and the answer to the questions is? I am using grey cast iron rings (not ductile iron or steel). I have a cylinder bore surface of 150 grit (max 220).
I am using ductile iron or steel rings (not grey iron). I have a cylinder bore surface of 280 plus grit that has been prepared with boring and honing plates.
I don't know!
I washed my cylinder in hot soapy water and scrubbed the surface with an sligtly oily clean white rag. I rubed the surface until no more grey honing residue comes off on the rag. I spent ten minutes or more on the two bores.
I washed the cylinder in the parts washer.
Break-in starts with knowing what rings you have and preparing the cylinder to accept them. Do things right and the oil used isn't as big an issue as when you don't.
Certain types of oils will help with break-in, but getting the bits right in the first place is whole lot more important.
Castrol 10/40.... Hmmmm interesting :rolleyes:
Re: breaking in rings#131481 12/27/075:47 pm12/27/075:47 pm
Interesting topic: break-in oil. Waiting to see opinions.
Mine is avoid oil with friction modifiers like Moly. That is tricky though, as manufactures change. Do they rally list what they put in? Modern auto oils have friction modifiers to increase gas mileage, and lighter weight ones are more likely to have them like 5-30 10-30, and maybe 10-40.
I think Walmart has its own brand oil, which I have been told has none, but it probably has a lot of wax, because it is made from cheap base oils. So would it make sludge to fill a clean sludge trap? I dunno. It would not be in there long, but I do not like the sound of the wax. One article said that you might as well melt a candle into your oil.
Maybe a diesel oil would be best. 15-40. Good base oils, and no moly, plus having zinc for the cams.
If you could go back in time and buy a case of oil of quality oil made from good base oil that was SG rated that would be nice, but quite impossible.
So the Walmart oil, or K-mart or whatever is SG only but what base oil group is it made from? I dunno. It is real cheap so I suspect not good base oil.
As of right now, that is all I know. I am interested to hear the opinions of experts.
Bob, Lifetime bike: '71 T120R, bought in '71 at Ken Heanes, England.
Re: breaking in rings#131483 12/27/076:46 pm12/27/076:46 pm
Expert`s opinion precedes your post. Every point mentioned by John is worth remembering if you rather have your rings broke in properly. I start the bike on the mineral diesel oil ( 15W40 ) which I change after first 60 km. I didnt baby my engine during this trip, just try not to overheat it.
Re: breaking in rings#131484 12/28/0712:43 am12/28/0712:43 am
Bond: Hepolite R11050 rings answers half of the question: cast iron rings.
The second answer is needed as we are at a fork: a. the cylinder was prepared for cast iron rings. b. the cylinder was prepared for ductile iron or steel rings.
If a. then your choice of oil, type of assembly technique, and break-in procedure is less problematic than if the choice is b., where and you might try to save the situation by using SG or other era oil, drier assembly techniques, and a rather aggressive break-in.
So why the problem? Ductile iron and steel rings are designed for modern WATER COOLED motors were the dimensions of the cylinder are prepared, and through elaborate engineering of the coolant system, maintain a perfectly round and true cylinder. It is in this world where you start to hear talk about narrow rings, total seal rings, and low ring tension, but this is another story.
Trying to break cast iron rings in on bores that were prepared for ductile iron or steel rings can be plagued with problems. There is even a chance they will never seat.
Grey cast iron rings, although used in some modern applications, came about in the day when, even though most cylinders were water cooled, engineering and manufacturing techniques could not produce a perfectly round and true cylinder and maintain this accuracy through assembly and use.
Think about our vertical air cooled twin cylinder, bolted to a crankcase that has a .010" step between the crankcase halves at the crankcase mouth, the crankshaft isn't at perfect right angles to the cylinder bore, the wrist pin and crank bores in the connecting rod are not parallel, etc..
Think about it and your perfectly round - HARD faced modern narrow low tension ductile iron ring.
Oh, I almost forgot the most important bit... the air cooled cylinder. So picture in your mind this perfectly round cylinder, honed so you can almost see yourself in the smooth finish (600 grit), that has the engineering to stay perfectly round no matter what you do to the motor. For example, if the cylinder starts to get hot when you lug the motor and is near detonation. The computer retards the timing on that one cylinder, puts more gas in the one cylinder or just shuts it off until it cools. Meanwhile that super efficient cooling system goes to work and quickly draws heat away allowing the cylinder to stay round and true.
