bearing are shot after 50 miles...

[6damian6]

I have yet to actually see a machine shop properly clean the oil passages in a Mitsubishi crank shaft. You have to remove the balls at the end of the passage to properly get them cleaned well. You would be very surprised how much crap is in there from years of running. Before i knew how to remove the balls i called about 5 machine shops in my area and not one single one knew how to remove them.

So how do you remove them?

 

[BogusSVO]

I have yet to actually see a machine shop properly clean the oil passages in a Mitsubishi crank shaft. You have to remove the balls at the end of the passage to properly get them cleaned well. You would be very surprised how much crap is in there from years of running. Before i knew how to remove the balls i called about 5 machine shops in my area and not one single one knew how to remove them.

^^^^^ THIS^^^^^

Here is how this game is played..... ( In most machine shops)

1) You, the customer take your crank to the machine shop.
2) Machine shop says your crank needs ground/polished
3) You, the customer agree that it does.
4) The shop takes your info and issues the crank a number
5) The crank goes to clean up, either in a spray cabinet or a hot tank
6) Crank gets "cleaned" by the low man on the totem pole
7) The clean up guy will take it to the crank guy
8) The Crank guy will do the work requested, grind/and or polish
9) The Crank guy will maybe blow compressed air thu the galleys, then spray crank with WD40 and place in bag.
10) The Crank guy will turn in the paperwork on your crank
11) The machine shop will call you and tell your crank is done for you to pick up.
12) You, the Customer will go pick up your crank

Now at this point, you take your freshly machined crank home, pull it out of the bag and see how clean the OUTSIDE of the cank is and think they did an amazing job of cleaning it.

AT THIS POINT, you are thinking WRONG!
(MOST shops) Have a disclamier tag on the crank or on the recipit
saying that it is up to the installer to check clearance and final clean the part.

You, not knowing or not reading, miss this little tidbit of info.

Place the crank right from the machine shop ,that has grit from the crank grinding wheel or the polishing belt in the oil galleys of the crank, on the brand new bearings.
You finish build the engine.
Like a good builder, you prime the oil system, that oil now picks up the grit in the crank oil galleys and pushes it right in to the new bearings.

Then the bearings fail.

Now you are back at square one with bad bearings again.

It is not the machine shops fault, they gave you a disclaimer.

 

[bryanwheat]

So how do you remove them?

The best way that i've found is to heat them up with a tig welder until they deform than cool them with air and remove with a pick. A mig and arc welder won't work well because they are constantly adding material. The tig you can concentrate the arc directly to the ball.

 

[awdspyder98]

^^^^^ THIS^^^^^

Here is how this game is played..... ( In most machine shops)

1) You, the customer take your crank to the machine shop.
2) Machine shop says your crank needs ground/polished
3) You, the customer agree that it does.
4) The shop takes your info and issues the crank a number
5) The crank goes to clean up, either in a spray cabinet or a hot tank
6) Crank gets "cleaned" by the low man on the totem pole
7) The clean up guy will take it to the crank guy
8) The Crank guy will do the work requested, grind/and or polish
9) The Crank guy will maybe blow compressed air thu the galleys, then spray crank with WD40 and place in bag.
10) The Crank guy will turn in the paperwork on your crank
11) The machine shop will call you and tell your crank is done for you to pick up.
12) You, the Customer will go pick up your crank

Now at this point, you take your freshly machined crank home, pull it out of the bag and see how clean the OUTSIDE of the cank is and think they did an amazing job of cleaning it.

AT THIS POINT, you are thinking WRONG!
(MOST shops) Have a disclamier tag on the crank or on the recipit
saying that it is up to the installer to check clearance and final clean the part.

You, not knowing or not reading, miss this little tidbit of info.

Place the crank right from the machine shop ,that has grit from the crank grinding wheel or the polishing belt in the oil galleys of the crank, on the brand new bearings.
You finish build the engine.
Like a good builder, you prime the oil system, that oil now picks up the grit in the crank oil galleys and pushes it right in to the new bearings.

Then the bearings fail.

Now you are back at square one with bad bearings again.

It is not the machine shops fault, they gave you a disclaimer.

Mmm... Intresting info. I didnt know about removing the ball.

 

[WES_393]

The first 4g63 I ever built had the exact same wear pattern (just much worse) after only about 200 miles. I took the block and crank down to a machinist who has literally hundreds of 4g63's under his belt. The second the machinist saw the bearings he said "dirty assembly". After I explained to him how much a clean freak I am, he popped out one of the plugs to show me the grime that builds up in the passages. This is not only full of carbon, but following an engine failure this grime can be full of metal shavings. Not to mention the oil passages being partially blocked can reduce oil flow. I had the crank cleaned (inside and out), new plugs in the passages, and had all the oil galleys in the block manually scrubbed (not just hot tanked). Following the engine break in I pulled a rod cap to find the bearings in perfect condition.

Moral of the story, I think that was your issue: Oil contamination eating up the bearings.

 

[importracr317]

None of you guys who've had this problem have had it with a new crank, correct? All this talk of improper or "dirty" assembly has me worried that after 50 miles on my build I'll be tearing it down again because of bad bearings.....only everything on my bottom end was brand new.

 

[donniekak]

If the steel balls in the oil galley drill holes aren't removed when these cranks are cut, this happens.

 

[awdspyder98]

If the steel balls in the oil galley drill holes aren't removed when these cranks are cut, this happens.

what a way to learn a lesson....

