Topic: Honing

[74750k4]

Put 3000 miles on freshly honed sleeves and new rings. Tore it down. Sleeves appear polished now, no sign of honing swirls. No scoring anywhere. No smoke at all, seems to be sealed quite well. It was broken in WOT 7K-10K, up steep hills.  Here's the question...
Do I need to re-hone, or just pop it back together again???

[KRONUS0100]

just asking why the tear down?  leak?   if it ran good with good compression before tear down, clean and wipe everything with oil on reassembly.  should be good to go.   ive seen motors in all kinds of vehicles and equipment where the hone marks were visible or not visible with wide ranges of mileage.  as long as they seal for compression, run em.

just my 2 cents from diesel and auto mechanic

[Ujeni]

If it were me and I had gone through the trouble of taking the engine apart, I would definitely hone the cylinders again. It shouldn't need too much.

[KJ790]

If I had it that far I would give them a quick hone to break any glaze and assemble it with new rings on the pistons. That's a lot of work to risk having a set of rings not seat correctly upon reassembly.

[70CB750]

Why hone?  Or are you swapping rings around?  The rings are already seated and 4 stroke engine rings rotate on pistons anyway, why would you take more material of the cylinder?

[lucky]

You MUST re hone the cylinder walls!! It does not remove much material.

If you just put the same rings back into the cylinders it will smoke.

Also I would not re use the same piston rings.

You can but I would not.

[lucky]

Why hone?  Or are you swapping rings around?  The rings are already seated and 4 stroke engine rings rotate on pistons anyway, why would you take more material of the cylinder?

The rings do not rotate very much at all .
That is why when you put the engine together you space the rings 120º apart.
The cylinder walls should at least have a hatch pattern with a dingle ball hone,minimum. IF you do not do that it will smoke.

[70CB750]

For new rings, yes.  For old rings I don't see a reason  - but I believe ring rotates on pistons 

[754]

Wether they rotate or not , they are spaced that way to get maximum compression..

For a shop situation,yes replace rings.. The labour cost to redo offsets the price of rings.
 
 Doing your own work.. You decide. If it can be done with motor in frame, its not as much work. . But the same piston and rings going back in same hole..how much has changed there?
That said, i have pulled a topend off one motor, installed  on another motor, and it ran fine.

[Powderman]

Spacing rings 180* is BS because they do rotate during use. I have always suspected this and it has been confirmed by the Institute of Diagnostic engineers.
This article sums it up:
http://www.diagnosticengineers.org/journal_%20articles/Ring%20Gaps%20vs%20Knowledge%20Gaps.php

There is also interesting theory on how not critical ring gap is. ring gap has no bearing on blow by (or minimal at best). They found little if any difference in blow by and oil consumption whether the gap was .015 or .0625. As the ring goes up and down it wears the the surface, as this surface wears the gap continues to enlarge. As it enlarges it loses the tension against the wall. It is this process that causes blow by and oil consumption.
I'm so pissed that so much of what they taught us in school back in the day (I'm 60) has been proven to be total bull#$%*.

[754]

Like i said it gives maximum compression at startup, and during breakin..maybe..

[KJ790]

For new rings, yes.  For old rings I don't see a reason  - but I believe ring rotates on pistons 

If you pull the cylinders and then try to reuse the rings then your chance of them not sealing properly goes up quite a bit. There are people that have gotten lucky doing this, but there are many that have tried only to have one or two cylinders burning oil. Rings are way cheaper than my time, so to me it is not worth the risk of them not sealing again.

[Powderman]

For new rings, yes.  For old rings I don't see a reason  - but I believe ring rotates on pistons 

If you pull the cylinders and then try to reuse the rings then your chance of them not sealing properly goes up quite a bit. There are people that have gotten lucky doing this, but there are many that have tried only to have one or two cylinders burning oil. Rings are way cheaper than my time, so to me it is not worth the risk of them not sealing again.

If you pull the piston from the bore and put it right back in what has changed to cause it to no longer seal?

