stuck cylinder liners

[Jason]

I'm in the process of disassembling the engine to do a rebuild and DPI SPEC 2 upgrade.

I've never done anything like this before, and so far its been quite an adventure.

I have the engine mostly disassembled, but I cannot get the cylinder liners out. I've read all about how careful you have to be when removing the cylinder heads so you don't break the liner seals, but in my case the liners are stuck to the block and I can't get them to move at all.

I pulled the heads off exactly how you're not supposed to (because the head locating sleeves were rusted in place, and the liners were going to be removed anyway) , spun the crankshaft without the liner clamps, pulled on the liners as hard as I can, whacked them with a rubber mallet, and put a wooden dowel against the bottom of the liner (going in through the bottom of the engine) and hammered on that. Nothing I do will make any of the liners budge.

Does anyone have any suggestions on how to get them loose? I'm hesitant to hammer on the bottom of the liners with something that can apply more force than the wooden dowel, like a metal punch, because I don't want to accidentally mess up the surface on the block where the liner seals go.

Also, how should I go about cleaning the block, especially the various gasket and seal surfaces?

Thanks

- Jason

[dmc6960]

Unbolt the connecting rods from the crankshaft. Remove the whole con-rod/piston/liner assembly.

[tgraham]

You didn't mention this, so I'll go ahead and ask... have you removed the big end caps (or taken the pistons out entirely)? The piston and liner should come out as an assembly - once you have the caps off, even if the liners are caked in there with coolant sludge, you should be able to muscle them free fairly easily. If you're having that much trouble, it sounds like something is pretty wrong.

I've had success cleaning the block/liner-to-seal surfaces with a Dremel and a soft (brass or plastic) attachment brush.

Good luck.

Travis

[Jason]

Unbolt the connecting rods from the crankshaft. Remove the whole con-rod/piston/liner assembly.

That's what I'm trying to do. I have the connecting rods disconnected from the crankshaft.

On one of the cylinders I went ahead and pulled the piston out without the liner, so that I had more room to attack the liner, but I still can't get that liner to move at all.

[dmc6960]

Torch it. If it still doesn't budge, there is a remote possibility a previous owner had the engine previously rebuilt and had new custom liners pressed into the block. What's the ID of the liners?

[David T]

I also agree using heat makes the use of excessive and damaging force less necessary. It is possible the motor was overheated and that's why you are having trouble. Taking the liner out with the piston does not make it easier. I say take as much as you can apart and if you still can't get the liners out send the block out to be boiled. That ought to get the liners loose and in any case will clean the block up like new.
David Teitelbaum

[DMCMW Dave]

Don't use a hammer.

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[Jason]

I've got 4 of the liners out.

I removed all the pistons and the crankshaft, and while doing that one of the liners fell out.

The other three I got out by putting a block of delrin against the liner bottom and hammering on that. But the remaining two are nice and stuck.

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So if I did want to take the block somewhere to have it cleaned, how would I go about finding a local place to do that? I'm not quite sure what I'm looking for.

[opethmike]

Look for an automotive machine shop. If you have a trusted mechanic, you can ask him/her what shop they use.

[vwdmc16]

2 of my engine's liners required over an hour of wiggling side to side for them to come free. I used a long thing screwdriver to carefully break up the coolant deposits and filth accumulated at the cylinder base which had become like concrete to hold the liner before the cylinders could even rock a mm.
It was very hard to not just go grab a hammer and go at them.

[Bitsyncmaster]

You could probably make us some sort of "plug" that could be put in the cylinder, expanded and then use the piston and crank shaft or just a hammer on the plug. Just a wooden plug (oak) with a split and wedge may work.

[DMCMW Dave]

The bigger problem you are likely to have is that once you do get them out, you will find tha the sealing surface of the block is corroded enough to compromise the seal. If enough bad coolant (i.e. water) got in there to lock it in, you will need to check that deck and the same surface on the cylinder (where the seal goes) for pitting.

PS the one I posted a few lines back actually broke off leaving the botttom part still in the block. I agree that a hot tank (what David T called boiling it) might be a good idea, as the aluminum block will expand faster than the cylinder and it should release, in fact it may fall out. Worth a try anyway.

[DMC5180]

Since the condition of the block that was posted looks pretty typical. How clean will the boiling process get a block in that condition? I assume the inside will be bright and shiny since it is protected with oil and coolant. I'm more curious about external corrosion/oxidation. Does anyone have some nice before and after pic? I've heard the block will darken in the boiling process because it's magnesium. Is this correct?



Jason,

Since your new here, please go to your usercp and fill in some basic Left column info. Location City,State , (last 5 of the VIN), any clubs etc. See others for reference.


WELCOME to Forum:thumbup:

[Jason]

I ended up making a liner removal tool and then using a press.

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Just a little bit of pressure from the press and they popped right out.

[dmc6960]

Wow, just wow. That is astounding. Great job. Must look away now to avoid expensive CNC purchase.

[David T]

The tanks they boil the parts in contain chemicals that dissolve deposits and brighten the metal. When the parts come out of the tank they will look like new. Of course they will need machining and any surfaces that are pitted have to be dealt with. You may have to have some ares welded up and machined if the pitting is bad enough. Typically parts become difficult to disassemble if things were leaking for a long time. Possibly from an overheat at some point in the motor's history.
David Teitelbaum

[Jason]

I had the block cleaned. All the surfaces look good except for one spot of pitting on one of the liner surfaces. The pit is too deep to just machine down. The local machine shop I took it to is recommending using epoxy to build up the area rather than welding because they're afraid the heat may distort things a bit. Does that make sense, or is epoxy a bad idea?

[Bitsyncmaster]

I had the block cleaned. All the surfaces look good except for one spot of pitting on one of the liner surfaces. The pit is too deep to just machine down. The local machine shop I took it to is recommending using epoxy to build up the area rather than welding because they're afraid the heat may distort things a bit. Does that make sense, or is epoxy a bad idea?

I would question epoxy since it will loose strength with engine block temps. I would have to agree that welding may cause distorting of the block. I would think a gasket sealer would hold up the best.

[David T]

There are ways to weld and minimize any heat damage. If the shop you are talking to is uneasy with this find a shop that can do it. Of course there will be some localized distortion but any good machine shop should be able to deal with it. One way is to over repair the area and machine it back to final dimensions. I would not recommend epoxy. If it gets too hot it will lose strength. While it is all apart check EVERY bolt hole and thread. Fix any that are not good now while it's easy to get to. If you are into blue-printing, you may want to remove any flashing, smooth all the edges, paint the internal surfaces with Glyptal, etc. There are many "tricks" you can do while the motor is all apart that don't cost anything but your time.
David Teitelbaum