable information.

This relates to both HX35 and HX40 turbos since they are the same chra with different size wheels.

Just before I switch to HX52 I had a HX40 on my car for about 6 or so years but because I was experimenting with other turbos I put between 10k-15k on that HX40. It's whole life its been fed from an OFH with an original #6 holset fitting in the chra and a #6 steel braided fuel line. My oil pressure fully warmed up at idle is about 25 psi and at 2500 rpms is about 50 psi, by red line its about 80-100 psi.

A little while ago when I still ran the HX40 I ended up buying a 62mm compressor wheel as an upgrade so in the process of changing the wheel I thought I might as well take the whole thing apart and look everything over. At this time turbo had about 8k-10k miles on it. When I took it apart, the shaft looked perfect, no excessive heat marks, the piston ring on the exhaust side didn't look all sludged up and a little bit of starting fluid cleaned up whatever was there. The heat shield on the inside didn't have any burned oil on it. I put that thing together and it ran perfect to about few days ago when I took it off to replace it with HX52. Turbo ran 26-35 psi of boost. Stock oil return line.

My friend Tristen (dsmcurse) has his HX40 for about the same period of time, fed with the same #6 line from an OFH with relatively same oil pressure. Turbo runs 30-35 psi of boost. Stock oil return line.

My friend Justin has a HX35 on his daily driver that he drives to school and work. He bought that HX35 used from a junk yard with about 100k miles on it. I have not rebuilt it for him yet but its been on his car for about 9 months now. It's fed with the same #6 line I have on my car. No smoking, no issues. Turbo runs 26 psi of boost. Stock oil return line.

Now let me tell you about a friend who wasn't so fortunate with his HX40. He bought this thing brand new and decided to use a #4 line and feed it from the head. Turns out it wasn't such a good idea. After about 600-800 miles the turbo started to smoke. So I took it apart it and right away I could see the cause of failure. The shaft was blue and the exhaust bearing was black. When I asked him what his egts were at cruise or wot he said between 1100 at cruise and about 1400-1500 after going through few gears so nothing out of ordinary. The only thing that wasn't ordinary was oil supply. Turbo ran only 20 psi. Stock oil return line.

I have another friend who has a 98 dodge ram 5.9l cummins. That truck has about 230k miles on it with an original HX35. I asked him what his oil pressure was, he said at idle its about 50 psi and at 3200rpms its about 90-100 and that's fully warmed up. That turbo is fed straight from the block with a #6 line.

My next door neighbor has the same truck with 250k miles on it with an original HX35, same oil pressure, same oil feed line.

The list goes on and on but I think you get the point.

Holset turbos are not your topical POS Garrett or Mitsubishi that in most cases is cooled by water. Every bit of cooling on the holset turbo is done by oil. I'm almost sure that if you were to take the water lines of a 14b or a 16g and feed it from the head like stock, that turbo is not going to last very long.

Some of you may say, diesel engines don't put out 120 psi of oil pressure like some of our DSMs, well I'll say that diesel engines don't put out as high of egts as some of our DSMs.

I've been around holset turbos for number of years and I've seen them fail for several different reason. Under feeding it with oil was #1. I've seen them fail because of really hot egts where the rear bearing gets so hot that it loses it integrity and starts to wear out causing excessive shaft play and shortly after the turbo starts to smoke. Improperly installed snap rings that hold the bearing in might cause the turbo to smoke, the same goes for the piston ring on the exhaust side. If your oil return is smaller on the inside then your oil feed line on the outside, its probably a good idea to get something larger. If you don't have good crank case ventilation, pressure in the crank case will push the oil past the piston ring. There are many variables that could cause the turbo to smoke and fail, let's not blame it on "to much" oil. I have never seen a holset fail because of to much oil was supplied to it, at least not by a normal functioning DSM. Now garrett turbos are a different story and we are not talking about garrett. I never liked them anyways.

I'm not trying to start an argument here, I'm just sharing some information from experience. So if you want to run a BEP .55 bolt on housing on you HX40 or HX35 running 30+ psi of boost with exhaust pressures damn near double and egts through the roof, on top of that you want to put a restrictor in it, well be my guest. It's money out of your pocket not my.

