K-341AS - Slight Knock - OK to use as is?

[Fordiesel69 263]

Crank looks good, rod not so much.  What would happen it I got a new rod and just let it be noisey?  Would the slop break the new rod?

 

Also there was never grenade gears in this one, the shaft holes are plugged on the inside.

 

The piston and rings are new.  Not one spec of carbon so the owner did a quick fix (probably an oil burning monster)  Didnt even bother to hone the cylinder.  

[RED-Z06 2,221]

10 minutes ago, Fordiesel69 said:

Crank looks good, rod not so much.  What would happen it I got a new rod and just let it be noisey?  Would the slop break the new rod?

 

Also there was never grenade gears in this one, the shaft holes are plugged on the inside.

 

The piston and rings are new.  Not one spec of carbon so the owner did a quick fix (probably an oil burning monster)  Didnt even bother to hone the cylinder.  

Eventually it can fail if the crank is out of round. My K181 was addicted to oil, i put in a new rod, piston, rings..no hone out...runs like new, this is the old rod i pulled out of it, it, I know i had about 100hrs on it, and it came off a completely worn out tractor when i transplanted it 20+ years ago 

[Fordiesel69 263]

So a quote from brian millers webpage:

• K-series and Magnum "new style" rod. This particular forged rod has a thicker beam section, which makes it just as durable as a machined billet rod, and with bearing inserts installed, it's suitable for high RPM and wide open throttle engine operation. And when used with a factory type piston with a thin-wall wrist pin, the rotating assembly will not need to be rebalanced. OEM Kohler part # 45 067 24-S and John Deere part # AM106441. $124.50 each, plus shipping & handling. Return To Previous Paragraph È

I think i have no choice but to just buy a new heavy duty rod, and let it knock a bit.  Ebay is dry on cranks it seems.  Nobody local to machine or I would consider it.  

[ebinmaine 67,768]

Did you check with @76c12091520h  Brian Badman or Lincoln at A to Z? 

[Tuneup 1,433]

OK, read through this on my vacation day today and it appears you're assuming the crank pin is out of round because of a tight spot in rotation but it's not been measured? Even a cheap caliper will help you out there so you're sure. About $20 at your friendly neighborhood Harbor Freight. If the crank pin is indeed out of round, there should be some shop out there that takes delivery. I had to drive 90 minutes just to get my 301 bored but they are out there and are more likely to do the work if you hand them the stripped part. Good luck!

[Fordiesel69 263]

I will be measuring.  I have a caliper that is digital.  I have worked on enough kohlers there is a egg spot around TDC or slightly after just by feel.  

Edited April 30 by Fordiesel69

[Fordiesel69 263]

1.494 on side away from TDC.  1.488 on side that is TDC.  I'm at my limit on photos so sorry.  

[RED-Z06 2,221]

17 minutes ago, Fordiesel69 said:

1.494 on side away from TDC.  1.488 on side that is TDC.  I'm at my limit on photos so sorry.  

Heres the tolerances, 1.494 is only 1thou under minimum, not ideal..but 1 488 is already beyond 10 under.  I personally wouldnt go 20 under, you never know how deep the surface hsrdening was back then.

Edited May 1 by RED-Z06

[Fordiesel69 263]

I have (2) c-160's with really nice 16HP K341 one is a 13 fin and the other is a 12 fin.  I think im going to buy a new rod, and button this bad boy back up and let it be a knocker to replace 312-8 at camp.  I think with the low hours it will see, it should be ok.  I am coming up dry on all searches for a crank and as I see it, if it get more egg shaped, or more worn, no harm it needs replaced anyways.  

 

The only think I can hope for is that if I get a new rod, it will take the pounding.

[Wild Bill 633 847]

Some engine shops can have the crank built up with weld and reground to size.

Edited May 6 by Wild Bill 633

[Fordiesel69 263]

Cant wait for the parts to come in.  Got a used crank that is just in spec, a genuine kohler rod, and a new old stock .003 piston that will put the top end one thousands inside the spec limit.  Due to lack of machine shops in my area and the fact the cylinder was not oval or egg shaped, I decided not to goto .010 over.  Will save it for the next rebuild cycle.  I figure with these new parts and proper maint I will probably never wear it out to ever need another rebuild.

[ebinmaine 67,768]

2 hours ago, Fordiesel69 said:

Cant wait for the parts to come in.  Got a used crank that is just in spec, a genuine kohler rod, and a new old stock .003 piston that will put the top end one thousands inside the spec limit.  Due to lack of machine shops in my area and the fact the cylinder was not oval or egg shaped, I decided not to goto .010 over.  Will save it for the next rebuild cycle.  I figure with these new parts and proper maint I will probably never wear it out to ever need another rebuild.

