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Coltri diagnostic, (summary to "lurking" thread)

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  • karl
    replied
    Re: Coltri diagnostic, (summary to "lurking" thread)

    I run my coltri at 30hz or 1/2 of the intended compressor rpm. It is a lot quiter and given that Coltri markets the same compressor as a mch-13, 11, and 8 with the only visible difference being the horsepower of the motor and the rpm it turns at I don't anticipate any issues running mine at reduced speed.
    I haven't found myself in a hurry to fill my tanks but if I was I could always crank the variable frequency drive back up to 60hz and decrease my filling time.

    As far as the fuelmakers products I really like my fm4 when it is operating normally. It frustrates me no end when a hose fails or a motor starting capacitor fails and their is little or no ability to source generic parts or service it yourself. The best aspect of the fuelmaker is that anyone can operate it safely. I wouldn't hesitate to let my wife or kids use it but with the colri they wouldn't have a clue about checking the oil, draining the traps, etc. It is relatively cheap and easy to get the fuelmaker rebuilt but aggravating that the factory won't sell a new/remanufactured compressor head to the end user to install themself.
    I have no experience with a phill but based on what I have read I would only use it if there were no other compressors available. They seem like a great way to generate business for fuelmake service techs.

    Karl

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  • trdscfjc
    replied
    Re: Coltri diagnostic, (summary to "lurking" thread)

    Originally posted by flatracker View Post
    " those idiot phill and fm joke pumps" I would go easy downgrading another mans product, you two just spent the last six months, and a sizeable amount of money trying to get your compressors working correctly.
    well considering this machine is cheaper then both a phill and FMQ, and even when my compressor was "broken" its discharge was still better then the both of those machines


    no wonder they went bankrupt

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  • flatracker
    replied
    Re: Coltri diagnostic, (summary to "lurking" thread)

    " those idiot phill and fm joke pumps" I would go easy downgrading another mans product, you two just spent the last six months, and a sizeable amount of money trying to get your compressors working correctly.

    Leave a comment:


  • trdscfjc
    replied
    Re: Coltri diagnostic, (summary to "lurking" thread)

    I think jthompson was looking into adjusting his speed drive, maybe send him a pm

    Leave a comment:


  • BritCNGUser
    replied
    Re: Coltri diagnostic, (summary to "lurking" thread)

    If I have to get the absolute max range out of a fill I do exactly the same. Most times I don't bother, but when needed, last thing at night my pump goes on, and then in the morn with the pump now stone cold, I run it up. This for the 15 odd mins it takes to get that extra 'nth' of fill.

    Now "trying to reach for that 2gge an hour for ad copy. "
    Whilst containing undoubted wisdom, I don't suppose you realise why I had a chuckle. I nearly spat out my tea.I see many on this forum write similar stuff, so i will try.
    I can assure you that no Italian in his right mind would be thinking in terms of a GGE in anything. He has likely heard of a gallon… just. Maybe. So, best we leave alone the American version of one. So he will certainly never ever have heard of a unit of measure derived from such a unit. Especially when the MCH5 was not designed for Americans. His mind would need to make the four to five leaps to get to the one you made in one. Yet the actaul point stands. He was designing to his marketing department's demand for 5m3 or whatever, so running to say 20% less has to be good. Very good.

    (I had to smile, and I don't suppose you understand why.)

    I have to say, 'faster is better' is great, but more often if my pump took an hour longer to fill I'd not care. It would still be filling at decent times over those idiot Phil and FM joke-pumps. And if it saved the pump somewhat, I might care very much. I will look into this. Would slowing it hamper the splash-lube any I wonder? I suppose even if it did, the pump rather than having its nuts thrashed off , is now cruising, so the need for the lube is likely reduced by a greater factor than any hampering.

    And with my supply-pressure on the ragged-edge of dealing with an MCH5 anyway I kill two birds with one stone. It could make real sense. I've never played with Speed Control. Is it simple?
    Last edited by BritCNGUser; 08-21-2015, 11:56 AM.

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  • trdscfjc
    replied
    Re: Coltri diagnostic, (summary to "lurking" thread)

    the 2nd stage w.p. and bearing can be changed relatively easily and doesn't require removal of the compressor from the frame, i really enjoy my fast fill times. For me it works, if i have to spend 30 min to a hour every 2000 hours to change out the w.p. and bearing at a cost of 14$ per bearing plus the pin is not a big deal. for others it may be something to consider (but i doubt it)

    As far as heat dissipation is concerned if i am ever going somewhere where i need to get the max range on my vehicle i just wait till the morning (after the tank has had several hours to cool) and turn the compressor on again and top off the tank (takes about 15 min.) however this is a very rare occurrence, maybe 5 times a year for me.
    Last edited by trdscfjc; 08-19-2015, 04:36 PM.

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  • flatracker
    replied
    Re: Coltri diagnostic, (summary to "lurking" thread)

    Yours is the third of these that i know of with a bearing failure under 3500 hrs, and i havent been exposed but to 4 of them total. I would give serious thought to dropping the inlet pressure to 1/4 psi and slowing the unit down about 20%. Would increase fill times some but would lower the stress on the overloaded second stage .
    Slowing the fill would also give your tank more time to dissipate heat and result in a better fill.
    I think these are great little compressors they just pushed the envelope on speed , and inlet pressure trying to reach for that 2gge an hour for add copy.

