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Reasons to be cheerful!

Started by Tank, June 26, 2010, 03:13:35 PM

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jumbojak

Never seen a knurled piston before... and the sheets aren't Buzz Lightyear. I sleep on smiling alien bugs.

"Amazing what chimney sweeping can teach us, no? Keep your fire hot and
your flue clean."  - Ecurb Noselrub

"I'd be incensed by your impudence were I not so impressed by your memory." - Siz

Biggus Dickus

Quote from: jumbojak on September 19, 2017, 10:06:25 PM
Never seen a knurled piston before... and the sheets aren't Buzz Lightyear. I sleep on smiling alien bugs.

To be honest I don't know what a knurled piston is, seem to recall coming across that in a Steinbeck book, I think it was either Cannery Row or Sweet Thursday.  :P

I have a good memory for the mundane. ::)
"Some people just need a high-five. In the face. With a chair."

xSilverPhinx

I am what survives if it's slain - Zack Hemsey


xSilverPhinx

Today's a holiday. Oh yeah.  :hammock:
I am what survives if it's slain - Zack Hemsey


Arturo

Quote from: xSilverPhinx on September 20, 2017, 01:55:53 PM
Today's a holiday. Oh yeah.  :hammock:

Oh yeah as in, realized? Or oh yeah as in
It's Okay To Say You're Welcome
     Just let people be themselves.
     Arturo The1  リ壱

xSilverPhinx

I am what survives if it's slain - Zack Hemsey


Arturo

Quote from: xSilverPhinx on September 20, 2017, 05:54:13 PM
As in



Did not need to hear that lol. I'm apologizing to myself for asking lol
It's Okay To Say You're Welcome
     Just let people be themselves.
     Arturo The1  リ壱

xSilverPhinx

I am what survives if it's slain - Zack Hemsey


Icarus

FYI a knurled piston is one that has been processed in a lathe that has caused the piston to have peaks and valleys in the cylindrical part of the piston.. The peaks make the piston slightly larger in diameter.  Knurling was an old time remedy for pistons whose cylinder bore had worn a too large.  The pistons would then slap or rattle around in the bore.  Knurling was a cheap and dirty temporary fix for tired old engines.  Yes, I have done that to a few pistons, back in the dark ages.

So there you have another chapter in the annals of useless information.  Some of you old timers already knew about that didn't you?

Dave

#2994
^
Do I remember correctly that you could get oversized piston tings to do a similar job? Certainly remember people changing the rings in old cars in the early 50s - back in the dsys when we had to do de-cokes every 10 000 miles or so!!
Tomorrow is precious, don't ruin it by fouling up today.
Passed Monday 10th Dec 2018 age 74

Icarus

Sure enough oversize rings were a viable, if temporary, fix for tired engines.  Actually valves were one of the more common causes of grief.   They had progressively diminishing efficiency. Today's metallurgy has all but made those problems rare. 

jumbojak

Wouldn't knurling wear the shit out of the bore? I can't imagine the fix lasting very long or being cost effective in terms of labor and machine time. Then again, an aluminum piston on a cast iron cylinder that already lost it's cross hatching wouldn't be too much of a concern. I guess over boring to cylinder and installing oversized pistons wasn't common.

"Amazing what chimney sweeping can teach us, no? Keep your fire hot and
your flue clean."  - Ecurb Noselrub

"I'd be incensed by your impudence were I not so impressed by your memory." - Siz

Icarus

Old time garages, that had the equipment, could do rebores. Actually it was often done without removing the engine block from the vehicle. High precision Sunnen, Rottler, Haas machines did not exist but boring machines did.  The machine would mount atop the block and rotate a carbide tipped tool inside the cylinder bore. The tool would advance downward in the bore as it turned.  Sometimes the crankshaft was not removed. A lot of chips would fall onto the rod journals but they'd be cleaned before the rod was reinstalled.  Such boring machinery still exists and is used to service engines in such stuff as giant draglines or ships engines. Those boring machines were not as accurate as todays sophisticated engines require, but they did do the job in their own crude way.

In terms of economics.....whether knurling or other makeshift fixes were worth doing, remember that shop rates were Maybe three dollars per hour, the flat rate book had not yet been contrived, and the mechanics wage was $1.25. and often less.

We are still doing repairs as opposed to replacement in certain applications.  I have a good friend who has been in the hard chrome business for many years. One of the several specialty things that he does is repair the ring grooves in ships pistons.  Those grooves get sloppy over time and he does some chemical and metalurgy magic to restore the grooves to original specs. Yes, he has giant rotary grinders and lathes to make the grooves perfect.  The pistons range from 36 inch diameter upwards, so repairing is less costly than replacement although he charges a plenty to refurbish a piston.

jumbojak

Another question for you, as an old timer, how available were good used engines and transmissions back in the day? Today it's a rather simple matter of getting on the junkyard hotline to find the engine or transmission you need for a particular vehicle and much cheaper - usually - to just swas one out rather than go through the trouble of a rebuild.

The only places I know of that service either are either dealerships that deal with brand new platforms or specialty companies like Jasper or Aamco. I work with a lady who was contemplating fixing the transmission in her jeep and pointed out that she could find a replacement used for A LOT less than the, rather shady, shop was going to charge for a rebuild. I think she found a transmission for $300 and it's a four hour job on a lift. Less than a grand versus $2500.

"Amazing what chimney sweeping can teach us, no? Keep your fire hot and
your flue clean."  - Ecurb Noselrub

"I'd be incensed by your impudence were I not so impressed by your memory." - Siz

Velma

Today my husband and I decide to visit some nearby used bookstores that we had not been to before. We discovered a wonderful one less than 25 minutes away, named Second Reading Book Shop in Alton, Illinois. It is a small, hole-in-the-wall, slightly disorganized, slightly dusty, shop with two resident cats. The owner is a slightly eccentric man who writes books about local history. It everything you could want in a second-hand bookstore. 

My husband found three WWII books he had not read and I found several books by Frederik Pohl, the late science fiction writer. We plan to go back very soon.
Life is but a momentary glimpse of the wonder of the astonishing universe, and it is sad to see so many dreaming it away on spiritual fantasy.~Carl Sagan