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Sep 26, 2019, 09:59 AM
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I have always wondered why full size aircraft engines don't have mufflers.
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Sep 26, 2019, 10:49 AM
DJS Johnny
johnshannon's Avatar
Quote:
Originally Posted by Frank Klenk
I have always wondered why full size aircraft engines don't have mufflers.
It would reduce horspower
Sep 27, 2019, 01:23 PM
Balsadustus Producerus
There is a club flying off an old landfill north of here, off Twin Oaks Canyon Road, can't remember their name. Over the years and loads of complaints, at least one thing stood out. It's not just the noise itself, it's related to pitch as well. That's why your average 4S engine is usually OK with the noise meter with a stock muffler. A 2S engine will need a better muffler, but oddly enough, they seem to say how, no matter the muffler or DB reading, the mosquito-like whine of a 1/2A engine is especially annoying. If the homeowners can hear it at all, they will complain.

And John is correct, piston airplanes don't have mufflers. They do have heat exchangers, for the purpose of heating the cabin, and carburetor if the airplane has one, for reduced power operations. As it happens, these exchangers are often referred to as mufflers, and may help in reducing noise, but in reality are not installed for sound modification. Many of the Beechcraft airplanes, especially the singles, come with 'resonators', which are an effort to reduce noise, mostly for those on board. If they were effective as mufflers, the exhaust flow restrictions would be too great. Moreso as the powerlines and trees in front of you on takeoff get closer and closer, but not smaller

Actually, many airplanes have a noise problem not from the engine(s), but the propeller. If you hear a North American T-6 or Cessna 185, especially with the seaplane prop departing, engine noise can be difficult to hear because of the prop. The FAA has been actively forcing airplane manufacturers to reduce noise by incorporating noise limits as part of the certification requirements.

Turbochargers make good mufflers, but the cost, weight and complexity place them beyond most light singles. They also can reduce engine lifespans.
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Sep 27, 2019, 04:44 PM
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Reginald's Avatar
You've probably seen this one before... George Luhrs miniature .074. He made only 10. Tried to run it in the past but not easy with that small pull-cord system. And the plug is not too good quality with bad insulation material used. One of these days I will fit a small spinner and use one of my tiny elect. starters. But jewel-like made it is. I do have even smaller plugs I made myself but too small for this engine. Can make one but that is tedious work.... I made the base from a copy sent to me by Paul Knapp.
Last edited by Reginald; Sep 27, 2019 at 05:03 PM.
Sep 27, 2019, 05:52 PM
Registered User
williame3590's Avatar
Thread OP
Nice job on the engine base Reggy.


Bill
Oct 01, 2019, 06:53 PM
Registered User
For those who don't own a copy of the American Model Engine Encyclopedia Vol. 1, this is a P & S 65 made by Matt Pierson and Lyman Steffen in Alhambra, CA circa late 1948. It is, of course, distantly related to the Orwick 64. After Al Cunningham and Henry Orwick went their separate ways, Al started producing his Cunningham Bluestreak 65 which did contain numerous Orwick parts, but differed from the Orwick in having integral beam mounts, a cast in venturi and a single rear ball race. The Cunningham engine was painted in hammertone blue to distinguish it from the trademark green Orwick. A year or so later in 1948, Pierson and Steffen used the remaining Cunningham parts to produce their Glow Streak 65, but the A.M.E.E. does not mention a sparkie version, so the engine shown below must be (as the seller states) an early prototype. Even the glow production only ran to around 50 units, compared with the preceding Cunningham Bluestreak at around 100 units. First 2 photo's below show firstly, the P & S 65, then a Cunningham Bluestreak 64, and on the end is another Orwick derivative, the Daniel 64. This latter engine was assembled by Bill Daniel in the 1980's and only about 25 exist. Note that the genuine Cunningham engine has a "Make" instead of a "Break" timer, opposite of the RJL Mecoa replica
http://www.mecoa.com/vintage/cunn/index.htm
Last edited by Twin Stack; Oct 03, 2019 at 08:02 PM.
Oct 01, 2019, 07:00 PM
Registered User
Quote:
Originally Posted by Reginald
You've probably seen this one before... George Luhrs miniature .074. He made only 10. Tried to run it in the past but not easy with that small pull-cord system. And the plug is not too good quality with bad insulation material used. One of these days I will fit a small spinner and use one of my tiny elect. starters. But jewel-like made it is. I do have even smaller plugs I made myself but too small for this engine. Can make one but that is tedious work.... I made the base from a copy sent to me by Paul Knapp.
Sweet little engine Reggy! Yes, like fine jewelry.
Oct 02, 2019, 07:27 AM
Thermals, Tom
RyanNX211's Avatar
Only 100 Bluestreaks?
I have one. And I saw one on
eBay go for >$200
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Oct 02, 2019, 04:01 PM
Registered User
Quote:
Originally Posted by RyanNX211
Only 100 Bluestreaks?
I have one. And I saw one on
eBay go for >$200
That's the genuine originals, as in the blue one shown above - MECOA I think, made repros, but they have a different timer. The genuine ones have the timer as shown on the example in the 3rd photo
Oct 05, 2019, 08:14 AM
Registered User