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  • flatracker
    replied
    Re: Coltri diagnostic, (summary to "lurking" thread)

    When your forced to disassemble your compressor for very low pumping rate, and have to replace entire third stage and second stage wrist pin and bearing, its rebuild time. Any time you do a major rebuild on a piece of equipment not every moving part is worn out but you address all areas at once and skip the piecemeal" replacement on failure" and keep the equipment in good order.

    Leave a comment:


  • cngtennessee
    replied
    Re: Coltri diagnostic, (summary to "lurking" thread)

    Great update....thanks

    Leave a comment:


  • trdscfjc
    replied
    Re: Coltri diagnostic, (summary to "lurking" thread)

    I don't think that a major overhaul is needed at 2500-3000 I just did mine because I had mine apart and figured why not...The only thing in need of extra attention is the 2nd stage wrist pin/bearing.

    Ill report back at 6000 hours and let everyone know where im at, I didn't see anything in the bottom end that looked suspect or on the verge of failure.

    Leave a comment:


  • flatracker
    replied
    Re: Coltri diagnostic, (summary to "lurking" thread)

    So 2,500 to 3,000 hrs would be a good rule of thumb as to major overhaul time on these compressors

    Leave a comment:


  • trdscfjc
    replied
    Re: Coltri diagnostic, (summary to "lurking" thread)

    got about 10 hours on the new rings and it seems that efficiency is up, I assume the parts are breaking in and sealing tighter

    Its now pumping at a solid 3.25-3.5 CFM @ 3500 psi

    .......

    interstage filling pressures are as follows:

    Current pressures, my intake gauge still needs recalibration (reads 1 psi too high)

    20150807_221428.jpg

    20150805_222420.jpg

    20150805_233202.jpg

    20150806_004407.jpg

    20150806_014603.jpg

    Final discharge pressures
    20150806_024617.jpg
    Last edited by trdscfjc; 08-07-2015, 11:20 PM.

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  • trdscfjc
    replied
    20150803_195902.jpg
    ...

    20150803_195932.jpg
    ...

    20150803_200005.jpg

    ...

    This picture is the modified head installed and a unmodified head sitting on top

    20150803_200147.jpg
    Attached Files
    Last edited by trdscfjc; 08-06-2015, 10:55 AM.

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  • trdscfjc
    replied
    Re: Coltri diagnostic, (summary to "lurking" thread)

    Pages 30-35

    ____________________

    when reassembling make sure to press the rear bearing in fully (i used a arbor press) and then make sure the race on the crank shaft is full inserted into the bearing before final assembly otherwise there will be alignment issues when installing the cylinders

    ______________________

    After a month long vacation I got my machine running 3 cfm at 1000 psi 2 cfm at 2500 psi still testing to find flow at 3600 will update. ..I have not installed the red head. ..yet

    ________________

    called nuvair, the fittings that came with the new head are for the new style mch5`s, my machine is an older model and the new fittings will not work with the old style intercooler tubes, mitch@nuvair has been very helpful in getting this sorted and has come up with some options for me to get this new head working on my machine....fittings should be shipping first part of next week

    ____________________

    just got back from Nuvair, 230 miles (round trip)....I was told over the phone to not drill/tap the new red head so I loaded up the compressor in my truck and drove it to Nuvair so they could get a first hand look at what I was dealing with, they said they could fit the new head and do the necessary modifications for 190$, went for a long lunch and came back to a freshly installed red head mch5.

    Pumping efficiency is much better I am now getting 3.25 CFM @ 1500 PSI, 2.75-3.0 CFM @ 3500 psi, so the saga is over it seems....im not sure if it was the cylinder or the valve or the rings in the old style head/piston assembly but the newly designed valve/piston/head configuration seems to be the winner... I will update on how things look down the road, but for a 3500 HR. machine im very pleased with this output

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  • trdscfjc
    replied
    Re: Coltri diagnostic, (summary to "lurking" thread)

    Page 20-30

    _______________________________

    [QUOTE=rcontrera;70505]Just a few points for clarification:
    1. The internal parts for the MCH13 and the MCH5 are mostly the same ... bearings, rods, pistons, cylinders, etc.
    2. MCH13 and the MCH16 are both three cylinder, three stage compressors and are rated for continuous duty up to 5000 PSI.
    3. The MCH6 is a four stage compressor rated for intermittent duty up to 4800 PSI.
    4. Intermittent/continuous duty has nothing to do with the number of cylinders. It is a rating of the bearings and sump size.
    5. Compressors that run slower and/or cooler will last a LOT longer as long as the proper lubrication is used
    6. There really aren't any U.S. dealers for the MCH5 CNG machine straight out of the box from Italy since they haven't jumped through hoops for whatever restrictions are imposed by the Feds/States.