Fortunately those holsets are not that expensive ;)

Now some of you might be running a holset with a restrictor and it might work for you but not all of us are fortunate to have good oil pressure in our DSMs. Just because it works for you don't mean it will work for a guy who has half the oil pressure you have and just because its been working for you SO FAR don't mean your holset will last you 100,000+ miles. There is no reason why a holset shouldn't last 100,000+ miles considering they go 250,000+ miles on a diesel truck pulling loads heavier then your car.
 
A couple things to keep in mind- a diesel itself operates cooler, so oil temps are often cooler than a gasoline car. They also use 15W40 as a standard where there are many guys on this site running 5W30 despite Mitsubishi recommending no thinner than 10W30. Big difference in film strength between 5W30 and 15W40.

With Holset turbos being the factory turbo on many Cummins diesel engines, their oil source is plumbed from an area with the exact pressure the turbo needs to operate. We're not quite that fortunate....we either have the head (too low) or filter housing (too high).

The factory application also has an ample drain where most of the aftermarket drains available for our cars are well-undersized. Preventing drain flow will definitely modify the volume and pressure of oil you can feed into the turbo before you start dumping oil past the turbine and compressor seals.

If your drain is ample and the pressure at the inlet is good, you can literally fire as much oil into the cartridge as it can effectively drain. The more the better- the cooler the cartridge will be the more oil that enters and drains. Like I said, though- too little pressure and much pressure with not enough drainage are the #1 killers...you're not going to easily kill a turbo that is fed the correct amount of pressure through a restricted source.
 
Nice guys. I'll add I'm having no issues at all with a -4AN feed from the ofh( extreme psi) no restriction, and a -12AN drain and a ported oil pan hole to accept the -12AN. Drain flange for an s600 BEP.(Race parts solutions)
9,700 miles right now in my motor. Ive been running the hx40 for 3k of those miles at 28psi daily and I'm about to give it HELL on the T3 .70 housing. 37-40psi. I'm not even worried about the turbo getting hurt in the least. More worried about my mahle pistons cracking LOL.

I'll also add that you MUST make sure that your drain WILL NOT KINK in any way. Thats also a known killer that Justin briefly stated about feeding as much as you want, as long as the drain can effectively drain what ever is being supplied.
 
The factory application also has an ample drain where most of the aftermarket drains available for our cars are well-undersized.

Because they're based off garrett :)

With Holset turbos being the factory turbo on many Cummins diesel engines, their oil source is plumbed from an area with the exact pressure the turbo needs to operate. We're not quite that fortunate....we either have the head (too low) or filter housing (too high).

Where did you get this information, did you actually put an oil pressure gauge on diesel oil supply to see what it was? If what you're saying is the case then I wonder why they use #6 line to the turbo even though its like a foot long :)

Since we are on a subject of oil which is a "possible" factor of turbo failure but not likely though of course there are extremes. My question is, why would a guy want to run thin oil like 5w30 in his turbo engine anyways? Yes you might get a little more HP but is that worth a possible rod bearing failure when you're making 500+ whp?

Just the other day I changed oil on my friends Honda, oil cap said 0w20, guess what I put in it, 10w30. A factory Honda has a lighter engine rotation assembly then your typical 4G63 even none turbo ones therefore it can get away with thinner oil. My 98 civic 5 speed calls for 10w30 in the tranny, no wonder those damn things get 30+ mpg :)

If 5w30 is thinner then 10w30 or 15w40 then it wouldn't take such a large hole to drain the same volume of 5w30 as you would for a thicker oil. We all know how pleasant it is to change gear oil on our trannys :) yes you can drain it when its hot but what are you going to do when you have to fill it, stick that shit in a microwave? ;)

Just because you have a shitty oil drain or bad crank case ventilation don't mean you need to short change your turbo of oil. Get that shit fixed so you can feed the turbo all the oil it needs. Anybody who can bolt an HX40 on their car can build an adequate oil drain. My is nothing more then two ends of a stock drain with a piece of good heavy duty hose connecting them together. I changed the upper flange to holset style instead of just cutting open the bolt holes. It makes life easier if you like to experiment with different turbos and housings.

Porting the upper flange hole and making it funnel like or (velocity stack) takes the sharp edge out and helps with the initial entrances of oil in to the drain tube. Yes I think of little things like that :)

Which MHI turbos make 600 horse in their stock trim. Lol

Even though I find this funny :) I have to say that Greddy turbos are built by Mitsubishi. One in particular I remember was my friends T78 he had on his rx7. Exhaust housing had Mitsubishi diamond stamped on the side of it. When that thing finally went tits up and bent the shaft I was trying to help him find parts for it. I believe the exhaust wheel on it was TD08 or TD08H. They are a little over priced that's for sure.
 
