TOPIC:

I'll check the weight and see what the differences are (here we go again - wait until the wife is out... only ones are the kitchen scales!)

I can see the logic on the effectiveness of the extra holes, but Kawasaki had them in the same place for the injection pistons and Stan has them in his carburettor version (1982), so they must have had a reason... anyway, they are there now.

I was also very surprised they drilled them by hand... They are a professional outfit with a good reputation and they did the head very well, but I had expected them to pillar drill whilst holding the pistons in a clamp of some sorts... I think the is why they did not charge me... they knew if was not a very good job. But I guess no real harm done.

If liquid gasket is required on one side, which side?

Paul

Not to keep writing a book about piston holes, haha, but a final remark from me.

Frank883:

But those holes will have no real effect. Oil holes belong in the groove. .......You can google images for “piston oil holes” and see that these go in the groove.

That is a partial truth though. If you have those pistons in hand, both older and later pistons so have holes in the groove. BUT - the later pistons have additional holes drilled partially in the extra bevel. So, they have a total of 20 holes, instead of 10.

I am borrowing a pick here from Wiseco website:



Here is what they have written about it:

Most pistons use drilled oil reliefs at the back of the oil ring groove. Some have slotted holes that open up when the groove is cut. They are equally effective but some designers feel they allow more flex in the ring land.

Their placement corresponds directly to where the 'extra' holes in the later KZ1300 pistons are. If the theory is that both placements offer similar performance, I find it quite logical to assume that adding extra holes overall increases efficiency. In other words - more oil exchange by volume desired and achieved. Plus, the bit about more flex is something new to me and interesting.

Here is the whole write up at Wiseco website:

>>>>> The Science Behind Piston Ring Grooves

As to the cylinder block gasket, applying sealant would be on one side, the bottom. I did apply it but conservatively, and carefully especially around the oil passages, after first applying some engine oil to the gasket.

Ok, the pistons are reasonably equally weighted, weighing them with kitchen scales, so I simply connected them all to the rods. Engine is pots no 3 and 4 in top position, I have two piston clamps, but they are quite thick (I think they are car piston clamps) and certainly when 2-3-4 and 5 are in, they will be too wide to take out of 1 and 6. Not sure how to progress now...

Once 2-5 are in, maybe I can turn the engine so that 1 and 6 move up a little?

I read Stan's epic thread and after 2-5 were in using bits of tin can, he squeezed the last rings in by hand... I have no helper, so can't fiddle the rings by hand and tap the block at the same time.

Suggestions anyone?

Paul

My suggestion would be to use plastic ties like I did - they will keep the cylinder block from sliding down. Two or three on each of the four end studs, and a soft face hammer to tap the block down. I ended up doing most of the pistons by hand, as the aluminum sheet started to slide inside the sleeves between the rings and the wall.

It will be very hard to do it all by yourself, unless you'd purchase a tool. (I have it bookmarked somewhere). It's not as tall and perfect. I will post a link if I find it.

I'd strongly suggest you involve your wife. All she would do is tap gently on the block while you are squeezing the rings fitting them. That's all my helper did, she should at least give you and the bike this much! Or ask you kids? It's an easy job if they are well instructed and can be gentle. It's a really gentle touch that's needed.

I think chance you will be swearing and cursing the engine is extremely high if you do it yourself. But who knows, without all the proper tools and setup luck is a big part of it, and you might just get lucky. It is possible to push the block down enough and apply some pressure on the top ring that it will slide in enough in the cylinder bevel when compressed by hand and stay there while you tap again gently to make sure it will not come out, and so on. But you might break a ring as well, and I highly doubt you would be successful with every one at first try. You also must work left - right - left and so on.

So.... my suggestion is to somehow find someone to assist.

I've done this job before, so here goes,
I got 3 and 4 in first , then 2 and 5, then 1 and 6. All done with my fingers and no tin can strips or zip ties. I will say that by the end of doing this I had a few cuts on my finger tips from the edges of the rings.
I did place 2 vice grips on diagonally opposed studs in the corners and had them placed such that I could move the cylinder block down about 1/2" to get 2 of the pistons engaged, then lowered the cylinder down and ready to get the next 2 pistons in, and installed the vice grips with 1/2" play, got the next 2 pistons in and repeated.
I worked the top rings in first on both of the pistons, then the second rings in on both of the pistons then the oil rings on both of the pistons. By doing this the block kind of shimmied down. I had no need of "tapping" anything.

Kawboy said:

I had no need of "tapping" anything.

I found plastic ties easier as they don't suspend the cylinder block rock solid in one place until vise grips removed. The block is heavy and to support it when it's free you'd need both hands - just try to do a one handed curl with it! lol I found it to be challenging when done with one hand. Supporting and balancing the heavy block with one hand and trying to shift your position around the bike securing the block with a vise grip with the other hand is a not easy. At least to me, I've tried it. Also, I found the vise grips slipping - metal on round metal. And of course I wouldn't want to leave any damage marks on the studs.
With ties, there is never need to hold or support the block at any time. It's safe, it will never drop! There is more control - slight tapping or pushing it down will move it, while with the other hand you can guide the piston into the cylinder sleeve. Those pistons do tip and need to be kept straight or the rings might snap.

Anyway, not suggesting one method over the other or trying to pick up a fight with Kawboy, hahahaha, I tried vise grips and it didn't work for me. Plastic ties did, and no cuts!

Cheers!