I'm doing some forward planning and have 3 sets of cylinders here for a pair of Thirty's and all the cylinders have 20-30 thou taper in the bore, 2 sets have freeze cracks in a couple of cylinders and 2 sets have been re-sleeved previously and have worn out again, the bore is 4-3/4", stroke is 6-1/2", cylinder length is 13-1/2". It looks like finding that 13-1/2" liner length here in Australia might be a challenge, the longest I've found so far is 12-1/4", so I was wondering who would be a good source for reasonably priced liners in the USA, the old liners in my cylinders look around 1/8" thick and interestingly 1 set of cylinders has 2 sections of liner in each bore, a top short section about 3" long that finishes just above the top ring, and a longer section that does the rest of the barrel.

I know a lot of folks would just throw a new set of rings in the old girls, lap the valves and button them up, but sadly my mind doesn't think that way, I could live with 10 thou taper but surely 20-30 thou is way too much, though when I got quoted $2,400 yesterday to fit new liners to just 4 cylinders by a Engine Shop my resolve to do it right did get a little shaken for a few hours but I soon recovered!

Regarding new piston rings, who are the best source, the originals are 1/4" and not available here in Oz off the shelf.
Thanks
Mike

Hi Mike.
Once I machined some liners for a home made engine to take a thin sleeve that was purchased and supplied by the customer.It was like a speedie sleeve but internal,a liner in a liner so to speak.Sounds rough I know but I wonder if this is common practice among engine machining shops,as we didn't specialise in engines but just did what the customer requested. The guy designed and built his own engine,So we made the Liner and had it include the hardened sleeve.It was slow revving but I never did hear how it went or if it lasted.
I'm curious to know,what sort of rpm do those thirtys run at?
The sleeve was purchased off the shelf down under somewhere but I don't know where.Is this an option? something to think about at least.
Would be good to come down to Echuca and check your thirty out at some stage.
Good luck
regards

"Mike wrote:

Regarding new piston rings, who are the best source, the originals are 1/4" and not available here in Oz off the shelf.
Thanks
Mike

Twice as many 1/8" rings. Stagger gaps.

Daron

"daron" wrote:

Twice as many 1/8" rings. Stagger gaps.

Daron

Yes, that is a option Daron, I hadn't thought of that, thanks for the suggestion.

Hi Lachlan, good to hear from you, the 30 runs at 850 revs flat out so not high speed, though I assume those five 1/4" rings on each piston would put a fair drag on the liner, in one of my cylinders I can see the liner has dropped over 1/4" and looking on the internet I see companies who sell new liners talk about cutting a step in the bottom of the bore for the new liner to sit on to keep it secure, others talk about using a Loctite type product to help secure the liner in place, another company talked about a 3 thou interference crush when fitting the new liner, following your experience I assume I could use a 3/32" thick liner that are 12-1/4" long inside the "old" 1/8" thick liner if we had to, cutting a step at the bottom for the new liner to sit on.
regards
Mike

If a liner drops far enough for a ring to pop above it & catch, you will have a wreck like you wouldn't believe. I saw that happen in a Perkins engine in a Massey-Ferguson tractor, & it was not pretty...yanked the whole liner down around the rod & broke it up, cracked the block, blew the piston into chunks...you do not want a 2-piece liner.

well with the state of my thirty motor i too have started to look for sleeves. they have a 4.750 x 14" long part CSL 565 that's with a 1/8 wall with .030 under for clean up after install. l have not done any more than look them up don't even know the cost or how they are to deal with. have not looked in to rings yet .
www.mellingcylindersleeves.com/Products

"mog5858" wrote:

well with the state of my thirty motor i too have started to look for sleeves. they have a 4.750 x 14" long part CSL 565 that's with a 1/8 wall with .030 under for clean up after install. l have not done any more than look them up don't even know the cost or how they are to deal with. have not looked in to rings yet .
www.mellingcylindersleeves.com/Products

Thanks for the link mog5858, having a liner .030 under would be handy because the pistons are worn too so it might give me the option to clean them up a bit, does anyone know if Cat were making tapered pistons back in the 1920's because if they were originally straight my Fitter and Turner buddy next door could make them a better shape while cleaning the ring lands, I'd need to be aware of the recess for the piston pin caps, don't want that getting too shallow, be nice to machine them to take a modern spring retainer too off a later D4, they share the same size piston pin, diameter wise, not length.

Ho ronm, I can just imagine the noise that little disaster created!! I agree, 2 piece liners are a very very last resort.

Morning Bruceoz, thanks for the PM.
regards
Mike

Hastings should have the rings you need Skinner

"Skinner" wrote:

Hastings should have the rings you need Skinner

OK, thanks Skinner, I'll check them out.

There was/is a company just over the border from Southwest New York State that makes custom Rings?
I had them make some for a CAT 10 project a while ago.
For the life of me I can't remember if its Ohio or Pennsylvania?
I think PA.....
Ron Meeder told me about them.