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Messages - aqmxv

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16

PS - You may also want to study up on gyroscopic forces if you have not already done so.  When you try to move a flywheel from its spin axis, it resists (creates forces) that are perpendicular to the distrurbing force...not what most folks would initially expect.

http://science.howstuffworks.com/gyroscope1.htm

http://en.wikipedia.org/wiki/Gyroscope

http://en.wikipedia.org/wiki/Precession

Just to pitch in something from a slightly different angle of approach, one bunch of engineers who have to deal with precession and crankshafts a lot is aircraft propeller engineers.  Thrust and centripetal loads are common and comparatively obvious, but they also speak of 'p-factor' which is the force the propeller applies to its bearings when the aircraft pitches.

While the listeroid flywheel turns a lot slower, it's also very massive.  There's a lot of energy stored in that wheel, and I can certainly postulate excitement occurring if the mounting allowed change of axial direction for the flywheel/crankshaft combination.

Frankly, I think the Chinese single-flywheel engines are probably at a greater risk of this than an 'oid as long as the two sides of the twin listeroid are made as similar as possible.  A single listeroid is probably nearly immune.

17
Ouch.  I'm sad to say that I've been there, and done that, exactly that way.  When I was 15 I was operating a rented hydraulic log splitter and removed the end of my left index finger to the first joint.  I'm lucky that I got off as lightly as I did - my thumb and middle finger were sore from the bite of the splitter as well, but I yanked my hand out of the glove fast enough to save them.

You have my sympathies, for what it's worth.  To this day, my left hand is cold most of the winter because of the messed up blood circulation...

18
Original Lister Cs Engines / Re: Lets try a tool poll
« on: December 22, 2008, 08:21:45 PM »
Taking it briefly back to the semi-serious, I have yet to buy, or need an actual Whitworth wrench, although I came close to getting some when I took the crank out (actually used the Rajkot spanners for that one).  Apparently nobody in Rajkot had a torque wrench or had eaten their beans the day my engine was built - it all came apart (too) easily with this or that metric or UNC wrench.  I'll probably pick up a small Whitworth socket set for assembly.

I'm not sweating it, though.  It's all mild cast iron, and I got pretty good fitment with the metric and UNC stuff I have...of course, I have 1 mm steps from 5-33 mm and 1/32" steps over most of the inch range that would fit the listeroid, so it's not a big worry, especially with six point tools.


19
Listeroid Engines / Re: crank case width
« on: December 22, 2008, 06:27:54 PM »
The only applications I've worked with that are somewhat similar to a TRB listeroid crankcase (iron/steel at temperatures below 200 F) are RWD vehicle final drives.  In one memorable example (a Corvair final drive) you set the pinion bearing preload to give 4-7 in-lb drag when the pinion bearings are lubricated with gear oil at room temperature.  This works out to a slight, but measurable, preload.

Of course, in this type of application, keeping the hypoid bevel gears in precise alignment is the critical concern, and I'm certain that the TRBs on pinion and ring gear carrier are oversized to cope with the preload specified.

That said, the TRBs on my listeroid's crank are huge.  There's no way that they are ever operating anywhere near any design load limit.  I suspect that's why we never hear about problems with TRBs on listeroids.  I'd believe .005" clearance.  I'd also believe -.002" clearance.  And I suspect that the bearings don't care either way.

20
Original Lister Cs Engines / Re: CS compression valve question ?
« on: October 14, 2008, 03:38:57 PM »
If it wasn't bombed during the blitz, somewhere there's a piece of paper that specifies the minimum cold start temperature the post office gen sets had to manage.  Since it was a cost-added component, it's a safe assumption that Lister wouldn't have added it unless the engine wouldn't dependably start at the required temperature regardless of fuel or cold-soak time.

One sees a lot of this kind of overkill in military/critical services applications.  It's one of the reasons that things are so expensive when bought on government contract - the customer dictates the critical limitations of the device, instead of the marketplace.

21
Other Slow Speed Diesels / Re: Junkers 2HK65 Diesel - 1936
« on: July 03, 2008, 08:56:58 PM »
Rated horsepower is 65?  That, ladies and gents, is big iron.  Any idea on weight?

22
Engines / Re: how thick to pour concrete foundation
« on: July 03, 2008, 08:38:22 PM »
There are those who maintain that a ton of concrete (ideally fixed to bedrock) is required to properly support a running listeroid.

There are others who state that a reinforced slab a mere 8" thick or so will do the job

There are others who maintain that concrete is unnecessary, and a resilient mounting of proper design attached to a rigid fabricated frame should do the job.

These three groups have had lots of arguments here over the last couple of years.  I recommend you search...

23
General Discussion / Re: Price of DIESEL FUEL in Alberta
« on: June 04, 2008, 09:32:07 PM »
I vividly remember the national speed limit in the US in the early '70s.  While it's fair to say that this saved some fuel, and probably reduced some accident fatality statistics, I think it had a lot of bad effects:

1.  The interstate highways were all desigined for a minimum of 70 MPH cruise: Wide lanes, wide-radius banked turns, and huge run-off shoulders and medians.  It was bloody obvious to John Q Public that 55 MPH was artificially low for these roads, and the sensation of crawling along on a huge slab of concrete made for a lot of angry people.  The result was that people were, to some degree, incited and entrapped into breaking the law, which didn't do societal order a lot of good.  Once the enforcement softened up in the late 80s, but before nationwide 55 was rescinded, most people habitually sped at least 15 mph over the limit.

