Oil level- Lister clone

[BruceM]

I'm a bit baffled about oil level on the DES propane 8/1 conversion engine.  The dipstick is still on the "little door", but only reads what's in the upper sump, so seems useless to me.  What is the proper oil level in the lower sump?  Has anyone tried to put a low oil
float switch in the lower sump? If so, where and how well does it work?

On my Metro Listeroid 6/1 with single sump, a conventional float switch didn't work due to splashing, so I had to hombrew a vinyl oil level sight tube with magnet in a HDPE tube float inside the sight tube, and a reed switch zip tied to the sight tube.  That works fine for both a quick visual check and for auto shutdown sensing, but a bit of a hassle.

So I was just wondering what might work best, and where the doggone full oil level really aught to be on the dual sump clone.

[Hugh Conway]

Yes Bruce .....dipstick is useless on a dual sump engine. . I suppose it will tell you if the oil pump is working.  The Dursley 6/1 engines do not have a dipstick.  I fill my sump at about 1" below the top of the fill port on the breather side.
Never have had to add oil between oil change intervals of 250 hours.
Cheers,
Hugh

[BruceM]

Thanks, Hugh.  It thought that dipstick odd- good to know it was a just a Rajkot screwup.  1" below the swing away lid on the sump makes sense.   I could mount a float switch there but I'm afraid the splash would screw it up hopelessly.  My nearing 3000 hr Metro burns 1/2 a quart in about 200 hours.  I usually just change it instead of adding oil.

[EdDee]

Hi Bruce,

I installed a T piece/Elbow at the drain and installed an external dipstick on my 2 beasts. I figured that max level was the lowest notch on the weir and the lowest level is 1/2" above the oil outlet to the pump, with the inside of the CC wet and lubricated, weir full. Below that is danger time!

Cheerz
Ed

[38ac]

Just as Hugh said I tell people to use the dipstick to confirm that the pump is working. The lower sump level is really of no consequence as longas there is enough there to keep the upper sump topped off.  This another advantage of the two sump setup, you dont have to add oil a few hours before a change or change early due to a bit of consumption. 

[BruceM]

Thanks, EdDee, 38ac.  It seems that sensing an oil pump/flow failure might be more important than sump oil level  in these CS clone engines.  Perhaps a pressure sensor in the oil supply line?  Or perhaps oil level in the upper sump would do the same thing?

[EdDee]

Hi Bruce,

An oil pressure sender in the pump line would work, but it would have to be a low pressure sender as there are no force fed bearings to provide any form of back pressure or reasonable amount thereof, to activate the switching. If you can find such a creature, it is quite easy to allow for the pulsing of the line simply by putting a capacitor over the coil of the relay that it is hooked to... this will hold the coil "in" as the switch drops power to the coil after every delivery stroke, the bigger the cap, the longer it would hold the coil energised...

I wouldn't use weir level sensing, it is just too clumsy to be effective in my opinion(by the time the weir empties, there is precious little oil left coating the insides, so other bits will take strain as well). I have found that a good old dipstick in the lower apron works wonders for peace of mind, always better to do the basic checks before starting I reckon... I haven't installed a low/no flow warning on the pump yet, I might do it in future, but so far, the oil pump seems way more rugged and reliable than the rest of the weak links mounted to it... One thing that did concern me, so much so, was the lack of oil filter, so as soon as I got a chance I made a couple up and installed them on my engines... There is a fair possibility that my first big end failure might have been avoided if I had sifted out the filings before they recirculated back into the bearing...

Cheers
Ed

PS - the mind wanders.... 2 oil pressure sensors, one before the filter and one after... the one before could be a normal pressure range one, hooked up to a relay to trigger a "oil filter replacement time" warning indicator, ie, when it lights up, its indicating that the oil filter is taking a bit of pressure/bypassing and is in need of replacement... the other one indicates no pump output or oil low etc.... How's that?

[BruceM]

EdDee,  I'd love to see a photo of your pump line oil filter setup.  No troubles with catching the peak or average of the pulsing oil pressure signal.   Any idea of what the pumping pressure range might be?

We will be using an Arduino for monitoring and auto/remote starting, and I've already got to do some minor signal analog signal messaging for the air compressor line sensor to see the pumping pressure variations as part of the automatic no load for ten minutes shutdown. 

[EdDee]

Hi Bruce,

The inline oil filter is pretty basic, I machined up a piece of 3" BMS to suit a 65mm or so seal diameter oil filter from a Geely motor ... I think its basically a Toyota look alike from an engine aspect... I then cut into the oil line and inserted it ... Once it was inline, I freehand cut a piece of 2.5mm plate on the band saw and made a securing bracket to attach to a bolt on the bearing trumpet just above. The little filter nestles in quite nicely behind the flywheel and sits easily within the inside rim diameter. Changing filters is a breeze, I have enough space and clearance to get to and loosen the filter through any of the flywheel spoke holes....

