ASK - Bauer with pressurized oil lubrication compared to Coltri splash lubrication

[IyaDiver]

Gentlemen,

I been a Bauer fan and have only owned Bauer all my life since early 90s.
In fact my new Mariner 200E is coming soon....Yipeeee !!!!
I like Bauer but the cost of parts made my cheap 1.5 liter Toyota spare parts cost look even cheaper.....

If I ever need to get a second back up unit, I want to try other brand.

There are only 3 brands available in my country :
Bauer ( poisedon ), Coltri and LW

Bauer sell the most
Coltri 2nd
LW, very rare user group.


I am doing a research and I know price difference means something mechanicaly is different.

I am tempted to get Coltri as a second/back up unit when the need arises and I am trying to see why its cheaper ( for my country ) than Bauer and service life usually shorter according to my friends who are doing air fills. I can't say how my friends maintain their unit but I know they run it hard on weekends, 40-60 bottles a day easy at their dive resort.

I know more about marine diesel engine than compressor, but the physics is the same. Excessive friction, higher RPM & heat will kill any rotating mechanical device fast.

I am not a fan of Bauer Junior or whatever Bauer running more than 2,000 RPM and a splash lubricated type.

As I was looking at ColtriSub data sheet, I find it odd that their units upto MCH18 ( 300Liter/Minute ) do not have oil pump like the Bauer Capitano or Mariner. Older Bauer use 50BAR oil pump with the ring-less floating final stage piston and sometime in early 2000s ( ???? ) they introduce a new block with 10 BAR ( ?? correct me ) oil pump, add an oil filter and introduce the final stage floating piston with polymer piston rings.

The part list book of 2004 for Capitano/Mariner did not put a service life on this final stage floating piston with polymer rings. In 2007 part list book of Capitano/Mariner, suddenly Bauer stated 1,000 hours service life, which they call B category. From a no time schedule suddenly to 1,000 hours is sad, if it goes to 2000 hours still not too bad.
Does this mean Bauer realized that their polymer piston rings can't stand the abuse as they initially predicted or they love to juice us for more dollars...?

What I can not confirm yet because my new Mariner 200 has not arrive, is whether the new Bauer block with oil filter and 10BAR oil pump feeds the second stage piston ring with pressurized oil. The old Capitano/Mariner 50 BAR oil pump has a feeding oil tube to the liner of 2nd stage piston, aside from the floating piston 3rd stage.

Does anyone knows if the new Bauer Capitano/Mariner block has internal pressurized oil gallery feeding the second stage piston liner with oil , or how does Bauer lubricate this 2nd stage piston rings ?

Looking at the 2007 part list, the 2nd stage piston of Capitano/Mariner is so different from the old one. Its not same diameter at the pin (big ) and at the rings area (small ).
In fact from parts list of a Coltri MCH13 to 16, almost similiar piston shape is used on Coltri 2nd stage piston too.

Now back to Coltri. The parts list of MCH 13 to 16 shows some sort of oil tube into the 3rd stage floating piston, I assume its fed by oil vapor from the crankcase since there is no oil pump. Is this the case guys ?

My old Bauer Mariner has similiar oil tube from crankcase but the feeding is at the cylinder head of 1st stage, so its for the inlet and exhaust valve ( reed valve type ) lubrication and that will mean the second stage cylinder head will get the oil mist too, untill its removed by the water separator.


So to sumarize OLD Bauer Capitano/Mariner lubrication system :

Bauer piston 1st stage - splash lubricated
Bauer 1st stage in/out valves - oil mist lubricated

Bauer piston 2nd stage - pressurized lubrication, pressure I don't know because its a "by-product" of 50 BAR pressure. Anyone knows?
Bauer 2nd stage in/out valves - oil mist carry over from by air line from 1st stage

Bauer 3rd stage piston ( connected to crankshaft ) - piston has holes, no oil or compression rings
Bauer 3rd stage floating piston - pressurized lubrication 50BAR

It will be nice if Craig can assist with my summary accuracy.

NEW/CURRENT BAUER
Capitano 140 Liter /Mnt..RPM 1,300.. IK100 block, different
Mariner 200 Liter /Mnt....RPM 1,300.. IK120 block
Mariner 250 Liter / Mnt...RPM 1,450.. IK120 block
Mariner 320 L/M ...........RPM 1,450 .. IK12.14 block, different

Now the question on Bauer.
Anyone owned both the new Mariner 200 ( 10BAR ) and the old Mariner (50 BAR) ? Which one is more reliable, assuming you have pushed both to 4,000+ hours ?



