Rod bearing replacement (Update 5)

George Roffe geo3@earthlink.net
Wed, 10 Dec 2003 19:20:22 -0600


Ben Fenner wrote:

>I'd like to know where I stand though.

I can't lie to you Ben.  You're standing firmly in the porta-potty.  A full
one.

>I remove the bearing, and wait for the correct sized bearing to come. I
>install it, notice it still won't move left to right, but hope for the best.

As Mike said, you can't build an engine this way.  Look at my beast
articles on my web site or if you have the December 2001 Sport Compact Car,
my article on my DET install has a sidebar on replacing bearings.

>I was rod knocking my way down thr street for the third time when I turned
>around and went home. This time I order three grade 2 bearings, and grab
>some 220 grit sandpaper. I attacked the journal with the sandpaper,
>getting it down to size where when I bolted the cap on with the bearing,
>it would move side to side like the others. I put everything back
>together, realize I forgot to torque the rod cap down, take everything
>apart again (ok so I'm venting a little), put it back together again. And
>now it's still knocking.

Did you use banana oil when you assembled it?

Ah, that was mean.  Sorry.

At this stage I'd say your crank is totally hosed.

>Is a new Nissan crank $300?

It was $377 when I built The Beast way back in, ah, geez, it was way back
in 1999.

>How much for an aftermarket one?

So such thing.

>Am I screwed?

Pretty much.  I don't mean to be harsh, but the reality is pretty harsh.

Mike had the best suggestion.  Get a JDM engine.

Where do you live?  You may be able to find a place near you that imports
JDM SR20s.

>Should I just get a new engine, and shelf this one and prep it for the boost?

You could buy my DET. :-)

It's not cheap though.  Too many really nice parts.

>What would you do in my situation?

JDM SR20DE

>Because right now, I don't know why I'm knocking.

Clearances are God only knows.  Did you measure them, even with Plastigauge?

Your crank journals are probably garbage and they are almost certainly far
from true.

>Maybe I haven't given the bearings time enough to bed?

No such thing.

>Maybe I need an undersized bearing. Do they make these?

Yes, but it's not worth the money or hassle.

For the cost of a crank and bearings, or the cost of finding someone who
can do a proper job on the SR20 crank (doubtful) and the cost of bearings,
you'd be way further ahead to buy a JDM SR20DE.

Sorry to be the bearer of bad news, but I have to be honest with
you.  Basically, once the crank is boogered, the short block is nearly
worthless because cranks are so expensive and JDM engines are so cheap.

George Roffe
Houston, TX  USA
http://www.nissport.com