GTR Forum banner
1 - 17 of 17 Posts

·
Registered
Joined
·
9,768 Posts
Discussion Starter · #1 ·
Stamped marking on the new crank to identify correct bearing sizes as per the pdf manual.

I guess the 0 is referring to std size, but what are the B's and the Green paint how does that match up to the chart? :confused:



 

·
Registered
Joined
·
9,768 Posts
Discussion Starter · #5 · (Edited)
What is the green paint referring to? big ends or main end bearings?

So the mains and thrust bearing are graded B and the big ends for the conrods are graded 0?

So in other words, I need grade 1 for mains and grade 0 for big ends right?

http://www.nismo.co.jp/en/products/competition/engine/pdf/metal.pdf

They still seem to be using the old method of identification...

I got the crank new from Nissan in Japan.
 

·
Premium Member
Joined
·
11,878 Posts
You need to know the grade of the opposing bearing face and work your bearing thickness. The sizes marked on the crank are only 1/2 the story, literally.
 

·
Registered
Joined
·
1,968 Posts
Are you using a new block and new con rods for your build??

Anyway, you need to get the big end of the con rods measured and then together with the 0 of the crank you can start choosing the right bearing.

Same for the block...

...new block would be marked and you need to work out the right bearing for the combination of B (1) on the crank and the correspondent letter (number) on the block.

If you're using a used block (maybe your old one) you should get it properly measured to check if the bearing surface might have already worn out a little, so the factory marking is no longer correct.

Furthermore if you're building a performance engine the factory oil clearance is too tight and you'll want bigger oil clearance, so the chart in the workshop manual is not that much help anyway ;)

Best is always to get both diameters of the bearing properly measured, check what bearing thickness is available and calculate oil clearance on your own until you find the right thickness for the desired oil clearance :thumbsup:

HTH

Leo
 

·
Premium Member
Joined
·
11,878 Posts
I'm not too sure the block bearing surfaces are going to wear too much. If you measure your block, you need to measure in 0.001mm resolution.
 

·
Premium Member
Joined
·
11,878 Posts
Can someone please double check I got the bearing selection right: Thrust bearing in ()

Block F-R 2 2 3 (2) 2 3 3

Crank B B B(B) B B B

Bearing 3 3 4 (3) 3 4 4
You have followed the book with your grades. They are in accordance with nissans recommendations.

Just to muddy the waters, a lot of tuners add 1 to the nissan grade to open up the clearance. Making 4-4-5-(4)-4-5-5 . Their thinking is it reduced the risk of spinning shells or something.
 

·
Registered
Joined
·
2,464 Posts
The green paint was solely used for nissan workers when building the engine they would have yellow,blue,green and pink inductors to let them know the correct grade of bearings to fit instead of measuring they would just match the colours upto to each engine when assembling ... When building mine it had green on the block
 
1 - 17 of 17 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top