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Because they're based off garrett :)
So is the factory 2G T25 drain. The 10AN aftermarket shit is even too small for Garretts....I have an entire thread about this. ;)

Where did you get this information, did you actually put an oil pressure gauge on diesel oil supply to see what it was?
I've installed gauge packages on a few friends' diesel trucks over the years- while I don't remember much, I recall the last one being an '07 Dodge which was probably about two years ago was tee'd directly into the top of the filter housing. After the install the idle pressure was about 25psi and I think it made around 55-60psi while cruising. Of course this is an engine that redlines at 3500rpms, so pressure will never be 100+psi like one of our cars during a 9K pull.

If what you're saying is the case then I wonder why they use #6 line to the turbo even though its like a foot long :)
Because the factory drain is a 7/8" metal tube with no sharp bends and zero chance of kinking. Going back to what I said earlier, the feed being 3/8" is totally acceptable when the oil pressure under load is 60psi and the drain is 7/8"....bigger than anything available for our cars.

Since we are on a subject of oil which is a "possible" factor of turbo failure but not likely though of course there are extremes. My question is, why would a guy want to run thin oil like 5w30 in his turbo engine anyways? Yes you might get a little more HP but is that worth a possible rod bearing failure when you're making 500+ whp?
Beats the shit out of me....but guys do it all the time. There are guys who will argue that 5W30 and 10W30 are exactly the same when warm despite Mitsubishi clearly stating that 5W30 should only be used in climates that never exceed 60*f while 10W30 is recommended all the time. Obviously there's a difference.

Just because you have a shitty oil drain or bad crank case ventilation don't mean you need to short change your turbo of oil. Get that shit fixed so you can feed the turbo all the oil it needs. Anybody who can bolt an HX40 on their car can build an adequate oil drain.
Again, I can only wish this were true. I've seen everything- the worst being a guy who plumbed the oil drain on a 50-trim Garrett with pipe fittings from Lowes directly down the center of the 1G roll stop then had some U-bend on the bottom like a damn sink drain before heading into the pan. If I could have gotten photos without embarrassing the owner too badly, I would've...it was hideous.

That in mind, people will cut corners and cheap out on everything needed to properly complete the install about 98% of the time. Always assume the worst. ROFL

Porting the upper flange hole and making it funnel like or (velocity stack) takes the sharp edge out and helps with the initial entrances of oil in to the drain tube. Yes I think of little things like that :)
Great minds think alike- I've been doing this for the past 4 years or so....ever since this thread was created:

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I've seen some weird things in my life but never a pee-trap on the oil return. You have to give a guy some credit though, you know he was thinking to come up with something like that :)

Good job on the oil return line mod, I didn't know people were doing that already. Maybe I should use a search option on this site more often :p
 
Porting the upper flange hole and making it funnel like or (velocity stack) takes the sharp edge out and helps with the initial entrances of oil in to the drain tube. Yes I think of little things like that :)
I agree this is a good idea i did this as well a long time ago when i created the holset drain write up. (Which i had to take down due to threats of perma ban over grammar mistakes in other threads.)

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Now about your greddy is made by mhi statement. That isn't a stock trim mhi now is it? Why you just said could be taken the same as saying fp turbos are the same as a stock garrett or mhi. Which is not the case. But greddy turbos are over priced crap that is slow anyway. But this isnt a debate thread about mhi turbos.
 
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Holset turbos are not your topical POS Garrett or Mitsubishi that in most cases is cooled by water. Every bit of cooling on the holset turbo is done by oil. I'm almost sure that if you were to take the water lines of a 14b or a 16g and feed it from the head like stock, that turbo is not going to last very long.

The 14b/16g is primarily cooled by oil. The coolant is only to prevent oil coking and heat related damage after hot shut down. If I'm not mistaken, MHI-based FP turbos don't even have provisions for coolant lines. Holset's lack water lines because they are used with Diesel engines which normally have much less need for heat resistance. However, Holset does make an optional water-cooled housing for heavy duty applications. So I guess Holset actually is just like those POS Garrett and Mitsubishi turbos. :)

Some of you may say, diesel engines don't put out 120 psi of oil pressure like some of our DSMs, well I'll say that diesel engines don't put out as high of egts as some of our DSMs.

