Micro CoGen.

Hi Jens !

I think what Bob is saying is that the holes are deliberately off center so that the lobe can only be mounted in the correct orientation....only one way.  It's not the pin that is being discussed, but rather how and under what circumstances the pin holds everything together.

And yes, the pin probably had the crap beaten out of it when it was installed originally. Accurately indexing the lobe to the shaft, the drilling of the holes and the general assembly techniques employed by the factory certainly leave a lot to be desired. Is it any wonder that the camshafts (in some cases) are hindering performance or at the very least are failing prematurely ?

Have a good day sir.


wormshoe

Hi Jens !

Crofter was seeing the same thing that I saw in your photos.

"There does seem a bit of non symetrical scoring on the piston but could be lighting in the photo. As you fit the bearings make sure that the side clearance in con rod to crank cheeks exists all 360 degrees crank rotation, not just at bottom dead center. That should indicate that the con rod is workably free of cock and twist."

Crofter is probably right.  It may just be the lighting, but it's worth a check. 

Jens, Re your question: If a rod and piston assembly are in alignment, the wear pattern on the skirt will be centered on the skirt ( 90 degrees to the axis of the piston pin).  If you notice that the pattern seems to be shifted on the skirt ( the centerline of the skirt and the centerline of the wear pattern are not one in the same), then I would immediately suspect a twisted rod.  (This wear pattern will be most apparent on the major thrust side of the piston.) Depending on the application, a rod with a twist can normally be brought back into alignment if the mechanic is comfortable with all of the known variables. His experience might dictate that a high rpm machine that is under heavy loading is not a candidate for this procedure, while a Lister at 650 rpm might be a perfect choice for this fix.  I can't stress this enough: The mechanic's own experiences and beliefs must rule the day.

A bent rod will present itself differently.  Instead of a vertically centered wear pattern on the skirt (normal), the bent rod will cause a diagonal pattern to be present on the skirt.  Yes, both 'twisted' and 'bent' conditions can be present on a single piston skirt.

Jens, I hope that my explanations are clear.  I look forward to hearing THUMPER at speed.  Good luck to you sir.

wormshoe

Hi Jens !

I have no direct, hands-on experience with Listers, so I am way over my head even suggesting anything to this group. It appears from the piston pictures that you posted, that your connecting rod might be twisted.  It would be a shame not to check its alignment before you reassemble your twin.  Just a thought.

I enjoy reading about this group's adventures.  Thank you for allowing me to sit on the sidelines and watch you guys.  Good luck Jens.

wormshoe

" I don't think anyone ever lost any money by breaking in an engine (whether it is "required today or not...) on conventional oil... switch to synthetic later, if you so desire... "


I agree with the use of conventional oil for the initial operating period.

Breaking in an auto-engine used to be (maybe not anymore) event-related as opposed to time-related.  Certain changes had to take place before it was considered fit for service. It was not uncommon to put four of your biggest friends in a car....then alternately load and unload (moderately)....finishing with one moderately-loaded run-up, all in about 30 minutes or so.  Change the oil and then put the boots to it. It was ready. The rings would always seat and all of the other machined surfaces would be happy.

If I were still doing rebuilds today, I would initially run a conventional oil and then drain it.  These synthetic oils appear to be just the ticket for extending the life of a properly broken-in engine, especially effective during a cold start warm-up. All hell breaks loose during the first few minutes of a frigid start (reminds me of someone I used to know...) and it seems to me that's where the synthetic stuff pays off in a big way.

I have driven the same pickup for twenty years so I have gotten to know her pretty well.  It ran conventional oil for the first 30k miles and then I switched to synthetic. The only difference that was immediately evident was the speed at which the starter would crank her over on first start-up in the morning.  It spun over noticeably faster...almost as if the oil had hung around all night just waiting for the daily grind to begin. It impressed me. It has run synthetic ever since.

Just my two cents....

The conclusions of the research which I initially mentioned only involved gasoline engines that, for the most part, create a manifold vacuum when running. The lister's speed is not controlled by limiting the airflow as everyone knows. Injecting the water spray into a partial vacuum (gas engine) probably behaves differently than injecting the water into a 650 rpm, low valve overlap cam profile, with a nearly non-existent manifold vacuum (minus design-based volumeteric efficiency losses coupled with a potentially dirty air cleaner etc.) application like many of you are dealing with.

