Type 4 - How hard is it to load Cylinders on the engine?

[mrcool]

I am replacing both heads and while I am here I would like to clean the pistons and cylinders. There is tons of baked on carbon/oil I'd like to remove. Hopefully I can keep the pistons on the rods but I have to replace the oil cooler so it is fine if I really have to remove the pistons.

I'd like to replace the gaskets on the cylinders too.

I know lots of people install cylinders on bug engines with the pistons on the rods already. Is this pretty easy to do on a type 4?

[timvw7476]

yes, can be done.
trouble is sending sealant all over the place when you extract the piston
ring compressor, I like using a one-piece type with channel locks, so
getting it out of there is a hassle. The installer for standard 1600cc type
ones works well, just make sure the gap left where the pliers squeeze
the oil/piston rings don't include a piston ring/oil ring gap
If you don't have one, (piston installer) a hose clamp big enough & wide
enough to compress all ring assemblies should do it, just oil it all well &
tap gently, wooden/plastic mallet.

[SGKent]

pull the engine. You are creating oodles of sub-par work for yourself. If you remove the cylinders you will have to hone them, and re-ring them. If there is a ridge at the top it has to be removed or new rings will be damaged by it. In fact if you change the height of the cylinder above the case that will also be a problem for the rings which means you will need a new piston and liner set. Analogy - try skateboarding into a curb in the dark. You are the piston ring, the step is the ridge.

I can't see anyone in their right mind trying to swap heads and cylinders while the engine is still in the bus.
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“Most people don’t know what they’re doing, and a lot of them are really good at it.” - George Carlin

[mrcool]

[SGKent]

You can mark each piston on the top and remove it and the cylinder as unit. Good luck (really), and may the Lord watch over you when you do it because the bottom (oil) ring is only a tiny distance from the wrist pin. If you pull too hard the ring will pop out. The surface of the ring is mated to the cylinder wall. If you rotate it at all the surfaces will no longer be mate and will leak oil into the combustion chamber. If you pull the top rings out by accident then they won't act as properly either. Basically if the rings pop out you are screwed. (and they will unless you are really lucky). So that means new rings, which means you have to hone the cylinders to put a new crosshatch on them or they won't seat thru the glaze that has built up. That is just how it is.
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“Most people don’t know what they’re doing, and a lot of them are really good at it.” - George Carlin

[mrcool]

Ok awesome! Thank you for explaining that to me. I had no idea! It is really nice to understand the bigger picture. I'm still a little confused though. Don't the rings spin when they are in the cylinder? Or do they remain stationary?

So what would you do if you wanted to clean the carbon deposits on the pistons and cylinders? Leave it? Unless the gasket is shot It would be better to slightly pull the cylinders out, clean the mating surface between the cylinder and engine block. I'd use mineral spirits and brushes. What surfaces could I use emery cloth on?

I'm guessing I can't reuse my wrist pins so replacing the cylinders and pistons isn't an option without pulling the rods and getting new bearings?

[SGKent]

each wrist ping is sized to a piston and wears in. You have to use the same wrist pin on the same piston in the same direction and each piston has to go back in the same cylinder.

If a machine shop with any reputation were doing the job you propose, and they were instructed to cut costs and not just replace them here is what they would do.

1) use an ingraving pen to mark each cylinder on a fin where it cannot be missed. Probably bold letters like I , II, III, IV so it isn't hard to spot. I might use 1, 2, 3, 4 but that can be really hard to see on cast when cleaned. Mark each piston top with the same number and an arrow towards the flywheel

2) pull one cylinder off, one farthest from the flywheel

3) Remove the wrist pin circlips on that one. Probably stick them in a baggie with that cylinder number. Use the engraver to mark the pin with a series of dots on the same side of each pin, usually the side away from the flywheel. one dot, two dots. three dots, four dots.

4) Remove the pin using a socket or drift without pounding on it I have an old small sized spark plug socket that works well. Some folks are lucky enough to have an aluminum or brass drift custom made. Once the wrist pin is out the piston comes off and into the baggie it goes.

