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New (to me) internet myth

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Old 02-08-2012, 08:15 PM
  #26
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Default RE: New (to me) internet myth

Unfortunately I have a few more than I need too, that just means I have more to experiment with porting on, Next I am going to make a pop-up piston and see how that works out. Messing with chainsaws is pretty addicting too.
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Old 02-08-2012, 08:18 PM
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+1
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Old 02-09-2012, 05:36 PM
  #28
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Quote:
ORIGINAL: aussiesteve

I didn't have a need to mention the final measurement / acceptance because I was referring to how the majority (by numbers sold) of RC engines are made (In china mostly). - there they set up for an approximate size, then use pretty much everythign that comes off the line.

A REAL cylinder is made slightly differently.

Casting
Rough Machining
Finish Machining (with a different cutting tool to what was used in the Rough Machining)
Inspection for acceptance / rejection
Plating / Coating (Either Electro-plating of multiple metallic layers with a Chrome alloy as the final run - or with a Silicon Alloying coating such as Nikasil)
Inspection for acceptance / rejection
Final Grinding to size
Finish Honing with fixed hone tooling
Final measurement
Acceptance or rejection
Grading.

Pe - the beauty of such manufacturers as MVVS is that the product is consistently great from one engine to the next - it took me a while to really ''get'' that but once it is experienced, it sure is a nice thing.
What is it about DA and 3W cylinders that causes them to turn pink if overheated. Is it a coating or something similar. Also, some of the better cylinders seem to be cast from an alloy that is very light in color ... almost approaching white in some cases. I assume it is just the particular alloy but does anybody know what that alloy is? On the other hand, quality cylinders such as Mahle have a darker appearance. I have also noticed the lighter alloy castings on high end racing glo engines such as Nelson and Jett. In most cases, these are not die castings. Just curious what the alloy might be. I'm a curious sort of guy and just need to know more about these things.
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Old 02-09-2012, 05:48 PM
  #29
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Default RE: New (to me) internet myth

I believe the pinking of the cylinders happens when the solvents used are exposed to high temperatures
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Old 02-09-2012, 06:12 PM
  #30
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Quote:
ORIGINAL: Truckracer


Quote:
ORIGINAL: blikseme300

Off to go make some popcorn and grab a soda. Be right back as this is going to be interesting.

Bliksem
And what is that comment supposed to mean? At least this isn't another stupid oil or ethanol in gas thread. I would like to see more real technical questions and comments on this forum. But no, we'll probably have more of the same old stuff that has been covered dozens of times before.
Look at all the posts that followed yours. Tell me if I was wrong that I predicted this would be interesting?

Good information to be had from the people here that know their business. I might not be a youngster but I appreciate any information about the things we use in our obsession.

Live and learn.

Bliksem
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Old 02-09-2012, 06:12 PM
  #31
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Chain saws = work

But I do love my Lil Husky though
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Old 02-09-2012, 07:33 PM
  #32
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Quote:
ORIGINAL: blikseme300


Quote:
ORIGINAL: Truckracer


Quote:
ORIGINAL: blikseme300

Off to go make some popcorn and grab a soda. Be right back as this is going to be interesting.

Bliksem
And what is that comment supposed to mean? At least this isn't another stupid oil or ethanol in gas thread. I would like to see more real technical questions and comments on this forum. But no, we'll probably have more of the same old stuff that has been covered dozens of times before.
Look at all the posts that followed yours. Tell me if I was wrong that I predicted this would be interesting?

Good information to be had from the people here that know their business. I might not be a youngster but I appreciate any information about the things we use in our obsession.

Live and learn.

Bliksem
Agree with you there Bliksem! No youngster here either and I enjoy real engine info rather than just the plain old stuff over and over again. I questioned you the first time around, but now .....would you please pass the popcorn?
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Old 02-09-2012, 07:34 PM
  #33
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Quote:
ORIGINAL: RTK

I believe the pinking of the cylinders happens when the solvents used are exposed to high temperatures
Solvents? Where do these solvents exist and where do they come from?
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Old 02-09-2012, 07:45 PM
  #34
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Quote:
ORIGINAL: aussiesteve
This is because the majority of the engines that are bought nowadays have a very basic manufacturing technique used. Teh cylinders are molded on a mandrel, chemically cleaned, flame plated with Chrome then the final surface finish is achieved with a basic hone unit.