 

[mrfister11]

also for future reference.... you should plastigauge the rod bearings and the main bearings... that way you know what oil to use and if you need to fix the clearances...
you should never use think oil on any engine unless it is built for that.. people think that thicker oil is better.. wrong.. like that SBC issue.. its more wear on things plus sometimes the oil is too thick to go through between the crank and bearings.. the low oil pressure might have been caused by too much clearance on the bearings... after it had worn..

ive built many engines and never use thick oil to "break it in".. if it works it works..

 

[bryanwheat]

also for future reference.... you should plastigauge the rod bearings and the main bearings... that way you know what oil to use and if you need to fix the clearances...
you should never use think oil on any engine unless it is built for that.. people think that thicker oil is better.. wrong.. like that SBC issue.. its more wear on things plus sometimes the oil is too thick to go through between the crank and bearings.. the low oil pressure might have been caused by too much clearance on the bearings... after it had worn..

ive built many engines and never use thick oil to "break it in".. if it works it works..

Comparing a small block oil pump that is driven by the distributor to the oiling system on these cars is kind of silly huh.

 

[mrfister11]

ye as far as that concept goes but I'm sure it would wearon oil pump bearings more

 

[bryanwheat]

ye as far as that concept goes but I'm sure it would wearon oil pump bearings more

Oil pump bearings? I am not sure what those are. I am also not sure if you know how many people run 20w50 in these engines.

 

[mrfister11]

Yes a lot of ignorant people if u must know

I was thinking the balance shaft ones for some reason

 

[bryanwheat]

Yes a lot of ignorant people if u must know

I am pretty sure that Dave Bucsher runs 20/50 in his cars, along with most of the guys out there running the fastest times in these cars. They must all be ignorant huh.

 

[mrfister11]

Also so no one gets theirs panties in a twist. That'd my opinion from my experience and it's worked do far

They plastigauged their engines and have more clearance maybe? Cmon. I know ## not smart ### of how many engines ####ed up that u built but seriously

 

[awdspyder98]

also for future reference.... you should plastigauge the rod bearings and the main bearings... that way you know what oil to use and if you need to fix the clearances...
..

Just wanted to ask. Ive seen videos on how to plastigauge the bearings but one thing Im alittle confused on is if its off then how would you repair it.. replace with another set of new bearings?

 

[cdm_sd02]

Just wanted to ask. Ive seen videos on how to plastigauge the bearings but one thing Im alittle confused on is if its off then how would you repair it.. replace with another set of new bearings?

The right way is measure it and do the math...
Plastigauge is an ok way to do it, but allows cleance issues when building race motors.
IN a daily beater, No problem

 

[Tyeler18]

The right way is measure it and do the math...
Plastigauge is an ok way to do it, but allows cleance issues when building race motors.
IN a daily beater, No problem

This. The proper way is to use an inside micrometer in the big end of the rod with bearings installed and the outside mic the crank rod journal.

To fix it you can SOMETIMES buy a different clearance bearing, however, if it's way out of spec generally the crank will have to be cut. (not a good idea on a 4g crank)

 

[1983gsp]

You use under or oversized bearings. Sometimes you can swap one bearing side for another and get the correct clearance. Loose lives in a high power dsm. Tight clearances are great for grandma but tight on a high power dsm can mean destruction. On a loose engine, thicker oil is great. My machinest asked what the Max HP my engine would see and adjusted clearances for my application.
My engine is pretty loose and he reccomended 20-50. I've used 10-30 and at hot idle my oil pressure hung around 15 psi. With 20-50 hot idle pressure is 25psi. Also, with tight clearances, when you turn up the wick on a dsm, bearings tend to get spun.


Tyeler beat me to it haha!

 

[mrfister11]

### disregard my rude post. I was driving in traffic getting pissed and didn't read everything. Sorry OP

 

[cdm_sd02]

This. The proper way is to use an inside micrometer in the big end of the rod with bearings installed and the outside mic the crank rod journal.

To fix it you can SOMETIMES buy a different clearance bearing, however, if it's way out of spec generally the crank will have to be cut. (not a good idea on a 4g crank)

Like I said, Measure it

 

[turboglenn]

Just to add some info, if your clearances are just a little off (talking range of .0005 - .0008) You can sometimes get away with new bearings of a different size. Mine was a little loose using OEM mitsu bearings so just for shits and giggles i brought my machinist a set of ACL race bearings and they made the clearances perfectly where he wanted them at .0025"

He was very picky about the clearance, I brought him 3 cranks before he finally went and got a different block and built the engine with the best combo of cranks and the new block..5then of course the ACL bearings over tyhe mitsu ones for the final little details.

Also, when using plasigauge don't forget to remove the stuff after using it to check clearances, not sure it would do much but i've got a friend who said he left it on there after checking his engine (it still runs though )

 

[evileagleawd]

The right way is measure it and do the math...
Plastigauge is an ok way to do it, but allows cleance issues when building race motors.
IN a daily beater, No problem

I second this i trust math over a little peice of crushed plastic!

 

[cdm_sd02]

Been doing these motors for a long time, and yes we are talking about tenths when you measure.

Now are we going to help this kid or keep bugging over how to measure something....

Anyways have you pulled the motor out yet?

 

[awdspyder98]

Haven't pulled it yet. dropping off a spare crank and block at the machine shop today to get looked at.planning on ordering a set of Weisco 10.5 pistons today. Might as well upgrade while in there. Whats a bit confusing is my prosport gauge showed 0 psi at hot idle but my stock gauge read alittle over the low mark. Not sure what to make of it. I will be installing a know working oil pump this coming weekend and recheck my oil pressure just to verify my pump wasn't part of the issue.