Line bore case and new oil pump.

Some time back I asked about a new oil pump
installation and the need to line bore because
a new oil pump would mean the front main
crankshaft cap was also being replaced as it is
part of a new oil pump. I called a machine shop
in Indiana who does work for a leading tractor
remanufacturing and tractor parts company. I
spoke with one of their techs and he told me he
has had this brought up before and some say yes
and some say no. His personal answer was yes,by
the book you should line bore. He went on to
say most folks just plasta gauge and if its
.003 or less they button it up. However as TOH
had told me the center of the crank would be
off and that is part of the reason he said to
line bore and the tech said TOH is 100%
correct. He told me I could take the liner out
and it may or may not show wear. I ask him if
the cap--liner and crank would self center, his
answer was no. So I can say yes line bore when
doing this job and avoid possibility of a
problem. If you did it the way I had done mine
and many others had you would get away with it
and never know. I going to leave mine alone and
not tear it out. At this point next time I
would have it line bored as TOH said it is the
correct way.To TOH I hope I explained the
centering of the crank correctly. <9))))))>{

WW2N,Yes with a main cap from a different engine or a new cap(oil pump)the block needs to be line bored.Some folks win the lottery but not me.If I have a engine that has a main failure or a main cap replaced I always he it line bored and not take the chance of a failure.

It is similar to pulling a tired motor and slapping in some new rings. You may extend the life another 20% or 50% ???
If you get a main cap that fits close you may get a few years of service out of that motor since you still have 2 full mains and the upper half of the front main that are in the correct location .
The illustration TOH had on the center line of the crank was to convey the message that the center line could be off . We don't know if the center line is a couple of thousandths off or tens of thousandths . We also don't know if it is off towards the block side or the cap side .
Sometimes people get Lucky or close enough . These motors work very well with loose tolerances and even run pretty good on 3 cylinders . That is one of the reasons they are still so popular .

Looks to me like if you want to go to all the trouble of "line boring" the block it would be a lot simpler to take the old pump housing to a really good macheinist and have him build up the worn part and re-machein it back to original tolerances.
Fact is I have an old friend (83) who has been doing this kind of work for about 60 years to look into doing it.
Might just start another business???

Zane

When you put that "new" pump housing in and have it line bored send me the old one and I'll have it fixed and start a swap you pump business.

Zane

(quoted from post at 10:09:55 03/03/15) When you put that "new" pump housing in and have it line bored send me the old one and I'll have it fixed and start a swap you pump business.

Zane

Click to expand...

A new pump is roughly $110 so your friend better work cheap. And even if your friend can somehow re-manufacture the old pump back to factory specs it STILL needs to be line bored to fit anything other than the block it came off of. Line honing caps is standard operating procedure in most/many shops and is not "complicated".....

TOH

I would assume that in the manufacture of an
engine block every surface would have to be
directly related to all the other machined
surfaces of the block???????????
Zane

(quoted from post at 19:30:03 03/03/15) I would assume that in the manufacture of an
engine block every surface would have to be
directly related to all the other machined
surfaces of the block???????????
Zane

Click to expand...

It's probably more accurate to say they are indirectly related to each other. The basic block geometry is defined relative to the center line of the crankshaft. That's why the first step in blueprinting an engine is truing the main bearing tunnel.

TOH

Ya I had read it somewhere"After" I did it. But hears the catch. It is the "technical" way it should be done TOH is right 100% no argue as Dell says. I bet there is a bunch of Ns running around not line bored with the new oil pump in them today, yesterday, years ago and years to come. If the plasta says it is ok a lot of guys will button them up and that will be that. To most guys they look down that crank, think abour taking the engine out and run it to town, it becomes easy for a knuckle banger like me to say I'll gamble. I guess I will live with my decision as it was 4 yrs ago and no known problems. You and anybody else that say you must line bore are correct, I really did not know. Thanks for the heads up on it. The best thing that will come of this is it will be in the archives for guys like me to find it and do it right. I know I had my manual out while doing it and it said nothing about it, I will say this any time I can fix something right the first time I would have done as your post said. Thanks

Ken take a look at my reply to Den in Ms let me
know what ya think.

Some are directly related. The main saddle, for example, is parallel to the block deck. Align boring the main caps insures the misalignment would not cause binding of the crankshaft. That causes hydrodynamic oil film breakdown and binding of the crankshaft which leads to a crankshaft breaking. But the caps are only half the story. The main saddle MUST be checked for proper alignment which is done with main caps torqued down to spec, block sitting on the table and use a .0015 feeler gauge to determine "warpage" of the saddle. If the .0015 won't go under then the saddle is not warped.