That technique results in bores that are neither parallel nor round. They are however cheap to produce that way and they will allow the engine to run. What they do not allow is good ring sealing so power is lost.
The newer DLE cylinders look to have machined bores? There have relatively clean, and what appear to be machined lines between the bore and the port edges. etc. A new ring inserted in the bore appears to fit quite well with very good compression when the engine is first assembled with all new parts. OTOH, I have an older 3MM 53 that I would believe has a bore that was probably plated as cast. There are visible mold marks everywhere and these even extend into the bore in places. I still don't have a lot of time on this engine and though it runs quite well, compression is poor and still improving. It would benefit from softer rings that could conform to the bore.

I'm curious if the DLE bore is indeed machined or just a very good plated as cast example. Can you shed any light on these two examples of cylinders?
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Old 02-09-2012, 07:52 PM
  #35
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Default RE: New (to me) internet myth


Quote:
ORIGINAL: Truckracer


Quote:
ORIGINAL: blikseme300


Quote:
ORIGINAL: Truckracer


Quote:
ORIGINAL: blikseme300

Off to go make some popcorn and grab a soda. Be right back as this is going to be interesting.

Bliksem
And what is that comment supposed to mean? At least this isn't another stupid oil or ethanol in gas thread. I would like to see more real technical questions and comments on this forum. But no, we'll probably have more of the same old stuff that has been covered dozens of times before.
Look at all the posts that followed yours. Tell me if I was wrong that I predicted this would be interesting?

Good information to be had from the people here that know their business. I might not be a youngster but I appreciate any information about the things we use in our obsession.

Live and learn.

Bliksem
Agree with you there Bliksem! No youngster here either and I enjoy real engine info rather than just the plain old stuff over and over again. I questioned you the first time around, but now .....would you please pass the popcorn?
I guess by comparison, some would classify me as a "youngster" though I feel a little wiser than others my age (32 next month). I do however value the "veteran" information and experiences that many members here possess. I come from radio control car experience of roughly 15 years now, and in the last few years have slowly gravitated towards r/c aviation. In that time, I've "discussed" with the car guys (young crowd, seemingly "know-it-alls") and the airplane guys (older, wiser, willing to share their experiences, not "what they heard"). I am by no means picking on one group or the other. I am merely sharing my opinion that the older generation of guys around here are far more enjoyable to converse with simply because the information is far more legit and free from "internet expertism".

No matter the subject, if you post your opinion in a car forum, there will be a 12 year old telling you you're wrong because "so-and-so" says so. I've learned more constructive information in the past year than I learned in the first 14 years of running rc cars.

Sorry I was off the subject a bit.. Keep on sharing the good stuff! My brain still has a little room for improvement yet (and I too have a chainsaw or two..).
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Old 02-10-2012, 10:29 AM
  #36
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Default RE: New (to me) internet myth


Quote:
ORIGINAL: Truckracer


Quote:
ORIGINAL: RTK

I believe the pinking of the cylinders happens when the solvents used are exposed to high temperatures
Solvents? Where do these solvents exist and where do they come from?
Solvents used in the manufacturing process
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Old 02-10-2012, 11:54 AM
  #37
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3-W puts something in the metal on purpose thats turns pink so they can tell if the engine has been abused. They can even tell what the temp was by the shade of pink. Stops a lot arguments about "I didn't do anything wrong". Never heard that DA does the same thing. Dennis
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Old 02-12-2012, 09:06 AM
  #38
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Quote:
ORIGINAL: DadsToysBG

3-W puts something in the metal on purpose thats turns pink so they can tell if the engine has been abused. They can even tell what the temp was by the shade of pink. Stops a lot arguments about ''I didn't do anything wrong''. Never heard that DA does the same thing. Dennis
I don't have any inside information but that sure sounds like be internet BS to me.
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Old 02-12-2012, 10:14 AM
  #39
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Quote:
ORIGINAL: dirtybird


