Engine machine shop work

Bob Bancroft · Mar 20, 2018

I was given a project which involves a little 3 cylinder diesel that has a spun rod bearing. Shop was able to save the crankshaft at .020 under. I just found out they ground the other two rod journals .020 also! I've not hear of this. I don't believe in doing, or paying for extra, unnecessary work. They said what they do to one rod journal, they do to all! I'm glad it's not a 6 cylinder. Is this common?

kevinecwi · Mar 20, 2018

Personally I'd prefer them to be the same. Only want to order one set of bearings then.

rrlund · Mar 20, 2018

I've never heard of only grinding one. I don't think you have to take off much to throw off the balance do you?

C. Amick · Mar 20, 2018

Never heard of only grinding one. Standard practice is to have them all the same size.

Mike(NEOhio) · Mar 20, 2018

I took a 6 cyl crank in with real bad mains (needed to go .020 under) and the rod journals were real good. The guy said right out that he would not do the mains only, which I expected and didn't want anyway. Grind only one and you can't be sure it's concentric with the others and could lead to early failure. Then you go back and complain about the lousy job he did. Do it right and do it once.

David G · Mar 20, 2018

You want it balanced, not grinding all would do this, standard practice.

Bob Bancroft · Mar 20, 2018

I've seen it done. But then it's been a long time since I worked in a shop for a living. And those were mostly relatively slow turning gas engines. I do recall helping an elderly neighbor, probably 20 years ago, on a David Brown 1200 which had one rod journal undersized.

504 · Mar 20, 2018

Yes I want all of them turned. But back in the day Chrysler might have four different sizes in one motor. Dad told me it was common to just tun one journal in the 1950s. But they did not take the crank out either.

marloweg · Mar 20, 2018

all get ground

Bob · Mar 20, 2018

Should have been your choice.

It's best to grind all "mains", at one time, if one needs it, but there's no reason to grind all the "rods" if only on has issues an the others are "in spec".

For me, it's not about the cost, simply WHY should we throw away good metal and limit future options?

used red MN · Mar 20, 2018

I?d like to see the tool that can grind a crank throw journal with the crank still in the engine. Not saying there isn?t such a thing, but that unit would have to be fairly elaborate. We are talking some pretty close tolerances here. Main journals would be easier to do, but that?s a lot of grit being washed around in the grinding wheel coolant stream.

John Deere D · Mar 21, 2018

QUOTE:
Used red mn

I?d like to see the tool that can grind a crank throw journal with the crank still in the engine. Not saying there isn?t such a thing, but that unit would have to be fairly elaborate.

Yes the Machine is fairly elaborate.

Between 1973 > 1995 "WASHINGTON IRON WORKS" out of Sherman Texas, ground several Connecting Rod Journals In Place on LARGE Natural Gas Internal Combustion Engines while I was a Power Engineer.

However, the Engines were Ingersoll Rand Models "DT" "FT"... Nordberg's 4000 HP and Clark 10,000 HP. They would grinned a Journal undersize up to 10% undersize from OEM specs:

The machine was assembled on the Journal, with the understanding, "Washington Iron Works" Journal Grinder was not up to every ones viewing:

"WASHINGTON IRON WORKS" Poured, Manufactured and supplied all Undersize Bearings.

Here is a Picture, of my late good friend "Richard" at "WASHINGTON IRON WORKS ". Checking a Journal on a Crank in "WASHINGTON IRON WORKS" Shop.

Bob...Retired Power Engineer....

Bob Bancroft · Mar 21, 2018

Precisely. I forgot to add what you say last.

caterpillar guy · Mar 21, 2018

I've got the crank in my 806 has one journal 20 under the rest are standard. Been there about 30 years now with no problems. It was the main horse for 20 years.

Mike M · Mar 21, 2018

If it's a common engine with good parts avail. then doing them all will be easier to buy a rebuilt kit. I had some oddball engines you could not find undersized bearings for so I had to have a journal built back up to standard.

markct · Mar 21, 2018

What extra you spent on the machine work you likely saved on the kit being all one size not buying individual bearings. And I doubt the cost was much more to do the other two, the majority of the time is the setup not the actual machining work

showcrop · Mar 21, 2018

I have a '46 Oliver 70 that when I got into it I found that it had one sleeve and piston that had been replaced. I am sure that this sort of thing used to be done. Can you imagine going into an old engine to replace bearing inserts and how long and how much hair pulling it would take to figure out that some one had just one journal turned?

tim s · Mar 21, 2018

I would never grind just one journal,,keep them all the same and the next guy that O/H's the engine will appreciate it..

Bob Bancroft · Mar 21, 2018

I don't see that as an issue. Last I knew bearing inserts have the size stamped in the back- std, 010., 020., etc. And a few minutes with a micrometer tells the story.

oldsarge · Mar 21, 2018

There's one for sale on E-bay right know

dr sportster · Mar 21, 2018

The tool has been pictured right here on this site.

dr sportster · Mar 21, 2018

The bearings are sold for all .

travis miranowski · Mar 21, 2018

X2 what has already been said!!!! I would never grind just one journal. Grinding just one is not a good practice and you did not really pay any extra. The work in turning a crank is in the setup not the actual grinding. And by grinding just one, you are going to be forced to buy individual bearings which is costlier than a set.

used red MN · Mar 21, 2018

Thanks D, ya it probably takes more than an hour or three to pull a crank out of one of those. Very interesting. The refinery I work at had 3 or so Ingersoll Rand V-8s with recip?s coming off the common crankcase. Pistons were the size of 5gal buckets. Came here in 2001 they were out of service then. Probably put in during the 60?s. Maybe even the 50?s. One the crankshafts was broke where the flywheel mounted. The flywheel was probably 6 ft in dia. and weighed the a couple tons. I?m glad I wasn?t around when she came loose the steel I beams of the enclosure building have some dents in them from the happenings.

jm. · Mar 21, 2018

You may want it that way but NO reliable engine shop will grind just one journal. Just not accepted practice now days.

jimg.allentown · Mar 21, 2018

Such a tool does indeed exist. It isn't all that elaborate, but it takes a lot of know-how and experience to operate it.

Some years ago, the dealer I worked for serviced a fleet of ambulances. In those day, they were modified Cadillacs. One came in with a knock in the engine. It was torn down to the extent of removing the oil pan, finding the bad bearing, and a machinist was called in to grind the crank in place. In those days, the repairs were done as cheaply as possible.

Another time, one came in with a cracked block. It was a vertical crack in one of the cylinder bores. Again, a machinist was called in once the problem was diagnosed and torn down. The machinist bored out the cylinder and installed a sleeve with the engine in the vehicle.

As far as I know, neither one of those vehicles had any further related problems.

Engine machine shop work

Well-known Member

Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Member

Well-known Member

Well-known Member

Well-known Member

Similar threads