Myth Busters

[Lou Schneider]

Once I bought new tires for my Ford F-350 and the shop inflated them to the full sidewall pressure which was 50% above the pressure on the truck's placard.  It was a 60 mile drive home (unloaded) and the truck felt very unstable, like it was sliding and fishtailing.  I almost brought them back the next day but I caught the error and setting them to the correct pressures solved the problem.

Edited January 20 by Lou Schneider

[rickeieio]

Yep.  Take the sidewall pressure and the door jamb sticker both as guidelines, but not an absolute.  In the case of my f-150, I need to run 48 psi for the load per tire as shown on a scale and the tire manufacturers chart.  Door sticker calls for 36 psi.  That may work for an empty truck, but I have a bed mat, optional big fuel tank, cross box, and several hundred pounds of tools and "stuff".

Next "myth".... never drag a file or hacksaw backwards across the work material?

[Danfreda1]

True but you don’t need to completely lift it off the material being filed or cut. Easy with a file to lift but on the backstroke just lift up on the pressure

[Deezl Smoke]

 Fireball tool made a video about 2 years ago using an old shaper to test the old file backwards myth. Normally I'd post a link, but I can't seem to get the video to play on youtube. It just opens then goes white screen.

 But if you search youtube for fireball tool file, it should come up. It was a very interesting video. I'll not spoil the results, you'll have to watch it.😉

 Ok, it was my computer. I got it to play. So here's the link.

 

Edited January 30 by Deezl Smoke

[rickeieio]

Back in the day, we had a power hacksaw in the shop.  Like a chop saw, but with a big reciprocating blade, oiler dripping on it.  Those blades lasted forever, even though they were dragged back every cycle with the full weight of that support arm.  Oil made the difference.

Also, if you look up filing machines, there's a lot of different variations, some quite large.  None reduce pressure on the return stroke.

[Danfreda1]

Not all Rick, we had some in different shops (hacksaw type saw) that lifted a very small amount. Maybe not enough to see but it you put a trained finger on it you could feel. Most of our saws were the horizontal bandsaws with at least a 1 inch blade

[Ray,IN]

On 1/30/2024 at 9:50 AM, rickeieio said:

Back in the day, we had a power hacksaw in the shop.  Like a chop saw, but with a big reciprocating blade, oiler dripping on it.  Those blades lasted forever, even though they were dragged back every cycle with the full weight of that support arm.  Oil made the difference.

Also, if you look up filing machines, there's a lot of different variations, some quite large.  None reduce pressure on the return stroke.

Our jack-xxx saw in the shop had a cam that slightly lifted the blade for the return stroke. Our blades didn't last long sawing the brake-die steel to length. It arrived already heat-treated to RC20. But with mild steel you're right the blades lasted a long time.

Edited February 1 by Ray,IN

[Ray,IN]

Myth or Truth,

You can sharpen a file with vinegar?  No fair using a search engine.

Edited February 1 by Ray,IN

[rickeieio]

2 hours ago, Ray,IN said:

Myth or Truth,

You can sharpen a file with vinegar?  No fair using a search engine.

Sorta....I've tried it, and it helps.  Not like new, but much better than they were.  But, I'll say, I was trying to revive files that had been wet, and rusted.  The vinegar took off most of the rust, so the file seemed better.  There are better ways to remove rust.

[Ray,IN]

18 hours ago, rickeieio said:

Sorta....I've tried it, and it helps.  Not like new, but much better than they were.  But, I'll say, I was trying to revive files that had been wet, and rusted.  The vinegar took off most of the rust, so the file seemed better.  There are better ways to remove rust.

The vinegar method is very old, long before Naval Jelly and like chemicals were invented. Left exposed to vinegar "fumes' long enough, it does actually erode the teeth enough on the tips to sharpen them.

[spindrift]

5 minutes ago, Ray,IN said:

it does actually erode the teeth enough on the tips to sharpen them.

LOL...I'm somewhat hesitant to ask how this was determined.

