Anyone ever extract an engine piston liner?
 

After doing a valve job the other day on an 87 300SDL, I noticed some unusual scoring on one of the cylinder bores. Since I'm planning on doing some head work on my own car next month, I was curious if anyone had ever removed a liner from an engine in the car.

The factory method of a complete engine teardown for the replacement of a single faulty or questionable liner seems insane. Certainly there must be someone out there who has removed one of these liners by dropping the pan, removing the piston and con rod, and extracting the liner from above. I realize that the factory tool might not work but making a special puller, then shrinking and extracting the liner certainly would seem possible. I have enough professional experience and a spare parts engine to serve as a guinea pig, so I'm willing to give this a whirl if there's any chance of success.

re-lining
 

'Are you talking about removing the cylinder liner(s) with the crankshaft still
in the block?

GOOD LUCK! (NON-: Georgia Tech,Virginia Tech,M.I.T.,Sanford,Etc.,Etc.
engineering) Hey, I'm not saying it's not dooable;BUT, Einstein will, in Absentia, have some Royal somewhere Knight you !

PLEASE ! contact me with the results !

unless you have a serious hammer or something under that car, your going to have a hell of a time getting those, pressed in liners.

I can only comment on how it is done on other diesels not Mercedes.

Liner pullers are usually made to match specific engines; so if you plan to make something be advised it has to have good fit and good alignment.

One type of liner puller consist of 2 metal plates witha big thick piece of rubber between the and a threaded rod going through the center to tighten the 2 discs and squeeses the rubber against the inner bore of the liner. A slide hammer is attatchd to the threaded road and hopefully the liner is slidehammered out. It is best to degrease the bore of the liner with brake cleaner and the rubber also needs to be kept dry. This type of puller usually only works on liners that are slip fit into the cylinder or "wet" type liners.

The more common type consist of a heavy plate that is machined to fit the bottom lip of the liner (it has to be a good fit and not be wide enough to score the bore of the block as the liner is comming out). There is a long heavy metal rod through the center of the plate that extends up and past the surface of the block. On top of the block is a metal tube (or a special frame work) larger than the liner diameter that is high enough for the liner to come completely out of the block.
(The place I worked at the just bought a couple sections of heavy tubing/pipe large enough for the liner to fit through and had them and the bottom plates sent to a machine shop. The used a metal beam that bridged the top of the tube, drilled for the alltread rod that attatch to the bottom plate and you turned a nut to pull the liner out.)
That is what I have seen used on Detroit diesel and Cummings engines. Except that Detroit diesels also have a liner puller that can go into the ports on the cylinder.
Back in the day there also was places that rented liner puller for trucks. Fore Mercedes???
It might be that a puller for Ford tractors or Perkins engins might work.

It can't be done. It needs to be pressed into and out of the engine and it has to be machined to match the piston diameter while installed in the engine.

They already did it at the trade school I went to back in 1975. The liner puller.

http://i242.photobucket.com/albums/f...sel911/1-1.jpg

The portable engine boring bar with electromagnetic base that attaches to the block..
http://i242.photobucket.com/albums/f...sel911/2-1.jpg

They also have tools to press liners in but you would probably have to tow the car to the shop to have the liner bored to fit your piston.

Forced induction is correct. Even if it were possible to pull the liner from above, it has to be bored to match the piston and the top has to be milled off to be flush with the block. The most you could do with it in the block perhaps is a little honing to clean up the bore.

The only way to do it is to pull the motor and strip the motor.

The force required to push out the liners is incredible. I have personally done mine at my favorite machinist's shop. We use a 30 ton hydraulic press. When you are pushing it, enough force is created that you actually feel the block flexing and wonder if it will break on each liner.

Tom W

Wow.

If this is so wouldn’t it be possible for a patient person to get a die grinder and a carbide bur at grind a groove the length of the liner and relieve all of that tension holding it in. You would not have to grind all the way through. If you took the time to do it to both sides it would even be easier to get out. (my problem would be fitting my hands in the bore; but they do have long die grinders.)
When the liner is installed you take a large draw file and file it down close to the block as you can.
After that you take a lapping plate and lap it down the rest of the way until it is flush with the block.
Skilled people are doing this sort of thing every day in shipyards around the world and where machinery cannot yanked out and brought somewhere to be fixed or is too large to do so.
Is the job he had in mind worth all that trouble. I don’t think so. I is easier and takes much less skill to pull out the engine and have the job done in the normal fashion.

Another method I've heard about (but have not tried) is to weld a bead along the length of the sleeve. The contraction is suppose to shrink and loosen the sleeve so it can be pulled out easily.

As far as installing, I agree with the others that the top of the sleeve must be milled even with the block, and honed to fit the piston, at least on Mercedes diesels of this vintage. Other brands of engines are not the same and the sleeves can sometimes be pressed in without further machining, especially wet sleeves. Usually if the sleeve needs replaced, the engine is due for a complete rebuild anyway.

I dunno...

I think the question would be which is the most time/cost effective approach.

I had a large diesel powered boat that had some engine issues (Cummins) created by a broken oil supply line. To fix it meant to either do the work with the engine in place or to remove the flybridge, the galley and salon to gain access to the engine room.

They came in with portable equipment to not just bore a cylinder, but also turned the crank.

So the tools must exist.

Yeah but not for our little engines. To re sleeve one of these you have to send it to a machine shop. Its probably not worth it, do they sell oversized pistons? Can you just bore it out?

The cheapest solution is to buy a used motor, they go up in price from their.

I may be totally off here, but one method which i have heard about for pulling the sleeve from bellow is to fabricate a plate with exact diameter of the piston, then weld it along the bottom of the sleeve and bore a hole in it to pump grease in you can put around 10-15 tons of pressure on that sleeve, but theres a catch, the hydraulic pressure will also be pushing the sleeve against the wall of the block cleating more friction. i had a dodge intrepid which i used this method to free the seized piston with i screwed a grease gun hose into the spark plug hole in the cylinder head and pumped away at it. it unstuck that piston AND managed to unstick two more pistons at the cost of warping the crankshaft badly. LOL

I would like to hear some feedback on all of the above from UberGeek the person who started the thread!

This idea, works wonders run a bead along the center of the cylinder and it will contracts and makes the diameter smaller just by a fraction, but thats all you need to pull it out.