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Discussion Starter #64
Well, it's midnight of the night I thought I was ready to pull the engine in the morning... I probably won't be pulling the engine until afternoon, if at all tomorrow.
I can't believe the shear numbers of parts, attached to this engine. If it were a small block Chevy the engine would have been out days ago and on it's way back from the machine shop by now.

Talk about 10 lbs. of shiot in a 5 lb. bag. Good grief. Oh well, I'm tired and cranky. Tomorrow is another day.
 

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I think you need to talk to some different engine shops about their capabilities. There are techniques for relining cylinders, like plasma spraying, but how available or affordable they are is a different question.
 

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No one says it cant be, but it's not the standard way to repair it. You would be developing and breaking new ground. Plus it probably cost a lot more than boring.
I get that and I'm not arguing, I'm just trying to get some understanding. A while back, I was reading a thread by someone that was rebuilding his engine. It was mentioned that Mercedes engine cylinders have a special coating, which is why these engines last so long. The person re-building the engine lived here in Southern California and said that there were only a few shops here that could do that coating and the cost was around $2K. I'm an old dog learning new tricks and just finished taking some Machinist classes. In fact, I'm starting a new job as a CNC Machinist on Monday. In my studies, I read about a plasma coating that is applied to engine cylinders, to extend their life, which I think is what Mercedes does. I'm wondering which would be better. Boring all cylinders oversize and no plasma coating, boring all oversize and plasma coating or sleeving one with plasma coating?
 

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Discussion Starter #70
I may do neither... it depends on what I find when I pull the #6 piston. I have no intention of spending $2K to have the cylinder re-bored and recoated. If I can have a sleeve put in for hundreds instead of thousands I'll consider it.

I've been driving this car all summer and put at least 3000 miles on it, and other than that annoying ticking sound it ran fine. I even drove it to Great Barrington and back. If I can smooth out those scratches and get rid of the loud ticking (more like clacking) then I'll be a very happy camper.

I was all ready to pull the engine today, I had the hoist connected and I started to lift when I got a call from the office that there was a problem. So here I am on a Saturday working on system issues at work when I should be removing the #6 piston right about now.

Tomorrow I'll get that piston out and then I'll decide. :)
 

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Was it Audi that at one time used sleeved aluminum blocks? I recall at least one car company having done this, but I can't remember which one(s).
Also, I'm away this weekend, but if you might need a hand after Monday, let me know.

Regarding the tick, how did #6's valves, cam lobe, etc., look?
 

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Discussion Starter #72
Was it Audi that at one time used sleeved aluminum blocks? I recall at least one car company having done this, but I can't remember which one(s).
Also, I'm away this weekend, but if you might need a hand after Monday, let me know.

Regarding the tick, how did #6's valves, cam lobe, etc., look?
#6 valves look just like all the other valves (except the exhaust vlave wasn't white). I mic'd the cam lobs months ago and all were perfect, well... within a thousands or two of each other. The hydraulic compensators are all new and half the cam followers are new. I used the go/no go gauge to set all the valves within the good range of the gauge. After all that you'd think there shouldn't be any ticking... but the ticking (actually clacking) was so loud you could here it at highway speeds with the top down. That's bad.
 

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Does that imply that all 8 cylinders must be bored to the next larger size (I assume 30 over). Would doing just 1 cylinder create a balance issue?
Never seen it done, but that doesn't mean you cant. Might be a good question to ask the guy that does the boring. Im sure you will get all sorts of
I get that and I'm not arguing, I'm just trying to get some understanding. A while back, I was reading a thread by someone that was rebuilding his engine. It was mentioned that Mercedes engine cylinders have a special coating, which is why these engines last so long. The person re-building the engine lived here in Southern California and said that there were only a few shops here that could do that coating and the cost was around $2K. I'm an old dog learning new tricks and just finished taking some Machinist classes. In fact, I'm starting a new job as a CNC Machinist on Monday. In my studies, I read about a plasma coating that is applied to engine cylinders, to extend their life, which I think is what Mercedes does. I'm wondering which would be better. Boring all cylinders oversize and no plasma coating, boring all oversize and plasma coating or sleeving one with plasma coating?
Only testing would tell, lots of it.
 

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Discussion Starter #74
Just got home after the day from hell dealing with an ISP... problem still not resolved. I've tried many times in the past to get the company I do consulting for to approve me bringing in a backup ISP (perhaps satellite) for just these kinds of cases where they are at risk of a single failure point. Customers get pissed when they can't get in touch with the people to whom they are paying money, for among other things... the privilege of getting chewed out if the customer so chooses. We'll see what tomorrow brings but I promise that engine is coming out tomorrow come hell or high water.
 

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Discussion Starter #75
Engine is out of the car and sitting on the ground. No pictures yet because the server I use to receive the pictures from my phone doesn't have Internet yet because Cable Vision doesn't appear to have enough in-field service staff to do the job in a reasonable amount of time. Two days and still no phones or Internet to a business location is unacceptable.

Anyway... the engine came out with no problem. I did it alone and it couldn't have been easier. The load leveler is a must but the crank handle on the Harbor Freight 2 ton load leveler is a joke. I took the plastic handle off and just clamped a vice grip to the part the plastic handle screws into and it cranked fine. Having the dip stick tube in the way didn't help. Later when/if I get Internet back at my company, I'll post the pictures.

Next step... pull off the tranny and mount the block on my engine stand. More later.
 

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Regarding your question about boring out just one cylinder, my gut feel says that the increase in capacity would be so small that that the change in cylinder peak pressure would be within the normal variance caused by differences in compression.
 

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Discussion Starter #77
I was thinking more along the lines of the greater mass of a 30 over piston but your analysis probalby holds true in both cases.
 

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The accepted practice is to have all bores equal. The 0.5mm oversize will incease the displacement of the 88 mm bore cylinder by about 1.1%, how this would affect this engine's operation is anybody's guess unless some one has experience with it. The oversize pistons I am familiar with from HD diesels have the same weight classification as the std size, as these need to be matched to the existing crank counterweight masses. The higher speed of gas car engines make even a slight imbalance a bigger problem, so the weight of the std and OS pistons should be the same. A bigger problem of only doing one cylinder is how to handle the others. You can't just put new rings in a used bore, and there is no way to just "lightly hone" the silicon embeded aluminum bores of this engine like what is sometimes possible for a traditional cross-hatch iron bore. These use what we used to call a "hone-lap" process (described quite well in service document 01-112), therefore for this engine I think it is all or nothing for all of the bores. It would be a shame to do all of this work and then have high oil consumption or other problems afterward.
 

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It seems that sleeving is a possibility since aluminum's expansion coefficient is greater than steel. You would be plowing new ground, but it seems the easiest way to repair one cylinder to original bore.
 

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Discussion Starter #80
I must assume that any machine shop that is knowledgeable with the Mercedes coating would know which is the best option. All I can do is ask the experts and go with their recommendation.
 
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