5) do another one at a time until all 4 are done.

6) clean in solvent or a parts washer to get the grease off.

7) pull the rings off each piston. They are like razors if you grab them in the wrong spot. Try not to break them yet.

Usually a machine shop will glass bead them under low pressure with fine beads and inspect them. They will measure them at the skirts and just below the bottom ring land to see if the skirts have collapsed. If they have they will knock/rattle. Sometimes if they are just barely collapsed the machinist will tap the skirts outwards equally with a rawhide mallet to bring them back the .001" or .002" they have collapsed. They will check the ring lands for wear. If they are too worn the pistons are junk. If the skirts are scuffed they are junk.

9) they will clean them in a parts washer again making sure that at each step they can read the numbers they engraved because sometimes they can get hard to read. They may weigh the pistons to be sure they are within tolerance.

10. I like to break a couple old rings while holding them in a rag to get a feel for how easily that style breaks. Especially if it has been awhile since I did one. Cast rings are incredibly fragile.

11) Clean the block area.

12) wash the cylinders in the parts washer then hone a fine crosshatch in them. Some machinists will just use a bottle brush hone and others a Sunnen machine.

13) check the new rings for end gap in the cylinders and adjust

14) check the side gap in the ring land.

15) wash everything in hot soapy water and rinse in hot water. Dry and spray with WD-40 to stop it from rusting.

16) assemble.

You can use a little GM top cylinder cleaner on a paper towel or rag and let it sit a couple hours. It will soften hard carbon. It is less messy than a wire brush or razor blade etc. If you want put the engine on one side and put a tiny bit in the cylinder, it will soak any carbon on the rings. Then do the other side. When I say a little I mean barely wet as I have had it etch steel lightly - not enough to cause an issue but enough to see it.

enjoy however I think you can see why so many folks just buy new pistons and cylinders in a kit. However a good 2.0L set is about $500. Then one says while I am here why not split the case.... Were it me if you are trying to save money, use some of the GM top cylinder cleaner.

If you want to reseal the cylinders you can turn the flywheel and they will normally lift a little. Use a rag with some alcohol or acetone on it to wipe under them until they are clean then use fresh RTV to reseal them. If you pull a space out under them then the piston will go up further in the cylinder by the thickness of the spacer and damage the rings when it hits the area it has never traveled. Same going down if you add a spacer but less so.

_________________
“Most people don’t know what they’re doing, and a lot of them are really good at it.” - George Carlin

[mrcool]

Thanks for the detailed reply! I think this will help a lot of others out too.

So if someone was only rebuilding the top end does this stop at replacing the cylinders and pistons?

Do the wrist pin bushings on the rods have to be replaced when they are on the engine at this time? Or in a top end rebuild are they also removing the rods?

[SGKent]

the rods have to come off to replace the wrist pin bushings. Then you have the issue of new rod bearings. Remember the plumber who went to replace a seal analogy and ended up replacing all the plumbing in the house?

The wrist pin (small end) bushings come as one size that the OD fits the rod with a press in fit Then each bushing has to be honed with a very expensive rod resizing machine. I used to do about 12 to 24 a day back when and it is an art form just to keep the honing stones from wearing uneven. You'll need a good machine shop if you are going to go father. Were it me I'd make one of two choices - spend 3 to 4 months and go thru the whole engine, or stop with just the heads. If you paid Len $1500 for a set of heads then you might consider doing the whole engine, but if you bought some right out of the box with no upgrades then they won't last as long so plan on an engine rebuild in 3 years if you drive 10,000 - 15,000 miles a year.

You need a crystal ball or clairvoyance to make any better an educated guess. You can go out into a 3000 mile trip and spin a bearing or you can go 100,000 miles on that lower end. Only God knows, get close to him.
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“Most people don’t know what they’re doing, and a lot of them are really good at it.” - George Carlin

[old DKP driver]

Please, do not forget to do a mock-up with your cylinders (without pistons)
to see if there is a parallel problem between cylinders 1&2 AND 3&4

You don't want the head to leak because you neglected to make sure BOTH
cylinders were the same height.

