Air filter  Listeroid 6/1 and 12/2

If you look over the stock air cleaner unit you may ask how the air finds its way in, and how effective the unit is at keeping dirt out? 

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Above is the highly restrictive stock air cleaner, the red line represents the oil level.

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Sure, this engine is slow turning, but that big ole bore and long stroke really sucks,  a less restrictive air cleaner might be a nice thing.  Can a person make more power, or increase efficiency by modifying this unit?   I would certainly think so, but a solid test is the only proof we should accept. One thing we know, a less restrictive unit can operate in a dusty environment longer before it impacts performance and demands cleaning.  Anything we do to make it less restrictive will increase that interval.

We should ask ourselves; why oil bath systems aren't popular on modern equipment? Maybe it doesn't work as well as a modern paper filter element, or foam element, or foam/oil element? my guess would be that foam and oil is superior to most anything.

I modified the wimpy looking stock unit  in about 5 minutes to take a standard filter element (see below). I placed it on the bottom of the stock cleaner bowl and found that the rubber end made a tight fit against the bottom.   Looking at the top cover of the filter, I quickly realized that a piece of rubber cut from an inner tube, and cemented in place, or heavy friction tape would cover the holes in the top and make a sealing surface for the top of the element. This works excellent. To finish things off, add a small connector for the 1/4 20 threaded post, and added a section of threaded 1/4 20 threaded rod to extend the post so you can screw down the top again. It all looks stock when you're done.

To finish off your work, take a piece of metal fabric, I used aluminum with 1/8 inch holes, and rolled it to fit all the way to the outside of the air cleaner housing. IMHO, it looks far more British than the stock piece. Since I like British stuff, this makes me happy.

Next, I took a chain saw file and cleaned up all the little burrs in the filter inlet, I lightly shaped a few things to try and lower the turbulence that might be created by square edges by blending them. 

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Above is the filter element I found at Boeing Surplus, it has a nice foam sleeve that fits on the outside. I would think this could be blown out a good number of times before you'd needed to replace it.

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Above left, the complete modified unit with the DIY outer guard in place. The complete stock unit is shown to the right.

One other item, save yourself some time, throw away the stock clamp that secures the air cleaner onto the intake pipe, get a stainless steel  hose clamp, the Indian clamp is designed to torment you.

Look at the following pictures of Harold Polle's mod, and note the part number he shares....

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This looks like a great fit, it has more filter area than my Surplus find.  Note the metal fabric in it's construction.  Thanks for sharing Ron!

Jeff Maier has agreed to test the modified air cleaner.  If you look at a stock pipe, you'll notice a reduction in ID for the last inch prior to the air cleaner. A Motor Head would suspect the possibility that this step could cause eddies and problems beyond the choked down pipe itself.  This reduction creates harsh transitions  at the inlet itself, and again an inch or so into the inlet.  I will modify an inlet pipe to remove this step, and to create a more conventional opening by increasing the diameter to max in the last inch of the inlet. This will help blend the transition from inlet pipe to the metal base of the air cleaner. If you look at the inside of the air cleaner itself, the air no longer has to make a 180 degree bend to find its way into the inlet, this is another area of concern for a Motor Head, the air in the modified air cleaner does not have to make this sharp bend to find the air inlet tube. Again, the proof comes in testing, we'll see what Jeff finds.


Adding a magnet to the sump

There's all kinds of really small and powerful magnets that can be dropped in the sump of an engine. This could be very beneficial in an engine with no oil filtration system. The hard metals could be trapped in the sump and you could easily check the magnet to see what's going on. There's an area right near the drain plug that looks perfect for such a magnet. A small neo often takes two hands to dislodge, if such a magnet is placed here, it's not likely to go anywhere. IMHO, this is worth the effort. I drop a magnet into the sump of all my engines. Start at otherpower.com, or windstuffnow.com for magnets if you don't know where else to look.