[GeorgiaHybrid]

Anyone else chalk your files before starting on aluminum, brass, bronze and other soft material?

[Ray,IN]

27 minutes ago, spindrift said:

LOL...I'm somewhat hesitant to ask how this was determined.

So I was told, the teeth are eaten away by vinegar, since the teeth tips are the thinnest part, they are "sharpened". I have no empirical evidence to support that though.

Georgiahybrid, I'd forgotten about that technique to reduce clogging with soft metal.

Edited February 1 by Ray,IN

[rickeieio]

Naval Jelly is phosphoric acid in a jell form.  Same acid as in Coke.  You can buy it dry too.  Works great to remove rust.  Ever heard about dropping a nail in a can of Coke, and the next day it's dissolved?

[Ray,IN]

The nail, no, but I have heard of placing a 1" cube of meat in a coke and a few days later there is a greasy film on top of the coke, but no meat left.

The original Coke/Coca Cola contained cocaine, I've seen a gallon jug of coke from perhaps a century ago and the label listed the ingredients.

[noteven]

Myth: it’s horsepower not torque.

It’s why heavy haul companies are replacing 2050lbs-ft torque Cummins’s’z with really Tuned up 6.7 Powerstrokes

[rickeieio]

Right......

Our old ISX made 480 ponies at the ground.  Our new-to-us PACCAR is rated 455 at the crank, but more torque at 1,100-1450 rpm.  I like this kinda torque.

[Deezl Smoke]

On 2/17/2024 at 12:23 PM, noteven said:

Myth: it’s horsepower not torque.

It’s why heavy haul companies are replacing 2050lbs-ft torque Cummins’s’z with really Tuned up 6.7 Powerstrokes

  "Myth: it’s horsepower not torque."

 Bar none one of my favorites.👍

 Why do the hp and torque graph curves cross at roughly 5252 rpm?

[rickeieio]

6 minutes ago, Deezl Smoke said:

  "Myth: it’s horsepower not torque."

 Bar none one of my favorites.👍

 Why do the hp and torque graph curves cross at roughly 5252 rpm?

Time to bust out the ol' slide rule.  Torque x RPM  = HP/5252  But where did 5252 come from?

I haven't driven enough new stuff to be sure, but it seems the newer motors are making more torque, but keeping the rpm lower, thus the great pulling power with low hp figures.

[Deezl Smoke]

1 hour ago, rickeieio said:

Time to bust out the ol' slide rule.  Torque x RPM  = HP/5252  But where did 5252 come from?

I haven't driven enough new stuff to be sure, but it seems the newer motors are making more torque, but keeping the rpm lower, thus the great pulling power with low hp figures.

 

 

 It's fun to know where the number came from.

[spindrift]

1980s GM diesels were converted gas engines...

[rickeieio]

11 hours ago, spindrift said:

1980s GM diesels were converted gas engines...

Don't you mean, swapped out to gas?  I know several people who bout those, and dropped in gas motors later.

[Av8r3400]

12 hours ago, spindrift said:

1980s GM diesels were converted gas engines...

The 5.7L GM diesel was based off the Oldsmobile gas engine block - Fact.  They even marketed a smaller 4.3 (260") V8 and 4.3 (262") V6 version also off the gas engines.

 

[Deezl Smoke]

10 hours ago, rickeieio said:

Don't you mean, swapped out to gas?  I know several people who bout those, and dropped in gas motors later.

 Been there, done that, got the tee shirt.

 The rig in my avitar was a 6.2L that I later swapped out for a 454cid. Easiest swap ever. 3 line fuel pump, ignition power to the coil, and homemade radiator hoses. Throttle cable, just a simple part swap. The torque converter on the 6.2 has different perimeters, but still works.

 The 6.2 has a vacuum pump to operate the trans and hvac, so simple to plumb that hose in the manifold on the 454.

[Lance A Lott]

As to files, I was always told not to put them in a pile because they dulled each other.