The Woodchuck and Firewood Hoarders Thread

vh20

Gunny Sergeant
Dec 2, 2012
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Aircraft engines generally have higher compression than auto motors.
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Scratching my head on this one. All the common ones I'm familiar with (say, Cont. C-85, 0-200, IO-550, Lyc. O-235, IO-360, IO-540) run around 8.5 or 8.6:1 or less (often significantly less, like 6.5:1 for a C-85). Auto engines generally start around 8.5:1 and go way up. I'm sure there might be exceptions, but as a general rule...? This just doesn't hold true.
 
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Feb 12, 2009
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Scratching my head on this one. All the common ones I'm familiar with (say, Cont. C-85, 0-200, IO-550, Lyc. O-235, IO-360, IO-540) run around 8.5 or 8.6:1 or less (often significantly less, like 6.5:1 for a C-85). Auto engines generally start around 8.5:1 and go way up. I'm sure there might be exceptions, but as a general rule...? This just doesn't hold true.
Thanks for pointing that out. You are correct. I was thinking about the super charger compression ratios
Man I've worked on and studied so many different engines this shit just runs together sometimes.
 
Nov 19, 2010
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t
Scratching my head on this one. All the common ones I'm familiar with (say, Cont. C-85, 0-200, IO-550, Lyc. O-235, IO-360, IO-540) run around 8.5 or 8.6:1 or less (often significantly less, like 6.5:1 for a C-85). Auto engines generally start around 8.5:1 and go way up. I'm sure there might be exceptions, but as a general rule...? This just doesn't hold true.
Normally aspirated? Where on the Rayleigh Huguenot line would a 6.5 cr engine exist at high altitude? Not running is my guess.
 

vh20

Gunny Sergeant
Dec 2, 2012
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t

Normally aspirated? Where on the Rayleigh Huguenot line would a 6.5 cr engine exist at high altitude? Not running is my guess.
Correct. Service Ceiling for a Cessna 120 with a C-85 is "15,500 ft", but it would take so long to get it up there I doubt it's got the fuel capacity for it. Nonetheless, the subject was 100LL fuel being for use in high-compression engines. The engines (and compression ratios) I listed are the most common/typical engines designed to run 100LL I can think of. To be honest, I can't think of a single engine designed to run 100LL with a compression ratio higher than about 8.6:1, but I'm sure there must be one. High altitude engines rely on turbo or supercharging, and typically/often have even lower compression ratios than their normally aspirated versions. If you really want to get way up there in a piston engine, a RR Merlin runs about 6:1 compression (with a two-stage supercharger).
 
Feb 12, 2009
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Engineer?

Now that's an engine! (With a high compression ratio too, of course). But better keep the 100LL way away from that thing.
Correct. And correct. Greatest diesel engine ever made for locomotives. Well, an sd45 had a 20 cylinder version but the railroad I work for found that they were breaking the crank shafts too frequently and sold them all.
Here's a snapshot from an engine monitor on a ge dash 9 Evo wide open.
Note the turbo speed.
 

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Rthur

Philomath
Apr 16, 2010
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Finished the first course in the third bay, and started the second, which we can go higher with. Nearly all Red Elm with a bit of American Elm (very light color), and Red Oak. All dead off the ground from a blow down. Heavy snow on the way and wanted to get it under roof and out of the weather.

View attachment 6871332
Looks awesome T.
You have a sickness lol.

R
 

vh20

Gunny Sergeant
Dec 2, 2012
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Correct. And correct. Greatest diesel engine ever made for locomotives. Well, an sd45 had a 20 cylinder version but the railroad I work for found that they were breaking the crank shafts too frequently and sold them all.
Here's a snapshot from an engine monitor on a ge dash 9 Evo wide open.
Note the turbo speed.
Cool display. Thanks for posting that.
 
Aug 2, 2009
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For what it's worth I had the poplar I posted earlier sawed. Was lucky to actually have rainbow poplar. Never heard of it until now. For anyone interested, here are a few pictures of the color. Seems odd to get blue lumber off a creek bank in upstate SC. Managed to get 450 bdf out of two 8 footers and a single 12'. It was all the IH 1066 could do to get it out of the ravine if fell over in. I made a mess but could not leave it to rot.
 

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Jan 23, 2010
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Morley IA
For what it's worth I had the poplar I posted earlier sawed. Was lucky to actually have rainbow poplar. Never heard of it until now. For anyone interested, here are a few pictures of the color. Seems odd to get blue lumber off a creek bank in upstate SC. Managed to get 450 bdf out of two 8 footers and a single 12'. It was all the IH 1066 could do to get it out of the ravine if fell over in. I made a mess but could not leave it to rot.
Very nice, I’ve heard of it, but have never cut one here even if we have it. Suppose it’s the same as Tulip Popular?
 
