Rod bearing size - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

socaldrifter13 · 11-02-2009, 04:55 PM

I would like to know if any one knows what size rod bearings I need for a stock KA24DE. I don’t know if I need to get the STD size or a bigger size to allow for any rubbing. And I do not have a gage to measure the size of the rod or crank shaft.

*let5l1de* · 11-02-2009, 05:26 PM

OMG are you serious? To allow for any rubbing?

This is a great example of why you need to take your engine to a reputable shop and have it built for you. Yes, building any engine in this world typically requires the use of special tools, the knowledge of how to use them, a mechanic of some sort that has basic knowledge the type of engine and selection of parts. Yes, many people may be able to assemble an engine, but there is much more to assembling an engine correctly than just turning nuts and bolts...

If anyone thinks differently, you're an idiot... turn your vehicle off, never operate an engine, motor or turbine ever again and walk for the rest of your life.

To answer your question:
If your journal is std and your rod is std, I would imagine you would use a std rod bearing. Use plastigauge (shutters at the thought...) to check the rod bearing clearance.

Did you check the big end of your rod to see if its within specs? Did you have your journal checked for size, roundness and taper?

pm me if you plan to have your engine built right.

~mario

Hashiriya415 · 11-02-2009, 06:04 PM

STOP Before you do any more damage and destroy your engine

sr20sean · 11-02-2009, 06:06 PM

the rod journals on the crank should be between 1.970" and 1.9675"

use a micrometer. go get your crank polished. it only cost me 20 bucks to get mine polished. lol

importdude · 11-02-2009, 06:15 PM

have the crank polished and most of the time the machine shop will measure and tell you what size bearing you should get

*Ceepo* · 11-02-2009, 06:49 PM

i assembed my sr20det, i had a shop do all the machine work and he did the crank, rods, and block journals for me, i had a spun bearing on my 3rd cylinder, i had to go .75 over on the rods. and .25 over on my crank, i have never rebuilt a motor nor did i have any help besides the stated above and the car has ran great for a month, no rod knock, or anything, just take your time, and if you dont know how to do it, research it like a motherfer or take it to a shop, oh yeah, afinity times check everything if you do do it yourself, i did and im glad i did, i had my timing off a tooth on the crank pully... better safe then sorry...

p.s. if your saying you need larger ones for rubbing take it to the shop, you dont want any kind of rubbing in your motor, you want it to turn over smooth and all your clearances to be right... you need standard i bet, the bigger size im assuming is for if you have to grind the crank(spun bearing, ect...)

*let5l1de* · 11-02-2009, 09:15 PM

Quote:

Originally Posted by sr20sean

the rod journals on the crank should be between 1.970" and 1.9675"

use a micrometer. go get your crank polished. it only cost me 20 bucks to get mine polished. lol

Where did you get your rod journal numbers from?

I see factory specs as (Any S Chassis KA24DE):

Journal Diameter
Grade No. 0 as 1.9672" - 1.9675"
Grade No. 1 as 1.9670" - 1.9672"
Grade No. 2 as 1.9668" - 1.9670"

Journal Limit
Taper of Journal = 0.0001"
Out of Round = 0.0002"

Bearing Clearance
Connecting Rod Clearance = 0.0004" - 0.0014"

Limit
Connecting Rod Clearance Limit = 0.0035"

~m

11-02-2009, 04:55 PM	#1
socaldrifter13 Leaky Injector Join Date: May 2008 Location: Santa Clarita Ca Age: 24 Posts: 95 Trader Rating: (4)	Rod bearing size I would like to know if any one knows what size rod bearings I need for a stock KA24DE. I don’t know if I need to get the STD size or a bigger size to allow for any rubbing. And I do not have a gage to measure the size of the rod or crank shaft. __________________

11-02-2009, 05:26 PM	#2
let5l1de premium bullsh!t sifter Join Date: Dec 2007 Location: 626DRIFT, ca Posts: 1,053 Trader Rating: (23) Rides Gallery: let5l1de	OMG are you serious? To allow for any rubbing? This is a great example of why you need to take your engine to a reputable shop and have it built for you. Yes, building any engine in this world typically requires the use of special tools, the knowledge of how to use them, a mechanic of some sort that has basic knowledge the type of engine and selection of parts. Yes, many people may be able to assemble an engine, but there is much more to assembling an engine correctly than just turning nuts and bolts... If anyone thinks differently, you're an idiot... turn your vehicle off, never operate an engine, motor or turbine ever again and walk for the rest of your life. To answer your question: If your journal is std and your rod is std, I would imagine you would use a std rod bearing. Use plastigauge (shutters at the thought...) to check the rod bearing clearance. Did you check the big end of your rod to see if its within specs? Did you have your journal checked for size, roundness and taper? pm me if you plan to have your engine built right. ~mario __________________ Don't Know How To Install? IM/PM Read My Sales Review 626 Friday Nights San Gabriel

11-02-2009, 06:04 PM	#3
Hashiriya415 Zilvia Member Join Date: Jun 2007 Location: San Francisco Age: 22 Posts: 158 Trader Rating: (3)	STOP Before you do any more damage and destroy your engine __________________ WTD 05 600 gixxer under tail exhaust.

11-02-2009, 06:15 PM	#5
importdude Zilvia FREAK! Join Date: Nov 2006 Location: san j0 Posts: 1,042 Trader Rating: (11)	have the crank polished and most of the time the machine shop will measure and tell you what size bearing you should get __________________ built ka-t

11-02-2009, 06:49 PM	#6
Ceepo Premium Member Join Date: Jan 2008 Location: Cedar City, Utah Posts: 1,245 Trader Rating: (6) Rides Gallery: Ceepo	i assembed my sr20det, i had a shop do all the machine work and he did the crank, rods, and block journals for me, i had a spun bearing on my 3rd cylinder, i had to go .75 over on the rods. and .25 over on my crank, i have never rebuilt a motor nor did i have any help besides the stated above and the car has ran great for a month, no rod knock, or anything, just take your time, and if you dont know how to do it, research it like a motherfer or take it to a shop, oh yeah, afinity times check everything if you do do it yourself, i did and im glad i did, i had my timing off a tooth on the crank pully... better safe then sorry... p.s. if your saying you need larger ones for rubbing take it to the shop, you dont want any kind of rubbing in your motor, you want it to turn over smooth and all your clearances to be right... you need standard i bet, the bigger size im assuming is for if you have to grind the crank(spun bearing, ect...) __________________ 1995 240sx SE (current)

11-02-2009, 06:06 PM	#4
sr20sean Zilvia Member Join Date: Apr 2009 Location: poughkeepsie, ny Age: 18 Posts: 175 Trader Rating: (2)	the rod journals on the crank should be between 1.970" and 1.9675" use a micrometer. go get your crank polished. it only cost me 20 bucks to get mine polished. lol

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