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Old 03-16-2013, 07:41 PM   #166
Plaka
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Originally Posted by Tin Woodman View Post
OK, I broke down and paid the six bucks for new feeler gauges - good point, Bill, about needing thinner ones to set the valves. Isn't it strange I'm still using Imperial measurements when the bike and the country I live in are metric?

Plaka, you'll appreciate this - was having a tough time pulling out the old seal which had been driven completely into the boss - whipped up this little slide hammer in about 10 minutes. Works like a charm.



Visited my local BMW mechanic who has piles of old thrust washers - brought my micrometer and picked a washer with the same spec as the old one. Could feel some high spots on the face so I dressed it with 1500 grit paper and oil on a piece of plate glass. Final result -



Installed new RMS and torqued the flywheel on. Checked the end float and it's a little tight at, believe it or not, .002". Good enough for me - moved the party to a new location.

Getting ready to put the jugs back on. Observations - the obligatory dings in the case from the conrod. Was fully expecting this -



Dressed out the dings and moved on to the cylinder studs expecting the worse. All four studs on the left were at finger tension. Weird because each had vicegrip marks on them -



Threads on the engine case appear to be fine -



Question - should the studs be Loctited when I reinstall? On right side, appears studs have never been removed. Took this opportunity to thoroughly clean engine case where it mates with cylinder. Old aluminum base gasket was devoid of sealant and had apparently been installed dry - was that typical for the 1980s? New base gaskets are only .020" thick compared to the originals of .048" - am I asking for trouble with the higher compression?



Spent some time making sure my torque wrench was calibrated in anticipation of torquing the top ends. Back to the shop for a couple of hours. . .
Definitely like the slide hammer. I do believe I'll copy it, I have a flooring installation problem the proper tool is expensive and the one I rigged up is working poorly.

Worst case the higher compression means you have to run a better grade of gas. But you will also be making more power. Mileage should be the same or better, often better (less throttle required to maintain a given speed with the increased power). You can advance the timing a hair to control detonation if better gas is not available. This hurts power and fuel economy. If you dual plug the heads you can burn anything. You can also just buy some low test base gaskets (the thinner ones.)

On a previous tear down the nuts might have been stuck on the studs and the whole stack threaded out of the case. The vice grips were used on the studs to get the nuts off. Or someone might have wanted to pull the studs for some reason and they were very tight. Who knows. Dress out the marks with a file for the best strength.

The stud install procedure is in your manual. I like a bit of antiseize (that steel to aluminum thing) and I put a tick mark on the stud crown so it's easy to see if it's turning when I torque the nuts.

The specified base gasket sealant was Hylomar. I was never impressed with it and I'm not alone. Seems people are recommending all sorts of other things now. I would try one. I like to buy things that are as multipurpose as possible. I hate having all these tubes around drying up. Sometimes it can't be avoided. Do a pay it forward and give the rest of the tube away is always an option.
Did you have the connecting rods out and check the big end bearing clearance? Did you balance the rods? A mechanic friend of mine says the 60/5 was one of the smoothest of the airheads, but Nothing wrong with obsessing over making it unbelievable smooth.

Speaking of obsessing: The process is one where you spend a great deal of time and attention on one thing to avoid thinking about or otherwise dealing with something else. The 'something else' is something strongly anxiety provoking. Essentially you avoid this by doing that instead. On projects like this you can get into infinite irrelevant details to avoid the stress of getting on with the project or dealing with whatever the next step is. You seem to be doing OK to me.
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Old 03-17-2013, 02:40 AM   #167
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i dont want to diss Diss but some of his advice is incorrect.

The 600s had a real problem with pinging, even when new with the higher octane fuel available back in the day. One of the ways of reducing pinging was to fit the thicker base gaskets, they might even be standard on the 600

I would fit the thicker base gaskets. this will lower the compression ratio and reduce the possibility of pinging. I have in the past used 2 gaskets on top of each other, which worked fine. This was when i was taking a 750 to India where at that time fuel was of very low octane.

