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View Full Version : ka24de graded bearing cannot find


kyral
12-03-2015, 06:18 PM
Ive been trying to rebuild my ka24de and im looknig for the graded bearings online and i cannot seem to find them anywhere besides frsport and they have them
But it doesnt seem that i can get that middle bearing (I think its the thrust bearing) as an individual graded Nissan bearing

And all the aftermarket kits and bearing packages always say that the bearings are "Standard Size" idk what that means since ka24de bearings varied from the factory to match the specific engine block and crank

anyone have any insight

thegr8one013
12-03-2015, 08:01 PM
I don't think the thrust bearing comes in different thicknesses but I'm not 100% sure.

Most aftermarket bearings come in the one standard size which is usually the middle size of all the ranges oem has. Every engine I built I used aftermarket bearing and made sure there was enough clearance and every time there was enough clearance

kyral
12-03-2015, 09:23 PM
now im seeing oversized bearing from DNJ and undersized bearing from every other brand, on rock auto?

how would i know what the standard is without buying it and measuring it

KAT-PWR
12-04-2015, 08:02 AM
I have used plain old STD size bearings in 2 rebuilds. Both times the machine shop verified tolerances to be correct.
Take it for what it is worth.
My father insisted on verifying the grade off the girdle/crank but in my younger days I impulse bought things and standard acl bearings were what I used and it worked out.

thegr8one013
12-04-2015, 08:09 AM
Oversized bearings are for cut cranks. Undersized bearings are for the rare occasion that the standard size aftermarket bearing are top tight in clearance

thegr8one013
12-04-2015, 08:11 AM
Based off you asking about this I'm assuming you are having someone else build your motor? If so, you should really speak to your engine builder about it to make sure u buy a good brand bearing and I'm sure he has no problem explaining the details with u

kyral
12-04-2015, 01:55 PM
im rebuilding the bottom end myself.

It sounds to me like the grading system stamped into the block gets forgotten about and everyone just buys a "standard sized" bearing kit and then plastigage it before reasembly.
is this right?

thegr8one013
12-04-2015, 03:14 PM
I don't know anybody who plastiguage anymore. We use micrometers and telescoping T's.

It's never forgotten about, but the difference in thickness is so small.

The main oil bearing clearance for a ka24de is .0008-.0040" and the difference in thickness between the thickness from stepping up a grade or down a grade is .0003"

Every ka24de motor I have assembled with standard sized bearings end up in the .002x"