Now you lug your AIR COOLED vertical twin. That perfectly honed nearly round and true cylinder starts to get hot. Hopefully you are not sitting still and that cool air hits, and cools the front of the cylinder. It flows freely around the outside fins and heats the air behind the cylinder. Meanwhile the rear and middle of the cylinder get no such rush of cooling air. (look at the pins of the pistons recently posted on this forum) the pins are showing that the inside of the piston got hotter than the outside... Even a basic understanding of iron castings is going to tell you the cylinder is not going to maintain that perfectly round true bore. Picture your perfectly round chrome plated ductile iron ring inside this distorted bore.
So now you have a grey cast iron ring that wasn't manufactured PERFECTLY round (it didn't need to be and remember it needs to be broken-in, which with these rings means made to mate with an imperfect cylinder) in a bore that is hone super smooth and distorted from heat. Two things start to happen: a. oil gets by the rings into the combustion chamber and lower the effective octane rating of the incoming gas... increase chances for detonation. b. The rings, having not broken-in do not have full contact with the "cooling" cylinder (75% of the heat in the top of the piston is removed through the contact of the rings with the cylinder). This increases both the heat in the top of the piston (increasing the chances of detonation) and the heat has no choice but to migrate down below the rings (where it should not be if rings are doing their job) and the pistons expands to be bigger than the bore - seizure results.
So, my point: cylinder finish, and over all cylinder preparation, should be matched to the rings AND engine design (cooling) being used. The only control you have over detonation in your old air cooled motorcycle engine during break-in is your shift lever and throttle.
Understanding this and using an appropriate assembly techniques can over come a lot of the problems. I once thought it was all about the new oil, but oil is only part of the problem. Modern oil combined with modern cylinder preparation (220 grit or higher cylinder surfaces - including planar honing) must be looked at together.
There are those who will jump in here and say that they have used steel or ductile rings in their racer, BUT I MUST remind them that they seldom LUG their motors, and that they run the motors at an rpm where detonation does not have time to happen. It's a different deal on a street motor unless the owner is 18, has a lot of testosterone to burn and likes to see 7,000 on every shift.
Guys, both Kevin Cameron and myself have been presenting articles about all this in Vintage Bike for the past ten years. It is hard in a couple of paragraphs to try to get you thinking about modern oil, modern gasoline, modern engine design and related parts like low tension steel rings. While you will read in current literature, and here about from your informed friends and automotive machine shops, about all this new and wonderful technology it must be understood that not all of it relates to an air cooled verticle twin. Even Kevin admits that he is still learning about what can be adapted from the modern technology pallet and what cannot. Grey cast iron rings running on modern planar honed 600 grit cylinders in an air cooled verticle twin is NOT one that can be used with any guarantee of success no matter what oil you use. John And thank you Steve Prince, and may you all have a healthy new year!
Re: breaking in rings#131488 12/28/074:56 pm12/28/074:56 pm
Dear Mr Healy. Did I note you forgot to mention the Norton bores that are not parallel with each other?? Mind you If you had seen the barrel boring jig at Aerco Tool and Jig shortly after Norton finally died you would understand why........It couldnt even produce std bores correctly!! Mind you overbored 850 barrels were VERY cheap if you wanted to go straight to plus 10 (if lucky) or plus 20 (If not lucky).......
Re: breaking in rings#131489 12/28/075:01 pm12/28/075:01 pm
There is one bit, though, that presents a logical question, not necessarily limited to break-in, but more post break-in.
The question concerns this phenomena: "Even a basic understanding of iron castings is going to tell you the cylinder is not going to maintain that perfectly round true bore".
If this happens, then it is an on going dynamic and not limited to break-in. Thus the bore will always be changing shape, even if the rings have seated, and some oil is going to get past, and some heat the other way.
This assumes that once the rings have broken in, the bore has smoothed and glazed, they are not going to continue to adjust but will maintain, their out of round shape. And also assumed is that once they have worn to the bore in out of round, they will tend not to spin. (pity to poor bloke who was unlucky enough to have them wear in so that the gaps aligned? )
A corollary of the proposition that the bore is going egg-shaped due to the difference in temperature is that the greater the difference, the greater the egg shape. Ergo: riding your brit bike in cold temps, say 23 degrees is not a good thing to do, since you are going to get more distortion, and thus blow by, and oil.
Of course, this logical deduction in no why detracts from what you have pointed out, but indeed adds to it. The best a street rider can do is use the grey rings with the bore properly prepared, and try to break the rings in to "a range" of egg shapes which are going to occur.