Use Dreibond as a sealant. Don't use loctite on the studs, because with the upper studs you will almost certainly block the oil supply to the valve gear. If you want to reduce pinging via the timing you retard the timing you don't advance it.
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chasbmw screwed with this post 03-17-2013 at 02:46 AM
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Old 03-17-2013, 06:17 AM   #168
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Agreed, Chas. As you said, pinging is a problem. The physical compression ratio on the R60/5 is 9.6:1 but the camshaft has an unusual figure with less overlap which further raises the effective compression ratio. Back in the day when 100 Octane, true Ethyl gasoline was available, all was well. But with the advent of Unleaded fuels in the late 70's (and even the unavailability of the Premium, Super grades) pinging on any fuel became a problem. The factory has as a optional part the thicker Low Test Base Gaskets which replace the thinner normal Base Gaskets. They work. By reducing the physical compression ratio to 8.5:1 you can run even unleaded Regular grade fuel. Sure, you take a slight hit on power output and fuel mileage, but all is otherwise well.

Because the cylinder wears and MAY develop a ridge at the top of the piston travel, you may not be able to go back to the thinner base gaskets since the ring will hit that ridge and might break. Clean the carbon ring from the top of the cylinder and feel for a wear ridge with your fingernail. If you feel nothing, you are good to go. If you feel a ridge, hone the cylinder.

But really, even with today's improved fuels, the bike will be prone to ping, so I'd suggest keeping the Low Test bast gaskets.

One alternative is to go with the higher CR and have the heads modified for dual plugs. Which is a whole 'nuther story (and probably thread)... :)

--Bill



Oh yes, Drei Bond, or Three-bond or Hondabond or Yamabond non-hardening, sealant is preferred.


Corrected. Thanks Lornce. This less-is-more situation sometimes confabulates me...
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Old 03-17-2013, 07:39 AM   #169
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Maybe the cure would have been to have fitted a 308 cam!

I posted a query on Boxerworks and a sensible discussion got going.

http://forum.boxerworks.com/viewtopic.php?f=1&t=5969.

Boxerworks is a good forum for airhead stuff.
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chasbmw screwed with this post 03-17-2013 at 07:45 AM
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Old 03-17-2013, 11:39 AM   #170
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Bill, The R60 cam actually has less, not more overlap, than a 308 cam. You are correct however, in that a 308 cam would result in lower dynamic compression.

Plaka, The lower compression base gaskets are thicker, not thinnner. And advancing the ignition timing would only exacerbate the problem. Retarding the ignition timing would actually be required.

I install studs into cases with a pair of nuts torqued against one another (double-nutted) on the top thread to permit lightly preloading the stud threads in the engine case.

Does this create an issue I'm unaware of.

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Old 03-17-2013, 11:48 AM   #171
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Hey, I'm dsylexic.

Honing a cylinder won't remove a ridge, you use a ridge reamer.

The outgoing gaskets were thick so moot anyhows.
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Old 03-17-2013, 12:56 PM   #172
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Gentlemen - I see you'e been taking good care of this thread in my absence. Some interesting banter.

Meanwhile, spent the morning cleaning up pistons and mounting the left jug. Cylinder slipped on nicely and wrist pin went on fine. Question - there is a 3/16" gap between the cylinder base and the engine case. Suspect it is simply caused by the new pushrod seals and torquing the head on will seat these seals and take up the slack. Is this correct or is there another potential source of interference?
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Old 03-17-2013, 01:22 PM   #173
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That sounds like it is normal.

When I was pointing out why there isn't really a reason to measure your rod big end bearings I forgot to point out that balancing rods is a lot more complicated than matching weights. Look into it. It's a tricky operation that takes well set up equipment and even then there is a lot of subjectivity to it. I gave up getting my setup to work last time so I went down to a friends. We closed the door to the shop. Even the slightest breeze can effect the readings. Very touchy!
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Old 03-17-2013, 02:33 PM   #174
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Gentlemen - I see you'e been taking good care of this thread in my absence. Some interesting banter.

Meanwhile, spent the morning cleaning up pistons and mounting the left jug. Cylinder slipped on nicely and wrist pin went on fine. Question - there is a 3/16" gap between the cylinder base and the engine case. Suspect it is simply caused by the new pushrod seals and torquing the head on will seat these seals and take up the slack. Is this correct or is there another potential source of interference?
Tin,
Did you fit new pushrod tubes?

If so did you measure the exposed length of the tube to the face of the washer that bears upon the rubber and have fitted the new tubes so that length is the same?