Lister 12/2, how to add  an oil filter

The Lister 12/2 is fitted with a plunger type oil pump that works off it's own cam lobe and drives the pump piston directly. If you were to look at Steve Gray's impressive 10/2, you'd see a neat gauge on top of the pump. The Indian units are usually fitted with a course threaded bolt at the top of the pump versus the pipe threads. Simply unscrew the top of the pump, remove the bolt, drill out with the proper drill, and re thread for 1/4 inch NPT. Now, screw in a tee, put a gauge on top, use the horizontal 1/4 NPT to receive a 1/8 NPT with a compression fitting for 1/4 OD tubing. I used a TP bypass filter from Gulf Coast filters, others are available. I screwed in a fitting at the filter end with a small valve so I could tune the restriction if necessary, this in theory would allow one to adjust a min gauge pressure. The return line from the Gulf Coast Filter is also 1/4 inch OD line.  I chose to remove the governor spring post, drill out the hole slightly and re-tap for 1/8 NPT. the new fitting doubles as the oil return, and  the spring post for the governor.  What could be easier?

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The above picture is genset UP12/2_ST7.5_#2, it took about two weeks to build and has lots of detail work and blueprinting. The head has been modified to 4 wire.  LH picture shows filter plumed in plastic tubing,  RH shows steel tubing which will receive a glossy black powder coating. This rig could have $100 worth of brass fasteners on it!   


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As you can see above, the 1/8 inch NPT pipe doubles as the post for the governor spring and works well for the oil return.

Above: here are the stock inner and outer valves springs from a stock Listeroid. These arrived on the engine caked with that beautiful Metallic paint. Although it doesn't come across in the the picture, these are now wet glossy show quality parts powder coated with my $79.00 powder coating kit, coating the cam covers, rocker arms, valve covers, access doors and a few other parts, makes the engine far more attractive. Paint the engine in dark hunter green,  and you'll have a masterpiece. It doesn't cost much to make things nice, but time is a factor..



At this time, I've come across several people who are running Listeroids 6 or more hours a day. One person replaced an idler gear in the cam drive, the other has had trouble free service for more than three years running. these are both off grid sites, and neither party regrets their selection of this old design.

Some folks are looking for ways to auto start old iron, if you look over my auto start battery charger, you'll see that this is possible if you take the time to experiment with the basic stamp microcontroller (do a search). I think the key is to make a decompressor that will latch or unlatch under orders of the controller, below is a crude drawing showing how you might approach this using a simple solenoid salvaged from ? Note the fulcrum and the advantage gained that help the solenoid force open the valve.

Some have adapted starter motor generators like those used on countless American garden tractors. Others are looking to fit an auto starter and auto ring gear to the crank shaft. Some will say this is too much messing around, others will have a great time adding features to this old design. 

Once this is in place, you have one of the primary interfaces for the controller.  In addition to the management of the starting process, this could be used for an emergency shut down. Also note, if you use a big American V8 starter and ring gear,   there may be little need to use the decompressor at all.

12/2/2003   I just got word from DIYer Rich Gaarden that he has fitted a Chevy ring gear and starter to the Lister 6/1 and it starts in cold weather with about 10 seconds of cranking. This happens without a decompressor, and without any pre heat, ether or other starting aid. rich will take pictures and forward them, we'll share his setup when we get the pictures.

Have you noticed there's not timing marks on your Listeroid?

After looking things over for a long time, this appears to be the best pointer for a timing mark on the engine. These are big wheels, and you'll quickly learn that one degree is pretty wide. If you don't wish to take the head off to find top dead center, consider pulling the injector, and dropping a wire down the hole onto the top of the piston to use as an indicator for TDC.


Ideas for a super quiet muffler, run your Lister in the suburbs !


Above: Here's a Listeroid getting a coat of proper paint. This Metallic crap has to go. The easy way to paint one is to take the head off, and attach a home made lifting bar as you see here. This allows you to work standing, to have good light, and to clean up around the base. 



Always more to add, stay tuned.


George B.