Bearing Grades question

[-Bradders-]

As you probably all know lol

 

I'm ordering my new bearings shells etc.. if i chose oem, they ask me for my bearing grades? they are odd like grade 0 grade 6 grade 9 etc...

 

How will i know what grade to go for as of now i just opted for ACL race bearings which are a one size fits all kind of option, is that ok?

 

Thanks in advance.

 

Brad

[evilscorp]

The crank and engine block have letters stamped on it to tell you the diameter of each journal,bearing groove(brain dead, just woke up,so not technical yet). These two marks are used to select the correct bearing thickness with oem items, but if you have to polish or hone the crank they won't be much use, it's a better more accurate way than acl General standard size, to which you probably will have to polish some journals so they are all similar sizes (using plasti gauge). Tells you it all in the workshop manual I think.

[-Bradders-]

found a linky on google on sr20 forum cheers! you put it into clearer words than i was reading lol! thanks.

[evilscorp]

I went for the acl as someone was selling them ages ago, also I am aiming for the largest gap oem tolerance, whereas you will probably want mid range for a standard rebuild. Shouldn't be an issue just have to measure a lot more whereas you could just pick that oem bearing as listed in the table and be confident it would give you the gap you are after without any work.

[evilscorp]

No problem, =)

[-Bradders-]

I've already ordered the ACL ones. here's what i've gone for

 

ACL Race Series Main & Rod Bearing Set w/ Thrust Washers, Standard - Nissan 350Z 03-06 VQ35DE Z33

[evilscorp]

Same as the ones I have. . . Somewhere.

[OllyB]

With the acl you have no control over your clearance. Oem bearings allow you to chose bearings based on crank journal size etc.

Edited February 12, 2016 by OllyB

[Mark@Abbey m/s]

We always use ACL bearings on our builds. We polish the crank to get the clearances spot on.

 

With the VQ we always run the centre main bearing with a little bigger than stock clearance.

 

Best to use plastigauge to check bearing clearances.

 

Always have the crank checked for straightness as well.

[evilscorp]

Nice to see traders/boffins/(Mark) post info like this. Not something I had ever thought of but, its basic mechanics checking things are straight.

When you say the center main bearing, do you mean the one with the thrust washer? If so is this to allow more oil to be squeezed out and over the thrust washers.

[-Bradders-]

Cranks off now in machinist being checked and polished along with the heads being pressure tested and skimmed.

 

Thanks for the input! I've ordered the acl bearings.

[Mark@Abbey m/s]

Centre main I am talking about the one with the thrust bearing.

 

It is to take into account the way the crank flexes under load. If you run the centre bearing right it will possibly pick that bearing up.

 

More oil flow is also good as well thou.

 

[Mark@Abbey m/s]

Cranks off now in machinist being checked and polished along with the heads being pressure tested and skimmed.

 

Thanks for the input! I've ordered the acl bearings.

 

Skim the heads the minimum to clean them if you skim them to much front covers won't fit nicely and lower inlet manifold won't fit as removing to material will change the angle of the V between the heads and the bolt position for the rear cam cover will not line up with the cylinder head bolts holes.