Re: Bad Moped Engine Brake-in Advice from Mikey the retard

#CrazyWayne™ rocks. #CrazyWayne /

Nothing is round

Re: Engine Brake-in Advice from qualified authority

Ha ha "They are only round when installed". The tension only appears to be concentrated in the ends. Once the ring is in the cylinder the tension is for all practicality even all the way around. If the ring gap were say 1" in a 3" bore then there would probably be more tension on the ends but as you know ring gap is typically .008 to .012. The pressure of the ring to the cylinder wall isn't equal on a new ring because it is not broken in and doesn't touch the wall all the way around. I am not sure how you could see the light in the gap of a ring to cylinder if the back lighting into your eyes from the cylinder is so glaring compared what small light would coming through the ring to cylinder wall gap.

Re: Bad Moped Engine Brake-in Advice from Mikey the retard

Mikey Antonakakis /

Crazy Wayne™ rocks your Mom's sister's niece's daughter's grandma Wrote:

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> Nothing is round

Not even my belly after eating Hungry Man #2 at the local diner????

Re: Engine Brake-in Advice from qualified authority

What happens if you have a moly filled ring ? Lapping a plated ring or a hard faced ring will not do much but put wear on the cylinder. Some rings are hard to even mark with a file and can't be broken by hand.

You should call Dawn at Hastings and ask her. She has been running the engineering dept for about 40 years. Call 800-776-1088 and ask for Dawn in engineering, she is happy to help. I don't think there is a more knowledgeable person to talk to about piston rings.

As far as ring tension when installed, you should read the book I mentioned. You can calculate the ring pressure against the cylinder wall at any point along the ring. It is not close to even. Just put a new ring in a worn bore and the ring end gap will position it's self at the most worn area. This is because the pressure is greatest at the ends.

I noticed the information from a "qualified authority" mentions iron cylinders and nikasil plated aluminum, what about nikasil plated iron ?

Pete

Re: Engine Brake-in Advice from qualified authority

Matt Mahloch -- MBM Customs /

I just tried a new method for me, I've always heat cycled then took it easy, but when I just replaced a piston I did a couple heat cycles, then got it in the pipe at about 8k, hit the brakes and held it wot until it got hot, did this a few times and blasted, no problems. Actually runs better then before.

Re: Engine Brake-in Advice from qualified authority

Yes dear readers if you are going to lap a moly ring of any type be gentle but then I say this a bit tonque in cheek because you are only going to lap it until it has the 'Look' all the way around anyway. And don't try lapping a hardened ring to cast iron. If I really cared I probably wouldn't put hardened rings in a iron cylinder. Lapping a hardened ring to a Nikasil type coated bore is fine although you will be at it for awhile.

You might ask yourself how this all relates to mopeds. Most lesser kits will have cast or nodular iron rings used either against cast iron or nikasil. The more narrow rings you see in the better kits are in the least steel of some kind. The bores in the better kits are always a Nikasil type coating over alu. And I am fairly certain that's all you will run into. I and maybe one other guy in all of Mopedom lapps in rings. We don't do it because we have to. We do it just for a faster more positive break in. During break in on your overstrung little sizzling hot 2 stroke hot still burning gasses can blow by an unseated ring heating the piston up to cause enough expansion for seizing. Lapping is just for the impatient to break in who also worries some 2 stroker. For the rest of you all know that you don't want to get her too hot for break in or you may seize so just break it in hard but not sustained hard. You might ask yourself that why in a perfectly round cylinder with a perfectly round ring in this wonderful you would even have this problem. I hesitate to shatter your paradigm but commonly made rings are not round. Come to terms with this and you will be able to get a good nights sleep

Re: Engine Brake-in Advice from qualified authority

Mikey Antonakakis /

Pete, if you're referring to my original post in this thread, I believe Mr. Thiel was working with nikasil/aluminum.

Re: Engine Brake-in Advice from qualified authority

What keeps the abrasive particles from embedding in to the soft moly? I can dent the moly with my fingernail. The only thing keeping the moly there is a groove in the ring that it sits in.

It is best to mismatch the surface/metal types for longest life of the bore and ring, just like gears, bushings, and other metal parts that wear together. The only possible cylinder/ring exception is cast iron which is somewhat self lubricating.

It is very common to have hard chrome rings in an iron cylinder and last for years, longer than iron on iron.

