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View Full Version : ConRod Bearings and Main Bearing Help



Punisher
07-25-2006, 05:49 PM
Hey guys, I need to order new conrod bearings and main bearings for the 3sgte.. How do I know which bearings to order tho? I do believe they come in different sizes.. My crank hasn't been turned.. so it should still be at stock size on the journals.

Should I just order std. size main bearings and then use the numbers found on the conrod bearing caps to order those bearings?

91 celica st
07-25-2006, 11:03 PM
why are you putting new ones on? you really should take the crank to a machinest and have them look at it and have him order you bearings

Punisher
07-26-2006, 12:30 AM
Well I can mic the crank myself.. I haven't done it yet.. not positive if I will replace them.. Only thing I can replace them with is standard size.. toyota doesn't offer oversized bearings. so yea..

91 celica st
07-26-2006, 12:37 AM
if theyre all in spec then use it, and sorry to tell you but i would never trust my calipers from home on a crank, your going 5 decimals down and calipers only go 4 so... plus it has to be climate controlled, goto a mechanic and ask him what temp he has his shop at, it will always be between 67-72....68 is the optimal temperature cuz if its hotter than that metal expands, colder it contracts....so if your garage is 90 degrees you will not get an accuarate reading

Punisher
07-26-2006, 12:45 AM
I have a caliper that reads 5 decimals mr. smart guy :lolhittin:

I guess I'm going to get fucked then because the machinist I took my head and block to works out of his garage.. same with all of the engine machinists around here.. maybe things are more sophiscated in your neck of the woods?

91 celica st
07-26-2006, 01:27 AM
even if it reads 5 decimals i would never trust it....at bare minimum you should go get a micrometer guage and use your calipers on it to see if it mics 100%, if it dosent i wouldnt use it at all

and things are more sophisticated over here, i just dont half ass shit

MrWOT
07-26-2006, 02:10 AM
Unless you have alot of time and money on your hands I'd take it to a good engine shop. They will size the bearings to each journal so they all have the right clearance.

No telling what you get with just a single package of bearings. I've seen variations of +-0.03 from standard in even Clevite and Federal Mogul bearings, as well as factory Ford, Honda, Mitsubishi and BMW. If you're insistant on doing it yourself, you need to buy at least 2 sets of bearings, and platigauge so you can size them the best you can. If you want to get fancy, you can chamfer the edge of the oil passages too, that will help the flow a bit.

Punisher
07-26-2006, 02:20 AM
even if it reads 5 decimals i would never trust it....at bare minimum you should go get a micrometer guage and use your calipers on it to see if it mics 100%, if it dosent i wouldnt use it at all

and things are more sophisticated over here, i just dont half ass shit

I am doing my work at my buddies machine shop.. and he's been a machinist for 20+ yrs... I'm sure we'll be able to get things pretty damn accurate :D

I really don't know what to do about the bearings.. I'll find out at the shop that is doing my engine work what he would charge to set the bottom end up..

91 celica st
07-26-2006, 06:02 AM
thats good, i thoguht u were doing it alone....im in my 3rd semster as a machinest at the college, gets pretty complex, i only get +-.00002 tolerance on my projects now

Dr.Auto
07-26-2006, 07:40 AM
I am doing my work at my buddies machine shop.. and he's been a machinist for 20+ yrs... I'm sure we'll be able to get things pretty damn accurate :D

I really don't know what to do about the bearings.. I'll find out at the shop that is doing my engine work what he would charge to set the bottom end up..
Ummmm......yeah. So why don't you get his reccommendation on what to do for bearings? You know, since he will be the one responsable for the machining and will know how it needs to be set up.

Punisher
07-26-2006, 04:54 PM
I am going to ask the guy I took my engine too what he would charge to set the bottom end up.. if it is to much I'll have to take everything down to my buddies machine shop and we'll mic everything up and get it together as close as possible.

I ain't made of money and I've just spent a shitload of cash already...

and a +-.00002 tolerance is really pointless.. unless you are going to be making some sort of high tech shit...

91 celica st
07-26-2006, 10:57 PM
cuz its good for practice. what you do when you practice is what your going to do in the real world...we started off at only having to get it to 1 thousanth +-