New rings or not - Page 2 - PeachParts Mercedes-Benz Forum

leathermang · #16 11-01-2011, 10:32 PM

Some of these things are slippery slope deals....
If you replace all the pistons and sleeves...
then are you not going to put new connecting rod bearings in ? If connecting rod bearings... you are very close to the Crank bearings... go that far in but not the next step ?

I was going by the first post compression numbers for the other three bores.. which are pretty darn good for what we usually see around here...he had a mishap which necessitated taking the head off... and also the replacement of that piston... He could do that one jug by the FSM and know he had it right for very little money.....many of the other parts and supplies and labor will be needed even with the used parts... perhaps even more if the used piston needs machine work and custom wider rings to qualify....

leathermang · #17 11-01-2011, 10:41 PM

Quote:

Originally Posted by 1960mog

By "but require pulling" I assume you talking about the cylinder sleeve?

The sleeve that petecooke has installed right now should have an inside diameter of about 90.9mm + wear, given that it is still STD and has no other damage.
If petecooke buys the $55 piston he has to enlarge the cylinder bore to about 91.7mm.
This will give him a straight round cylinder with a new cross hatch surface.
Combined with a new piston and new rings one of the best ways to go.

If he installs a new sleeve he has to press the old one out and then the new one in.
The sleeve will perturb above the blocks parting surface and has to be cut even with the block somehow.
After installation the bore will be about 90mm.
He has to remove 1.7mm to make the new piston fit.

The end result will be the same then just honing the old sleeve to 91.7mm.

Why do you need a new sleeve?

Yes, I was referring to pulling the sleeve .

On a used sleeve the potential for it not being concentric is great... as the side pressure on the pistons in the bore is different between top and bottom... thus a four stone hone held in line with the center line of the crank would be standard operational procedure.
BUT a new sleeve can be carefully honed out with just a spring loaded stone hone with spring connector.... does not have to be held rigid as it works to compensate for the correction needed to the bore by the lack of concentricity due to wear.
So in other words... one is a machine shop job and one he can do.. just as he can pull and install the sleeve himself with hand tools...
I believe the top of the sleeve needs to be left proud a tiny bit off the head for the sealing with the head gasket to be proper.

petecooke · #18 11-01-2011, 10:48 PM

leathermang,

What tools do you use to pull a sleeve out? I thought a machine shop would be required to remove and install a sleeve.

I've never honed a sleeve before but I've seen the 4 stone hones that attach to drills. Is that the type of hone that would be needed?

Thx.

pete

Skippy · #19 11-01-2011, 10:53 PM

Quote:

Originally Posted by jt20

If you want a quick answer for whether you should replace the other rings, then check the ring clearance on the piston you removed (referred to as "side clearance" in the FSM). Not to be confused with 'end-gap'

Oh,************* Illegal SOFTWARE sorry and here's that manual you so desperately need.[/URL]

THANK YOU! Bookmarked.

leathermang · #20 11-01-2011, 10:53 PM

Yes to the second question...

and a lot of patience.... stopping and measuring carefully as you go... but it IS a low tech operation..

There are many good threads WITH PHOTOS in the archives... there is a home built slide hammer puller which just pounds them out gently....LOL hand slide hammer action....
If someone remembers the best one of those threads please speak up... I mean post the reference...
The sleeve also knocks right back in... the trick is to cool the sleeve both directions... I mean the old one coming out...and the new one going in....

petecooke · #21 11-01-2011, 11:07 PM

Wow. I thought I'd need a machine shop to pull the sleeve.
I will search the forum and see what info I can find.

I also need a gauge to measure the cylinder diameter. I think I can get the gauge as a loaner tool at the local auto shop.

leathermang · #22 11-01-2011, 11:09 PM

Lots of people here have used the slide hammer with no problems.... it IS shown as legit in the FSM... now, if you have the big hydraulic press thing made for that kind of pulling... more power to you (pun)....
I have been trying to find pics of it in the archives.... no luck yet...but if you go look at that FSM ref it should be there... and all the instructions on honing correctly also....

One trick... drop Dry Ice into the sleeve.... or plastic bags fixed like you do for making homemade ice cream... ice and rock salt.... in just long enough to cool it down...and then attack it... I mean use the slide hammer on it....LOL

petecooke · #23 11-01-2011, 11:17 PM

Thanks leathermang. I will keep searching archives also. If you find the link, please post it.

pete

leathermang · #24 11-01-2011, 11:21 PM

I will...
In the FSM the ' shop made' tool dimensions for the end of that slide hammer puller are given... in mm of course....

1960mog · #25 11-01-2011, 11:37 PM

Quote:

Originally Posted by leathermang

On a used sleeve the potential for it not being concentric is great... as the side pressure on the pistons in the bore is different between top and bottom... thus a four stone hone held in line with the center line of the crank would be standard operational procedure..

