To rebuild or not to rebuild this old engine?

[Soundguy]

Nice... yet another example.

soundguy

 

[TYMinColton]

Any good suggestions for internet sites that sell reasonably priced engine parts for a 172 ci diesel engine?

I've checked out Phil's Tractor & Supply and Walt's tractors and I can pick up most of my shopping list, is there somewhere else you guys trust that I should check out??

My Shopping list:
1. Complete engine gasket set.
2. 0.02 sized piston - complete ring set
3. Main bearings (probably 0.001 undersized)
4. Rod Bearings (probably 0.001 undersized)

Thanks
Pete

PS Might be a few weeks. My wife side-swiped a (stationary) telephone pole last weekend and we have a $500 deductible. . . ugh.

 

[Soundguy]

Try the parts section at Antique Tractors - Yesterday's Tractors : Antique Tractor Headquarters

check Just 8N's .. they sell some parts for the hundred series.

also check out restoration supply Tractor Parts Restoration Supply Antique Tractor Parts - John Deere Farmall Allis Chalmers

soundguy

 

[john_bud]

I bought a cheap gasket set. It was worthless trash. The holes were punched in the wrong places, gaskets stretched too big, etc. I'd go to a NAPA and buy local. Buy junk, get junk.

Have you plastigaged the bearings? They may be fine...

jb


Oh, I know it's being a stickler, but bearing are OVERSIZE not undersized. The crank is ground down smaller, so the bearings have to be larger to keep the clearance the same. When I see "undersize" bearings, it's like fingernails on a chalk board for me. (Sorry!)

 

[larso1]

I think pistons are oversized (unless you resleeve the cylinders), but technically speaking crank bearings would be undersized because the OD of the bearing shells stays the same but the ID is actually smaller than stock to compensate for the material removed from the crank journals. If they were "oversized", the clearance would be way out of spec, right?

 

[TYMinColton]

I think pistons are oversized (unless you resleeve the cylinders), but technically speaking crank bearings would be undersized because the OD of the bearing shells stays the same but the ID is actually smaller than stock to compensate for the material removed from the crank journals. If they were "oversized", the clearance would be way out of spec, right?

Yup. This engine's cyls were rebored for 0.02 oversized pistons (unsleeved block), so I will be buying a 0.02 oversized ring set. As I understand it for the bearing shells, your explanation seems correct. Seemed strange at first, shells only coming in undersizes, but when you think about it, it does make sense. I've looked at the shells and they seem to have a 001 stamped on them.
Pete

 

[TYMinColton]

I bought a cheap gasket set. It was worthless trash. The holes were punched in the wrong places, gaskets stretched too big, etc. I'd go to a NAPA and buy local. Buy junk, get junk.

So, do you think that these gasket sets that are being sold by Walt's and several others are junk? My worry is that there are soooo many little gaskets that I won't be able to find them at NAPA. Perhaps I need to take a trip to my local New Holland dealer?

Have you plastigaged the bearings? They may be fine...

I have not - on the list. There does appear to be some "minor" wear on the inner surface of the shells - at least as it compares to the pics in the ford shop manual. If I have to cut corners here I might just buy a set of rod bearings and reuse the main set.

Oh, I know it's being a stickler, but bearing are OVERSIZE not undersized. The crank is ground down smaller, so the bearings have to be larger to keep the clearance the same. When I see "undersize" bearings, it's like fingernails on a chalk board for me. (Sorry!)

Hmmmm. . . . everywhere I look bearings (both main and rod) seem to be advertised as either STD or "undersizes" of 0.001-0.002; 0.01-0.03. I guess I just figured that if you grind down the crankshaft, this would result in a smaller shaft OD. Consequently, a STD bearing shell would now have an ID that is larger than the OD of the shaft, creating a larger than spec gap between shell and shaft. To compensate you would use an "undersized" shell that has a smaller ID to match the smaller OD of the crankshaft. I would also expect that the stock material would have to be slightly thicker to keep the bearing OD the same. Am I wrong here? You may be right, but I'm having trouble picturing it. . . .sorry.
Pete

 

[Soundguy]

Bearing sheels are so cheap.. If I cut corners i'd throw all the shells in.. same size as they came out, and not turn the crank / cam unless I saw gouges in the journals or bearing surfaces.. not really saving money by not putting new shells in.. of course.. you can plastigauge them and see how close to spec they are.. might be close enough to not mess with if oil pressure was good .. etc.

soundguy

 

[RobJ]

I think pistons are oversized (unless you resleeve the cylinders), but technically speaking crank bearings would be undersized because the OD of the bearing shells stays the same but the ID is actually smaller than stock to compensate for the material removed from the crank journals. If they were "oversized", the clearance would be way out of spec, right?

correct, shell bearings are sized to the crank, not the rod. If I recall from my former trade, pistons will have a + on them and the bearings will have a - on them.

Of course don't forget cam bearings and such. Easy to replace...if you have the right tool.