So, do you know of this problem with type4 engines?
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V.W.owner since 1967

[mrcool]

Old DKP,
I did not know about the parallel problem. It makes sense though. I'll have to look into that more

SGKent,

I am totally that plumber right now... I hate doing things half assed and once I start reseraching what I thought was such a scary fix it becomes apparent its not that bad... These Type 4's are like legos for adults... Sort of

My heads are just straight out of the box AMC heads. I am not concerned with the quality of the valves or valve angles, it sounds like that is an old issue people keep holding on to.

If I didn't need to replace the wrist pin bushings I would do the P&C but since that is not an option I will just clean them as best as I can, replace the oil gaskets, heads and get her back on the road!

[mrcool]

Ok, old cylinders and pistons are out getting cleaned and honed..

Should I do anything to prepare the case surface for the cylinders? I can clean the outside without much worry. But I am not sure what I should do to the case surface that mates with the cylinder.

It is really the inside that is a bit dirty, not where the cylinder gasket/shims go. I guess I can stick to the good ole mineral spirits and rag. I would think emery cloth or a brass brush might mess up the surface too much?

[SGKent]

just clean it with some mineral spirits and try to keep any dirt from out of the engine. Use a little black or red RTV between the cylinder and case when you put the cylinders on. You'll wash the pistons and cylinders with very hot water and soap, rinse and immediately dry. Then spray the cylinders down with WD-40 to prevent rust. If you marked them with a pen or sharpie be sure not to loose the marks.

Take your time putting the rings on. Old DKP is in your area. You might ask him for help if he is available, or if he knows someone in case you aren't sure about checking ring land gap, putting the rings back onto the pistons, or putting the pistons back into the cylinders. I am in Sacramento but that is about a 5 hour round trip from where you are in San Jose.
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“Most people don’t know what they’re doing, and a lot of them are really good at it.” - George Carlin

[Starbucket]

If it was me I would leave the pistons/cyl.s alone. The gaskets under the cyl.s will reseal when you re-torque the heads, forget about putting sealant on cyl. gaskets as there is no pressure there that will overcome the seal from properly torqued heads (you don't see any on the head end do you?). Put a quart of Rislone in with your oil (replacing 1 qt. oil) and drive it 500 miles and it will dissolve your deposits and leave the inside of the case and everything that gets oiled free of carbon/sluge deposits when you drain it out.

[old DKP driver]

You do need to reseal the cylinders regardless what was said as they will
leak if you don't.....

.I was going to respond to your post yesterday as i do
live in your area but, i am headed to Monterrey this weekend to protect
some property i have there.

you can pm me for help next week if you like. i am in Willow Glen

Chris
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V.W.owner since 1967

[mrcool]

Thanks for the offer Chris!

So... I took the cylinders in to get honed and there was too much wear. I've had to buy new C&Ps. About to take the rods off today and inspect the crank wear.

[Starbucket]

When you took the cyl.s off was there sealant on the case/cyl. gasket?

[mrcool]

[Starbucket]

[SGKent]

You can have the machine shop that inspected the cylinders check the big and small ends for size. Take the 4 rods and caps, and wrist pins to them. Make sure you mark the wrist pins on the end with an engraver, or individually in plastic bags so the don't get mixed up. They need to go back in the same pistons. Be VERY careful not to get anything on the crank - not one spec of dust or sand. That means keep a clean towel over it so the kids, dog, cat, wind don't blow any dirt in there. Might be worth having them balance the rods while they are out. You will want new rod bearings. Since you've gotten this far successfully consider whether you want to just go ahead and split the case. You are 80% of the way there.
_________________
“Most people don’t know what they’re doing, and a lot of them are really good at it.” - George Carlin