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K341 rebuild questions

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I noticed in your pic that you already have a .010 undersized connecting rod per the tiny hole drilled in the main beam.  Make sure you buy the correct one.

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Personally,  I would have the bore sized while you have it down. If it needs to be bored, now is the time do it. I would also take a close look at the valve seats and guides. 
Even If your plans are to baby the tractor, you have the opportunity now to make this motor right for the next 30 years.

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You're all gonna hate me, but I'm changing the governor, ditching the balance gears and sewing it back up, con-rod included! All new gaskets though.

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Lets look on the bright side, I sew it up all works fine, happy days.
If it goes Pete Tong in a couple of weeks I now know how it comes apart and goes back together, thats one lesson, and the second is I should have listened to you guys!

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No hate, but with that dipper being hit like that, it could snap off.  A rod is $30.  May be worth considering.  You do not want a port hole in the side of the block.......

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Ok I may replace the rod, I just can't warrant replacing the piston and having to hone bore etc for no reason, if the engine was smoking or knocking I wouldn't hesitate.
 

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Fordiesel69 you are correct the crank is .010 under.

I've had a look on ebay and there are a few sellers with varying prices, Bat4kids lists them for two different prices??

Is there a better brand to look for?

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I would definitely buy the full kit from Kevin. It was a great service and good quality parts, I should have had my crank pin reground though. Despite measuring it slightly under it has knocked more since rebuilding than it did before.
I've had to retire the engine and swap with another K341 - my next job is to split it and send the crank for regrinding before ordering a 0.10 under - or by the way it sounds probably 0.20 now :(

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I've just ordered the con rod from him, got the gasket and seal kit coming too. The crank measured .010 under bang on!

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Still waiting on my parts, I sure hope I remember how it all goes back together!

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Con rod arrived today so hopefully going to get at least some of the motor back together today :D

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Head de coked, all gasket faces cleaned, governor in, camshaft in, still cleaning top of piston, ran out of time today, but a good start.

Q. the head bolts, are they supposed to be differrent sizes? I have them in order just want to make sure.

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Sorry I did not get back sooner.  The .010 under rod should be some SBT brand or something with green lable, it will look nice, and well built.  A bad piston or worn rigns will not cause a port hole.  A bad rod will.  Thanks for replacing, the K341 is hard to find.  A K301 is literally a dime a dozen.

The piston actually looks fantastic.  Do not hone / deglaze the cylinder while apart.  Put that piston / rings back just the way they are.  It does NOT appear to be burning oil.   

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I've de-coked the head in the blast cabinet, obviously I can't do that to the piston. What's the best way to remove the build up from the top of the piston?

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Wire wheel on a bench grinder.  Will shine it right up.  If you take the rings and wrist pin off, you can use the blast cabinet.  Just do not shoot the skirt area as you do not want to remove any metal by accident.  The ring lands would benefit from a blast.

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If the rings are off a quick & easy check of the ring end gaps could be done.

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I went the wire wheel route, all nice and clean, just need to give all my parts the once over in the wash before assembly.

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Ah crap! 
Another set back. When I was removing the wrist pin I dicovered the piston had a crack. I don't know if I caused it, but I really only very gently tapped the pin out with a socket and a very light plastic hammer, there wasn't a lot of resistance but I checked every couple of taps to see how far it had moved.
I've since been told it may have been caused by the temperature in the building and the two metal types? Not sure if I'm going to continue with this engine build now as it's getting expensive.IMG_5281.thumb.JPG.bf3b10199de686b279a86

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If you had a K301, I would say abort.  But a K341 is certainly worth a piston and rings.  No doubt about it.  That is impact damage.  Nothing you did.

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New rod bolts torque to 22 Ft Lb, used at 17 Ft Lb

 

Question for the mechanics. 

 

Why would the old bolts be torqued less? I assume to avoid stripping or snapping them, but if so, would they hold as well as new bolts torqued to 22 ft/lbs? Or are new ones torqued more because the new threads will loosen as they age/wear?

 

I'm far from an expert, but I agree it appears to have impact damage on the bottom of the piston. 

 

Are the rest of the parts returnable? If not, then you are out that much, might be better to finish the rebuild, rather than lode that money. 

 

Plus you have to factor in the cost of a new or used engine, which if used, may or may not be a lot better than what you have now. 

 

Edited by WNYPCRepair

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@WNYPCRepair, The torque settings are different because the old bolts will have been stretched.

I had to get all my parts from America and the postal and import charges to the UK are almost as much as the part purchase price, so returning isn't really an option.

A piston is going to cost over £50 with the postage. 

If I take what the tractor cost, which I bought because I wanted the engine, and then add what I have payed out so far, it's getting to the point where I wonder if it is worth going forward. 
I still have my original 10hp motor which I have re fitted to my refreshed WH.

And to add to my dilemma I have lost the use of the work shop at work, which had the back up of the mechanics on hand, and some of the specialist tools.

What to do :eusa-think:

 

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