Knurled Pistons
Seasoned HDF Member
Joined: Aug 2008
Posts: 5,064
Likes: 1,003
weeks ??????
pretty slow mechanics.
https://www.google.com/url?sa=i&url=...AAAAAdAAAAABAK
this in 3 days. vertical opposed piston, that is in place. if you have to do more than one cylinder, best to pull the coffin cover an upper crank assy.
pretty slow mechanics.
https://www.google.com/url?sa=i&url=...AAAAAdAAAAABAK
this in 3 days. vertical opposed piston, that is in place. if you have to do more than one cylinder, best to pull the coffin cover an upper crank assy.
Last edited by bustert; Feb 17, 2024 at 09:43 AM.
Club Member
Joined: Apr 2016
Posts: 11,545
Likes: 8,380
From: Inland NW
weeks ??????
pretty slow mechanics.
https://www.google.com/url?sa=i&url=...AAAAAdAAAAABAK
this in 3 days. vertical opposed piston, that is in place. if you have to do more than one cylinder, best to pull the coffin cover an upper crank assy.
pretty slow mechanics.
https://www.google.com/url?sa=i&url=...AAAAAdAAAAABAK
this in 3 days. vertical opposed piston, that is in place. if you have to do more than one cylinder, best to pull the coffin cover an upper crank assy.
Go take a nap.
Seasoned HDF Member
Joined: Aug 2008
Posts: 5,064
Likes: 1,003
You learn a lot working on old 2 strokes 
I was one of the techs taking care of old 567 and 645 EMDs in stationary power plants up in AK, and "wear limits" was a very real thing. You would spend a week tearing down 16 cylinder kits at 645 in/3 per cylinder to measure and inspect. As a younger tech, I just wanted to replace it all!
generic statement as was mine.
ONE OF is not the same as MYSELF.
try doing an EMD 645E5 inside of a 225 foot cargo vessel with just enough headroom to do the job. still not a week unless you have to cut the upper deck to pull the block. shoot even the crank bearings are easily changed in place.
tear down is a snap, going back is another story, pulling 1500#/ft on the head bolts even through a 10:1 torque multiplier will put Arnold Alois Schwarzenegger arms on you.
once again simple tests will determine whether to pull parts are not. EMD is more friendly due to the bleed ports on each engine for running diagnosis. that was a big stickler with EMD some yahoo cranking it over without checking for head jumper o-rings coolant leaks, VERY easy to bend a rod.
ever do an engine like a DeLaval that has siamese or articulating rods? how about an engine that fires on both sides of the piston @ 3000hp at 600rpm, run through a kort nozzle that make it near 6000hp. or an engine that you have to reverse rotation since the is no transmission for reverse.
I was one of the techs taking care of old 567 and 645 EMDs in stationary power plants up in AK, and "wear limits" was a very real thing. You would spend a week tearing down 16 cylinder kits at 645 in/3 per cylinder to measure and inspect. As a younger tech, I just wanted to replace it all!
generic statement as was mine.
ONE OF is not the same as MYSELF.
try doing an EMD 645E5 inside of a 225 foot cargo vessel with just enough headroom to do the job. still not a week unless you have to cut the upper deck to pull the block. shoot even the crank bearings are easily changed in place.
tear down is a snap, going back is another story, pulling 1500#/ft on the head bolts even through a 10:1 torque multiplier will put Arnold Alois Schwarzenegger arms on you.
once again simple tests will determine whether to pull parts are not. EMD is more friendly due to the bleed ports on each engine for running diagnosis. that was a big stickler with EMD some yahoo cranking it over without checking for head jumper o-rings coolant leaks, VERY easy to bend a rod.
ever do an engine like a DeLaval that has siamese or articulating rods? how about an engine that fires on both sides of the piston @ 3000hp at 600rpm, run through a kort nozzle that make it near 6000hp. or an engine that you have to reverse rotation since the is no transmission for reverse.
Seasoned HDF Member
Joined: Dec 2005
Posts: 19,900
Likes: 8,007
From: poway
While It was a good old time fix, I don't think that it would work that well on newer stuff. The main reason being that the later pistons are cam ground. It would be hard to roll knurl a skirt.
One thing you can do now is put a coating on the piston to build it up.. IIRC the coat is some derivative of teflon and it works very well. IIRC WFO larry has been using it..
One thing you can do now is put a coating on the piston to build it up.. IIRC the coat is some derivative of teflon and it works very well. IIRC WFO larry has been using it..
Seasoned HDF Member
Joined: Aug 2008
Posts: 5,064
Likes: 1,003
be VERY selective on who and how part build up is done. seen several splayed cranks from a company in houston, tx that flaked off in less than 1000 hours. did the company save money, hummmmmmm, well no.
they had to do the job twice and eat the down time.
they had to do the job twice and eat the down time.
Seasoned HDF Member
Joined: Mar 2010
Posts: 38,543
Likes: 6,418
From: Honah Lee
I had 2 summers of Automobile trade school, one summer of machine shop and my senior year took machines shop for a certificate in the 60s.
That's what we did on the motors we rebuilt. The local automotive wrecked car lot supplied us with an endless supply of motors, transmissions, differentials, brake drums .. ECT , to check out, turn and rebuild.
The valve guide tool looked like a roller burnishing tool. One to swell knurling and another smooth one.
We used a hand manual knurling tool also. We didn't knurl to a sharp point. Not sure what kind of life it resulted in but the motors were quite.
That's what we did on the motors we rebuilt. The local automotive wrecked car lot supplied us with an endless supply of motors, transmissions, differentials, brake drums .. ECT , to check out, turn and rebuild.
The valve guide tool looked like a roller burnishing tool. One to swell knurling and another smooth one.
We used a hand manual knurling tool also. We didn't knurl to a sharp point. Not sure what kind of life it resulted in but the motors were quite.
Last edited by Jackie Paper; Feb 29, 2024 at 09:28 AM.
Road Captain
Joined: Oct 2018
Posts: 539
Likes: 284
From: Coldstream B.C. CA.
As bustert mentioned about knurling valve guides, In my day as an engine rebuilder we knurled piston skirts on our oval track race car engines with pistons fresh out of the box for oil retention. An old practice seldom spoke of today.
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Road Master
Joined: Mar 2013
Posts: 817
Likes: 380
From: Central Ohio
I've got a set of Venolia pistons circa 1970s like that. Thermal growth wasn't as controlled as it is now either