Lister 12-2 Flywheels

[Samo]

Hey folks,

It's been a long time since I've had time for working on my 12-2, but I'm back to it. Bought at a farm field auction in Bookham, NSW. Spent 12 months stripping and restoring. She runs up fine but I have a balance issue... One flywheel was buggered, and I was able to find a replacement from another destroyed twin. On further exploration the replacement flywheel "a" side is 605mm diameter, but the original is bang on 600mm.

So... I'm thinking it's for another model, with different internal mass?
Just wondering if there's any known literature on flywheels per model?

Thanks!
Samo

[38ac]

There is some information in David Edgington's book The Lister CS Story but my copy has gone missing. The flywheels for cast iron piston 5/1 and 6/1 and twin counterparts have more off set weight than the trapezoid disk flywheels for an 8/1 and 16/2. Any round spoke flywheel will be weighted for cast iron pistons, any lightweight trapezoid disk flywheel will be for aluminum. The heavy SOM type flywheels could be either. Another thing on a twin is you must be certain you have the correct keyway orientation. The #1 side of a twin is the same as a coresponding HP (per cylinder) single but the #2 side is keyed 180 opposite. To check for correct key position decompress both cylinders and rotatebthe engine until one cylinder is at at overlap, the exhaust valve just closing, intake just opening. At that point the off set weight on that side should be down and the other side should be up.

[Samo]

Thanks 38AC,

I can confirm that the flywheels are 180 degres out, and operate as per your overlap advice.

Even though both flywheels have similar markings,  5-1/E4, the sourced flywheel is dimensionally bigger in all regards. Namely the diameter, inside rim thickness and rim height.

I think I'll try and source another, or a maybe get a keyway cut in a 6-1 if I can find a match...

Thanks again.

Samo

[ajaffa1]

Hi Samo, Rob at Old Timer Engines in Queensland will probably have what you are looking for. He used to have quite a few CS engines that were beyond economic repair.

Bob

[38ac]

Quick question, have you had this engine running previously? Have you been around other twins? Reason I ask is no twin CS will settle in and run as smooth as a single.

[Samo]

Hi Samo, Rob at Old Timer Engines in Queensland will probably have what you are looking for. He used to have quite a few CS engines that were beyond economic repair.

Bob

Thanks Bob,

I actually sourced the flywheel from Rob. I didn't realise that it was different, they look the same unless side by side!  I bought it a long time ago and only just got around to fitting it. A bit late to send it back!

[Samo]

Quick question, have you had this engine running previously? Have you been around other twins? Reason I ask is no twin CS will settle in and run as smooth as a single.

No, it was seized when I got it. The right side of the engine - old flywheel, sits nicely, but the LHS jumps and the engine will spin the trolley if revved. I have been able to improve it a bit using the chalk method and lead weights. I have stopped it spinning the trolley at least. It definitely not as smooth as other twins ivd seen at field days.