YABEB - Yet Another Bottem End Build
 

So, after planning for this for three years, I finally started the build on my bottom end. Of course I have some questions:

Most importantly: I'm installing a VVT crank in a NB1 block. What type thrust bearing do I need? Or to put it differently is the difference with the block or with the crank? Or did I screw up and they're both different and this combination is not allowed?

Secondly: Ebay China-rods. crank clearance looks good on all 4 (ACL race bearings). But the wristpin clearance seems low to me. I'm right at 0.0004" +/- 0.0001", essentially between 3/10 of a 1/1000 and 5/10 of a 1/1000. They feel snug. They actually feel more snug in the rods than in the pistons (Supertechs). One I had to open up a bit with a hone, because it was maybe 1/10000- if that.

Last but not least, my front and rear main seal surfaces look a bit 'used'. The dips can easily be felt with a fingernail. Shut I cut them down and sleeve, or am I OK? Pictures attached.

On the thrust bearing you'll have to measure the saddle width on the block to see if you need the old narrow bearing or the new wide bearing. The NB1 block is when the thrust bearing issues were discovered (though some '97's have been seen with the same issue), so depending on when the motor was assembled, it could be ither.

NB2 crank in NB1 block is fine, use NB1 thrust bearing. NA8/NB1 crank in NB2 block is not OK.

NB1 Bearings ordered- Thanks!

You can just sleeve the crank seal surfaces, you don't need to turn them down first.

Ive used these a handful of times with great success, theyre kinda pricey though.
https://cimg0.ibsrv.net/gimg/www.mia...4bd83134d0.jpg

Speedisleeve looks interesting. And of course SKF is near my hometown, so I have to like their products!

Any word on the wristpin clearance?

I am going to have to look into these. Any good suppliers?

Found them on Amazon. Not sure if they would have the size needed though. Friend of mine has a machine shop in Trenton- I'll ask him too.

I look up the skf catalog and google the part number. Ive bought them on ebay and your local skf dealer (bearing house, autozone) can order them for you. They're usually $30-50.

Ill dig up some part numbers in a bit if I have time.

Awesome - thanks!

Posting all info for others, hopefully this shit formats. Rockauto has these under: engine> crankshaft repair sleeve.

Front seal:
90-91 1.6, short nose, up to vin 209446: national or SKF #99114

• Redi-Sleeve
• Front
• To Serial Number: 209446
• 1.4 Inch O.D.
• 0.315 Inch Width
• Material: Stainless Steel
• Flange Diameter (In): 1.400 Inch
• Flange Diameter (mm): 35.56mm
• Maximum Shaft Size (In): 1.184 Inch
• Maximum Shaft Size (mm): 30.07mm
• Minimum Shaft Size (In): 1.179 Inch
• Minimum Shaft Size (mm): 29.95mm

91-05, long nose 1.6 and all BPs: national or SKF #99145

Flanged Outside Diameter (Inch) 1.781
Flanged Outside Diameter (MM)45.240
Installation Depth (Inch)0.812
Installation Depth (MM)20.620
MaterialStainless SteelOuter Diameter (Inch)1.781
Overall Width (Inch)0.500Overall Width (MM)12.700
Part TypeRedi-SleevesShaft Size Max (Inch)1.46
Shaft Size Maximum (Inch)1.460Shaft Size Maximum (MM)37.080
Shaft Size Min (Inch)1.453
Shaft Size Minimum (Inch)1.453
Shaft Size Minimum (MM)36.910
Width (inch)0.375
Width On Shaft (Inch)0.375
Width on Shaft (MM)9.530


Rear seal:

All B6 and BPs: It would appear there is a gap for this size range in the Nat/SKF product range, so Im only finding the rear in Timken #KWK99328

Minimum Shaft Diameter Range3.225
"Maximum Shaft Diameter Range3.231"
Installation Depth1.732"
Width On Shaft0.661
"Overall Width0.85"
Flange Diameter3.587"


And I found some pics of when I used one on my nissan.

Attachment 182904

Attachment 182905

Attachment 182906

Attachment 182907

Attachment 182908

Use a sealant between the crank and sleeve. I use RTV.

Ordered the sleeves- thanks for the pointer! Have a kitty.

Still: Any pointers on the wristpin clearance? To hone or not to hone? What should my clearance be? Can't plastigage- don't like that part.

Sorry to bump this, but I want to get the rotating assembly buttoned up on Saturday and still would like to know, if I'm OK with the wristpins as-is. Or is my question so dumb that I don't deserve an answer? Not impossible.....

My opinion is that they should be fine. But if you're worried, open them another tenthou or 2. You say they spin in the piston easier that the rod, but things are different when its all running and loaded. Im not expert though so....

I had my ebay rods honed on the small end to get the clearance right, they were tight out of the box. If they are out of spec I'd fix it before final assembly.

Also if in a pinch on a crank with wear from a seal, I've just not pressed the seal in to the same spot so the new seal lip touches forward of the old one. Works, but a sleeve is probably better if you got the time to do it.