S13 SR20 OEM Bearings - Help - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

s13louren · 12-26-2018, 10:00 PM

Hey guys, I pulled my SR apart (after finding a nut in the oil pan) and after measuring bearing clearances realized that the main bearings are slightly out of spec, and may as well replace the rod bearings while I have it pulled apart to this degree.

I will try to include as much information as possible, but then have a handful of questions. First, the crank has not previously been machined and the previous bearings were OEM bearings. I would like to replace with OEM bearings, however, I am having trouble deciphering the markings on the crank and block. I have included a picture of the crank / block markings below, am I accurate in saying I need to order STD bearings 3 - 3 - 3 - 2 - 3?

As for rod bearings, how do I determine which OEM bearings to order?

Outside of RHD Japan, who else sells OEM bearings? Is there a better place to order from?

Thank you in advance for any help and suggestions.

jedi03 · 12-27-2018, 08:16 AM

https://forums.nicoclub.com/diy-rebu...t-t309576.html
This series of numbers is a code that says that each journal is a particular inner diameter on the block. The first digit is the first journal and each one after that is the following journal.

Next, you look at the front of the #1 counterweight of the crank. Nissan says that there are two different styles of stampings on their counterweights, I have only seen the one I highlighted in red below.

This is a very light engraving, so if you didn't have your crank tanked and cleaned, you'll probably need to wipe the oil residue off to see the stamp.

The most common style has two rows of numbers. One row has 4 digits, the other has 5. The row of 4 references the connecting rod bearings, while the row of 5 is for the main bearings.

For our example, we'll assume that the crank has a stamping that looks like:001001320

And our block has the stamping:11123

Nissan supplies a chart in the service manuals that you cross reference the stampings to get a bearing grade.

You take the stamp from the cylinder block and find it along the top row, then find the crank stamp on the left column. Then trace them till they cross each other. That is the bearing grade you need. Tip: It's simple addition.

For example, we're trying to find the Number 3 journal size. On the crank we have 0 1 3 2 0 and the block has 1 1 1 2 3. The number 3 is a 3 for the crank and a 1 for the block.

I highlighted the column and row for the grade numbers and where the intersect. Our grade 3 and 1 crank and journal will require a Grade 4 bearing.

Finding rod bearings is easier. The row of 4 digits on the crank is all you need. The left most number is the bearing grade you need for the number one connecting rod, the second is number 2, etc. The reason you don't have to do a cross referencing for the rods like you do for the main bearings is that Nissan considers all rods to be identical for the races. There are stampings on the rod indicating other than the cylinder number stamp. These stamps are to denote what size wrist pin bushing is needed.

When you order bearings from Nissan, you will need to order 2 bearings of each kind for the rods as Nissan sells them in bearing halves. When you order main bearings, you will get both halves.

12-26-2018, 10:00 PM	#1
s13louren Join Date: Dec 2018 Location: Edmonton Age: 34 Posts: 4 Trader Rating: (0) Feedback Score: 0 reviews	S13 SR20 OEM Bearings - Help Hey guys, I pulled my SR apart (after finding a nut in the oil pan) and after measuring bearing clearances realized that the main bearings are slightly out of spec, and may as well replace the rod bearings while I have it pulled apart to this degree. I will try to include as much information as possible, but then have a handful of questions. First, the crank has not previously been machined and the previous bearings were OEM bearings. I would like to replace with OEM bearings, however, I am having trouble deciphering the markings on the crank and block. I have included a picture of the crank / block markings below, am I accurate in saying I need to order STD bearings 3 - 3 - 3 - 2 - 3? As for rod bearings, how do I determine which OEM bearings to order? Outside of RHD Japan, who else sells OEM bearings? Is there a better place to order from? Thank you in advance for any help and suggestions.

12-27-2018, 08:16 AM	#2
jedi03 Nissanaholic! Join Date: Jul 2008 Location: albuquerque Posts: 1,836 Trader Rating: (8) Feedback Score: 8 reviews	https://forums.nicoclub.com/diy-rebu...t-t309576.html This series of numbers is a code that says that each journal is a particular inner diameter on the block. The first digit is the first journal and each one after that is the following journal. Next, you look at the front of the #1 counterweight of the crank. Nissan says that there are two different styles of stampings on their counterweights, I have only seen the one I highlighted in red below. This is a very light engraving, so if you didn't have your crank tanked and cleaned, you'll probably need to wipe the oil residue off to see the stamp. The most common style has two rows of numbers. One row has 4 digits, the other has 5. The row of 4 references the connecting rod bearings, while the row of 5 is for the main bearings. For our example, we'll assume that the crank has a stamping that looks like:001001320 And our block has the stamping:11123 Nissan supplies a chart in the service manuals that you cross reference the stampings to get a bearing grade. You take the stamp from the cylinder block and find it along the top row, then find the crank stamp on the left column. Then trace them till they cross each other. That is the bearing grade you need. Tip: It's simple addition. For example, we're trying to find the Number 3 journal size. On the crank we have 0 1 3 2 0 and the block has 1 1 1 2 3. The number 3 is a 3 for the crank and a 1 for the block. I highlighted the column and row for the grade numbers and where the intersect. Our grade 3 and 1 crank and journal will require a Grade 4 bearing. Finding rod bearings is easier. The row of 4 digits on the crank is all you need. The left most number is the bearing grade you need for the number one connecting rod, the second is number 2, etc. The reason you don't have to do a cross referencing for the rods like you do for the main bearings is that Nissan considers all rods to be identical for the races. There are stampings on the rod indicating other than the cylinder number stamp. These stamps are to denote what size wrist pin bushing is needed. When you order bearings from Nissan, you will need to order 2 bearings of each kind for the rods as Nissan sells them in bearing halves. When you order main bearings, you will get both halves.