Bob, Lifetime bike: '71 T120R, bought in '71 at Ken Heanes, England.
Re: breaking in rings#131490 12/29/073:54 am12/29/073:54 am
When the time comes I will send mine off to SRM for a rebore.
I stripped my bike down and took the rings off the pistons but replaced them in the same order but not with the gaps where they were before. It didn't make any difference so if the bores are an odd shape it must be a minimal problem on my machine.
Re: breaking in rings#131493 12/29/073:24 pm12/29/073:24 pm
I've found that opinions on oil, break-in or otherwise, differ as much as the number of people with opinions. Ditto with run-in procedures. I've seen engines that were run-in gently and those run hard from their first startup that both ran well.
On one end of the spectrum, I worked with an aircraft A&P who would only break in Lycoming engines with Ashless dispersant mineral oil, then run a good mineral based aircraft oil after break in. His engines broke in very well and used very little oil in routine operation. On the other end of the spectrum, Porsche runs Mobil 1 synthetic in their engines from day one. While the modern Porsche's definitely have better tolerance control on new parts than what we have with our Britbikes, the engines still need to be broken in and they do break in with Mobil 1 in the first 1,500 miles. I was always told by the experts that an engine would never break in with a synthetic, but Porsche has proven that they do.
I suspect that the best advice given above is to ensure that tolerances are the best that you can make them and that the parts are absolutely as clean as you can get them before assembly (minus all sand-blasting, bead-blasting, and honing residue).
Which oil to use though? I'd recommend using any quality, mineral-based oil. But then, that's just my opinion among many.
Re: breaking in rings#131494 12/29/075:03 pm12/29/075:03 pm
Thanks John for all the technical stuff.Just a couple of things i forgot to mention. The set of rings i am installing are the second set, the first set were hastings +20 I ordered when i had the cylinders rebored, in the set was a chrome compression ring none of them seated at all well, i'm not sure what grit the cylinders were honed at after the rebore.The rebore was done by British Only here in Detroit, i assumed they would have given me the correct honing. The cylinders now seem quite smooth although you can still see some of the cross hatching . This time i want to get the honing correct you had mentioned 150-220 grit just wanted to confirm that is correct before i take them in for honing. By the way how much metal is removed during honing keeping in mind they have been honed already after the rebore. Today i found some 30 Weight non detergent oil with a SF rateing for older engines, would this be better to break in the rings initally? Thanks Bond
Re: breaking in rings#131495 12/29/075:30 pm12/29/075:30 pm
One must understand break-in and resultant oil control is relative. Expectations of oil control with air cooled engines and grey cast iron rings vs. modern vehicles designed to use ductile iron and steel rings are vastly different.. Our old air cooled engines, with all their faults, would never pass modern exhaust emission tests. Instead of using monikers as parts per million our owners manuals list pints per thousand miles. When was the last time you opened the hood of your modern car and actually check your oil. And if you are a hold over from times past, was the level ever "low?" Compare that experience with checking the oil in your oil-in-frame Triumph, or other British air cooled motorcycle.
Our old motors are designed and expected to consume some oil… It is in the design and production of the engine as a WHOLE. To change this is it is not as easy as putting a 600 grit surface on your cylinders and putting in a set of chrome plated steel rings. Just because your machine shop has modern machines doesn’t mean this is appropriate. Today motors are engineered to be produced on machines that can hold tolerances unheard of when our bikes were manufactured. While the engineers of the day could think about round and true cylinders the machines and metal alloys were not available to turn their dreams into reality.
Engine cylinders that actually get rounder when assembled and heated to operating temperatures are only one engineering adaptation to allow modern vehicles to run "clean." There are automotive machine shops that actually pre-heat the casting and honing oil and hone the cylinder hot. Our cylinders will never be round and a certain amount of oil consumption is expected. It is just that grey cast iron, which can match themselves to the cylinder through what we call break-in, is typically better adapted for our application than perfectly round, hard faced modern steel or ductile iron rings.
Often when an un-experienced enthusiast installs modern rings, or grey cast iron with modern cylinder preparation instead of the 150ish grit finish, initial oil consumption is in the range of quarts per thousand. Amazingly there is very little white exhaust smoke. The only indication that some thing is wrong is oil fouled plugs. Continued use will almost insure detonation and a heat related piston seizure, especially if the motor is lugged.