Most manufacturers (BMW included) only use iron rings on a nikasil bore because the hard rings may not seat and oil consumption will result. Lapping a nikasil bore is a no-no because abrasives are the only thing that ruin the coating. If you must lap your rings, make a truing sleeve with the same bore size. Actually small displacement engines suffer much less from blow by than bigger engines because of more ring area, and reduced time to leak. We assemble a nikasil bore with no lubrication, or just WD40. It is recommended by many manufacturers for proper seating of the rings.

The gasses blowing by the rings are so minimal that it is insignificant in a properly fitted assembly. If they were significant something is wrong. The ring end gap is a huge hole that allows 100x more blow by than anywhere on the face of the ring. You could not have an end gap if rings needed lapping in.

If you put the ring in the cylinder and hold it up to a bright light any gap will show as the light is very thin. A gap smaller than 0.0001" can easily be seen by this method.

You really need to look at engineering information for piston rings to see the pressure distribution is not equal around the ring. Look at SAE papers and ring engineering manuals.

Here is a link to information on ring pressure distribution and you can see high pressure at the ring ends.

http://www.federalmogul.com/en-US/Media/Documents/18AachenerKolloqium_FM3D.pdf

Rings are made round, the pressure distribution gives the illusion that they are not.

Repairs to iron cylinders now include nikasil on iron so it is something that appears more and more.

Pete

Re: Engine Brake-in Advice from qualified authority

Just a little anecdote: When I was in school just the mention of Perfect Circle Piston Ring brand would cause snickering and chuckles.

Re: Engine Brake-in Advice from qualified authority

#CrazyWayne™ rocks. #CrazyWayne /

Do Ring land porting or use a dikes ring. and blast hard when the cylinder is warm to the hand = 110f to 120f or 1 min of put put 5K riding.

1st run.

WOT to 7K use brakes to hold RPM/speed @ WOT for 20 seconds, put put at 5K 20 seconds, kill and let cool 20min in shade.

2nd run.

WOT to 7K use brakes to hold RPM/speed @ WOT for 40 seconds, put put at 5K 40 seconds, kill and let cool 20min in shade.

3rd run.

WOT to 7K use brakes to hold RPM/speed @ WOT for 60 seconds, put put at 5K 60 seconds, kill and let cool 20min in shade.

4th run.

WOT to 8K use brakes to hold RPM/speed @ WOT for 20 seconds, put put at 5K 20 seconds, kill and let cool 20min in shade.

5th run.

WOT to 8K use brakes to hold RPM/speed @ WOT for 40 seconds, put put at 5K 40 seconds, kill and let cool 20min in shade.

6th run.

WOT to 8K use brakes to hold RPM/speed @ WOT for 60 seconds, put put at 5K 60 seconds, kill and let cool 20min in shade.

7th run.

WOT to 9K use brakes to hold RPM/speed @ WOT for 20 seconds, put put at 5K 20 seconds, kill and let cool 20min in shade.

8th run.

WOT to 9K use brakes to hold RPM/speed @ WOT for 40 seconds, put put at 5K 60 seconds, kill and let cool 20min in shade.

9th run.

WOT to 9K use brakes to hold RPM/speed @ WOT for 60 seconds, put put at 5K 60 seconds, kill and let cool 20min in shade.

10th run.

WOT to 10K use brakes to hold RPM/speed @ WOT for 20 seconds, put put at 5K 20 seconds, kill and let cool 20min in shade.

11th run.

WOT to 10K use brakes to hold RPM/speed @ WOT for 40 seconds, put put at 5K 40 seconds, kill and let cool 20min in shade.

12th run.

WOT to 10K use brakes to hold RPM/speed @ WOT for 60 seconds, put put at 5K 60 seconds, kill and let cool 20min in shade.

13th run.

WOT to 10K hold RPM/speed for 5 min, put put at 5K 20 seconds, kill and let cool 20min in shade.

Repeat steeps 6 thru 13.

WOT under load will seat the rings faster. (edited)

Re: Engine Brake-in Advice from qualified authority

So I checked out the Federal Mogul site and it only shows maybe 3% of the circumference with a different ring pressure than the rest. I thought you meant maybe 18%. You are right that the ends are under higher pressure but it is very localized and its indicative of a in round ring that goes out of round when compressed into its new circumference. You can see in the illustration that the ring pressure is for the most part equal almost all the way around.