(quoted from post at 22:28:11 03/03/15) Ken take a look at my reply to Den in Ms let me
know what ya think.

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I have seen a lot of "get-r-done" repairs that were temporary patch jobs that outlasted the rest of the vehicle . These N's perform well past typical normal wear limits .
I have an N that was patched up from used parts that we use to pull a feed / hay wagon . I don't think I would want to strain it out in the field bush hogging but then again I didn't think it would last more than one winter feeding either .

(quoted from post at 07:29:53 03/04/15) Some are directly related. The main saddle, for example, is parallel to the block deck. Align boring the main caps insures the misalignment would not cause binding of the crankshaft. That causes hydrodynamic oil film breakdown and binding of the crankshaft which leads to a crankshaft breaking. But the caps are only half the story. The main saddle MUST be checked for proper alignment which is done with main caps torqued down to spec, block sitting on the table and use a .0015 feeler gauge to determine "warpage" of the saddle. If the .0015 won't go under then the saddle is not warped.

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I don't understand your description - please elaborate. What is the reference surface for the feeler gauge examination?

TOH

(quoted from post at 15:35:05 03/04/15)

(quoted from post at 22:28:11 03/03/15) Ken take a look at my reply to Den in Ms let me
know what ya think.

Click to expand...

I have seen a lot of "get-r-done" repairs that were temporary patch jobs that outlasted the rest of the vehicle . These N's perform well past typical normal wear limits .
I have an N that was patched up from used parts that we use to pull a feed / hay wagon . I don't think I would want to strain it out in the field bush hogging but then again I didn't think it would last more than one winter feeding either .

Click to expand...

These N's perform well past typical normal wear limits .
That's the standard excuse for why you see so many misinformed recommendations they accept and stand behind that statement... Its there backup plan when they don't know the correct way to fix it to start off with...

I have never understood why there are so many that refuse to understand the correct way to fix a issue and will fight you over there hack repairs... We are lucky have TOH explain the proper fix...

(quoted from post at 09:04:24 03/04/15)

(quoted from post at 15:35:05 03/04/15)

(quoted from post at 22:28:11 03/03/15) Ken take a look at my reply to Den in Ms let me
know what ya think.

Click to expand...

I have seen a lot of "get-r-done" repairs that were temporary patch jobs that outlasted the rest of the vehicle . These N's perform well past typical normal wear limits .
I have an N that was patched up from used parts that we use to pull a feed / hay wagon . I don't think I would want to strain it out in the field bush hogging but then again I didn't think it would last more than one winter feeding either .

Click to expand...

These N's perform well past typical normal wear limits .
That's the standard excuse for why you see so many misinformed recommendations they accept and stand behind that statement... Its there backup plan when they don't know the correct way to fix it to start off with...

I have never understood why there are so many that refuse to understand the correct way to fix a issue and will fight you over there hack repairs... We are lucky have TOH explain the proper fix...

Click to expand...

Thanks for the vote of confidence and for saying what I wanted to say but didn't.

The factory engineers set their manufacturing tolerances (not clearances) based on a designed service life and level of performance. If you want something close to the factory service life and performance out of your rebuild then you need to try as best you can to build to their tolerances. If you are happy with reduced performance and/or a shorter service life then build it to your relaxed tolerances.

TOH

These N's perform well past typical normal wear limits .
That's the standard excuse for why you see so many misinformed recommendations they accept and stand behind that statement... Its there backup plan when they don't know the correct way to fix it to start off with...

I have never understood why there are so many that refuse to understand the correct way to fix a issue and will fight you over there hack repairs... We are lucky have TOH explain the proper fix...

Click to expand...

Once upon a time money was tight , parts were expensive , and people made a living farming the land with these little tractors , hacking was a way of life because of necessity .

Now with the internet knowledge super high way any parts availability , hacking is done because someone decided to take the easy route .

(quoted from post at 20:36:21 03/04/15)

These N's perform well past typical normal wear limits .
That's the standard excuse for why you see so many misinformed recommendations they accept and stand behind that statement... Its there backup plan when they don't know the correct way to fix it to start off with...

I have never understood why there are so many that refuse to understand the correct way to fix a issue and will fight you over there hack repairs... We are lucky have TOH explain the proper fix...

Click to expand...

Once upon a time money was tight , parts were expensive , and people made a living farming the land with these little tractors , hacking was a way of life because of necessity .

Now with the internet knowledge super high way any parts availability , hacking is done because someone decided to take the easy route .

Click to expand...

Yes, we are all guilty at some time are another... I should have used farmerized my dad did it his dad did it I don't consider either a hacker...

A straight edge. I forgot to include that. My mistake.