Rebuild Question: Bearings

[unicoder]

Question, I read that the KA24DE doesn't do bearings the typical way other engines do (my only build experience was a 4G63-T engine)

That you have to specifically buy each bearing based on numbers posted on the main cap, and same for rods.

However, when I watch KA builds on youtube, they just have a pack of bearings all the same size (like I would expect)

Can someone who has put one of these together reply here to enlighten me which way this works?

[kyral]

they say your supposed to check the numbers on the block and crank and match them together to figure out what bearing to use. its really expensive to do so and nobody really does that

I did a cheap rebuild and just threw standards in it was low budget had no issues

when I did my second rebuild my machine shop told me to just use standard size bearings. have had no issues

[Jrguzman]

I am running standard bearings as well for my rebuilt ka24det. Also had the crankshaft journals polished. I would get some plastic gauge though to check clearances.

[brndck]

Originally Posted by kyral

they say your supposed to check the numbers on the block and crank and match them together to figure out what bearing to use. its really expensive to do so and nobody really does that

totally not true. any decent machine shop or engine builder WILL check the clearances to make sure the correct size bearings are selected. anyone who skips this is asking for issues.

granted, MOST of the time, the size bearing that came out is the size bearing you will order and use.

BUT. why would you skip such a simple step, that can cause such massive headaches and wallet pains later on down the line???

do it right the first time, or do it twice.

[NiSilS14]

Most 90s nissan engines used this method, and this only applies to factory bearings with factory set clearances. If you have the crank or the block remachined then they won't apply anymore. They are a set of 4 numbers and a set of 5 numbers on the block and numbers on the crank, each corresponding with rod and main journals. For ka24de, the numbers 0,1,2 are used. The numbers are added to give you which "grade" bearing to use for that specific journal. for example, if the crank reads, 1111 / 11111 and the block is 0000 / 00000. those numbers would add up to use grade 1 bearings. there is total of 4 different grades of bearings.

[kyral]

Originally Posted by brndck

totally not true. any decent machine shop or engine builder WILL check the clearances to make sure the correct size bearings are selected. anyone who skips this is asking for issues.

granted, MOST of the time, the size bearing that came out is the size bearing you will order and use.

BUT. why would you skip such a simple step, that can cause such massive headaches and wallet pains later on down the line???

do it right the first time, or do it twice.

Actually VERY true. clevite, ACL, KING, they do not offer bearings like that. they offer them in stardard and oversized. most ppl have their machine shop measure their clearances and let them know which direction they need to go.
very few ppl go with oem Nissan bearings (they are good bearings though)

If you don't use the machine shop then plastigauge is gonna be your best friend. Youll likely have no issues running standard bearings but like I said just plastigauge it if youre not doing any machining

regardless of which direction you go, after you install the crank check to make sure it spins freely. then each piston you install check and make sure it spins freely (once the pistons start going in expect there to be a little extra resistance every half turn, this is normal and is caused by the pistons sliding through the bores and the resistance should free up when they get around TDC and BDC. then you should feel the resistance again as they leave TDC and BDC)