Quote:
ORIGINAL: DadsToysBG

3-W puts something in the metal on purpose thats turns pink so they can tell if the engine has been abused. They can even tell what the temp was by the shade of pink. Stops a lot arguments about ''I didn't do anything wrong''. Never heard that DA does the same thing. Dennis
I don't have any inside information but that sure sounds like be internet BS to me.
Well, they certainly turn pink if overheated! There is no disputing that. My guess there is some kind of coating on the outside of the cylinder that causes this. What this is or how it works ... I have no clue. In normal operation, there seems to be just a bit of pink near the exhaust port. So far I have avoided the dreaded pink cylinder condition but have certainly seen it on other people's engines. Mostly on engines of people who do extended hovers.
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Old 02-15-2012, 10:17 AM
  #40
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Default RE: New (to me) internet myth


Quote:
ORIGINAL: Truckracer


Quote:
ORIGINAL: dirtybird


Quote:
ORIGINAL: DadsToysBG

3-W puts something in the metal on purpose thats turns pink so they can tell if the engine has been abused. They can even tell what the temp was by the shade of pink. Stops a lot arguments about ''I didn't do anything wrong''. Never heard that DA does the same thing. Dennis
I don't have any inside information but that sure sounds like be internet BS to me.
Well, they certainly turn pink if overheated! There is no disputing that. My guess there is some kind of coating on the outside of the cylinder that causes this. What this is or how it works ... I have no clue. In normal operation, there seems to be just a bit of pink near the exhaust port. So far I have avoided the dreaded pink cylinder condition but have certainly seen it on other people's engines. Mostly on engines of people who do extended hovers.

INTERESTING....I "cooked" the cylinders on an old 3W 140 two years ago and did not notice any "pinkening" of the cylinders. I have noticed this on DA's though. My 3W was in a Trueworthy Pitts M12. I'm pretty sure my overheating issues were cooling air related. I continued flying the plane as I tried various baffling/exit air combos. Well...before I got things worked out...the engine quit on a flight and after landing the nose of the crankcase and prop hub were still so hot that it was uncomfortable to touch for long. After cooling...the engine would restart but was WAY DOWN on power at mid to high throttle. When I pulled the jugs off...one had an area roughly the size of a quarter in the exhaust port area of the cyl wall that was missing the plating. The other cyl had a few very small spots where it looked like the plating was just starting to go. I learned on RCU that quite a ways back 3W had some issues with poor plating and/or out of round cyclinders. I'm guessing that since my engine was VERY hot...the damage was caused by that and not faulty cylinders. I'll have to find these cyls and look again at the color...

On a side note...after the above incident I bought a cheap "laser/infared thermometer" and started checking both my own and others engine temps. I know this method of temp checking on engines that have just returned from a flight is not "usefull" to the engine experts but I was just playing around. I was pleased to find that the temps on my other 3W's was very close to the temps on other guys 3W's that I checked. I was usually getting ~250-280 deg in between the top cooling fins on the cyl. I only have one DA right now. Its a well used "older" 100 and the temp on that eng was ~200 deg taken right after landing. I checked a buddies and got about the same so it looks like DA's run cooler?? I know...not the most accurate method to monitor temp and many variables...cooling air, oil, prop loading... Just found it interesting though.

Steve
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Old 02-15-2012, 08:01 PM
  #41
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You are right, not be the best way of testing, but it does give you a little insight
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Old 02-15-2012, 08:55 PM
  #42
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MVVS> you can sell them used for more that what you paid for them new [X(]

yee-up

Jim
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Old 02-16-2012, 10:12 AM
  #43
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Quote:
ORIGINAL: Antique

A customer told me today he heard that the A stamped on top of a Sachs piston means top of the line, a D on top means industrial grade...What a CROCK...Maybe we should start a thread with all these internet MYTHS listed for newbies..We ALL know the old timers don't perpetuate these things, don't we ?
I didn't read the whole thread, but you are correct it is a CROCK. "A" or other letter stamped on a part generally means revision A,B...or whatever revision they are on.
All of the car manufacturers do this that I am aware of, any number of other industries do this as well, including the printing press manufacturer I used to work for. It is an extremely common SOP. Whatever the Letter scheme denotes on a Sachs piston, I don't know but I am sure it denotes differences in the parts that you can't just look at and see easily.


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Old 02-16-2012, 11:11 AM
  #44
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As stated in a previous post by Antique, on a Mahle piston, the "A" or "AB" has to do with the size tolerance
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Old 02-16-2012, 06:02 PM
  #45
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Quote:
ORIGINAL: w8ye

As stated in a previous post by Antique, on a Mahle piston, the "A" or "AB" has to do with the size tolerance
Your right...
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