K341 16 HP clank noise?

[953 nut 51,721]

I have a K-301 that was spec number crossed to a Simplicity. It makes the same little clank noise when turned over by hand near TDC and the Simplicity engine has no balance gears from the factory. Runs smooth and the clank goes away when operating. Could it be the ACR? I have tried to replicate the clank on older K-241s that have no ACR and they don't do it.

 

 

[ebinmaine 63,156]

46 minutes ago, 953 nut said:

I have a K-301 that was spec number crossed to a Simplicity. It makes the same little clank noise when turned over by hand near TDC and the Simplicity engine has no balance gears from the factory. Runs smooth and the clank goes away when operating. Could it be the ACR? I have tried to replicate the clank on older K-241s that have no ACR and they don't do it.

 

 

I'll check that too.   

[wallfish 15,926]

I've had that engine running. Originally thought piston slap because that's what it sounded like. It doesn't go away when running

Engine runs nice otherwise.

[ebinmaine 63,156]

On 10/10/2022 at 8:46 PM, wallfish said:

I've had that engine running. Originally thought piston slap because that's what it sounded like. It doesn't go away when running

Engine runs nice otherwise.

 

 

Folks I finally got a minute to go a little further.  

 

Cam (to crank??) is making the clanking noise.  

Loose gear mesh?

Are the balance gears attached here?

 

 

 

 

 

 

 

What do I look for next?

 

 

 

[Snoopy11 5,713]

16 minutes ago, ebinmaine said:

What do I look for next?

When you move the cam like you did in the video, does the crank move with it... or does it feel sloppy?

 

EDIT: I tried to slow the video down to see if the crank was moving while you were moving the cam... I didn't see the crank move at all.

 

Seems as if you've those gears are worn...

 

Wouldn't be the first time someone has encountered that problem...

 

Don

Edited October 25, 2022 by Snoopy11

[Jeff-C175 7,195]

I haven't looked at vid yet...

 

How is the cam end play?

 

 

[ebinmaine 63,156]

10 minutes ago, Snoopy11 said:

When you move the cam like you did in the video, does the crank move with it... or does it feel sloppy?

 

EDIT: I tried to slow the video down to see if the crank was moving while you were moving the cam... I didn't see the crank move at all.

 

Seems as if you've those gears are worn...

 

Wouldn't be the first time someone has encountered that problem...

 

Don

 

Crank does not move. 

 

 

Just now, Jeff-C175 said:

I haven't looked at vid yet...

 

How is the cam end play?

 

 

 

Side to side movement makes a similar noise

[Jeff-C175 7,195]

3 hours ago, ebinmaine said:

Side to side movement makes a similar noise

 

Do you have a dial indicator to measure how much end play?

 

I've read that cam end play is a source of noise in the K series.

 

 

[ebinmaine 63,156]

5 hours ago, Jeff-C175 said:

 

Do you have a dial indicator to measure how much end play?

 

I've read that cam end play is a source of noise in the K series.

 

 

 

I do. There is definitely plenty of end play.  

 

How's that adjusted out?

 

[Jeff-C175 7,195]

5 hours ago, ebinmaine said:

 

I do. There is definitely plenty of end play.  

 

How's that adjusted out?

 

 

I don't know the spec offhand.

 

If it's out of spec it means disassembly and shim selection.

 

 

[ebinmaine 63,156]

Just now, Jeff-C175 said:

 

I don't know the spec offhand.

 

If it's out of spec it means disassembly and shim selection.

 

 

Yeah that's no problem because this engine is going to be rebuilt. We're just trying to narrow down the actual source of the noise before I disassemble it completely.

 

 

[Jeff-C175 7,195]

4 minutes ago, ebinmaine said:

Yeah that's no problem because this engine is going to be rebuilt. We're just trying to narrow down the actual source of the noise before I disassemble it completely.

 

 

 

What would puzzle me if it's found to be excessive, WHY is it?

 

Typically with shim type adjustments, once properly set up they won't increase more than a couple thousandths as the shims wear.

 

An amateur 'rebuilder' may not realize and not install or not check when assembling, can you tell if that engine has been apart?

[ebinmaine 63,156]

8 minutes ago, Jeff-C175 said:

 

What would puzzle me if it's found to be excessive, WHY is it?

 

Typically with shim type adjustments, once properly set up they won't increase more than a couple thousandths as the shims wear.

 

An amateur 'rebuilder' may not realize and not install or not check when assembling, can you tell if that engine has been apart?

 

@wallfish may know some of its history.

 

Fuel pump has definitely been replaced.

Sheet metal has all been off at some point because the screws / bolts are not original.

Camshaft side cover appeared to have some sort of brown gasket shellac type material but I don't know if that's Kohler manufacturing original or not.

There was very little carbon on the valves or piston top and the cylinder head gasket looks so good I almost considered reusing it but I won't.

 

The piston is Standard size but that doesn't mean it's original.

 

Not sure about the bottom end.... 

[Snoopy11 5,713]

1 hour ago, Jeff-C175 said:

What would puzzle me if it's found to be excessive

I thought about this overnight. It could be that there is so much end play and the cam is so off-center that the cam and crank gears are not parallel... perhaps with the cam gear riding on the edge of the crank gear...

 

Stating the obvious... that cam gear is supposed to be tightly meshed with the crank... no play. When you move the cam, the crank should move. THAT is what can break gear teeth...

 

Going over the video again... it is VERY hard to tell... but am I seeing bite marks on the inside of the cam gear?

 

 

Don

[ebinmaine 63,156]

3 minutes ago, Snoopy11 said:

am I seeing bite marks

I can check that later today

[Snoopy11 5,713]

1 minute ago, ebinmaine said:

I can check that later today

Do check that, and see if any gear teeth look thinner than others, bent, chipped... etc.

 

Don

[Jeff-C175 7,195]

10 minutes ago, Snoopy11 said:

tightly meshed with the crank.

 

With helical cut gears if there's end play in the cam, the cam will slide sideways when you move the gear up / down.

 

I  think  I recall seeing a 'relief' cut on the edge of that cam gear last I had mine apart.

 

 

[Snoopy11 5,713]

16 minutes ago, Jeff-C175 said:

With helical cut gears if there's end play in the cam, the cam will slide sideways when you move the gear up / down

Which would make it roll on the edge of the cam gear...

 

If that cam shows any signs of damage... I would NOT put it back in that engine...

 

I may have a spare k341 cam around here... somewhere... if you need it Eric, just let me know and I'll go lookin' fo' it...

 

YIKES... I forgot that I bought it from VM when I was thinking about going performance on my K341... I think you might be able to find one cheaper elsewhere, Eric if you need one...

 

Don

Edited October 25, 2022 by Snoopy11

[Jeff-C175 7,195]

Just for reference, I posted this pic in another thread, but it shows the relief cut on the balance and crank gears, I recall seeing this same type of cut on the cam gear.  I also recall having the same sort of clearance between the cam gear and the crank gear.

 

In this pic the arrow is pointing to what I believe is the source of the earth shattering kaboom when the bearings on the balance gears get worn.  The balance gear can slide over just enough to contact the crank gear at that point.  When that happens, game over.

 

[ebinmaine 63,156]

46 minutes ago, Snoopy11 said:

YIKES... I forgot that I bought it from VM when I was thinking about going performance on my K341... I think you might be able to find one cheaper elsewhere, Eric if you need one

PM me what you have. Specs. Pricing. Whatever. Not likely I'll buy it this fall but I've also been thinking about doing a grunt performance 16 Kohler.