Again, there are people who use these modern rings and cylinder finishes in these old motorcycles. a.. They are prepared to insure cylinder bores are parallel and at right angles to the cylinder base as well as honed with boring plates and the rest of the motor is checked, often called "blue printing." b. Break-in in the motor in a manner that insures the cylinder pressure is managed (motor not lugged) . c. Be prepared to replace the rings if the rings don’t quickly take control of oil consumption (plugs remain oil free). This requires the ability to determine if the spark plugs are oil or gas fouled… and for a lot of people this seems not to be as easy as people make it out to be. John
Steve while I agree with you about using mineral-based oil for break-in, which one to use would be based upon what rings are being used, how the cylinder was prepared, and how it was going to be broken in.
I certinly come from the school of aggressive break-in, often taking a brand new Triumph off the sales floor and driving it to Triumph in Baltimore for the first 500 mile oil change. I might ahve ept under 50 for the firs mile or two, but mainained highway speeds for the trip. But that was a differnt time and different oil (SA - SB).
We have been Hepolite (nearly 40 years), JCC, and GPM pistons distributors for the past 30 years. About the time SH oil came on the market we saw an increased occurrence of detonation related heat seizures during the first 50 miles, often with a rider over 50 years old and happening in high gear pulling up a grade or passing (we kept a survey).
It didn't seem matter which piston was being used, but most often the cylinder was prepared with a finish smoother than 220grit and modern oil was being used. It got worse as the MOTOR octane number (not to be confused with pump octane R+M/2) of the available gas fell.
While complaints have decreased when British dealers came to grips with all this, consumer complaints continue as indicated by the frequent posts about piston problems on this, and other forums.
There is cerainly no one way to approach this, but approach it you must or continue to suffer heat related pistons seizures. 30 yers ago there was no choice and honing stones that today are marked on the box as "Roughing" were marked "Finishing." Common hand honing stones AN220 (150 grit) had boxes clearly marked Finishing while today the same AN220 stones are marked Roughing.
I might note that you will seldom find a set of 150 or 220 grit stones in a modern automotive machine shop. They are just not used, or a part of, modern motor cylinder preparation.
So when I asked which rings were being used and how the cylinder was prepared I was not just be a wise axx,,,
Re: breaking in rings#131496 12/29/076:36 pm12/29/076:36 pm
In "popular mechanics" circa 1999 they aquired permission from the city of NY to use the taxi fleet to test engine oils! The test was that each taxi co recieved,free of charge, one yrs supply of oil! each co got a different brand and at the end of the yr each co had their cabs inspected by the mags reps! the finding were that if you are using regular, non-synth dinosaur based oil, that is LEGALLY labeled us being compliant with the society of automotive engineers for the its purpose, then the only difference between them IS THE PRICE!!!!
Re: breaking in rings#131498 12/30/071:09 am12/30/071:09 am
I send all my cylinders to Bore Tech in Ohio. They make the bores round, straight, and impregnate the surface with a super-hard finish, followed by planar (sic?) honing. The modern rings I use seat immediately, have almost no oil consumption and I DON'T HAVE TO TAKE THE THING APART AGAIN FOR A LONG, LONG TIME!
When people who should have known better cautioned me about the dangers of motorcycle racing, I always told them that a fear of death is nothing more than a fear of life in disguise.
Re: breaking in rings#131500 12/30/077:46 am12/30/077:46 am
John, Just for those of us who have been terrified to a standstill by the seeming impossibility of rebuilding our engines by the apparent certainty of high oil consumption and subsequent seizure, can you add some meat to the bones of your survey? Was it all new machines sold that were returned with the problem? All machines you rebored that had the problem? 10% of the machines you rebored, or what? The only oil I can find is Morris 20/50 but I think it is only SH or SJ. All the rest is too new. How about adding some kind of octane improver while we are running in to prevent/deter detonation? Blapper
Re: breaking in rings#131501 12/30/0710:48 am12/30/0710:48 am
I use Duckhams 20W/ 50 or Shell X100. Both are API SF.
When I say I ran in the machine by the book I meant 1/4 throttle for the first 250 miles etc, etc. When I have done this I have had no problems, no smoke, no marks on the pistons. I think that on these forums people come up with all kinds of crazy ideas for running in and the next thing you know the engine has started smoking or worse.
When you get a rebore etc, send your barrels, pistons and specs to a reputable shop and you will be ok. There is no need for all this worry!
Listen to Nick as he has a good story to tell.
Re: breaking in rings#131502 12/30/072:17 pm12/30/072:17 pm