I don't know how the water would behave when entering the Lister's combustion chamber.  I can only make some assumptions which may or may not be relevant. If the water is injected at a point beneath the air cleaner, there is a possibility that the water might might 'puddle' as a result of any 90 degree turns that might exist in the intake manifold and/or condense out of the air stream because of cold, ambient temperatures. Just some thoughts.

Engine corrosion is another possibility that I would like to think through before considering anything other than an infrequent application of water. Folks like Veggie and others might not be too concerned about the sulphur in traditional diesel fuel reacting with water vapor, forming sulphuric acid and raising hell not only in the cylinder, but also being scrapped down the cylinder wall and returning to the oil sump. I would think that any increase in the amount of water vapor being pushed through a Lister (many of you not using thermostats with subsequently lower engine operating temperatures) would run the risk of damaging a whole load of stuff in the crankcase (worse case) or at the very least, drastically reduce the time between oil changes. Just some thoughts.

Returning to the original research: their conclusion was that the optimum injection point was directly behind the intake valve. They went on to say that this point of injection offered the maiximum amount of charge cooling entering the cylinder and also positively affected the flame propogation (the rate of burn and the manner in which the mixture burns). These characteristics allowed them to increase the ignition timing without encountering some of the more typical problems associated with this technique. In addition, the expansion associated with the change in state from liquid (any remaining small water droplets) to steam would also add to this affect.  All in all....pretty cool.

One last concern was voiced by Jens earlier in this discussion.  I agree. When the water vapor reacts with the carbon (at least in a gasoline engine) a sludge-like material is emitted from the exhaust....varying in color from black to brown.  I have noticed in your discussions that some of you have constructed some elaborate exhaust systems that not only silence the exhaust note, but involve a lot of plumbing as well. It would be my guess that continued use of water as a maintenance procedure would result in a buildup of a carbon-like residue in some remote corner of your exhaust system which may lead to an unwanted restriction and/or some additional exhaust system cleaning procedures in the long run. Just some thoughts.

Wormshoe here.....

Sadly, I do not own a Lister, but I enjoy reading about everyones' adventures with these magnificent machines.

Injecting water has its benefits.  Metered in the correct amount (with the engine under a light to moderate load) water will remove a great deal of the buildup as several have already pointed out.  I would not attempt to plumb an automated system for several reasons. At some point, the water will find its way into the cylinder while the engine is at rest with the obvious consequences. Another real concern is the potential pressure rise in the cylinder when the water changes from a liquid into steam (1200 times expansion rate ?  I have forgotten) and the added stresses (rod angularity exerting more force on the major thrust side of the piston/cylinder - rod bearings - crankshaft twisting etc.). Spraying a mist into the airstream would be fine. Mistakenly shooting a hefty stream of water from a spray bottle might be another matter.

This is not from my own research. Experiments on WW2 reciprocating fighter planes showed that not only did the engines run cleaner, but that tremendous power gains were to be had if, as the experimentation showed, if the water was metered right behind the intake valve as opposed to anywhere else in the airstream.  Test showed that the ignition timing on these gasoline engines could be advanced and as a result, power gains could be realized.

Several of us, as instructors at an automotive trade school (late sixties in Saint Louis) experimented using water carefully poured into a carburetor with the gasoline vehicle under a moderate load on a dyno. The water always did a marvelous job of breaking the carbon loose....brown deposits would always show up on the shop floor under the exhaust outlets.  Two points to consider: the engine had to be under a load to ensure that the carbon deposits were hot (not glowing) so that when the cooler water vapor came into contact with the carbon, the thermal shock would be enough to help in dislodging the crud....AND...you had to be real careful in how much water came out of the used coffee cup and how it was distributed in the primaries and/or multiple carbs.

I know of experiments being run using the old Rochester Dog House Fuel Injection (Chevy) were a water system was plumbed and another nozzle was added to each intake runner aimed at the backside of the intake valve. Worked great until the water leaked into the cylinder after the engine had been shut down....don't ask.

I apologize for drifting off the primary topic of Lister water injection. I would stick with spraying and periodically adding a fuel additive to your day tank. 

Thank you for allowing me to lurk in the shadows while you fellows are doing all of the work and having all of the fun.

Nils