NEW/CURRENT Coltri MCH 13 - 18 Lubrication system :
* I hope Ray can help me out here if there is anything I miss or made mistake

- No oil pump
- Splash lubrication for all pistons
- Oil mist lubrication for 3rd stage floating piston

NEW/CURRENT COLTRISUB
MCH 13 ( 200 L/M )...RPM 1,350
MCH 16 ( 265 L/M )...RPM 1,550
MCH 18 ( 300 L/M )...RPM 1,800
The parts list is in Italian for parts description, I am lost. I think all share common parts, output is boosted thru higher RPM, similiar to Mariner 200 to 250.


Now for the final consideration.
Assuming I do 1,200 hours a year compressor running (+- 3.3 hours a day ) and will use the compressor for 4 years. I don't know Coltri cost of parts, but I assume its cheaper. Purchase cost , cost of parts for very proper maintenance in order not to have unscheduled breakdown in 6000 hours and final resale value = actual cost of ownership.

Which is a better choice, MCH 13 or Bauer Mariner ? Filter catridge cost no need to consider.

Part of my side job is trouble shooting ( my man rip them apart, I only trouble shoot ) marine diesel engines, the high speed 2,300RPM ones. If i merely based my choice on the pressurize oil lubrication system, I will go for Bauer again as back up unit. However compressor does not have upper valve trains like engines that need good lubrication. The shape of the crankcase of a Coltri and Bauer also seems to allow splash lubrication to do better/decent than say a 4 cylinder in line engine.

If anyone owns Bauer Mariner 200/250 and a Coltri MCH 13/16, I would like to hear your experience please.


Many Thanks guys...
IYA

 

[veriqster]

wowwwwwwwwww, you've been doing a lot of reading.
wish i could help you but i can't get anything useful out of the manuals i have - hopefully somebody who deals with them on a daily basis will chime in.
one thing to think about though: why do you think about any modern engine out there, I4, V6, V10, V12, boxter, shortly put everything is pressure lubricated? and if you worked on engines you know that the oil goes not only to the valvetrain;
there are two ways of reducing friction, one is materials (like special aloys, teflon, etc) and the other is lubrication.since special materials tend to have "special" prices as well i'd take lubrication any day. also, the higher the pressure of the oil in between piston and cylinder the higher the tolerance of the fit.

 

[IyaDiver]

Hi verigster,

Engine is different in the sense the fuel explosion power the piston down and turn the crankshaft.
Compressor works the opposite way, we spin the crankshaft and the piston goes up/down producing compression. So I am quite blind on compressor and more so for its pressure loading on different stages.

I am wondering what is the "sweet temperature" for operation on a compressor.
I mean like minimal operating temperature to get proper thermal balance on engines for best burn.

Oil in engines aside from providing lubrication, it remove heat quite a bit. I don't know how much heat is removed by compressor oil from its piston liner which is the hottest zone the oil can wet. I am tempted to use oil cooler if I can on my Bauer, actually. Maybe get one from a motorbike.....

IYA

 

[veriqster]

a compressor is the same as a diesel engine operating in "brake" mode, something seen quite a lot in trucks, the difference is that pistons instead off operating in parallel are connected in series. In a well designed compressor the power load of every stage will be roughly equal at optimal rpm due to the difference in piston diameter. you seem to go pretty deep regarding operating principles and wonder on the limit of compressor design - while i'm sure there are people on the board that can answer your questions most of us can't help you. the oil removes quite a lot of heat; on my "military type" compressor it takes about 45 min to bring it up to temperature - it has a HUGE oil reservoir and is pressure lubricated (about 15 BAR). I'm not sure an oil cooler would be a good idea as the oil needs to get to a certain temperature to be able to easily penetrate in all spaces it's supposed to go by design. an oil cooler might increase the warm up time which mean increased ware. I would also try to post on the compressor group on yahoo and see what those guys think - a lot of them run and service military design pumps which run at high rpm, some of them used to do it for a living, maybe they can get you some data on oil types used at different temperatures, it would be a point to start.

