4.0 main bearing oiling hole to bearing shell hole cover up ?

[GoatBoy4570]

Ive noticed that the oil hole in the bearing shell does not line up on all but the thrust bearing with the oil passage in the block, are people addressing or ignoring this potential restriction to flow ? seems to me you would at least want the slotted hole in the bearing to line up with the far edge of the oil galley passage ? A little work with a dremel and a small carbide ?

Whats the hot setup here in stroker world for laying the grooved half into the block ?

[jsawduste]

There are three different bearing sets. Each slightly different. Oiling holes and tang locations. Thrust bearing sides also.

If you do decided to grind don't use an abrasive.

Russ can help you.

[KarmaKannon1]

I'll be checking my mains soon. Hopefully this weekend, if I'm lucky. New baby just showed up and yadda yadda that takes some free time away. Anyway, I did run into an issue with the bearings my machine shop got me. Here are some observations that may or may not be directly related to the questions raised by the op.

4.0 main beatings are not the same as 4.2. The rod bearing look the same, but the mains had a different tang location. I found 4.2 mains in a .06 undersize and only .03 or maybe .04 for the 4.0 mains. Long story short, tell, double tell, or triple tell, and explain to your machine shop that you are using a 4.0 block and not a 4.2.

Federal Mogul/ speed pro main/ crank bearings... I'm not a fan. I ordered two sets from summit and both didn't wow me. I talked with Russ and he suggested clevite. We'll see how the clevite mains look. The Federal thrust bearing had cracks in the thrust surface that could grab my fingernail. Maybe it doesn't matter, maybe it does. I didn't like it. See picture.

That's what I've learned over the past few weeks of waisting time and money. I should have just paid Russ for a full kit. I tried to save some pennies and shave some time to get my XJ running before our new baby got here and it probably ended up costing more or the same and taking longer. Live and learn.

Brand new bearings

[Bertismyname]

It looks like your main bores are not concentric. Having wear concentrated on one spot like that is a good indicator of that. For some reason you had uneven crush on your bearings. Or speedpro has really gone to hell.
I've used speedpro quite frequently over a 20 year period, not only as a d.i.y. but also as a professional. I haven't had the issues that I've heard about here. I don't know if its a jeep specific thing, or is it improper installation/oversight. Im not defending speedpro. Just saying. I don't want you to waste anymore time or money. Be double sure that your block is ready to accept the new bearings.

As far as bearings not lining up with oil holes is concerned. Many engines have this issue. Most people just tear an engine down without looking at what was there or going on. Many engines go hundreds of thousands of miles with bearing and block holes being a perfect match. Sometimes it was deliberate to restrict oil. Depending on how much mismatch there is will dictate the fix. If possible I would choose to chamfer the holes in the block before grinding on a bearing. But, first I would be sure that I have the right part.
One engine that comes to mind with a deliberate misalignment of oil holes is the Ford f.e. engines. Oil to the mains was restricted this way to keep pressure up at the rods. Im not sure if jeep did this or not. Nobody seems to have an actual write up on jeep oiling modifications other than deburring the block and baffling the pan. The fact that people can't agree on standard vs. High volume pumps is concerning too. Maybe Russ can chime in on that. Some engines have inherent problems that have well documented and accepted fixes. There seems to be alot of argument over the way to fix the problems that are inherent to jeep engines. Sorry for the high jack.

[KarmaKannon1]

It looks like your main bores are not concentric. Having wear concentrated on one spot like that is a good indicator of that. For some reason you had uneven crush on your bearings. Or speedpro has really gone to hell.
I've used speedpro quite frequently over a 20 year period, not only as a d.i.y. but also as a professional. I haven't had the issues that I've heard about here. I don't know if its a jeep specific thing, or is it improper installation/oversight. Im not defending speedpro. Just saying. I don't want you to waste anymore time or money. Be double sure that your block is ready to accept the new bearings.