 

 

Given the scenario that you have and non availability of machining, sounds like that may be a best case scenario for you.

[Fordiesel69 263]

Well, all I can say is it is way better than before but not 100 percent.  Found a nos Kohler rod and an. 003 over piston with standard rings.  End gaps checked out with plenty of room and piston slap is one thousandth inside the spec limit.  The nice used crank I acquired is. 003 and. 004 using plastiguage.  The. 004 is right at or slightly after TDC so yes it does have a tiny knock unloaded.  If you run the mower deck and apply a load the knock goes away.  It will probably last a very long time this way but I wished it was a touch quieter for all the work I had to do trasplanting the new used crankshaft.  Flywheel was an insane pita to remove even with a puller.  

 

The way the engine was with its std piston and scored up rod, and crankpin worn ten thou shortly after TDC I felt it would have blown up at some point.  Now I think it will at least last a while at least. 

 

The original crank needed a real expert, it would need to be turned to 12 thou under once the egg spot was found, and then a. 010 rod would need to be resized slightly and frankly I don't think many machinests are good enough to do that, they'd want to just take it the full twenty under and all the hardness would be gone. 

 

The k341 16hp is sure an awsome beast to own, but I think the durability on these k series goes away after thr k301 12hp.  I think Kohler should have made the bottom ends a touch bigger for the 14, 16, and rare OHV 18hp.  

 

I also feel that the k341 and k361 with it's cylinder bore being offset from center of the crankshaft promotes more one sided piston skirt wear.  

Edited May 19 by Fordiesel69

[Fordiesel69 263]

Happy to report, put a few hours on this engine since mid may (now its july) and I did (2) one hour oil changes as the engine was making some metal most likely from the cylinder cross hatching. 

 

Runs good and the K341 if you ever remove the balance gears, they become a full throttle engine only.  Mid throttle will vibrate quite a bit.  But I am happy that the gears wont get blown thru the block!!!

 

 

[ebinmaine 67,768]

34 minutes ago, Fordiesel69 said:

the K341 if you ever remove the balance gears, they become a full throttle engine only.  Mid throttle will vibrate quite a bit. 

 

 

I've been doing some poking around for a few months and I find a lot of variable experiences with those.

 

My own "Balance gear deleted"  C160 Automatic is usable at about 3/4 throttle but if I bring it up to 3,600 RPM it'll about rattle the teeth.

 

[RED-Z06 2,221]

26 minutes ago, ebinmaine said:

 

 

I've been doing some poking around for a few months and I find a lot of variable experiences with those.

 

My own "Balance gear deleted"  C160 Automatic is usable at about 3/4 throttle but if I bring it up to 3,600 RPM it'll about rattle the teeth.

 

I havent run my M12S much since i pulled the gears, at 3600 its violent 😐 

[ebinmaine 67,768]

2 minutes ago, RED-Z06 said:

I havent run my M12S much since i pulled the gears, at 3600 its violent 😐 

Try about 3200, 3300. 

[RED-Z06 2,221]

38 minutes ago, ebinmaine said:

Try about 3200, 3300. 

Its not as bad there but its still pretty bad, im done with that entire engine, its been a costly headache literally since day 1, new rod, piston, rings, crank was mic'd and measures well within spec but it knocks, pulled grenade gears, still knocks.  Ive put over 100hrs on it knocking the past 2 years...I think its the cam/crank gears making noise.

[Fordiesel69 263]

1 minute ago, RED-Z06 said:

Its not as bad there but its still pretty bad, im done with that entire engine, its been a costly headache literally since day 1, new rod, piston, rings, crank was mic'd and measures well within spec but it knocks, pulled grenade gears, still knocks.  Ive put over 100hrs on it knocking the past 2 years...I think its the cam/crank gears making noise.

Its proably an egg shape directly at or shortly after TDC.  Very hard to measure.

[bds1984 1,435]

4 hours ago, Fordiesel69 said:

Happy to report, put a few hours on this engine since mid may (now its july) and I did (2) one hour oil changes as the engine was making some metal most likely from the cylinder cross hatching. 

 

Runs good and the K341 if you ever remove the balance gears, they become a full throttle engine only.  Mid throttle will vibrate quite a bit.  But I am happy that the gears wont get blown thru the block!!!

 

 

I guess having a shaker plate K341 is what keeps my tractor from vibrating apart.  I removed the balance gears from my engine a decade ago and only really notice the engine shaking like a nervous Boss 429 at idle.  She begins to smooth out around 1,800 and then nearly completely around 2,200 RPM until the tachometer maxes out.  I guess I'm the only one with a shaker plate engine that actually works to quell the vibrations.  I did have a pretty balanced crankshaft and an Alcoa connecting rod and piston for a K361 to begin with.  But, yes, no more ventilated block (at least from the balance gears)!