First, the pics.






Clearances:
Journal #1: .0017" (crank pulley)
Journal #2: .0016"
Journal #3: .0019"
Journal #4: .0017"
Journal #5: .0015" (flywheel)

Service Spec: .0009" to .0017"
Service Limit: .0020"

So, they are all pretty loose, but they are within spec. I'm happy.

For reference, my factory bearing codes are:

Journal #1: C2 (Green)
Journal #2: C3 (Brown)
Journal #3: B2 (Yellow)
Journal #4: B3 (Green)
Journal #5: B2 (Yellow)

Those numbers were right in the middle of the bearing chart.


Sonny

 

congrats sonny
how many hrs you having into rebuilding your motor?

 

damn, very nice....

mine should be within those areas then,. mine were
green
green
green
yellow
green

stan

 

Man...I lost count a looong time ago. It's always a few hours here and a few hours there. Generally when I'm wrenching, it's night time when the wife is asleep.

Sonny

 

sonny, mine looked similar with acl bearings on my b18c1.
how can you give such numbers when plastigauge doesn't give you that much resolution? bottom line is, with the acl standard set of bearings and a stock crank and block, you will fall within the spec. You just wont get down to what Honda does where they make bearings to get out to .000x decimal place. my motor has only 430 miles on it and running very well as i'm breaking it in. Very soon I'll be boosting hard again!

 

Torin,

I am able to give those numbers because I did not use the plastigage "ruler" to measure the thickness of each crushed strip. My caliper showed that the width of the .0015" ruler marking was 0.134". The width of the .0020" ruler marking was 0.167".

So, by using my caliper to measure the width of the crushed plastigauge, I was able to figure it out down to the .000x.

Sonny



[Modified by Sonny, 9:15 AM 8/6/2002]

 

I've noticed that!

I am usually making my posts late at night as I get home usually from work at 12-1AM....That is usually when I see your new posts on this and the performance forum....funny.

 

Night owls rule!!

Sonny

 

I am a nite owl myself...

 

Wow Sonny. Thanks so much for posting this. I feel much better about going with the ACL's now. My only problem is that on the Journal #4 the factory calls for a pink. Now, on your Journal #3 you had the loosest clearance at .0019". Im just hoping that with my "pink" that I fall within spec. If not I guess I will have to order a factory bearing and mix it in.

I think I recall Earl commenting on how loose a motor should, or shouldn't be. Loose would obviously let more oil in, but stand for an opportunity to spin a bearing. Tight obviously wont get the needed oil and create heat---then I guess bind and still spin the bearing. I'm not sure if I remember exactly what he said---hopefully he will see this and post. What would be the best for FI?? Especially if I plan to take my LS into the 8K range with new valvetrain.....

Great thread

 

I am not sure what Earl recommends (I am sure he will chime in), but on a high hp/race engine, Mike Kojima (Nissan engine building guru) recommends that the main bearings be loose and the piston-to-wall clearance be tight.

Sonny

 

TTT to go alongside its sister post.

Sonny

 

i think the width of the .001 ruler is .164" and the .0020 is .095". you made a misprint there.

 

sweet man, cant wait till im doing that again!!


chris

 

How do you use that plastigauge anyway? I have always wondered.

 

very good stuff...

 

Very good info Sonny So when you gonna boost that thing already

 

Damn Sonny, brilliant idea.
Remember, your goal is to have the largest clearance at #3 (middle)

 

Remember, your goal is to have the largest clearance at #3 (middle)
__________________________________________________ __________________

why is that? thanks.

 

SONNY rules.. i love your posts..pics, detailed descriptions..

 

Two reasons I can think of but I'm not sure of either is the exact reason. The middle bearing oils differently than the other bearings and needs more room or the centerline of the crank would have the most runout in the middle. Anyone else have a different idea.

 

That may make some sense, since the last 2 motors I saw spun a bearing was in the middle. hmmm

 

That is interesting. If you notice, there is not an oil hole in the middle main journal of the crank.

 

Back from the dead >?

 

I think it may be crank whip. Main #3 is the center of the crank assembly. On a rotating assembly that's not perfectly balanced, it will absorb more of the force (more then 1 2 4 and 5). Think of a weight bar with weights on the ends for an example....so much that the bar begins to sag. (seen those weight pro lifters?) Now imagine sandwhiching the bar between to pieces of metal and spinning it at 8000rpm, more force will be on the center of the bar the any other space. This is a very exagerated example, but this is my theories as to why #3 is looser. My machinist agrees....hrm.