Ok, I need someone that knows their stuff to let me know if I'm an idiot for buying the King Engine Bearing CR6775XP bearings instead of the OEM Brown Bearings.

Im replacing them on a low milage JDM engine, the ones on it looked not bad but I wanted to make sure I got good parts on everywhere I touched. I figured id get a set of really decent ones that I could thrash, but I neglected the step of verifying it will actually work with my Grade 1 crankshaft pins. I tried cross-referencing the specs between the King Engine Bearings site and the FSM, but Im either misreading one or both of them, or the information on the KEB site is actually useless in answering this question. I bought the 'Standard' size bearing, assuming that Grade 1/Brown is also the "Standard" size for the VQ35DE.

If you know better than I, please tell me on a scale of 1 to 10 how stupid I am, and if I should get ready to return them immediately for OEM Brown bearings. Thanks


Information:
JDM Import VQ35DE
Crankshaft Grade 1 on all 6 cylinders
​​​OEM Brown Bearings
King Engine Bearings CR6775XP- 'Standard' size

 

Referencing my 06 VQ35DE FSM.
Note: King Bearing has these sets listed as compatible with all VQ35DE (including the Revup) & VQ35HR engines.

Main bearing thickness in mm Grade-1 (aka Brown): 2.003 - 2.006 (0.0789 - 0.0790)
Rod bearing thickness in mm Grade-1 (aka Brown): 1.503 - 1.506 (0.0592 - 0.0593)
Rod Bearing Oil Clearance: 0.034 - 0.059mm (0.0013 - 0.0023in) | LIMIT: 0.070mm (0.0028in)
Pin/Rod journal diameter Grade-1: 51.962 - 51.968mm (2.0457 - 2.0460in)

I would give King Bearing a call for detailed specs on the CR6775XP-STD (rods) & MB4058XP-STD (mains) bearing kits as I don't see them posted for each specific bearing P/N listed. But they do show a range and it does appear to be very close to the FSM specs. King Bearing Catalog Specs as shown online...

Crank Diameter (Rods): 51.98 / 51.96 mm
Crank Diameter (Mains): 59.97 / 59.95 mm
Thickness (Rods): 1.502 mm
Thickness (Mains): 2.007 mm

Side Note: In race engine applications, it's fairly normal to run on the more "loose" side of spec, so perhaps that is why the King Bearing specs seem to have larger clearances. But take that with a grain of salt, this is just what I've picked up from watching pros build race engines, I'm not a machinist or engine builder myself. A sort of rule of thumb for determining bearing clearance is .001-inch for every inch of crankshaft main journal or rod journal diameter.

Do you have a micrometer? I would recommend checking over the crank with that before buying any bearings. Even if things look good, I would still choose the bearings from measured values and not what the grade markings claim on the crank. I would also get some plasti-gauge to check clearances are within spec.

Hope you got something out of that.
Cheers!
-Icer

 

Thats very much useful.

I sent them an Email but not going to get a response until later today. From my interpretation of what I read from my FSM, and what you provided, it should be A-Ok to use. I do not have a micrometer or plasti-gauge unfortunately, so I hoped that given little wear on the old bearings that I would be safe to assume the grading on the crank is still accurate.

For reference, the below photo is how all my rod bearings looked, no scoring at all I could feel, just a little discoloration.