2. A lot of municipalities, counties, and states were suffering from reduced tax revenue during the early 70s oil shock/inflation cycle.  The 55 MPH limit and speed traps were seen as a godsend to boost the public coffers, and a lot of people got fined for doing less than 5 mph over the limit.  The problem with this is that police are actually supposed to keep the peace and protect the public, not act as a revenue stream.  The national (versus backwater town in the middle of nowhere) police culture of ticket quotas and aggressive speed limit enforcement based on revenue collection versus limiting unsafe vehicles and unsafe operators dates from then, and it has done us no favors at all.  When was the last time you heard of a LEO ignoring somebody doing 16 mph over the speed limit in order to pull over a car with an inop headlight or a driver who merged without signaling?  I thought so.

3.  By mandating that no vehicle in the USA was ever expected to exceed 60 MPH, several generations of cars were built with gearing that was inefficient at any speed above 60 MPH.  It wasn't until CAFE regulations and rising speed limits coincided in the mid 80s that four-speed automatic transmissions with lockup torque converters became common.  Ditto five-speed manuals in the few cars that shipped with a clutch.  Likewise, aerodynamic development was slower than it needed to be because the marginal value of a change is less at 55 MPH than at a higher speed.

Using a big, crude stick was a stupid way to get people to burn less fuel.  Carrots would have worked just as well, and wouldn't have had the undesirable consequences.  Compare what happened in the solar/renewable power and insulation businesses because of the tax credit schemes that were set up at about the same time.


24
General Discussion / Re: Price of DIESEL FUEL in Alberta
« on: May 29, 2008, 10:15:43 PM »
What I can't figure out is why people just use their brains. 

Instead if they just lowered the speed limit by 10 km/h they could save waaaay more "carbon" than simply by raising the price of gas even more.


True within limits.  The rub is when you push the speed limit so low that the vehicle (which, in most cases, was geared to get best possible fuel economy at ~90-105 km/h).  So yes, you get better fuel economy at 90 km/h than you do at 100.  But then you slow down to 80 km/h hoping for a fuel economy improvement.  And you might get it, if the vehicle is empty, if the road is flat, and if the wind is still or following.  But torque availability on the engine that far below the cruise band in overdrive is probably not good, so the transmission will force a kickdown (or at least a t/c unlock) if you climb a grade or hit a headwind.  There went your fuel economy gain.  We have a full-size Crown Vic that does this at about these speeds.  There's a milder version of the same phenomenon with a manual transmission vehicle - you hold it in high gear below the torque peak and end up getting into power enrichment (what used to be called 'power valve') as you try to maintain speed climbing a hill.  Again, there goes the fuel economy.

Of course, the marginal fuel economy improvement decreases as you slow down further, because air resistance is an exponential function with respect to speed.  So you save more fuel slowing down from 100 km/h to 90 km/h than you would slowing from 90 to 80 even under ideal circumstances.  The Crown Vic reflects this too - loafing around on back roads at 65 km/h you spend more time off the gas than on it, and it gets shockingly good fuel economy, as long as you can use momentum to carry you up the next hill instead of goosing it out of overdrive.  But then it's aerodynamically very well designed, for all that it's the size of a barn.


25
That is just plain cool.  I'll have to remember that trick if I see some dead iron somewhere I want to make into a semi-stationary anchor...

26
Frankly, given the size of the TRB mains on my 6/1, anyone doing a better job than a gorilla at key fitting will be unable to damage the bearings in any case.

There have been several good posts on the proper method of fitting a gib key.  If done right, very little force is required to fully seat the key.  If you're paranoid about things, you can always put a retaining collar on outboard of the key, as has been suggested elsewhere.  More hammering won't get you anything you want.

27
General Discussion / Re: Algore
« on: May 16, 2008, 06:27:51 PM »
ALGOR?  Never used it much.  Have some time on MatLab, though.

28
General Discussion / Re: threatening the admin
« on: April 25, 2008, 09:51:52 PM »
I'm a mod on another board.  Threatening mods and admins is just dumb.  But then y'all knew that.

In any case, it was a silly thing to get thin-skinned about...

It always surprises me that people who are nice folks in person, have lives, families, productive careers, etc sometimes turn into giant flaming rectal orifices in a forum like this one.

29
Engines / Re: DIY surface grinder or Coleman Lanterns?
« on: April 25, 2008, 01:54:02 AM »
I've got several Aladdin lamps and two vintage coleman white gas lanterns.  My favorite of the colemans is the 200a  I found that it's quieter, functionally about as bright (the chimney/shade is white underneath) and burns half the fuel compared to the two-burner.  I do, in fact use it when I go car camping now and again.

Two of the Aladdins are model B's (from the '30s) and one is a model C.  The C (and the model 23a that followed it) use less fuel per unit light, but all work quite well, with a wick and kerosene, as opposed to pressurized gasoline.  Pressurized gasoline doesn't please me... Quiet, too.  I really like them on cold winter nights and light them now and again just because it's fun.

There's a pretty strong collector culture surrounding the Aladdins, but since they're still made, you can always just buy a new one.  Likewise, parts for anything model B or later are easy to come by.

I also have three Aladdin Blue Flame Heaters, which are the best small kero heater I've ever used.  Fine product of British Engineering there.

30
General Discussion / Re: They don't build them like this anymore
« on: March 07, 2008, 09:52:41 PM »
Yes, they did, but the upside was precisely one unscheduled downtime in 30 years continuous operation (it was a cracked upper main bearing on the crank.  They had a spare.  Scraping to fit took an afternoon and they were pumping once they had steam up the next morning).

The replacement pumphouse had all its equipment removed during the WWII scrap metal drives.  Apparently the hand-stacked stone pumphouse building saved the walking-beam engines.  While their massive iron was desirable, it was regarded as too much work to tear down the granite walls to get to it.

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