hondamn1320

Let me just throw out that I SUCK at math.

Okay, now, I used this formula, BT = (ID - OD - 0.0015")/2

This is for my rods

My average OD = 1.7717"
My average ID = 1.8898"
Desired Clearance = 0.0015"

Plugging in the numbers got me, 0.0583" - 1.4808mm

This does not match up to anything on the chart.

Rod bearing thickness by color
Blue 1.510-1.507 mm 0.0594”- 0.0593”
Black 1.507-1.504 mm 0.0593”- 0.0592”
Brown 1.504-1.501 mm 0.0592”- 0.0591”
Green 1.501-1.498 mm 0.0591”- 0.0590”
Yellow 1.498-1.495 mm 0.0590”- 0.0589”
Pink 1.495-1.492 mm 0.0589”- 0.0587”
Red 1.492-1.489 mm 0.0587”- 0.0586”

What should I do? Did I do something wrong?

I have not measured the mains yet, still need to tear apart my block. I'm using a different crank.

PyroProblem

Did you measure the rods in 3 different places? Or perhaps they are out of round?
Your only .0004" from the red, so if your even .0005" off on more than one measurement, add .001 and now your on the other end of the scale...
But I suck at math too so i may be waaaay off, lol

hondamn1320

I measured horizontal and vertical as if the rods were installed.

Going to remeasure everything tomorrow.

PyroProblem

Good luck Let us know what you find. Perhaps plastiguage can re-affirm your measurements..
Was this a running motor before the rebuild? any knocking? damaged bearings?
Or is this all new/aftermarket peformance parts?

killer_siller

If you're averaging the ID and OD on ALL of your rods, that could be your problem. You need to be considering each rod individually.

Here's why: If you have one rod that is tighter than the other three which are all very close, then that one rod will skew your results rather drastically. You'll end up with one VERY loose rod and three somewhat tight rods. That's not good.

newtron63h

^agreed

you need to measure and calculate each bearing individually. also check to make sure that your micrometer is zeroed at .0000 AND check the calibration.......it should come with a standard for you to measure and check the calibration.

also measure in 3 different spots across the bearing surface AND at least 4 different axes around the journal to check for taper and out of round.

when checking the rod bore you have torqued the rod bolts right?

just a few things that might help.

hondamn1320

I'm using an aftermarket crank and eagle rods. I just pulled the rods out of the box and measured them. I'll torque them down and remeasure.

By average, I meant each only varied by .0001 - .0002 so I used the most common number.

killer_siller

An aftermarket crank and rod combination may not fall within Honda factory specs.

Once you've got your rods torqued down and remeasured, if they still don't fall within Honda specs, talk to an aftermarket bearing company. Any good bearing company should be able to work with you to get proper clearances.

hondamn1320

Thanks. I'll keep that in mind.

PyroProblem

I think you can also get the rods re-sized.

newtron63h

true story, rods and mains......they take the caps off shave them down at the mounting surface, then reassemble and torque them, then rebore them.

LowE.T.

hey your not suppose to use the number you want her this will Help !!
BC=IDBT-ODCJ-(2xBT)
BC= Bearing cleareance
IDBT=Inside diameter of bearing tunnel ( Meaning inside main Caps torqued to spec)
ODC=Outside diameter of crank journal
BT=Bearing thickness
This gives you the cleareance you already have (You Need Bearings to do this )
Take the numbers you get, look at the bearing chart and you will no what you need !!

LowE.T.

and if you need to do machine work cause aftermarket crank ,you ask for a line hone were they bore out the main caps

PyroProblem

Even though its all new, remember its still aftermarket.The chance they all "fit" perfectly to each other outta the box is slim...They may need to machined again to perfectly fit together with the other aftermarket parts...

(I had to have my Eagle rods resized to match my Scat crank to match my Clevite bearings)

newtron63h

again this is true......eagle in particular uses very good quality materials........but their finish machining is not the best

mar778c

iTrader: (1)

For you to be able to use green bearings, the big end of ID your you rods will have to be increased by 0.0016".

PyroProblem

LOL, Ive heard this more than a couple times.
Id also pay to have the crank balanced being that its also aftermarket...Cheap insurance in the grand scheme of things!

hondamn1320

So I should just order my bearings, then have everything machined to fit right?

newtron63h

thats what its looking like.

hondamn1320

Ok, so according to my original measurements, everything is on the looser end of the scale, correct?

So if i were to order some std acl bearings, i could get it all to work?

mar778c

iTrader: (1)

No

No


You seem to have missed the following advice.

PyroProblem

I think you meant to say your average ID is 1.7717" (crank journals)
and your average OD is 1.8898" (BE of rod)

So..........1.8898 -1.7717 -.0015 /2 equals .0583
Any bearing you use thats thicker than .0583" is going to decrease your clearance which isnt what you want...
So you need to make the rods big end a little bigger. If my math is correct, your rods should be sized to 1.8913".
1.8913 minus 1.7717 minus .0015 equals .1181 right?
.1181 divided by 2 equals puts you right at a green/yellow bearing...

Let your machinist do the math. Thats what he gets paid to do.
Good luck!

mar778c

iTrader: (1)

hondamn1320

Gah, I suck at math. You're right, I've decided to let the machinist do all the measurements for me. This is something I really don't want to mess up.

I'm planning on heading down there to have the block bored out, crank polished and balanced/measured, rods/main caps measured.

After that, I'll figure out the bearing issue.

hondamn1320

Took everything to the machine shop. Getting the block bored, crank polished and everything measured. I'll post the measurements when I get them.