Aug 2, 2009
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Very nice, I’ve heard of it, but have never cut one here even if we have it. Suppose it’s the same as Tulip Popular?
as far as I know it is yellow poplar that is on a creek bank. it was neat to see the colored poplar on the side facing the creek and the regular poplar color on the side up hill. I have read that it looses its color over time but that should be remedied with a good solar kiln dry and some polyurethane.
 
Likes: barneybdb
May 20, 2006
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Winnipeg, Mb.
For what it's worth I had the poplar I posted earlier sawed. Was lucky to actually have rainbow poplar. Never heard of it until now. For anyone interested, here are a few pictures of the color. Seems odd to get blue lumber off a creek bank in upstate SC. Managed to get 450 bdf out of two 8 footers and a single 12'. It was all the IH 1066 could do to get it out of the ravine if fell over in. I made a mess but could not leave it to rot.
Nicely done, and with practically no wane, either. But, um... you sure you want that in the firewood thread? :D
What are your final plans for that lumber?
 
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vh20

Gunny Sergeant
Dec 2, 2012
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Starting torque on that thing is going to be impressive.

As funny as that is, I actually do have something that is only slightly less dangerous, probably some of you as well - a wheel for a hand grinder with a saw chain around the perimeter. I can't believe they're even legal to sell. It's definitely reserved for those rare situations when practically nothing else will do, and wielding it gives me the willies (and a case of white knuckles from the death grip I have on it).
 
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Geno C.

Dirty Carnie
Oct 24, 2007
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Starting torque on that thing is going to be impressive.

As funny as that is, I actually do have something that is only slightly less dangerous, probably some of you as well - a wheel for a hand grinder with a saw chain around the perimeter. I can't believe they're even legal to sell. It's definitely reserved for those rare situations when practically nothing else will do, and wielding it gives me the willies (and a case of white knuckles from the death grip I have on it).
Those grinder/chainsaw things are used a lot in wood sculpting. You can do some cool shit with them
 
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mtrmn

Sergeant
Oct 7, 2009
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Starting torque on that thing is going to be impressive.

As funny as that is, I actually do have something that is only slightly less dangerous, probably some of you as well - a wheel for a hand grinder with a saw chain around the perimeter. I can't believe they're even legal to sell. It's definitely reserved for those rare situations when practically nothing else will do, and wielding it gives me the willies (and a case of white knuckles from the death grip I have on it).
I have one that fits my Maruyama trimmer (weed wacker) but I never knew there were some intended for a hand operated grinder. Wow.
 
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Geno C.

Dirty Carnie
Oct 24, 2007
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Yep, it's just a boiler. A heat exchanger is in the house furnace so it can go back and forth with propane and there is a separate furnace in the shop
 

sandwarrior

Gunny Sergeant
Apr 21, 2007
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in yooperland
Scratching my head on this one. All the common ones I'm familiar with (say, Cont. C-85, 0-200, IO-550, Lyc. O-235, IO-360, IO-540) run around 8.5 or 8.6:1 or less (often significantly less, like 6.5:1 for a C-85). Auto engines generally start around 8.5:1 and go way up. I'm sure there might be exceptions, but as a general rule...? This just doesn't hold true.
Compression in this case is a misnomer. Higher power might be more apt.

The technology for light aircraft still resides in the 1940's and that with roots and myths from the beginning of compression engines. Unlike your car, which now has a wide lattitude of igniton and lubrication capabilities, aircraft with their "old" technology rely on manual leaning of the fuel and fixed ignition point. And because they are built with old technology, it's impossible to use new lubricants as the engines seals aren't compatible. Redesigning the lifters would help in that regard too. But, considered too expensive. You also have to consider that an aircraft engines is air-cooled (usually) so having to dump extra fuel through the engine is what is used to provide extra cooling at high power settings.

Slick now offers sealed capacitive discharge type "mags" that help with reliability, first and foremost, but with fuel management as well.
IIRC, and it's been awhile, most of the compression ratios I ran across were in the 6-7 to 1 range. I was told my '79 F-100 302 was high @ 7.5-1.
 
Feb 12, 2009
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SW Virginia
Starting torque on that thing is going to be impressive.

As funny as that is, I actually do have something that is only slightly less dangerous, probably some of you as well - a wheel for a hand grinder with a saw chain around the perimeter. I can't believe they're even legal to sell. It's definitely reserved for those rare situations when practically nothing else will do, and wielding it gives me the willies (and a case of white knuckles from the death grip I have on it).
Surely you'll provide us with a pic.
 
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