    ________________________________

    Originally posted by karl View Post
    Britcnguser writes,
    "Only I'm not sure I know what speed I am supposed to be seeing and at what pressures anyway.
    My mch-13 runs approx 95 psi on the first stage, approx 600 psi on the second stage. These measurements come from $20 Wika liquid filled gauges that are presumably accurate for identifying changes in operating parameters but doubtful they are precisely calibrated.
    I haven't calculated the exact rpm based on motor speed and pulley size but my unit was sold as a max air 90. I am a little concerned that max air may be running the compressor at a higher speed than coltri designed it for as they rate it at 10.8 scfm and Coltri rates it at 7.5 cfm.
    I do know that I get .5 cfm blowby with my variable frequency drive set at 60hz (full motor speed) and the blowby flowmeter stays virtually unchanged if I drop the vfd down to 20hz. 1st and 2nd stage pressures remain unchanged as I vary the speed. The only thing that seems to affect the pressure is the pressure the stage upstream is pumping at. With a priority/backpressure valve installed on my output the compressor always runs at a constant pressure on the third stage hence the lack of pressure variation in my case.

    Ultimately I prefer to run the compressor at a slow speed to keep temperatures and noise level down. I am not especially concerned with pumping rate as long as it does it in a reliable and predictable manner.
    Coltri specifies the mch 13 run at 1350 rpm and the mch-8 run at 900 rpm. They are both the same pump so I don't see any issue with running mine at reduced speed.

    If Ray Contreras doesn't often see bearing failures on his Coltri'ss I am guessing Maxair badged Coltri's like my own trash their bearings due to the increased volume Maxair sets them up for. I plan to calculate my compressor speed at my first opportunity.

    It seems like Britcnguser and Trdscfj both have blowby issues that are difficult to pin down. I have found the compressor inlet is very sensitive to changes in pressure and restriction and changes in those parameters have a profound effect on the blowby. Running a restrictive supply line or solenoid gas valve regardless of pressure can double my blowby to 1cfm.

    Anyone running an inlet filter would do themselves a favor if they added a blowby flowmeter and checked the blowby prior to installing the inlet filter and after installing. It doesn't seem logical to me but I find that even if you have a gauge showing the inlet pressure remains unchanged, adding additional elements to the supply plumbing will increase blowby.

    All I can speculate is that the pulses on the compressor inlet may act like a tuned exhaust on a two stroke or a tuned header on a four stroke and the volume and size of the supply piping may assist or obstruct the incoming gas in maintaining a steady flow.


    Karl
    __________________________
    20150403_154736.jpg

    After a quick trip to my local harbor freight I got a arbor press, bearing and seal driver set and a bearing separator I was able to get the race's out (using the 44.5mm driver)

    more updates to come....been taking it easy this week but going full bore next week
    ________________________

    Originally posted by rcontrera View Post
    There IS actually a tube that runs from the sump to the intake of the first stage so that it can suck up the oil mist. This is called top lubing and is what will get some oil to the top ring or two on the piston. That bit of oil is moved to the second stage for top lubricating there and then to a separator to remove the excess. The air then goes to the third stage where oil is "splashed" into the lubricating area and there is a drain like to allow excess to flow off and back to the sump. Oily, wet air is then sent to a coalescer where it it is battered around and most of the condensate is removed. From there it goes to a chemical tower where the remaining oil and water is processed/removed.
    _____________________

    Got more spare parts... 3x crankshaft bearing, 3x crankshaft bearing spacers, 6x 1st/2nd/3rd stage wrist pin bearings, 4x main shaft bearings (front and rear),2x rear main oil seals ...265$

    20150421_114907.jpg

    __________________
    Just figured since I got it out gona change everything...

    Also found this in a box on my porch...

    20150422_003511.jpg

    ______________________

    Just a quick but important note about the crankshaft bearings...

    These are no longer produced by INA or FAG as far as the shop was able to find, the only company making this bearing is IKO out of Japan (very high quality)

    The main hub for my bearing supplier did have them in stock so not really a issue for me but they did have to do some digging to find out what it was as there was no part numbers on the oem bearings, these IKO's are marked RNAF354716

    ___________________


    Originally posted by cowboy View Post
    I do know if the third stage pressure backs up in to the second it will wipe out the rod. this is what happened to daves compressor.
    ________________

    Upon reassembly I found that the wrist pin was rather tight in the first stage piston, only way I was able to assemble was to press the wrist pin in with my arbor press and then stick it in the block and then install the crankshaft (threading it through the big end of the already assembled connecting rod/piston assembly)

    Despite the order of assembly in the coltri videos you sometimes need to get creative.

    Just a tip if anyone runs into a similar problem

    Another thing...
    Pay close attention to the assembly of the bearing races on the big end of the connecting rods.

    They should stick out equally on each side, only way to do this is to have some sort of relief on the backside of your press, this allows the race to pop out the other side....again make sure they are equally sticking out of each side.

    ______________

    Originally posted by BritCNGUser View Post
    I had the same issue with my 2nd stage gudgeon/ wrist pin. Used a socket slightly smaller than pin diam and a long nut & bolt thru' the lot with a larger socket at the other end all acting as a puller. It is an interference fit but er... tight. First stage was the same.
    _____________________

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