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Jul 09, 2011, 08:57 PM
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earlwb's Avatar
Russian KMD 2.5cc model diesel engine:









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Jul 10, 2011, 02:08 AM
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Reginald's Avatar
Quote:
Originally Posted by earlwb
Fortunately acetone will not affect anodizing on aluminum. Solvents have no affect, but a caustic solution will though.
I remember several guys using acetone to clean their anodized parts prior to using locktite etc on them when reassembling them. It didn't affect the aluminum any.
Some manufacturers clean the anodized parts with acetone before they assemble them too.
May I add the following, one exeption in anodising is OS, I think they use a different method of anodising. I have never had any problem in the anodised parts losing colour when put into the U-son but until I did put some black
cylinder sleeves of a Pegasus twin in the bath : colour gone. Be warned on that one ( sounds a bit like the Woodstock warning no .....?) lol R
Jul 10, 2011, 08:30 AM
Registered User
earlwb's Avatar
Sometimes I wonder if something was really anodized or not. I have some engines that people say were anodized, but to me they really look like the engines were painted or coated with something, not anodized.
My Drone engines for example, look like they were painted instead of anodizing.
Jul 10, 2011, 08:55 AM
Registered User
Yes, powder coating. See the later Irvine engines made by OS.
Jul 10, 2011, 09:22 AM
Registered User

Frog


Have a visit to
http://www.houseoffrog.co.uk/index.htm

pictures of all the kits,
and
diesel engines available for them.

great prices too.
Jul 10, 2011, 12:50 PM
Time for me to Fly...
Mr. Wiz's Avatar
Wow, that KMD looks positively industrial. What kind of prop are you using and RPM are you getting with that?
Jul 10, 2011, 01:40 PM
Voices through wires? Ha!
Chas's Avatar
You should see Soyuz and Apollo mated together in Space City!...solid state, titanium and flush surfaces welded to Jules Verne, bolt heads, pushrods and portholes! Still, whose launcher are we using now...?
Jul 10, 2011, 03:27 PM
Vi ne donu ĝin
coriolan's Avatar
"Function" always beat "look" in result!
The russian T-34 was very crude compared to its german foe the Panther,this is what a Panther looks like after meeting a T-34 at Kursk in 1943.
Jul 10, 2011, 04:46 PM
Registered User
earlwb's Avatar
Quote:
Originally Posted by Mr. Wiz
Wow, that KMD looks positively industrial. What kind of prop are you using and RPM are you getting with that?
The engine works quite well. It is a high RPM design diesel engine that runs as good as many of the high performance glow engines in its class.
It does not like large props and low RPMs.
15,500 rpms with a APC 8x4 prop.
19,000 rpms with a APC 7x4 prop.
22,000 rpms with a APC 7x3 prop. But the vibration is becoming phenominal at this speed though.
ref: http://www.google.com/url?sa=t&sourc...QyeLbw&cad=rja
Jul 10, 2011, 08:05 PM
kill your idols
ZEROSKIN76's Avatar
Quote:
Originally Posted by earlwb
The engine works quite well. It is a high RPM design diesel engine that runs as good as many of the high performance glow engines in its class.
It does not like large props and low RPMs.
15,500 rpms with a APC 8x4 prop.
19,000 rpms with a APC 7x4 prop.
22,000 rpms with a APC 7x3 prop. But the vibration is becoming phenominal at this speed though.
i did not know these numbers were even possible with deisel engines
Jul 10, 2011, 08:09 PM
Registered User

KMD specs


Earl, good reference on the KMD

From the above...

"No way would the KMD achieve its
peak of 0.48 BHP at 19,500 RPM with one of those. A
quick comparison with a published test of the
contemporary Bugl Mk 2 shows that it also peaks at the
same RPM, but gives over 20% more power. Unlike the
Bugl, the KMD’s torque curve drops off quite significantly
as it approaches and then passes the BHP peak. Not
surprising really, you get what you pay for.
As a final check potential candidate racing propellers were
tested. The APC 7x6 recorded 16,400 RPM and Thunder
Tiger 7x5.5 maxed out at 16,800 RPM."
Jul 10, 2011, 08:58 PM
Registered User
earlwb's Avatar
Quote:
Originally Posted by JohnAV8R
Earl, good reference on the KMD
From the above...
"No way would the KMD achieve its
peak of 0.48 BHP at 19,500 RPM with one of those. A
quick comparison with a published test of the
contemporary Bugl Mk 2 shows that it also peaks at the
same RPM, but gives over 20% more power. Unlike the
Bugl, the KMD’s torque curve drops off quite significantly
as it approaches and then passes the BHP peak. Not
surprising really, you get what you pay for.
As a final check potential candidate racing propellers were
tested. The APC 7x6 recorded 16,400 RPM and Thunder
Tiger 7x5.5 maxed out at 16,800 RPM."
John left out the part about that they were discussing the old style large paddle props of the time period that people were using for combat at the time. Thus the those props would be below the RPM range that the engine was designed for.
Jul 10, 2011, 09:09 PM
Registered User
earlwb's Avatar
Quote:
Originally Posted by ZEROSKIN76
i did not know these numbers were even possible with deisel engines
Most people don't know that diesels can run as good as a glow engine. it depends on the design though. Many diesel engines were intended for free flight sport kind of purposes for the time period just after WWII. But along the way competition free flight and combat as well as control line speed became quite popular outside of the USA mostly. So competition diesel engines were developed for those purposes.

The modern diesel competition engines tend to beat the old KMD design of course. But not by all that much. One can do some performance mods to improve the KMD even more too.
Jul 10, 2011, 11:10 PM
Registered User
TLyttle's Avatar
Team race was also a big contributor to these engines. I have a few t/r engines that really howl, using only fumes to run. I used to buy ex-t/r engines for sport use (too worn out to pull the required lap times); pretty quick I found out that I only needed a really small fuel tank to stay in the air for a long time. (Seems to me I bought an ETA from Bruce Matthews, and may still have it...) Meantime I have a NIB MVVS 2.5 and an Oliver or two, just in case my youthful exuberance finally overtakes my old-age senility...
Jul 11, 2011, 03:18 AM
Registered User

Gee


A 7x3 at 22,000 , I wonder how long that would last
The diesels I have go through a certain vibration period, and usually come out fine at peak revs , but I found it difficult to get that 50% of the reciprocating weight of the piston balanced out by the counterweight, even with 3 copper weights in the counterbalance it still was not right ,

those iron pistons are heavy , also the big crankpins dont help weight wise either

On a C/L model it doesn't worry me , I dont balance props , just put them on
I just got a self start propane torch, diesels start better warm , and if I get frustrated I can torch the whole model


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