Piston Hole Kz1000LTD 1982

Cartal the blasting process normally doesn't "erode" that pot aluminum, does the opposite, lifts the grain. This will cause the bucket to catch in the bore. PLEASE don't use that flapper wheel, you Will distort the bore and not even that brake hone, not necessary. Rolf, you are braver than i using that much grease in the bucket bore!! The thick viscosity of that stuff "can" slow down reaction time and You could end-up hanging open a valve as the piston approaches TDC and bend a/multiple valves!! 

Just a big wad of steel wool with a bit of light viscosity oil to polish it up, power-wash after using some store "engine cleaner" to remove the debris. That bucket "might be ovaled like Wookie mentioned, overheated. This happens a lot of times because of running too tight clearances so the heel of cam remains in contact with shim, friction heat transfer.

Thank you for your comments. The steel wool approach sounds like a good plan. 
regarding buckets being oval, i ran them over a flat surface, and they seem to be ok. I will do the same steel wool treatment to them, and post back results 

Here to help. As far as being oval, running them over a flat surface, if i understand what you're say, isn't what you need to check. They normally don't "flare" they warp like an egg. Need to check inconsistencies in diameter, pic shown.  

Stuff if it helps. Knocked the cobwebs of this thing sitting. Same premise, maybe different style of head but he same concept. A nice complimentary bucket to bore, when dropping the bucket in should seat with a "ting" when it goes to the bottom. Yes that's an "industry term", ha. Regardless, should be easy to pick-out with a pocket magnet. When first aligning the bucket it may prove fractious but don't just smack it, it'll find it's Happy spot and push right thru. If You force it you'll just be whacking off shards of aluminum and forcing it in the clearance area.   

asphalt900 wrote:

. Rolf, you are braver than i using that much grease in the bucket bore!! The thick viscosity of that stuff "can" slow down reaction time and You could end-up hanging open a valve as the piston approaches TDC and bend a/multiple valves!! 



Well if that red stuff was grease it would be crazy !  It is not grease it is redline assembly lube that dissolves in the oil superfast and it does not clog oilfilter.It is made for this  and all other metal to metal parts in a new buildt engine to protect it at startup.I used it several times like this before.The buckets slide very easy.
 

Just messing with You Rolf!! I've just never deemed it necessary to put any kind of assembly lube in these hoes, he. Just a light swipe of dino 30Weight. Actually more critical then jamming them up with that lube is filling the cavities in the head above the buckets/below the cam lobes with a puddle of the same oil. That's why those recesses are built into the head, keeps a "reserve" of lubricant.

Just my personal choice but if I was going to run the motor within a day or two of build I would use oil, if there is going to be a time delay between build and fire up I would use assembly lube as oil will "run off" and potentially leave dry spots 

I concur Wookie but if one was to fill the built-in pockets before slapping the camcover on, ya never run dry. I've completed engines that have sit for well over a year waiting for persons to pick them up and as long as you keep them up-right, never a problem.

There is no amount of steel wool that will get my buckets to fit the bores. For some reason, they seem to be “swollen”. 
My theory here is that this engine was severely overheated at some point in time (remember the holed piston), and probably due to that, the buckets are shot.

Don’t know if this is at all possible​​​​​, but it sounds feasible to me.

At over 450 euros per set, new is definitely not an option. Have found some sets on ebay and will ask in the wanted section of the forum, just in case.

Thank you all again for putting up with my ramblings.

 Cheers!

 

It's common for a bucket bore to distort when it's been subject to concentrated high heat from alloy welding being performed on the head close by and the solution is to ease back the high spots with fine emery until the bucket slides freely.
BUT!  if the buckets came out easily when stripping the head the cause of the sticking isn't prior heat related by any means and must have happened after they were removed so the blast cleaning is the likely suspect.
Buckets don't 'swell' so i wouldn't waste money on new ones that still won't fit and just concentrate on working evenly around each bore with fine wet and dry until the originals do.. 
The clearances are a very close fit and the vapor blasting ( which DOES contain abrasive ) is enough to distort the surface and cause the issue.



 

Thank you Zed. What you say makes a lot of sense. The fact I don’t recall any trouble getting them out, rules out my overheating theory.

So the most probable cause here is the Vapor blasting. I’ll give it a go with wet and dry emery paper and see what happens.