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Old Jun 09, 2011, 08:04 PM
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Thanks

Nice link
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Old Jun 09, 2011, 10:00 PM
Good Better Best quest.
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Brass is also good for laps.
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Old Jun 09, 2011, 10:35 PM
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NX-687, nice work. You may end up with a "better than new" crank, smoother, less vibration, and a little more power. Are you setting the crank at 90 degrees for "zero" balance (with the rod and piston attached)?
John
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Old Jun 10, 2011, 01:16 AM
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Hi John

It doesn't even balance out 50% of the reciprocating weight ,with all those weights
And my honing , oh no ,may not even run,

and I might have my 5th crank failure in 5 weeks coming up , I hope it holds together, at least for 6 flights


Its tight and flicked for about an hour with a 10x6 until it ran slow

the piston is barrel shape not touching at the top
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Old Jun 11, 2011, 03:23 AM
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Some Progress

3 flights OK at full power , 2 tanks on ground , rich, to run in the P/L ,, needed it ,

I leaned it on the first tank and it stopped hot,

power OK slightly down as the inlet and EXH ports are a little smaller,
holds its tune OK,
Ive got 20/40/40/1.5 fuel, and 8.5 x5 prop
Crank is pretty smooth not much vibes at all , although its probably got only 10 flights before the pin goes

Good bit of Diesel mess on the wing
Maybe engine parts coming out the exhaust?
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Old Jun 12, 2011, 09:14 AM
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NX-687, looking good. That's a lot of prop for a .15 (if glow), but the diesel is pulling through.
Smoother run, less vibration....you may be getting closer to the balance point.
That "black" residue may indicate that you have severe wear going on inside. Maybe bump the castor up to 25%, and don't push for a lean run.
John
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Old Jun 12, 2011, 09:41 AM
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Mainly black residue indicates high loads.....I usually aim for a 'brownish-black', or brown goo, which makes me feel like playing on the safe side...

25% castor helps in this respect, as well as not using too high pitched props.

Most of my '15' diesels, typically thrive on 9x4 props, providing a good acceleration/low speed pull, at a slight cost of top speed...

My 2 C's....
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Old Jun 13, 2011, 02:22 AM
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Hi

Its a challenge to start as its my own parts in there ,my finger is bruised and black , needs a rest , I dont think my piston seals well until it get to the top and then its tight , and also my cyl is loose in the case and so my case compression may be bad , that may explain the poor starts , heating with LPG helps , a glow is pretty easy after this. Gluehand , yes I think the 9x4 is a good choice ,
John
It looks like what they say about balancing 50 % of the reciprocating weight is right , seems closer I get to that the smoother it is, at the risk of increasing the secondary , sideways rocking
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Old Jun 13, 2011, 09:11 AM
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Originally Posted by NX-687 View Post
Its a challenge to start as its my own parts in there ,my finger is bruised and black , needs a rest , I dont think my piston seals well until it get to the top and then its tight , and also my cyl is loose in the case and so my case compression may be bad , that may explain the poor starts , heating with LPG helps , a glow is pretty easy after this. Gluehand , yes I think the 9x4 is a good choice ,
John
It looks like what they say about balancing 50 % of the reciprocating weight is right , seems closer I get to that the smoother it is
You might find this article helpful in your quest for better dynamic balancing,

http://modelenginenews.org/etw/etw_bal/p2.html

sparks
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Old Jun 13, 2011, 06:38 PM
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Thanks

Good article, and it says about 50% of the reciprocating weight
My Chinese engines have very thick pistons , so they are up against it
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Old Jun 16, 2011, 02:39 PM
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Originally Posted by NX-687 View Post
Im hoping this will go better
Next one I will make with a thicker web towards the conrod about 1mm at least
For those interested, here are some pics of the crankshaft of a YS DZ-160.
It is the first time I've seen the use of a ring on the web of a crankshaft, I was quite surprised when I dismantled the engine but then I realised that this was probably needed on this engine because of the use of the air-chamber
greetz Reggy
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Old Jun 16, 2011, 02:46 PM
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Originally Posted by NX-687 View Post
Im hoping this will go better
Next one I will make with a thicker web towards the conrod about 1mm at least
These are the pics that go with the text elsewhere
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Old Jun 16, 2011, 03:44 PM
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I just asked my "better half" if she checked the mailbox yesterday afternoon.....no, she'd forgot about it......
So, rushed out (half an hour ago), and...among the 'lesser' mail was a little cardboard box that's beeing sitting there since YESTERDAY.....obviously the Schlosser !

What a little jewel....so well made....and I particularily like that the NVA is proportional to the engine size (such details make a lot)....not always seen on small engines, where manufacturers sometimes use the same NVA to a number of engine models, making it look giant on the smaller ones...

Now I have to find a couple of suitable props...a run-in report will eventually be posted here...

Here's a picture of my Schlosser 0.25, prop is a 15-10 or 6-4 inch Graupner
Of all the very tiny diesels I have this Benno Schlosser is the top of the pops.
You have probably experienced yourself the wonderfull compression-feel, I have often wandered how he managed this delicate feel. Have another one NIB
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Old Jun 16, 2011, 03:47 PM
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Originally Posted by JohnAV8R View Post
Thanks Mike. If we all add a few pictures now and again, we should be good for a long time.
I've still got a few more pics of the Merco 5 cc. It's back together.
I'm still waiting for someone to have another shot at the "unknown" diesel with the strange logo print on the side. I think I've found the logo on another diesel so I'll post it later.

A pair of Clans, .48 and .24 cc ? Have you run them, and if so, what size props?
Hello John, my experience with the Clan was leaking on the intake probably caused by the choice of plastic for the intake greetz Reggy
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Old Jun 16, 2011, 04:24 PM
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The ring in the YS crank is to aid in increasing crankcase compression ratio, similar to stuffing the crank in a two stroke.

Greg
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