 

[IyaDiver]

Yes, brake mode , nice to imagine it that way. Same way they take regenerative power on hybrid cars yah.

I am not really a diesel mechanic, I trouble shoot marine propulsion because engine only mechanic does not usually understand the complete power package of a yacht. They tend to always look into engine problem instead of looking at overloaded condition, wrong running angle/attitude, marine growth on hull, out of tune propellers, poor engine room ventilation and whatever bad things a prime mover can experience when installed on yachts with planing hull.

Its easier to troubleshoot a genset with dummy load but when connected to marine propulsion its a bit more complex, that's where sometime I get called in by yacht owner to assist the diesel mechanic.

WOW, 45 minutes just to get to working temperature on those big compresor. Are those water cooled ?

 

[veriqster]

i was talking about my small 3.5 cfm JAB unit; the 3rd stage warms up completely only somewhere on the second tank, definitely not before 30 min. it's got a HUGE oil reservoir, i accidentally drained like .5 liters when i got it and that could barely be seen on the oil level glass (about 3 mm out of 2cm + total oil level). according to the operator notes i got from the US distributor for JAB the oil change interval is 1200 hours, yea twelve hundred hours, they started laughing at me when i asked if this unit has any useful life left in it at 600+ hours ; of course i'll change the oil beginning of the season (for the first time).
on a side note, they actually used engines as brakes in diesel powered trucks, the ones i know of are the USSR made KAMAZ trucks.
My advice is to buy the best you can afford, a time proven design and leave the engineering to those who get educated and paid to it (why the hack can't i make myself do the same???)

 

[IyaDiver]

Yes, that is one sound advice....

 

[CraigAClark]

I get a chuckle when I hear people complain about Bauer parts prices. I used to feel the same way until I started working on Reavell (Mako) and Hamworthy, that is.

Craig

 

[veriqster]

It would be nice if somebody would run a statistical analysis on reliability / warranty issues / service requirements / costs of a pool of compressor pumps but then again, even if the data would be available from manufacturers / distributors / dealers nobody would release it for the fear that it might bring down their business (quite true for some companies).
I lot of things would be nice to have but I don't think anybody in this world is interested in providing info to the general public, unless that info is thought to improve their bottom line that is. Just have a look at the Toyota mess, SAFETY issues for the last 10 years and nobody even bothered to warn the owners.
bottom line, there's a couple of people on this board that deal with compressors for a living, if you can convince a couple of them to share some data with you, even under the condition of confidentiality, that is about the only way to make an informed decision. It's not going to help all of us, but you are not after bettering the humanity are you?
sorry, i'm in a very "capitalistic mood" today, bad day / week.

 

[IyaDiver]

V,

Comparing reliability or dollars of operation per hour and resale value to get REAL cost of operation is hard to do unless the test parameter is the same, hence the need to get data from many owners plus hearsay here and there and filter them out.

True to what you are saying, since this board consist of brand A or brand B representatives, its hard to get real answer without having the risk of offending the others when comparison is made.

I am thinking along the line of as a consumer, this is the biggest group in this forum. Next to a simple dive boat, new compressor is the other expensive hardware to buy for 200L/min class or bigger.

In high speed marine diesel engines we have 3 known category :
- 1,800 RPM heavy duty , tug boats and the like
- 2,100 RPM intermitten duty , ferry and the like
- 2,300 RPM pleasure craft duty...blow those engines fast but get highest power

And then in USA typical 60hz spec, this 1,800RPM engine becomes prime mover for generator. 1,500RPM is when its a 50hz spec. They break it down again into stand-by, prime and continuos rating. Basically same machine connected to various alternators that produce power from less to most , all in the end resulting to desired reliability. There is no free lunch, push it hard, it dies faster. Manufacturer will spec out maximum operating hours per year and overload capability, but of course A and B brand reliability is never the same in the end. Some brand is just better built but not always for its entire range of models.

This is the kind of information I want to get for compressor, hence I always look at operating RPM but obviously the lubrication system is also very important. The uniqueness of floating piston from ring-less 50BAR and then come polymer rings and at reduced 10BAR oil pressure makes me wonder, why it is done ? I have rip open only Bauer old Mariner, never other brand or model. So my knowledge is very narrow but I like learning about them, the very reason this section of the forum is born, isn't it ?