[70CB750]

Spacing rings 180* is BS because they do rotate during use. I have always suspected this and it has been confirmed by the Institute of Diagnostic engineers.
This article sums it up:
http://www.diagnosticengineers.org/journal_%20articles/Ring%20Gaps%20vs%20Knowledge%20Gaps.php

We read the same stuff

[Powderman]

Like i said it gives maximum compression at startup, and during breakin..maybe..

With the emphasis on "maybe" . Who cares what it is at start up and breakin when it won't be the same in real world use?
While gas and pressure may get by the gap on the first ring it doesn't have time to navigate through the second ring gap while this is happening at a rate of every 1/100 of a second.

[lucky]

For new rings, yes.  For old rings I don't see a reason  - but I believe ring rotates on pistons 

If you pull the cylinders and then try to reuse the rings then your chance of them not sealing properly goes up quite a bit. There are people that have gotten lucky doing this, but there are many that have tried only to have one or two cylinders burning oil. Rings are way cheaper than my time, so to me it is not worth the risk of them not sealing again.

Some people have to learn the hard way.

[lucky]

Spacing rings 180* is BS because they do rotate during use. I have always suspected this and it has been confirmed by the Institute of Diagnostic engineers.
This article sums it up:
http://www.diagnosticengineers.org/journal_%20articles/Ring%20Gaps%20vs%20Knowledge%20Gaps.php

There is also interesting theory on how not critical ring gap is. ring gap has no bearing on blow by (or minimal at best). They found little if any difference in blow by and oil consumption whether the gap was .015 or .0625. As the ring goes up and down it wears the the surface, as this surface wears the gap continues to enlarge. As it enlarges it loses the tension against the wall. It is this process that causes blow by and oil consumption.
I'm so pissed that so much of what they taught us in school back in the day (I'm 60) has been proven to be total bull#$%*.

I was taught 120º piston ring gap offsets.
But remember we are talking about engines that ARE 40 years old. Not a modern Toyota car engine burning 65:1 fuel ratios with direct injection into the cylinder head and all computer controlled with 9 different inputs and varible valve timing with molybdenum inserts in the compression rings.

[74750k4]

Well the reason for the teardown is to change the cam to a WebCam 61 so it will idle once again, and also to replace the base gasket (a bit too much thickness)with a CycleX MLS . I also found out my new aftermarket chain tensioner small roller was torn off, and the chain was rolling on the hub. Yikes! It was purchased from CB750parts.com Part #: 05-8008 might use caution on that one. Trying to find a racing tensioner arm/rollers. CycleX is currently out of stock.


Looks like the consensus is to Hone, or not, depending on what you believe!   I'm getting used to pulling the engine, so I think I might slap those cylinders right back on. If it smokes, well, I learned something, right?

[lucky]

Well the reason for the teardown is to change the cam to a WebCam 61 so it will idle once again, and also to replace the base gasket (a bit too much thickness)with a CycleX MLS . I also found out my new aftermarket chain tensioner small roller was torn off, and the chain was rolling on the hub. Yikes! It was purchased from CB750parts.com Part #: 05-8008 might use caution on that one. Trying to find a racing tensioner arm/rollers. CycleX is currently out of stock.


Looks like the consensus is to Hone, or not, depending on what you believe!   I'm getting used to pulling the engine, so I think I might slap those cylinders right back on. If it smokes, well, I learned something, right?

To hone the cylinders is NOT a big deal, it only takes a few seconds on each cylinder with a dingleberry hone. Use a 1/2  inch drill.

[Gordon]

You MUST re hone the cylinder walls!! It does not remove much material.

If you just put the same rings back into the cylinders it will smoke.

The rings do not rotate very much at all .
That is why when you put the engine together you space the rings 120º apart.
The cylinder walls should at least have a hatch pattern with a dingle ball hone,minimum. IF you do not do that it will smoke.

You state all of this like it's a fact, but it absolutely is not.  My experience proves this.  I have re-used the same rings on half a dozen engine rebuilds, after measuring to make sure they're still in spec, and have not once had an issue with smoking afterwards.  I'm not saying it would never happen, but it is far from a foregone conclusion, and as long as the ring end gap is in spec there is no good reason to believe that putting the same parts back in will cause a problem. 