As far as bearings not lining up with oil holes is concerned. Many engines have this issue. Most people just tear an engine down without looking at what was there or going on. Many engines go hundreds of thousands of miles with bearing and block holes being a perfect match. Sometimes it was deliberate to restrict oil. Depending on how much mismatch there is will dictate the fix. If possible I would choose to chamfer the holes in the block before grinding on a bearing. But, first I would be sure that I have the right part.
One engine that comes to mind with a deliberate misalignment of oil holes is the Ford f.e. engines. Oil to the mains was restricted this way to keep pressure up at the rods. Im not sure if jeep did this or not. Nobody seems to have an actual write up on jeep oiling modifications other than deburring the block and baffling the pan. The fact that people can't agree on standard vs. High volume pumps is concerning too. Maybe Russ can chime in on that. Some engines have inherent problems that have well documented and accepted fixes. There seems to be alot of argument over the way to fix the problems that are inherent to jeep engines. Sorry for the high jack.

The pictures I posted are brand new bearings. They are dark like that for some reason or another, but it isn't wear.

The issue I heard sited about high pressure oil pumps vs standard was wear on the drive gear. Looking at the gear on mine I'd buy that as a potential issue.

[Bertismyname]

I've seen bearings like that. Not sure what causes the dark spot. Probably just a spot where the coating settled.

[KarmaKannon1]

I've seen bearings like that. Not sure what causes the dark spot. Probably just a spot where the coating settled.

Dark spot aside, the cracks on the thrust surface is what really bothers me.

[Cheromaniac]

Oil pressures of over 60psi can accelerate distributor gear wear. If the engine's built to the correct tolerances and you use a standard volume oil pump plus the factory recommended oil viscosity, you won't have this issue.
A high volume volume oil pump will raise the oil pressure by ~20% over a standard volume oil pump all else being equal. If the oil pressure is at the lower end of normal with a standard volume oil pump, a HV oil pump will rectify this.

[KarmaKannon1]

So I checked a 98 block with factory bearings and the oiling ports on the mains looked the same as the 93 block I have with clevite bearings. The clevite bearings looked much better than the sealed power bearings I posted. Thrust surface was crack free, no burrs on the edges of the bearings, and color was uniform.

image uploader

Maybe you could port the oiling holes to line up with the bearing, but the 4.0 engines last 200k+ if they don't run into head issues so maybe it's a non-issue.

[GoatBoy4570]

[/quote]Dark spot aside, the cracks on the thrust surface is what really bothers me.
[/quote]

I don't know what bronze alloy Federal uses on their thrust but being a premier manufacturer you would assume its the best, may not the best here tho ?
So for bronze to crack you probably need heat and pressure, i have to ask if your a keep it in gear, clutch in while standing idling at a red light type driver cause that's hard on the thrust ?

Away if there is not enough oil in the mix to carry away heat and create a barrier and there is metal to metal contact your gonna have local heating and stress cracking.
Is there evidence of burnt oil on the surface ?

[KarmaKannon1]

Dark spot aside, the cracks on the thrust surface is what really bothers me.
[/quote]

I don't know what bronze alloy Federal uses on their thrust but being a premier manufacturer you would assume its the best, may not the best here tho ?
So for bronze to crack you probably need heat and pressure, i have to ask if your a keep it in gear, clutch in while standing idling at a red light type driver cause that's hard on the thrust ?

Away if there is not enough oil in the mix to carry away heat and create a barrier and there is metal to metal contact your gonna have local heating and stress cracking.
Is there evidence of burnt oil on the surface ?
[/quote]
I hate to mention it again, but for emphasis.. These are BRAND NEW bearings that have not been installed. The BRAND NEW bearings that have never been installed have cracks on the thrust surface. The clevite bearings did not have this.

[GoatBoy4570]

So I checked a 98 block with factory bearings and the oiling ports on the mains looked the same as the 93 block I have with clevite bearings. The clevite bearings looked much better than the sealed power bearings I posted. Thrust surface was crack free, no burrs on the edges of the bearings, and color was uniform.

image uploader

Maybe you could port the oiling holes to line up with the bearing, but the 4.0 engines last 200k+ if they don't run into head issues so maybe it's a non-issue.

