acrocat

I tried searching and didnt find anything that helped me with my questions.

Here is the problem. I just spun a rod bearing and my crank doesnt seem to be in that bad of shape. Of course the rod journal with the spun bearing has excessive clearance. I am trying to figure out what to do. Here are the options

1. Get my crank cleaned and polished order 3 standard size bearings from honda and one undersized bearing for the damaged journal.

2. Get my Crank ground and polished and order 4 undersized ACL bearings

3. Get a Used GSR crank have it polished and order 4 new Standard size ACL bearings.

Just wondering what you guys think is my best bet. what are your oppinion on running 3 standar bearings and an undersized one and does anyone know what honda bearing colors are what sizes.... I have a chart that says which ones are bigger then the others but i dont know what color i would need for the right clearance.

Any advice would be greatly appreciated. Thanks

Crazydave

You could measure the crank size, and the rod bore, and calculate the size the bearing needed, and just order those ones. (but this takes a few machinists tools, and some time or have your machine shop measure for you)

There are something like 7 different sized bearings for hondas (color coded ie: Green, brown, pink, black, etc) (search this there are plenty of threads)

another method, which I did, was order the size of the bearing from the bearing codes on the motor, install the bearings, measure the clearance with plastigauge, then based on the clearence needed, buy 1 or 2 sizes smaller or larger, and then install and measure again. repeat as necessary. This may be cost more, but may or may not be cheaper than buying the tools, or paying a machinist.

Rememeber that the bearings have a tolerance too, they are not always exact.

There is no "Standard bearing"

On my motor, the factory bearing colors used were Green / Yellow / and Brown.

It just depends on your motor.

The honda bearing are very good and offer more choices as far as clearance are concerned comparted to ACL

acrocat

I think the cheapest option for me would be to have my current crank cleaned and polished and then just order the correct size bearings from honda. The only thing i am worried about is when a machine shop grinds the rod journals ($170) they do all of them. So is it going to matter if i have one undersized bearing and 3 standard ones.\

I did a plastigauge test on my crank using STD ACL bearings.
#1 .00325"
#2 .0015"
#3 .0015"
#4 .0015"

b18c1 standard new spec is .0013-.0020"
service limit is .0024"

This is the chart for honda bearings from biggest to smalles. Smaller being thicker bearings
#1 Red-Pink-Yello-Green
#2 Pink-Yellow-Green-Brown
#3 Yellow-Green-Brown-Black
#4 Green-Brown-Black-Blue

Now my assumption is that I would need a Green bearing? for my #1 cylinder. Can anyone else help me out. My rod journals are all stamped C. I would assume the 3 rod journals are still C Spec and my damagaged Journal would be differnet now. Sorry if this is confusing for some people... It's confusing for me too.


Any help or suggestions would be great


Modified by acrocat at 2:30 PM 6/14/2007

Crazydave

are you going to be replacing the Rod bolts?

If so, then have them grind all the rod bores after the new rod bolts are installed.

If you have damanged the rod & crank with the spun bearing you need to have it fixed. and mesaured.


Get all the work done on your crank, block, rods, then remeasure and order bearings after.

Also find out how thick the ACL bearing are.

Search search search, I found a lot of good threads here on HT

Crazydave

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by acrocat &raquo;</TD></TR><TR><TD CLASS="quote">
Now my assumption is that I would need a Green bearing? for my #1 cylinder. Can anyone else help me out. My rod journals are all stamped C. I would assume the 3 rod journals are still C Spec and my damagaged Journal would be differnet now. Sorry if this is confusing for some people... It's confusing for me too.


Any help or suggestions would be great


Modified by acrocat at 2:30 PM 6/14/2007</TD></TR></TABLE>

Don't assume what bearing you need. Find out how big that ACL bearing is.
Then find out how big the honda bearings are.

https://honda-tech.com/zerothread?id=276379
If a green is the same size as the ACL bearing you are in trouble as #1 cylinder is out of spec. You need a bearing that will bring that clearance down to 0.0015



Modified by Crazydave at 2:43 PM 6/14/2007

acrocat

Thanks that thread was helpful. So even if i got the thickest size honda bearing it would only make the clearance go from .00325" to .00285" which is still .00045" out of spec

So either i get this crank ground and get undersized bearings or i pick up a used gsr crank get it polished and just use a standard set of acl's...

Any pro's and cons of using undersized (thicker) bearings on a ground crank

Crazydave

Deleted...

Crazydave

https://honda-tech.com/zerothread?id=1706658


and

https://honda-tech.com/zerothread?id=1970666


from what I found in the thread above ACL bearings are in the Green to yellow range

given that:

Green .0591-.0590
Yellow .0590-.0589

we will work with .0590 is the average ACL bearing size thickness.

Then your total bearing thickness (for both halves) is .0590 * 2 = .1180

if your platisguage is giving you 0.00325 with those bearings installed then you have a total clearance (without bearings) of .12125

Now if you use the Blue Bearnings your Bearing thickness increases to
.0594*2 = 0.1188 since your total clearance without bearings is .12125 the clearance will now be:
.12125-.1188 = 0.00245

0.00245 which is beyond the service limit

You may need to get another crank.

Modified by Crazydave at 3:30 PM 6/14/2007


Modified by Crazydave at 3:34 PM 6/14/2007

Crazydave

Found this on ACL's Website:

http://www.aclperformance.com....s.htm

The clearance for STD is .0591

therefore

Total Bearing Thickness: 0.0591 * 2 = .1182
Measured Clearance = 0.00325
Total clearances without bearings = .1182 + 0.00325 = .12145

If you use Blue Bearings (.0594) then your clearance will be .12145-(.0594*2) = 0.00265 which is just beyond spec

here are the bearing sizes:

Blue .0594-.0593
Black .0593-.0592
Brown .0592-.0591
Green .0591-.0590
Yellow .0590-.0589
Pink .0589-.0587
Red .0587-.0586


Modified by Crazydave at 3:51 PM 6/14/2007

acrocat

arent the ACL undersized bearings .01 not .001

Crazydave

=<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by acrocat &raquo;</TD></TR><TR><TD CLASS="quote">arent the ACL undersized bearings .01 not .001</TD></TR></TABLE>

I edited my post


the 4B1925HX bearing has an oil clearance + 0.001 above that of the 4B1925H
the bearing thickness for this is .0586

the 4B1925H has a bearing thickness of 0.0591

4g hatch

just give the machine shop the bearing u want to use and have him size the rod to that bearing thats what i would do

acrocat

Well i just talked to one of my friends and he said i would be better off getting a new crank since i would more then likely want to get the crank stress relieved and magnufluxed