Thread: choosing bearings

my bad. You guys know what i meant. lol. Plastigauge doesnt even go to .022, haha.

Yeah ill go and change it in my original post.

forgive my stupidity but where does the 34343 fall into the chart you posted?

dre is there a second number stamped on the rod aswell? i know there is a number stamped next to each bore on the deck.. but this is piston grade isnt it

hey, im looking at this website:
ACL 5M2964H/X Race Main Bearing Set Nissan SR20DE/SR20DET

and the specify the following about the ACLS:

MIN. STD. SHAFT SIZE 2.1636" / 54.956mm
MAX. STD. SHAFT SIZE 2.1646" / 54.980mm
MIN. STD. TUNNEL SIZE 2.3206" / 58.944mm
MAX. STD. TUNNEL SIZE 2.3216" / 58.968mm
MAX WALL AT CROWN 0.0780" / 1.980mm
MAX. OVERALL LENGTH 0.752" / 19.10mm

My question... is the 1.980 mm the bearing thickness?
if so wouldnt that make the ACL's as thick as the stock Nissan Grade 1 bearing? (ie. not the middle grade)

ummm... Those numbers on the crank and block are just for the factory. From the factory they install slightly different sizes of bearing to make them all the exact same clearance. When you rebuild your engine, those numbers aren't necessary to go by. The oil clearance is a fairly broad range from .0008 up to.002 with a safe margin being .0015 as a common standard. These numbers vary from engine to engine and between manufacturers and I've seen some clearances as large as .004 and larger. I've also seen some as small as .0002.

The numbers that you need to pay attention to are the ones stamped on the back side of the bearing near the alignment tab. You need to look for STD or some oversize number. If they are standard size bearings than you get standard bearings to replace them as long as your crank is in good condition and doesn't need to be ground to an oversize.

I recommend having the crank micropolished before installation of new bearings. I also plastigage each and every bearing before considering a crank instal complete. This ensures that your clearances are where they should be and that you won't have any problems when you run the engine.

You do not need to worry about the numbers stamped into the crank and block when purchasing bearings. The only place that you'll be able to get the grade specific bearings is from Nissan and you will pay out the ass for the same bearings that you can get anywhere else for $50 for a set of rods and mains...

And to edit myself, rods are $37 or so and mains are $48 or so at the local parts stores. I purchase my bearings online as a package and get them for a dollar more than the mains alone. It also isn't always necessary to replace the thrust washer, but isn't a bad idea to do so.

The FSM for the S14 KA engine says specifically to use the SUM of the markings on the crank and on the rods for selecting rod bearing grades and the SUM of the markings on the block and on the crank for selecting main bearing grades. I cannot imagine that Nissan would change its methodology to a less stringent specification for one specific version of one specific engine when they do it this way for every other engine they produce - especially when that engine is considered to be one of their high performance models, as in the case of the SR.

Hey guys. Not here to bash anyone else's methods but I am a little OCD I guess. You need a micrometer and some snap gauges to set your oil clearances. The reason you can just throw any grade bearing on the mains is because all of the standard size bearings are between 0.0007 and 0.0017 or 0.0009-0.0022 on some other fsms. That's one thousands of an inch. Who do you know that owns a micrometer that can read into the tenths of thousands and does not work at a machine shop? So my question to anyone here would be does anyone know of a cheap reliable caliper or micrometer that can read down to .0001? I am currently rebuilding a p10 motor for high boost with forged internals yada yada.

I'm not really following your post, EVH.

If you're rebuilding a motor with forged internals, go ACL race or ACL STD.

thx but I think I'll stick with oem and get the machine shop to mic it out. Gunna set it around 0.0015 right in the middle. It's a burnt up p10 motor from pap. I've got a few 4cw se cranks laying around I'll probably use. I'll post up pics of my build if anyone cares.