Yeah this is a good picture of how some 3/4 of the oil galley is covered up and not much of a hole remains to transfer oil to the grove in the bearing, seems to me the bearing manufacturer and the engine manufacturer were not on the same page as to where that slot should be or where the oil galley passage was gonna get drilled.
Its hard to conceive that this is how this would have been engineered, why a slot instead of a hole ?
A slot would allow the engine manufacturer to determine the oil galley position in relation that slot and control oil flow in that way, if they want more they could just shift the hole ,, or can they ?

So if there is more oil sent to the crank is less oil going to the cam and lifters ?
The 4.0 is not a priority main oiling system, crank and rods are end of the line, so if a little more is sent to the crank is the cam and lifter still gonna get enough ?
Is engine oil pressure determined more by oil hole slot size or bearing clearance ? i would hope its the later !
So in theory anyway it seems to me making the slot bigger would guarantee more oil flow at higher rpm when more oil is being thrown off the crank and demand is higher, if bearing clearances are correct having a bigger oil transfer slot should not effect pressure anywhere in the system, right ?

[GoatBoy4570]

[/quote]
I hate to mention it again, but for emphasis.. These are BRAND NEW bearings that have not been installed. The BRAND NEW bearings that have never been installed have cracks on the thrust surface. The clevite bearings did not have this.
[/quote]

LOL! i guess my brain can't compute new bearings as being cracked, that's a fail on Federals part. So have you considered KING bearings , they are made in Israel and they look like hi grade stuff, bi-metal, Enginetech sells them, look for the K symbol on the shell.

[KarmaKannon1]

I hate to mention it again, but for emphasis.. These are BRAND NEW bearings that have not been installed. The BRAND NEW bearings that have never been installed have cracks on the thrust surface. The clevite bearings did not have this.
[/quote]

LOL! i guess my brain can't compute new bearings as being cracked, that's a fail on Federals part. So have you considered KING bearings , they are made in Israel and they look like hi grade stuff, bi-metal, Enginetech sells them, look for the K symbol on the shell.
[/quote]

I considered them. I didn't know king was made in Israel though. Being a gun guy, I can appreciate some of the stuff that's come out of that place. I went with the clevite and they looked great though. I'm just surprised that two sets of sealed power mains looked like crap. My machine shop got me a set of 4.2 sealed power mains and no kidding they had burrs of the soft bearing material on the bearing surfaces. My sealed power for bearings look fine. Maybe they just forgot how to make crank bearings?

[KarmaKannon1]

So I checked a 98 block with factory bearings and the oiling ports on the mains looked the same as the 93 block I have with clevite bearings. The clevite bearings looked much better than the sealed power bearings I posted. Thrust surface was crack free, no burrs on the edges of the bearings, and color was uniform.

image uploader

Maybe you could port the oiling holes to line up with the bearing, but the 4.0 engines last 200k+ if they don't run into head issues so maybe it's a non-issue.

Yeah this is a good picture of how some 3/4 of the oil galley is covered up and not much of a hole remains to transfer oil to the grove in the bearing, seems to me the bearing manufacturer and the engine manufacturer were not on the same page as to where that slot should be or where the oil galley passage was gonna get drilled.
Its hard to conceive that this is how this would have been engineered, why a slot instead of a hole ?
A slot would allow the engine manufacturer to determine the oil galley position in relation that slot and control oil flow in that way, if they want more they could just shift the hole ,, or can they ?

So if there is more oil sent to the crank is less oil going to the cam and lifters ?
The 4.0 is not a priority main oiling system, crank and rods are end of the line, so if a little more is sent to the crank is the cam and lifter still gonna get enough ?
Is engine oil pressure determined more by oil hole slot size or bearing clearance ? i would hope its the later !
So in theory anyway it seems to me making the slot bigger would guarantee more oil flow at higher rpm when more oil is being thrown off the crank and demand is higher, if bearing clearances are correct having a bigger oil transfer slot should not effect pressure anywhere in the system, right ?

No idea on the bigger implications of oiling and oil system engineering, but I have a 4.0 that was said to have 180k on it with a head that looks rough and rod bearings that had almost no silver left. The mains all looked good on that engine. Not sure if opening those ports would help or hinder the rods since there's always a volume/pressure thing. Sometimes a change in one impacts another and yadda yadda