If not it is possible that if the tubes are installed to the wrong length, then the pushrod rubbers are either over or under compressed. dAMHIKT.
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Old 03-17-2013, 02:45 PM   #175
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Charles, nope, left old tubes on. Good observation, though.

SS, agreed - I'm keeping things as simple as possible. I'll be thrilled to see this thing fire up even if there is a bit of vibration. Can leave the fine-tuning for another time. I'm just trying not to break anything. Went back and read your comments on rings - good stuff!

Doesn't appear to be a ridge so I've opted to use the thinner base gaskets - looks like I'll be running hi-test gas.
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Old 03-17-2013, 02:49 PM   #176
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Gentlemen - I see you'e been taking good care of this thread in my absence. Some interesting banter.

Meanwhile, spent the morning cleaning up pistons and mounting the left jug. Cylinder slipped on nicely and wrist pin went on fine. Question - there is a 3/16" gap between the cylinder base and the engine case. Suspect it is simply caused by the new pushrod seals and torquing the head on will seat these seals and take up the slack. Is this correct or is there another potential source of interference?
Ah, the notorious $3000 air gap...


Make sure the pushrod tube seals are on with the indicator line facing down. The pushrod tubes can telescope into the jug. You pull them back out again with a push rod tube drift to tighten the seals. Tighten things to the 2nd stage and see where you are.
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Old 03-17-2013, 06:07 PM   #177
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Hey, I'm dsylexic.

Honing a cylinder won't remove a ridge, you use a ridge reamer.

The outgoing gaskets were thick so moot anyhows.
Actually that is what I always thought until we had this Japanese four banger come in once that had very heavy ridges. I had a ridge reamer and tried to remove the original metal at the top which I considered the ridge. Turns out this tool or at least the one I owned, a Craftsman Ridge Reamer, was not made for doing this. This tool will remove a Carbon encrustation type of deposit ridge. Not for removing metal.

When trying to remove the metal at the top of the cylinders the ridge reamer would "bite" into the metal and produced a very jagged top portion of the cylinder bore. Needless to say this engine was not usable there after.

I don't think Honing will produce the desired effect either. The proper way to remove a ridge that is metal, not Carbon, would be to have the cylinder bored
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Old 03-17-2013, 06:33 PM   #178
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Just trying to keep it real but I have never seen pushrod tubes telescope into a cylinder unless I was beating on them pretty hard with a hammer. The pushrod drift tool moves the tubes compression rings, not the tube itself.
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Old 03-17-2013, 06:41 PM   #179
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Actually that is what I always thought until we had this Japanese four banger come in once that had very heavy ridges. I had a ridge reamer and tried to remove the original metal at the top which I considered the ridge. Turns out this tool or at least the one I owned, a Craftsman Ridge Reamer, was not made for doing this. This tool will remove a Carbon encrustation type of deposit ridge. Not for removing metal.

When trying to remove the metal at the top of the cylinders the ridge reamer would "bite" into the metal and produced a very jagged top portion of the cylinder bore. Needless to say this engine was not usable there after.

I don't think Honing will produce the desired effect either. The proper way to remove a ridge that is metal, not Carbon, would be to have the cylinder bored
I'm using one of these:

http://www.amazon.com/Lisle-36500-Ri.../dp/B000P0ZK1O

it rides the bore on w rollers. The cutter floats and is guided by a plastic bad. it's a carbide cutter and it cuts cast iron very nicely. No chatter.

if a bore is worn enough to have a metal ridge it's worth measuring up for a bore job and oversized pistons---unless it's a toyota truck then you just ridge ream it, throw in fresh rings and drive it another 250,000mi.
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Old 03-17-2013, 07:09 PM   #180
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I'm using one of these:

http://www.amazon.com/Lisle-36500-Ri.../dp/B000P0ZK1O

it rides the bore on w rollers. The cutter floats and is guided by a plastic bad. it's a carbide cutter and it cuts cast iron very nicely. No chatter.

if a bore is worn enough to have a metal ridge it's worth measuring up for a bore job and oversized pistons---unless it's a toyota truck then you just ridge ream it, throw in fresh rings and drive it another 250,000mi.
Having ruined one engine trying to ridge ream it I don't feel up to ever doing it again. When I related the story I was told the "ridge reamer" is not for a metal ridge but for Carbon, only.

You may have different results than I had I'm sure. I going to stick with what I suspect is what works for me.
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