Just refreshing this topic, I ended up buying a new set of rings from Otto 2 years ago, they were around $US235 from memory, but I'm still struggling to find the long sleeves needed, I contacted L.A. Sleeves 2 days ago and their longest sleeve in 4-3/4" bore is 12-1/4", which is exactly the same as I can buy here in Oz, so I'm now leaning towards using 2 pieces of sleeve to make the length.

The top of the 30 piston stops 2" before the top of the cylinder, and the top of the top piston ring stops 2-1/4" before the top of the cylinder, it looks like the bottom piston rings stops around 1/4" above the base of the cylinder. Most my old cylinders have been previously re-sleeved 50 or 60 years ago, and worn those sleeves out, and the big issue is when those sleeves were fitted way back when, the cylinder skirts were bored out to maybe 1/8" thickness, there is definitely no opportunity to cut a nice lip down there to support a new liner because I'm 100% certain the skirt will break.

Keeping in mind my old girls will be lucky to do 5 hours a year light work for the rest of their lives, can I look at fitting a short 1-1/4" long sleeve at the top of the cylinder, sitting on top of a 12-1/4" sleeve, to give me the 13-1/2" needed for the full length of the 30 cylinder? I realize it is not accepted practice, but I don't see any realistically priced option other than buying a heap of cast iron pipe and making new 13-1/2" sleeves, the join of the 2 sleeve sections will be safely above the travel of the top of the piston.

I know a couple of real nice Mechanics here in Oz who had quite a few old Cats over the years, one, a 20, needed re-sleeving and for some reason I can't remember, they used 2 pieces of sleeve, and the join was right in the middle of the bore, they might have run a bead of solder around the join.

Anyway they ended up selling that 20 to a guy who loved tractor pulling comps, and every time they went to a old machinery rally they would see the old fella on "their" 20 giving her a real hiding on the sled, expecting it to blow up at any minute, it never did.

If I was rebuilding a high HP high RPM engine with the aim of 10,000 hours hard contracting work ahead of me, my idea would be stoopid I know, but a old slow revving low compression Cat 30 producing what, about 10HP per cylinder at 850RPM flat out, for 5 hours a year, do you think it's worth taking the risk, I could always Loctite the short 1-1/4" section of sleeve in place just to help hold everything snug.

What do the Mechanics and Engineers think?
Thanks
Mike

Leave ring below the piston pin off if that helps. How many new pistons have rings below the pin anymore? The couple of Thirty jugs that I have had to have sleeved were stepped at the bottom and we left the bottom ring off so as to make sure that there was no chance of the ring catching the step. The other two jugs on that engine had already been sleeved. They had been bored all the way through, the sleeve shoved in and then the sleeve and the cylinder skirt were brazed at the bottom to hold the sleeve in. Who ever did those two used steel sleeves and the machine shop was not happy about boring them to the next size up. If you want some real fun get some seamless steel tube or some DOM tube and turn your own sleeves.

HI Team,
what naylorbros said above about leaving lower ring out is the go.
Oil control was still an issue in the days of these machines.
Today's oil control rings work well and most engines today only run one oil control ring.
If the first ring groove above the piston pin does not have oil control ring relief holes drilled then by studying the oil relif hole pattern in the lower ring groove or check any other pistons with oil control rings above the piston pin you will see the pattern and sizes that work--replicate these into the existing pistons and you should be good to go--do not get too carried away drilling too big a diameter of a hole or too many holes or the piston could break in two--not good.
Cheers,
Eddie B.

Thanks Ken and Eddie, those cylinder skirts on the 30 are wafer thin if they have been bored for sleeves, I measured one yesterday and got 0.09" thick, so even pushing a new sleeve in with a .002" crush would put a lot of pressure on the skirt.

I've got some cylinders here with old worn 5.00" outer diameter sleeves, and if I can't find any decent cylinders I'd be tempted to sleeve those 5.00" sleeves with new 4.94" sleeves. The 2 sizes available here in Oz in new sleeves in 4-3/4" bore are 4.94" outer dia and 5.0033 outer dia

Trying to work with old cylinders that have been re-sleeved a lifetime ago, and worn those sleeves out is a real challenge, my preferred option is to find cylinders either in good condition, or cylinders that have not been sleeved yet.
Thanks again for your help, I appreciate it
Mike

Another option for the unsleeved cylinders would be to find gas Thirty Five pistons. They would be .125" oversize for the Thirty but I have seen it done before. One Thirty I bought had 12,000 foot high altitude, Thirty Five pistons in it. I have yet to try that combo but plan in it.
Ken

The 30 that I got from the scrap yard has cylinders on it. I haven't done anything with it yet and probably won't until the weather warms up. The guys at the scrap yard were familiar with it and said it ran not long before coming in. I can't really say anything about it's condition except it looks well used and has sat for a while.

Hello Ken, I only know of two Gas 35's in Oz, there might be a couple more, but not 10 of them, so parts are just not out there, I can buy the new 12-1/4" long sleeves here in Oz for about $US40 a piece, so if I can't buy some good used cylinders out of the USA for a reasonable price, the next option is to buy worn cylinders that have not been sleeved yet, and re-sleeve them, because trying to re-sleeve cylinders that have been sleeved a lifetime ago and worn those sleeves out is too dangerous I think, there is no opportunity to cut a support ridge and the cylinder skirts will almost certainly crack.

I can see fine cracks in the skirts of several of my old cylinders, particularly those cylinders fitted with thicker sleeves, worse case scenario I'd look at fitting a thinner sleeve into those old thick sleeves.
Thanks for your input
Mike 
Thanks

Mike I just had new sleeves installed in my thirty. Got new rings ( 5 ) per cyl. and as mentioned above I'm not going to install the bottom ring.
The ring groove just above the wrist pin is drilled for oil relief. The extra ring below the pin is just more drag and I don't think I need it.
Hope this info will help on your short sleeves.
Cost for sleeves and labor $2000.00
C u Claney

OK Claney, thanks for that input, very interesting, were your sleeves full length of the cylinder, or were they shorter and sit on a ledge?
Thanks
Mike

Mike i sent you an email about the scrap yard 30