By "center line of the crank" I assume you talking about the center line of the Piston?

Every hone follows the given cylinder. If the cylinder is offset or not in the right angle to the crank, you can not fix it by honing. The cylinder has to be bored.

Quote:

Originally Posted by leathermang

BUT a new sleeve can be carefully honed out with just a spring loaded stone hone with spring connector.... does not have to be held rigid as it works to compensate for the correction needed to the bore by the lack of concentricity due to wear

I would not recommend honing 1.7mm out of a high chrome alloy cast iron cylinder with just a spring loaded stone hone with spring connector and a hand held drill.
Newly installed sleeves are so far out of round and tapered that you will have great problems to even get them straight with a hand hone.
This is a job for a machine shop.

Quote:

Originally Posted by leathermang

I believe the top of the sleeve needs to be left proud a tiny bit off the head for the sealing with the head gasket to be proper

The sleeves have to be even with block.

leathermang · #26 11-01-2011, 11:53 PM

No. I meant the center line of the Crank....
a straight line from the center line of the crank to the center of the top of the bore... that is the hole which needs to happen.

If you visualize ' line boring the block' then if you used that rod to anchor the hone it would allow correction for off concentric wear.

Hones do not have to follow the sleeve.... there are hones which keep their stones in line... do not allow them to follow out into ' holes' ... and just keep taking out material which is in the way of the correct hole needed..

Here is the type I am talking about..
Amazon.com: Lisle 15000 Engine Cylinder Hone Set: Automotive

You are thinking about spring pushed hones which will only follow the sleeve...

Sleeves have to be even with the block ? Can you quote from the FSM on that ? I remember it because that would be easy to do with a file... whereas what it called for was more tedious....

1960mog · #27 11-02-2011, 12:56 AM

Quote:

Originally Posted by leathermang

a straight line from the center line of the crank to the center of the top of the bore... that is the hole which needs to happen.

Sorry, I am not following you here.

Could you say a line perpendicular to the center line of the crank through the center of the bore?

If a cylinder is not in this line, no hone will fix that.
The hone you refer to will remove the high spots first,
and give you a straighter cylinder and faster material removal then a spring loaded one.
A spring loaded hone will only follow the unevenness in a cylinder.

Quote:

Originally Posted by leathermang

Sleeves have to be even with the block ? Can you quote from the FSM on that ? I remember it because that would be easy to do with a file... whereas what it called for was more tedious....

When I get home this weekend I will check on that.
I don't think they recommend using a file.

I always resurface the block after sleeve installation,grinding the sleeves down to the level of the block.

t walgamuth · #28 11-02-2011, 06:20 AM

My best friend runs the best automotive machine shop for many miles around here. In a case like this he and I would discuss it and I am pretty sure we would simply measure the bore (though he probably can tell by looking at it), and if the bore is within the tollerances specified by the FSM and install a good used piston which he would examine and verify its goodness, hone the cylinger to remove any slick spots and install new rings on the one cylinder. If the engine were out of the car the minimum would be to replace all the rings and hone all the cylinders.

But if the engine is out of the car we probably would also as a minimum replace the cam chain guides as well and the chain if it looks too worn.

And look at the head and do a valve job if that looked to be warrented.

My biggest question though is what melted the piston in the first place. Of course that needs to be fixed before putting it all back together.

47dodge · #29 11-02-2011, 07:54 AM

It is normally best when resleeving to bore all holes then hone. Also redecking is needed.Need a big mill for this.

The hone only follows what is there, even the good four stone hones. Which by the way have two stones and two wipers.This is the type mentioned by Leathermang. This hone will make a round bore out of one that is not round but will not correct alignment. A flex hone only gives a surface treatment. Also figure no more then .010" for honing and this is really pushing it. I leave my bores .002" undersize for honing.

Now I will say on a detriot diesel that the liners come bored and honed and just drop in. There is a requirment to measure the block to insure that aliqnment is correct.

As the big end of the rod( on a detriot) is to large to fit through liner, the pistons and rods are installed in the liners then put in the block. Deck clearance does need to be set with shims though.

Again measure what he has and see if the bore is ok. measure the used pistons and see what they are. A few minutes of measuring will give a go-no go answer.

leathermang · #30 11-02-2011, 08:01 AM

Sure Tom, I could go with that.... experienced machinist, big correct machinery to do the jobs with....
I was trying to balance the criteria I thought the OP gave us... while getting to the lowest required BUT correct by the FSM fix for what he does... We had no promise that the pistons from the other engine would mic out to being acceptable to replace number three...
but for matching new piston and rings at Half a hundred dollars I thought putting that into a new jug... since MB did make it replaceable... sounded like a nice balance which might live a long time....a huge percentage of the labor described would be required whichever combination was chosen....