So if you want to run a BEP .55 bolt on housing on you HX40 or HX35 running 30+ psi of boost with exhaust pressures damn near double and egts through the roof, on top of that you want to put a restrictor in it, well be my guest.

Sure, oil flow is important. But higher exhaust temps don't automatically require exceeding the recommended oil pressure. At least not without knowing the actual flow rate and temperature of the oil, which I've yet to see mentioned. Here's how Holset feels about that subject:

Holset said:
12. Oil pressure of 150 kPa (20 lbf/in2) must show at the oil inlet within 3 - 4 seconds of engine firing to prevent damage to turbocharger bearing system. A flexible supply pipe is recommended.
13. The minimum oil pressure when the engine is on load must be 210 kPa (30 lbf/in2). Maximum permissible operating pressure is 500 kPa (72 lbf/in2) although 600 kPa (88 lbf/in2) is permitted during cold start up. Under idling conditions pressure should not fall below 70 kPa (10 lbf/in2).
14. Recommended oil flows for the turbochargers are 2 litre/min at idle and 3 litre/min above maximum torque speed.

Without verifying the flow rate is too low at recommended pressure, there's no basis for exceeding the safe oil pressure. Same goes for temperature; If your not feeding the turbo with excessively hot oil, I see no reason to believe the CHRA is overheating. Even then, how likely is the turbo to be directly causing high oil temps? Look at BB turbos. They don't experience significantly lower EGT's than a similar journal bearing turbo, yet require very little oil. Even journal bearing Mitsu's and Garrett's require a fraction of whats being fed to restricted Holset's.

Just because you have a shitty oil drain or bad crank case ventilation don't mean you need to short change your turbo of oil. Get that shit fixed so you can feed the turbo all the oil it needs. Anybody who can bolt an HX40 on their car can build an adequate oil drain. My is nothing more then two ends of a stock drain with a piece of good heavy duty hose connecting them together.

According to Holset, the oil drain should be at least 19mm ID (3/4" or 12an). Considering my 3/4" hose slips right over the stock pipe, I'd say the ID is around 16mm. Don't get me wrong, the stock pipe and rubber hose setup gets the job done (I'll be using a similar setup). But it's still considered inadequate by the manufacturer, so it's not easily capable of handling the maximum amount of volume the turbo should normally receive. Which has now been seriously increased...

Sorry, but I still see no reason to remove the restrictor, disregard manufacturer guidelines, and expect nothing but positive results.
 
You see no reason to remove an oil feed restrictor wes? Why is that. Cause there are plenty not using one, including myself. Pair that with a -12 drain. Which technically is still to small, a -14AN ( if they existed) would be proper. (19mm ID)

However since -14 is non existent and -16 is WAY too big. A -12 (18.3mm if i remember my own measurements)must suffice for the best and most easily obtainable drain system. Beveling the lip of the drain to funnel down also helps alot like my pic. .
 
Wes, in my very first post I said that me and few of my friends have been running #6 feed line with no restrictor from OFH for a very very long time, why are you still trying to prove your point, argue with someone who's turbo has failed ;)

I didn't say that if the turbo is water cooler its POS, I said that garretts are POS. 8-10 years ago when people started to bolt holsets on their car, the same turbos that are still making 600+ whp, garrett had nothing out there in a relatively same size that could make the same power as holset. Their compressor wheel design was just junk. I don't know what kind if wheels they build now but because I didn't like them then I don't care to keep up with their stuff now.

Urbansmoker, you and I are on the same page, I ment no offence by what I said about greddy.
 
I fail to see the warrant of a new thread on the topic.

The oiling thread is 6 pages, not 30.
 
Just going to quick say a cummins does not run 100psi of oil pressure. I used to work for a performance diesel shop and i have a 637whp cummins.. They run right around 50-60 at wide open 35 ish at idle. And my truck even with a 66mm charger will hit 1600 deg egts very fast diesels do have hot exhaust temps.
 
boostdriven, id like to special request a larger drain line for my hx40. im thinkin same type of hose set up befor, but instead of 5/8''s id like to go 3/4'' hose from unter turbo to oil pan. all in do time i guess.

oh, AND, my number 4 meth hose (closest to my TB) keeps poppin out....

kinda scary... :(
 
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