The first filter I made up as a test is still working well on TM1, the better one is on TM2, the earlier unit was fabricated out of 3mm plate, a large bolt suiting the inner thread of the oil filter and a couple of bastardised brass fittings. The later one on TM2 is a way better unit - with the machined top section, there is plenty of material to put in pressure sensors before and after the filter... this allows for playing at a later stage...!

As to the pressures involved, I haven't a clue, but once drilled, tapped etc, it would be a simple matter to put on a guage to take pressure readings and then plug the holes with blanking plugs should the pressure switches in the required ranges not be available....

I have considered 'electrifyilng' my Setup with PLC or micro, but I kinda like the old school stuff and am trying to stick with the 'theme'... One thing I have considered though, is the most basic of monitoring, just over temperature, over voltage and low oil pressure... These I would plug directly into my home alarm system on independent zones and set up the alarm system to yowp when it gets prodded! I might even, if really energetic, put in a rack closing solenoid, simply releasing the governor spring and allowing the governor to kill the engine to shut it down... this would also be via my home alarm system, easy to do and little or no bit bashing to get it to work.... Sorry, but if you haven't yet realised, I am actually a lazy bugger at heart!

If I get a chance, I will take a couple of pics of the oil filter setup on TM2, feel free to pillage and modify to suit your needs!

Cheers
Ed

Edit: Here are pics of the unpainted/uncleaned but finished and trial mounted filter and filter mounting: http://www.warriorpaintball.co.za/private/TM2 Oil Filter Mounting 20160224 Sorry about the pic quality, lighting wasnt too good... The first pic is the view from the CC door side, gives an idea of the position behind the flywheel, the second is through the flywheel hole showing how it gets accessed for changing, for the last, I pulled the flywheel off a few inches just to show the pump/filter relationship....

[BruceM]

Nicely done on the filter mod, Ed.  Is the pump OK with the additional back pressure? I was not exactly inspired by the quality of machining in Rajkot made pump.

On automation my approach has been to design for full manual reversion; the processor is there to monitor and auto start, but if turned off, you can still operate completely manually and/ or still use the air starter.  That way I'm never without power because of electronics failure.  Even my AVR can be switched over to straight harmonic regulation.  On my 8 hour oiling intervals, I do manually start (with air), to check everything out.  The processor can then be switched on, and when it sees the engine running it just starts monitoring.  I can remote start, switch between compressor and generator remotely, and the processor does auto shutdown when 10 minutes of no load running is detected, unless I have the remote timer override switch on also.  I used a Picaxe 40x2 (40 pin dip) chip and my Basic software is free for the asking.  The Picaxe chips require no expense for development software, and run about $10.  No support logic or external clock is required for them, though I did wire up a 3 pin header plus 2 resistors for serial programming in place from a laptop.  It's a single chip basic stamp on steroids for $10, with the option of going to a wide range of compiled languages (C for free) and a faster external ceramic clock resonator later if you want.

No need at all for a processor to just provide emergency shut down.  The simplest rack closer is a brass wire "fuse" on a terminal strip to hold the governor spring.  12V will blow the "fuse", and the rack shuts.  I tested this out and it works quite well.  It's not suitable for anything but emergency only shut downs, since replacing the fuse and readjusting the governor is then required.

[Hugh Conway]

@ Bruce:

If you do not have a machine shop, or do not want to put in fabrication time, these work just fine. I have been using one for some time now. Replacement filters are inexpensively available from your local NAPA dealer.
http://www.stationaryengineparts.com/Oil-Filter-Kit.html
Probably available from Dieselgman as well.

Cheers,
Hugh

[BruceM]

Thanks  Hugh, that looks even better!  I'm up to my neck in projects as it is.

I'm going to drop a note to Gary right now and see if he has this available.

[EdDee]

Hi guys, out here in the sticks I have to make the bits if I want to use them within a year... that filter looks good too!

 I like your plc reasoning, good to b able to run manual if needed!

The back pressure doesn't seem to worry the pump or the 'squirt distance' to the bearings and journal pickup, all seems fine on my beast, about 500 hrs on the filter setup so far....

Noted re the pickaxe, nice stuff!... I am not a big fan of the fuse shutdown, mainly because of the replacement time required... I am working on a simple shutdown trip system, my criteria is that a, it must be simple, b, it must be easy to make, c, it must be resettable, d, it must be repeatable, and finally e, it must be able to be tripped manually as well as electrically with minimum force required... I will post pics when and if I get it right...

Cheers
Ed

[BruceM]

I expect your rack closer will be a gem, Ed.    About 10-12 lbs of force are needed to overcome the governor spring, if applied directly to the end of the rack. 

[EdDee]

Hi Bruce,

10Lb is a lot for small mechanisms to overcome... This equates to high wear/large currents electrically for a compact mechanism. I am looking at a governor spring disconnector ala similar to those used to quick disconnect large loads on overhead cranes, in miniature of course. When the governor spring disconnects, the rack should be closed fully by the unsprung governor.... My reasoning is: Why work against the governor? Let the governor weights do the work of closing the rack. Of course, a link failure where the rack is disconnected from the governor is not catered for, but link failures hardly, if ever occur... They do happen of course, but very seldom....

Your thoughts?

Cheerz
Ed