Cylinder Liners/Sleeves?

[LV_live_steamer]

Hello, I have a question about cylinder liners/sleeves. I'm planning on designing and building my first IC engine with an open crank. I've seen other peoples engines and that they install cylinder liners during the build. Whats concerning me is how the cylinder liner stays in place and how its installed. Is the cylinder heated up and the liner inserted letting it cool and shrink around it? Is it bolted in? Its the only part of the engine that I do not fully understand how it works.

Thank you,
Dylan

 

[kvom]

I've seen the shrink fit method and the press-in method. In either case the liner won't move of it's own accord.

 

[Mechanicboy]

Steel sleeve in aluminium: Light press fit due expansion by heat in aluminium is larger than steel hence the contact between sleeve and engineblock/cylinder jacket must be tight to lead the heat away from sleeve. Air between sleeve/cylinder jacket make bad cooling.

I had never shrinked the sleeve into the cylinder jacket and never had problem with light press fit sleeve into the cylinder jacket. See my picture of the OS MAX 61 with new sleeve..

 

[Swifty]

The sleeve can be a slide fit, but you need a small shoulder on the sleeve at the top end, then it can be clamped in by the cylinder head.

Paul.

 

[LV_live_steamer]

Ok, so by bolting the cylinder head onto the cylinder it should apply force on the shoulder of the sleeve keeping it from moving.

Thank you,
Dylan

 

[Mechanicboy]

Ok, so by bolting the cylinder head onto the cylinder it should apply force on the shoulder of the sleeve keeping it from moving.

Thank you,
Dylan

Yes, the cylinder is hold on place with cylinderhead + bolts.

 

[Swifty]

Dylan, here's a picture of the liner from my Lynx showing the shoulder that is clamped by the head.



And another showing it in the cylinder, the head has a recess just a bit shallower than the thickness of the flange so it can hold it down tight.



Paul.

 

[LV_live_steamer]

Thank you, this is quite helpful information!
One more thing though, what would the proper material be for liners? Is mild steel O.K. to use?

Dylan

 

[Mechanicboy]

Use high tensile steel or annealed steel from driveshaft from old car to example. Cast iron is too good material as sleeve.

 

[Swifty]

Dylan, the liner in my picture was cast iron, however I've used 4140 in the past as well. I think that traditionally a fine grade of cast iron is preferred. Others may care to give their thoughts.

In my case, once an engine is finished and running, it spends the rest of its days as a shelf model, so I probably could have used mild steel for the liner. I may start the engine once a year just for interest, but if you intend to run an engine on a regular basis, liner material may be important to you.

Paul.

 

[Mechanicboy]

The inside sleeve must not be blankpolished as mirror! The surface has crosshatch honing angle approximately 45 degree. We need a lot of oil pockets in the surface to lubricate the piston ring then the engine will last long time before next overhaul is needed with new piston ring + deglassing inside the sleeve with honing tool to make new oil pockets.

 

[goldstar31]

Somehow I expect that this is 'old rechnology'.

I can understand what is being said and the reasons for it. Old cars etc were done this way and had to be 'run it' for 500 miles or whatever but modern cars- and I have FOUR of various makes could be run virually flat out from coming out of the dealers show rooms. Agaoin, I;m quoting the top of the range Mercedes- I have an SLK 230. I have an Audi A 4 Avant S line. I have a rather cheaper Skoda Fabia Monte Carlo and a bargain basement- shopping trolley Hyundai Getz. None were run in because the bores were properly bored and honed.

On the other hand, I did overbore by 60thous a 997cc Mini Cooper which was bored with a boring bar, cross hatched and whatever- in the land of the early 1960's.

However, going back to the time of the Dodos, Lawrence Sparey described in the Amateurs Lathe how to hone- not cross hatch or whatever his model engines.

There you have it, I'm afraid. Rather more than a one line and somewhat confusing remark.

It should be a bit clearer but this a big subject that has occupied professional engineers since George Srephenson's foreman packed a steam cylinder with his hat. True!

Norman