DOM tubing cylinder sleeve

[oltrucks39]

Hello all. I am currently working on the Perkins kit and through a long story have overbored the cylinder. I am considering sleeving it with DOM tubing. Any thoughts? Thanks in advance.

[Brian Rupnow]

It depends a lot on what your piston and ring material is going to be. If you are using an aluminum piston and Viton o-ring, you should be okay. If however you are using cast iron rings you may run into trouble as the dom tubing is quite soft and has little or no graphite content to keep the rings from galling. What material was the cylinder that came with the kit?

[oltrucks39]

The culinder is cast iron.

[oltrucks39]

It seems to me, and I may be all wet, that automotive engines have cast iron cylinders and hard plated chrome moly rings which implies that a difference in hadness is needed. DOM tubing has to be much harder than cast iron.

[Dave Otto]

I don't see any reason why the DOM tubing would not work. If I was faced with this problem I would probably make the sleeve from cast iron bar stock.

Dave

[Jasonb]

The DOm should work OK, just run a cylinder hone through it to roughen the surface slightly and that will help the rings bed in. Also makes it easier to get a straight bore as the Perkins is a blind bore.

Then again unless you have gone a long way overbore it does not really matter if the bore is say 0.025" over, just make the piston and rings to suit.

[derekwarner]

Drawn over Mandrel is a formed  [usually SAE 1010 carbon steel] and resistance welded in the process of making a tubular profile

Despite any post heat treatment, the parent material on either side of the resistance weld is harder than the balance of the circular tube form

Honing of larger bore sized DOM material will only progress to an oval bore due to the two hard longitudinal lines on either side of the fused joint

Considering alternate materials & remedial processes available, using any DOM material would be a poor last & only cause more heartache than it is worth

If the original cylinder was steel [and not iron]....you certainly could consider using hollow steel bar [ASSAB 750V] as a suitable choice  for a sleeve

Derek

[b.lindsey]

How much too large is the bore? I agree with jason, unless it's way oversize adjust the piston and rings to suit. If you can't do that, make a sleeve out of cast iron, heat shrink it to the cylinder and then hone it to size.

Please also post an intro in the "introduce yourself" section so others can welcome you to the forum.

Bill

[oltrucks39]

The bore is 1/8 oversize.

[b.lindsey]

Probably to much to adjust then. I would sleeve it with cast iron as noted ...heat the cylinder, freeze the sleeve and shrink fit it in.

Bill

[derekwarner]

This is a little more problematical than first mentioned

1/8" oversize in the bore represents a 1/16" [0.0625"] wall thickness finished size bush.....which in a quality Grey Iron is a delicate item & easily damaged by compression 

You mention Perkins...is this a single or multi cylinder engine?...
What is the nominal cylinder bore size?
.....or what is the Model of the Perkins engine?
You mention that a cylinder is currently "bored" oversize......was this achieved in a lathe or mill, or borer?

Answers to the above will assist in understanding the best mechanical solution/fix & will dictate if a cylinder liner of smaller bore could be manufactured, inserted via a shrink fit & later bored to standard size

Derek

[Rustkolector]

I have used DOM tubing for cylinder liners on a number of slow speed gas engine models with CI rings. In my opinion and experience it makes an excellent cylinder for model engine use with CI rings. Buy the closest ID and OD combination to your meet your needs. I suggest using the parent bore of the tubing and make a lap to check the bore for roundness. The bore must be round for rings to properly seal, and not all DOM tubing is perfectly round throughout. I found one piece of DOM tubing where the tube weld showed up as shadows when viewed against a light. A lap or Sunnen hone must be used to correct this problem. Cross hatch hone the final bore and then make the piston and rings to match the final bore. I think you will be happy with this choice.
Jeff

[oltrucks39]

The bore is supposed to be 1.500.  I already have some DOM tubing that is a very close slip fit to the bore as it is right now.  If I remember correctly, the ID of the tubing measures something like 1.468.  It is the common perkins hit n miss kit with the blind bore.

[Jasonb]

1/8" oversize in the bore represents a 1/16" [0.0625"] wall thickness finished size bush.....which in a quality Grey Iron is a delicate item & easily damaged by compression 

If you do go down the grey iron liner route then you don't have to shrink fit it so no worries about compressing it, a high temp Loctite like 648 will keep it in place, I've done several engines with 1/16" wall CI liners held with Loctite and they all run fine.

Another option if you are worried about the welds is to use hydralic tube that comes ready honed though the wall thickness may be a bit much and reduce your bore. Then again nothing to stop you buying the bore you need and turning down the OD

1.468 bore should not cause problems

For those who don't know what a Perkins is look here http://www.cmodele.com/GasEngines.html

[john mills]

as a engine reconditioner long time ago now we fitted lots of sleeves in full size engines.hear in australia repo used to make std A size sleeves cars iron.
1/16 wall thickness just a lite press fit even for 4 " bore we had air jack hammer to knock the in on a production line  we used a press from memory .0015" interference was sufficient.bored to size finished by honing.