On a different note Pete, In your machine shop what kind of cutters do you use on the really hard cold quenched steel parts you run into? Carbide aint doing for me. Are the ceramics the best bet?

Re: Engine Brake-in Advice from qualified authority

We have a motorcycle shop and do machine work as part of the package. I have cut car axles with ceramics when carbide was not enough. I think ceramics are good on steel with a hardness up to Rc65. It seems really odd when chips fly off and burn in the air. No interrupted cuts and no light skimming cuts or you will destroy the ceramic. Some grades of coated carbides are used for materials up to Rc65 also.

Of course, there is the grinding option, that's what I do when I have to cut ceramics. What type of cut do you have to make ? A flat surface might be best ground, but grooves and other shaped surfaces might be best with ceramics. I made a tool holder for a 1/4" die grinder and can mount a cutoff tool on the lathe. The right thickness cutoff wheel can even make snap ring grooves.

Parts can be thrown in the wood stove until red hot, then thrown in a garbage can of ashes to anneal it. Machine it soft and re-harden. Sometimes this is the easiest method, but not possible on some parts.

CBN is an excellent grinding material that wears very little and can be used dry. It is used for machining bits also.

What are you machining?

Do you know the hardness?

What type of cut do you need to make?

How much money is budgeted?

What machine are you using?

With a little more detail I might be able to help more.

Pete

Re: Engine Brake-in Advice from qualified authority

Thanks for your kind response. I am not currently up against a hardness issue right now. I have resorted to annealing in the past but then when I re harden I am a bit concerned I've made it too brittle. I have no Brinell or other tester. All of which to date has not been a problem because of the low value of what I work on. I will at some time confront a valuable part. I have a mid sized Grizzly Chinese lathe. I was apprehensive about the Chinese make but some older machinist assured me they had made great strides over the recent years. I perfectly happy with it. For twice the price I could have had a thoroughly worn out Jet or whatever. I am going on about it not for you but for the other readers here that they can have a very effective but not perfect lathe for cheap. I don't use the term effective lightly and I reserve perfect for large heavy machines. Am keeping a look out for a 1 ton or less mill. For those who could use a machine it helps to make the leap when you realize you can re-sell them on Craigs for close to what you paid for the new ones and the same of what you paid for the used ones

Re: Engine Brake-in Advice from qualified authority

I like to help even if I don't always agree with everything. You seem very nice and kept our disagreement civil, I respect that. Just remember I like to argue.

I have a Grizzly mill bought new. It was a good decision for our shop. If you used it every day for production work it might be different.

A little practice and study and you will harden the parts exactly the way you want. No hardness tester needed, color and procedure are all you need.

Pete

Re: Engine Brake-in Advice from qualified authority

Mikey Antonakakis /

Pete, you're the man. Thanks for contributing.

peter heid Wrote:

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> I like to help even if I don't always agree with

> everything. You seem very nice and kept our

> disagreement civil, I respect that. Just remember

> I like to argue.

>

> I have a Grizzly mill bought new. It was a good

> decision for our shop. If you used it every day

> for production work it might be different.

>

> A little practice and study and you will harden

> the parts exactly the way you want. No hardness

> tester needed, color and procedure are all you

> need.

>

> Pete

Re: Engine Brake-in Advice from qualified authority

here we go with on of the most controversial topics...

Re: Engine Brake-in Advice from qualified authority

#CrazyWayne™ rocks. #CrazyWayne /

joe muncey Wrote:

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> here we go with on of the most controversial

> topics...

Speling and gramer?

Re: Engine Brake-in Advice from qualified authority

I didn't read this whole thread, but I run 4 thou ring gap on all

rings. Maybe more if you have two and worried.

Re: Engine Brake-in Advice from qualified authority

Overpriced Parts /

7-8 thou

Re: Engine Brake-in Advice from qualified authority

Well this certainly narrowed down the breadth of this discussion. Thanks!

Re: Engine Brake-in Advice from qualified authority

I would like to offer my experience on the subject these days considering I am doing the whole 125 track bike thing after owning mopeds

Bottom end break in is different from top end break in

Bottom end break in is slow and sweet with multiple heat cycles.

Top end break in new cylinder etc involves two heat cycles and then go racing

Top end break in new piston only involves 1 heat cycle consisting of two laps at 75% load and 75% peak rpms reached

Top end break in new piston ring only = go racing

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