2 bad rod bearings new motor

[buddy3824]

I built the motor from the ground up. After 15 miles i get bad knock from bottom end. We checked oil pressure and it was 90psi at idle. Guess gauge wasnt workin. So I tear down the oil pan amd #2 and #4 rod bearings have dark rub marka in center of bearing, on the caps and rod it self. I had standard sized king rod bearings and clearance was at .002 using green plastiguage prior to enine assembly. What would cause 2 bearings to start clunking around while the two on 1 and 3 are just fine?? Could all that oil pressure have something to do with it??
Thanks.

 

[hubz91talontsi]

Well, if you gauge does work--How do you know you ever had oil pressure?

Edit: I see what you mean.. You used another gauge and had 90psi at idle? My has over 100 at first start up, so thats probably not the issue.

 

[JusMX141]

90psi at IDLE? WTF

If that's the case, there's your problem. When oil is injected at high pressure into a tight tolerance, it will burn instead of lubricate. The same holds true for turbochargers....too much oil pressure can be just as dangerous a too little.

 

[thomcasey]

^^^Agreed. That seems very high. I have performed the BSE, and have yet to port the OPR valve or clip the spring, and at warm idle (850 rpm) my oil pressure is at 15-20. On cold starts it is at 75. 90 sounds like something is definitely clogged.

 

[hubz91talontsi]

I get 110psi at start up - I've never had an issue like this, but i still haven't figured out why its so high.

 

[ramsack]

High pressure with cold oil is no worry. High pressure when fully warmed up is a bad thing. Mitsubishi recommends using an OEM filter or one capable of holding (not exploding from) at least 256 psi of oil pressure, for cold starts.

 

[buddy3824]

It wasnt a cold cold start. Had been unnin for about 5 mins and temp outsid was 60 degrees. I habe bse and porting the relief port is on the to do list.
If indeed the pressure caused te burning of the bearings, then why just cylinders 2 and 4??? Any ideas there?

 

[matt98eclipse]

Dam my king bearings just failed like 2 weeks ago but mine was due to too much gas in my oil i believe.

 

[donniekak]

Dam my king bearings just failed like 2 weeks ago but mine was due to too much gas in my oil i believe.

I run valvoline vr1 20w50 synthetic racing oil. It holds up to fuel contamination great from the e85 i run.

 

[olddsmer]

Did you have the crank checked to see if it was in spec? I wonder if for some reason it isn't perfectly straight it would cause a journal to rub the bearings.
Did you assemble using moly lube? King makes good bearings. They aren't as soft as the clevites or acl's. Have your crank checked, cleaned and polished.

Good Luck
Greg

 

[matt98eclipse]

I run valvoline vr1 20w50 synthetic racing oil. It holds up to fuel contamination great from the e85 i run.

Dam donnie i really never thought about running the thinker oil with the E85 fuel. I bet if i had done that my bearings may have still been good.

 

[donniekak]

Dam donnie i really never thought about running the thinker oil with the E85 fuel. I bet if i had done that my bearings may have still been good.

It says right on the bottle" formulated for gasoline and alcohol fuels".

If i could see all of the bearings out of that engine, i have a good chance of being able to tell you exactly what caused the failure.

Also, everytime i fill up, i check the oil, and smell it. When it starts to smell like alcohol, i change it, no matter what the mileage.

 

[ziggo0]

You probably had a journal or 2 out of round. What prompted the motor rebuild in the first place?

 

[buddy3824]

Detoation on cylinder 2 caused the rebuild. Melted piston and rings. Still unknown cause. Everyhing was checked and inspected for rebuild. Block was looked at for cracks, honed and bored. The crank had te main journals cut .25mm and was polished and balanced. I would sure as hell hope they guy checked the roundness of the rod journals. I did use clevite bearing lube in assembly process, im putting clevites in it this time and recheck tolerances to see of that is of an issue on wednesday.

 

[JacksonAuto]

Did you check to make sure that the rod caps didn't get mixed up?

If there is a problem with the oiling system you will typically see damage to the whole engine not just two rods.

It's also possible that the detonation which caused the first failure distorted the big ends of the rods. Just like if the rod journals are out of round, if the big end is not concentric you can end up with tight spots.

 

[buddy3824]

Well it has eagle rods in it now, before was just factory. By getting rod caps mixed up, your saying that each rod has a cap that is specific tothat rod?

 

[JacksonAuto]

Yep. Each cap is specific to the rod

 

[buddy3824]

Are there markngs that would allow me to figure out which cap goes to which rod dedinetly?

 

[donniekak]

Are there markngs that would allow me to figure out which cap goes to which rod dedinetly?

You should mark them when you get them.

An easy way to tell is to torque the cap onto the rod, and run your fingernail around the inside. The correct rod/cap, should have no noticeable ridge between the cap and rod, you should be able to slide your fingernail from rod to cap, and not feel anything.

 

[JacksonAuto]

Youre lucky this time. Eagle rods have a number laser etched on each rod and cap. Take a peek and make sure each cap has the same number as the corresponding rod. If not, then they got mixed up.

 

[buddy3824]

Update:
Cylinder 2 and 4 caps were on backwards thus causing a lip to form and shear the bearing. New Clevites are in.
New question. Do i still need to port my ofh? Could excess contact area on these 2 bearings have caused a rise in oil pressure??

 

[JusMX141]

I'd port the housing anyway- too much pressure is never a good thing. Also, keep an eye on your turbo as any metal from the bad bearings has undoubtedly found it's way to the turbo.

 

[buddy3824]

Sounds good. Thanks all for the help

 

[rlacasse1]

Is your crank still in good shape after it fried those bearings? Are you going to just put it back together without checking it out?

 

[buddy3824]

I plastigauged the clearances and everything seemed ok. the crank had a faint smear on the rod journal. mic showed no variance in the roundness of the journal so I'm assuming it is ok. I do believe the tolerance is .015mm for 6 bolt crank?

I dont have time to drop the whole tranny and crank to have the crank machined and checked, as I have no vehicle and having to move out of town in a couple weeks.