 

[TYMinColton]

Bearing sheels are so cheap.. If I cut corners i'd throw all the shells in.. same size as they came out, and not turn the crank / cam unless I saw gouges in the journals or bearing surfaces.. not really saving money by not putting new shells in.. of course.. you can plastigauge them and see how close to spec they are.. might be close enough to not mess with if oil pressure was good .. etc.

soundguy

Well, I'm definitely NOT going to turn the crank. The journals look spotless and there are no detectable gouges. I'm looking at about $70 for main and rod bearings, which isn't "cheap", but probably worth the investment at this point.

RobJ -
I haven't looked at the cam bearings, but plan to do so. I suspect like the other replaceable bearings, they're also in decent shape, and I can most likely get away without replacements. Moreover, depending on what you mean by the "right" tool, I suspect I don't have it. . . . . Good suggestion nonetheless. . . .

Haven't seen any + or - markings on pistons/bearings, but that doesn't mean they're not hidden. . . . the top of pistons are clearly marked .02 and backside of bearings have a part # and a 001 stamped on them. I'm guessing this means they're 0.001 undersized, but I haven't spec'd 'em with a plastigage yet.
-Pete

 

[Soundguy]

As much work as it is to tear down an engine.. unless I could'nt eat or something.. the 70$ for the new shells would be worth it.

soundguy

 

[TYMinColton]

As much work as it is to tear down an engine.. unless I could'nt eat or something.. the 70$ for the new shells would be worth it.

soundguy

I know . . . I know. . . .look at me whining like a little baby. Yeah, I can afford bearing shells. Now if only they were pasta shells it'd be a whole lot cheaper . . . and tastier. .

 

[Soundguy]

Everyone's got their own stuff to worry about. I'm sure we've all been there when the 70's for new sheels where thehere were already good shells would make a difference.

if you can swing it.. do it.. if ya can't and they are good.. don't loose any sleep over them.. We've also all put stuff back together with worn parts before... that's life.

soundguy

 

[TYMinColton]

As much work as it is to tear down an engine.. unless I could'nt eat or something.. the 70$ for the new shells would be worth it.

soundguy

Hey soundguy,
Do you have any recommendations/experiences dealing with gaskets sets? It seemed like a no-brainer to just buy a whole kit, but as jb points out, they can be crap, and that would clearly more trouble than it's worth. For example, Walt's sells the following kit that apparently replaces (172-6008D -original part #).
1.UF15190 Complete Engine Overhaul Gasket Set 801, 901, 4000. 4 cyl. Diesel.(Complete Engine Overhaul Gasket Set-)$68.85

How do I know if this kit is any good?
Pete

 

[john_bud]

RobJ -
I haven't looked at the cam bearings, but plan to do so. I suspect like the other replaceable bearings, they're also in decent shape, and I can most likely get away without replacements. Moreover, depending on what you mean by the "right" tool, I suspect I don't have it. . . . . Good suggestion nonetheless. . . .
-Pete

Look all you want, but you won't find. The 172 has no cam bearings. Hey, look at the savings!

Re: bearing talk. The spec on a bearing is the thickness. Oversized is thicker to account for the crank being whittled down smaller. You buy the bearings oversized for a crank that is undersize. But who knows ... that's just me


jb

 

[Soundguy]

In the past i have used gasket sets from CNH.. which i'm sure are tisco. I've also used aftermarket sets.. I've actually had some problems with aftermarket sets with some gaskets not being thick enough.

soundguy

 

[Soundguy]

Look all you want, but you won't find. The 172 has no cam bearings. Hey, look at the savings!

Re: bearing talk. The spec on a bearing is the thickness. Oversized is thicker to account for the crank being whittled down smaller. You buy the bearings oversized for a crank that is undersize. But who knows ... that's just me


jb

Before i passed over that I'd make sure it has not been bored for replaceable cam bearings. We've all seen the pic's of the 8n blocks with custom machine work done to allow for such.. etc.

soundguy

 

[RobJ]

Forgot to att these on the parts...I have used these before for MF and JD stuff.

brandon@endurancepower.com (he might still be there).

P & D Mechanical Heavy Equipment Repair & Service - Upstate & Central NY

Might only have a replaceable cam bearing in the front. Unless really worn, I'd leave it to.

Your basic cam bearing replacement tool...

 

[TYMinColton]

Re: bearing talk. The spec on a bearing is the thickness. Oversized is thicker to account for the crank being whittled down smaller. You buy the bearings oversized for a crank that is undersize. But who knows ... that's just me
jb

Setting aside the question of whether bearings are undersized or oversized for a moment, how do tell what I currently have? Is there a number stamped on the bearing shells (there are numbers but I don't know what they refer to) or do I need to take measurements? If so, of what and with what? (plastigage? micrometer?)
Thanks,
Pete

 

[john_bud]

There is normally a number stamped on the back of the bearing shell