I'm guessing this belief that one must always replace the rings and hone the cylinders after the top end has been removed started back with older cars, and it may have been true at that time and for those engines, but it doesn't translate directly to these engines.

I'm a big advocate for doing what you want to your own bike, and I do a lot of things to my bikes that may or may not be necessary just for peace of mind, but it bothers me when an opinion or personal preference is stated as being a fact or as mandatory for proper functioning of a bike.   

[Powderman]

Spacing rings 180* is BS because they do rotate during use. I have always suspected this and it has been confirmed by the Institute of Diagnostic engineers.
This article sums it up:
http://www.diagnosticengineers.org/journal_%20articles/Ring%20Gaps%20vs%20Knowledge%20Gaps.php

There is also interesting theory on how not critical ring gap is. ring gap has no bearing on blow by (or minimal at best). They found little if any difference in blow by and oil consumption whether the gap was .015 or .0625. As the ring goes up and down it wears the the surface, as this surface wears the gap continues to enlarge. As it enlarges it loses the tension against the wall. It is this process that causes blow by and oil consumption.
I'm so pissed that so much of what they taught us in school back in the day (I'm 60) has been proven to be total bull#$%*.

I was taught 120º piston ring gap offsets.
But remember we are talking about engines that ARE 40 years old. Not a modern Toyota car engine burning 65:1 fuel ratios with direct injection into the cylinder head and all computer controlled with 9 different inputs and varible valve timing with molybdenum inserts in the compression rings.

The point is what we were taught 40 years ago is BS. Ring gap spacing has no bearing on anything at all and the ring gap is much less important for the same reasons.

[PeWe]

I believe in too small ring gap must be avoided.
If no hone marks are visible...it's easy to use a Flex-hone brush 5-10 seconds fast up-down-up.... in each hole.

I also believe in the hard break in.  I read an article written by a guy at a university that compared the hard and old school soft break in by practical tests.
The harder was better with no leak. The article related to this site.
http://www.mototuneusa.com/break_in_secrets.htm

The best method is to alternate between short bursts of hard acceleration and deceleration. You don't have to go over 65 mph / 104 kph to properly load the rings. Also, make sure that you're not being followed by another bike or car when you decelerate, most drivers won't expect that you'll suddenly slow down, and we don't want
anyone to get hit from behind !!

The biggest problem with breaking your engine in on the street (besides police) is if you ride the bike on the freeway (too little throttle = not enough pressure on the rings) or if you get stuck in slow city traffic. For the first 200 miles or so, get out into the country where you can vary the speed more
and run it through the gears !

I can drive my bike as I want from the very beginning. (My bike is soon ready for start-up)

[Powderman]

I asked my engine builder about break in miles and he told me to ride it like I race it right out of the box.

[iron_worker]

If you're re-using the same rings and going into the same bores (un-honed) then absoltely nothing has changed. Why in the heck would you need to hone the cylinder walls to get the rings to seal if they are already sealing fine? Seems like a load of horse crap to me.

The honing leaves a semi rough finish to create some friction with the rings. The friction allows the rings to wear into the cylinders (somewhat like lapping) giving both surfaces very close to the same shape. For new rings I think it is necessary but if you haven't changed the rings then whhhyyyy?!

Also, I'm almost positive that the rings will rotate within the cylinders after the piston makes its several million cycles up and down. So I'm also on the bandwagon of ring gap spacing is a load of crap as well. Having too small of a ring gap however is very very bad. Things expand with heat and if that ring gap closes up and continues to expand it has no where to go but out into the cylinder wall. There will be a LOT of excess friction and heat and you will score the cylinder walls and possibly seize the engine.

IW

[74750k4]

I think one thing is certain...   honing is going to cause a bit more wear, and friction. Necessary? Maybe, but doubtful, since they (cyl/rings) just got put through all that during the first hard driven 3000 miles.

When it's all back together again, we will see, and I will give a report.

Thank you all for opinions/facts, and Happy HS.