Noisey valve train - Listeroid 6/1

[veggie]

It could be that my engine is just breaking in...or is it breaking down  
The tappets seem to be getting noisier as time goes on.
Valve clearance adjustment is correct, but the tappets are getting quite noisy.
During shutdown when other noises disappear, the tappet noise is quite evident.
It's as if the cam lobes were colliding with the tappet instead of gently engaging.
Excessive clearance somewhere?
I realize that the compression release will hold the exhaust tappet away from the cam and make a noise when the lobe hits the tappet..
But my intake tappet seems to be clacking also.
clack..knock.......clack..knock.......clack..knock.................clack..knock...............clack..knock...

Is this normal for a lister type?

veggie

[oiler]

Nothing unusual, sounds like mine.

[Carlb]

my 6/1 sounds just like that.

[Chris]

Check to make sure one or both of your valves is not hanging up. The piston could be slapping them shut. If starting is not a problem. The above is probably not happening. Dribble a little penitrating oil down the valve stem while the engine is running and see if that helps. The valve train clanking IS quite load on these engines.

[JohnF]

Veggie;

The valves sound OK, but what I hear is a gear train noise.  I suspect your idler backlash needs adjusting - that sound is typical of an idler that is not exactly centered.

[playdiesel]

You better unload that grenade before it goes off!! PM me for my shipping address

Kind of sounds like my Metro but it is realy hard to tell from a video.  

[XYZER]

Veggie;

The valves sound OK, but what I hear is a gear train noise.  I suspect your idler backlash needs adjusting - that sound is typical of an idler that is not exactly centered.

Yep!

[veggie]

Thanks guys !
Very helpful.
I will check the idler gear.

veggie

[veggie]

By the way....

How does one adjust the backlash (centering) of the idler ?

Wave of panic.... Does my flywheel have to come off again? 

What's the procedure ?

cheers,
veggie

[Crofter]

Nah! you dont have to take the flywheel off but you do have to devise a way of offsetting the camshaft drive idler gear. Xyzer made some eccentric shafts that shifts the idler position closer to the crank and camshaft gears which reduces backlash. John F has described to me a method of making a double eccentric bushing and shaft arrangement which is adjustable. I chose to make the type XYZER does but you really should measure accurately to see how much you need to offset. Most likely at least .035" or whatever you need to bring tooth mesh clearance to around.008 or less. You only need to remove one nut from the idler and position the crank correctly and you can drive it back into the crankcase. Dont get it out of timing!

I wouldnt fret the driving the gib key home. Time it accellerates the weight of the crankshaft and at least one or two flywheels it will be nothing compared to the diesel hammer on that big piston!

[Crumpite]

Nah! you dont have to take the flywheel off but you do have to devise a way of offsetting the camshaft drive idler gear. Xyzer made some eccentric shafts that shifts the idler position closer to the crank and camshaft gears which reduces backlash. John F has described to me a method of making a double eccentric bushing and shaft arrangement which is adjustable. I chose to make the type XYZER does but you really should measure accurately to see how much you need to offset. Most likely at least .035" or whatever you need to bring tooth mesh clearance to around.008 or less. You only need to remove one nut from the idler and position the crank correctly and you can drive it back into the crankcase. Dont get it out of timing!

I wouldnt fret the driving the gib key home. Time it accellerates the weight of the crankshaft and at least one or two flywheels it will be nothing compared to the diesel hammer on that big piston!

I haven't seen any documentation on this anywhere.
Is it posted somewhere or just a private chat ?
It would be nice to have this info available to us listeroid owners.

Thanks,
Crumpite

[Crofter]

I did some searches and it appears that most of the discussion on measuring offset required, was on the other forum. It appears some engines will require .045 or so offset to get decently tight gear mesh so they dont get to pulse hammering themselves to pieces. There is no adjustment aside from having a custom idler shaft bolt machined. I can't remember who the member was who described the measuring jig he made by having a two piece dummy shaft fastened together with a screw so he could fit the gears tight, tighten the screw to hold the two shaft sections securing the offset, and disassemble to measure actual offset at the junction between the .625 stub and the .875 diameter the idler runs on.

The bore of the idler is not guaranteed true or the cam gear either so it is important to make sure you are not creating an interference fit at some point of gear contact combination as they rotate.

[veggie]

I pulled the inspection cover and checked out the idler.
- Bushing is nice and tight
- Very little side play
- Backlash may be a bit excessive. Felt like .010 to .015". How much is too much ?
- Wear marks seem to be in the right place.

Have a look......

veggie

[lowspeedlife]

Lucky you on the tight gear to  bolt clearance, mine has approx. 3/16 inch of wobble. the hole in the gear is larger on one side that the other. when my lathe is running (hopefully by the end of the month) I will bore it out to take a bronze bushing & fit it to one of XYZER's bolts.  My under standing is you are looking for about .008 inch of lash in the gears.

Scott R.

[veggie]

Have you not run that engine before ? Do you realize that you need to use oil in there ? Why is the inside not a virtual black hole ??

LOL !  This engine only has about 6 hours on it.  ( It's already had two oil changes :-)  )

I love my roid 

veggie