Lister Type Timing Gears

As I often say, if you express an opinion, it's bound to be contrary to another man's opinion. Sometimes that other man expresses his opinion when he has never even owned a Lister Type Engine or run one....

I think what gives me an advantage over the average owner is a relationship with people from around the world, and a good many reports on what is working and what is not. If there is one thing that seems to fail more often in these engines, it's the timing gears.

I get the reports often enough, and it is not just one brand. I have sold gears for Ashwameghs, Metros, Vidhata, and a good many names you'd recognize.  Joel Koch paid a good sum of money to hire an American gear company to find out what was wrong, some of it was obvious; other bits not so obvious. I have seen gears that looked like they had been made on worn out equipment. We also had the gear material tested and found out it was just plain junk metal in some cases.

I have worked with a number of folks to establish what it was that the British R.A. Lister Company did, and you may be surprised. The idler gear was not bushed in many engines, the high quality #20 cast iron gear they used ran directly on a steel idler shaft with no bronze bushing, and it lived a VERY long life! Some people think the Indians took a short cut here, not true! One of the leading reasons for train wrecks is the idler is sometimes made of junk cast, as was found in some Ashwamegh engines, I had first thought the entire problem was with some heavy handed punch marks on the Ashwamegh gears, but later learned that this only made the problem worse, and the root cause was the poor metal and the fact that the gear teeth were cut in a way that created blacklash issues, again this was discovered by Gear making professionals.

I saw one seller who suggested he had the best gear train, he said all his gears were 'cast steel'. This means if you do have a problem, all three gears are likely to do the train wreck thing! When you are pulling that Gib key, and fishing the crank out of the case to replace that broken steel gear, you'll be cussing that decision!

If we are looking for an idea situation, the gears should be made of dissimilar materials, and there is probably no better material than bronze gear material for that idler. As you might imagine, this material is not cheap, but changing out that junk cast gear before it causes a train wreck and takes all the teeth off your cam gear is a good thing! Many rail road engines use bronze gears because they wear in to the other gears and then work harden to live a long life, RRs use this material for this reason.

Where we see these problems first is in the twins, and it is no wonder when we have twice the loads on these gears, they are driving two injection pumps and double the valves, shouldn't we expect to see troubles here first? We recommend that all Ashwamegh Twins run this bronze Idler, and we have a supply of gears for this purpose, if you have an Ashwamegh engine, you bought thru me or Joel; email me with the serial number. For the price of $10 shipping, this expensive to make idler will be sent to you,  I recommend you get it in the engine before you run it again. Changing out the cam gear is a lot of work, changing the idler is easy! Again, if one breaks, both the idler and the cam gear will need to be changed, and we often find that the cam gear an shaft were drilled and pinned in such a way where a new cam gear may not line up with the shaft hole! This might mean some additional skill will be required to join them, or a complete new cam shaft assembly may be needed!

As for Ashwamegh singles, it is best to watch this gear train for wear, and check the lash, if you see problems, consider the bronze gear. I have written Ashwamegh about problems, but they are the least responsive company I have found in India..     

For the rest of you, this bronze idler is $66 plus $10 shipping, and I will run one in all my personal engines, the way I see it, if I'm going to have stuff flaking off the gears, I'd rather it be bronze bits versus ferrous metals that will find their way into soft metal bearing shells, and more. of course I  plan to run my engines long hours, and I don't want problems when I need the engine most.

My Associate, "John Ferguson" in Ontario Canada is the Lister Twin expert, he has changed this idler, and I'll see if he'll write up the procedure to make this easier.

I don't think we can trust India to make a #20 cast iron Idler, some probably do, but how are you going to tell it from the junk gear? until I learn of a place to buy certified gears, I'll be looking for the bronze idler.

I am involved in an ongoing study of gear failures, this will be a topic covered here as soon as we sort out the causes, we need to be certain of our findings.

All the best,

George B.

It is easy to jump to conclusions when you tear into an engine with faile