Cwarta

iTrader: (12)

TOday I bust out the mic. and start checking clearences on the mains and rods. ANd here is were I got pissed. Turns out the mains are turned .020 and the rods .030... I SHOULD have checked this immeadiatley upon arrival of the crank and like an idiot I didn't.



For the mains im ok, I can just get .020 underside bearings and be sitting at .0028 clearance. Pretty decent



The rods, not so much. With an .030 undersize bearing I will be sitting and .0015 clearance, and I need more clearance. Ideally order up some .029 undersize bearings. I cant find any .029 bearings and im at a loss. WHat are my options? I don't think a crank can be turned .0001 can it? consistently?

KCS

iTrader: (20)

You can have the crank turned for more clearance. I'm assuming you're shooting for more than .002" which a good crank grinder can do.

For future reference, I always measure the bearing ID's before sending the crank to be turned. That way I can give him the journal OD of each rod and main journal to grind the crank to so I get exactly the clearance I want. Saves a ton of time, money, and especially frustration.

Cwarta

iTrader: (12)

That's a great idea. I assumed like a dumbass the seller on hear was honest and I'm getting burned for it.

chrisfrost

iTrader: (8)

You might check Federal Mogules website or better yet call Them ,,,,I know They have probably the most options of anyone I've seen

Cwarta

iTrader: (12)

I wound up ordering .020 under mains and .030 under rod, and having my rods taken to the high side to gain a little clearence. That will put me at 3.5 thousandths main clearence and hopefully 2.5 thousandths on the rods. I run 15-40 rotella oil FYI. I would prefer to be closer to 2.8 on the rods and 3.0 on the mains but I'm running out of feasible options ::

A.R. Shale Targa

iTrader: (2)

That's the wrong way to gain rod clearance as you are removing bearing
crush. Even the RA (cross hatch) finish in the large end of a rod is important
to grab and hold the back side of the bearing shell. I have two suggestions
for you to try on the .030 rods bearings. Now I know some will come on here
and call this "hack" but I've seen/done it plenty at several different engine
shops. Using a parts washing/solvent tank, take some 3M scotchbrite pads...
I use the red... and lightly scuff the primary babbit layer on each shell. You
will quickly see the change. Hot water rinse and blow dry. Next set the shell
on the bench top like a teter totter and use a piston pin as a roller (like mak
ing pizza dough)...using your fingers press the wrist pin down onto the clean
bearing babbit and rock the shell back and forth on the bench several times.
Again you will visually notice a slight change in the surface. Pop the bearings
back into the big end of the rod, retorque, and set the bore guage to the rod
journal diameter and measure. If done right this will typically add .0005"-
.0008" to your clearances and put you dead on without needing to spend any
more money.