Shipping International


Quote:
Originally Posted by Twin Stack
Bill, while it is possible that I simply didn't notice it, experience has shown that not 100% of engines listed on eBay US will appear on my Aussie screen - maybe something to do with whether the seller will ship overseas or not ?
I was wondering why my Ebay sales to Australia and NZ were down and a friend from Australia said a lot of my engines are not showing up in Australia even though I show I ship world wide and I have the International shipping price in my listings. Since I pass on my shipping discount from Ebay I had fixed pricing on my listings. I changed the fixed pricing on International sales to calculated and include weight and dimensions of package and my engine sales to Australia and NZ are almost 4 times what they were before I made that change. I still have to send a invoice to complete the transaction and my shipping costs are cheaper then what is quoted on the Ebay calculated shipping price. So either the Aussie's are spending more money or just making that little change opens exposure of my items on the International market.
Oct 05, 2019, 09:21 AM
Sticks, Tissue & old Diesels
brokenenglish's Avatar
Hi Dave, Personally, I don't trust eBay to show things in other countries, so I log into eBay.com to identify stuff on sale in the US.
I don't think items show up world-wide just because the seller ships world-wide.
When selling from France, I sell on eBay UK, and pay a small supplement (a few cents) to have the item show in eBay US and Ca.
My items obviously wouldn't be displayed on eBay.com, or anywhere else, just because I ship world-wide.
The bottom line is that, IMO, the guys in Oz need to log into eBay.com and not rely on items showing up on eBay.au, which is obviously not happening!
Oct 05, 2019, 04:59 PM
I'm a balsa butcher
Quote:
Originally Posted by gatafish
I was wondering why my Ebay sales to Australia and NZ were down and a friend from Australia said a lot of my engines are not showing up in Australia even though I show I ship world wide and I have the International shipping price in my listings. Since I pass on my shipping discount from Ebay I had fixed pricing on my listings. I changed the fixed pricing on International sales to calculated and include weight and dimensions of package and my engine sales to Australia and NZ are almost 4 times what they were before I made that change. I still have to send a invoice to complete the transaction and my shipping costs are cheaper then what is quoted on the Ebay calculated shipping price. So either the Aussie's are spending more money or just making that little change opens exposure of my items on the International market.

It is because our smart government bowed to the pressure of one large retailer and put GST on all imports regardless of value or condition. Said business was complaining that people were buying similar products cheaper from overseas and not paying their over-inflated prices.
Oct 05, 2019, 09:49 PM
Registered User
Quote:
Originally Posted by udlman
It is because our smart government bowed to the pressure of one large retailer and put GST on all imports regardless of value or condition. Said business was complaining that people were buying similar products cheaper from overseas and not paying their over-inflated prices.
Rather than just add the 10% GST like other online stores, Pitney Bowe's Global Ripoff Program adds 20% to the selling price plus 20% to their already inflated shipping fees.

In your watch list you see something like this:

Current price: $40
Shipping: $28
Tax & handling $13.60 (based on current price)

This really puts me off bidding, and It seems more and more US based sellers use the Global Ripoff Program, which sort of puts me off even searching.

I note that some of the established ebay sellers like gatafish and rureallybob don't use the program.

BTW: Gerry's incessant whinging to government achieved a couple of things:

1) GST applied to low value items.

2) Myself NEVER purchasing anything from Harvey Norman again.
Oct 06, 2019, 08:08 AM
Registered User
Quote:
Originally Posted by brokenenglish
Hi Dave, Personally, I don't trust eBay to show things in other countries, so I log into eBay.com to identify stuff on sale in the US.
I don't think items show up world-wide just because the seller ships world-wide.
When selling from France, I sell on eBay UK, and pay a small supplement (a few cents) to have the item show in eBay US and Ca.
My items obviously wouldn't be displayed on eBay.com, or anywhere else, just because I ship world-wide.
The bottom line is that, IMO, the guys in Oz need to log into eBay.com and not rely on items showing up on eBay.au, which is obviously not happening!
Thanks for the info and I was wrong on thinking my items were showing up Internationally. I checked with my friend from Australia and my items still don't show up unless he does a different search and it still does not say that I ship Internationally. It still says to contact the seller for shipping.
Oct 09, 2019, 07:14 AM
Registered User
Gluehand's Avatar

Piezo-electric sparks....


Sparks by bashing a crystal.......sounds so simple....
Lightweight, few components, no battery etc......
Despite these advantages, I can, however, think of an obstacle or two to get over to make this practically useable with "our" engines...
As shown in the film clip below, the method does clearly work, at least in lo-rev contexts, and where a "high mileage" isn't topping the wish list, thus making me wonder if someone, somewhere, has brought this ignition method any further......?
What are the limits...!
What will break first...?

FILM CLIP


.
Last edited by Gluehand; Oct 09, 2019 at 07:30 AM.


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